/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by wavey@wavey.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

/*
    Dynamic playlist design (based on design originally proposed by ricII)

    There are two files associated with a dynamic playlist:
    1. Playlist file : This file contains the initial songs in the playlist.
                       The file is created by the user and stored on the hard
                       drive.  NOTE: If we are playing the contents of a
                       directory, there will be no playlist file.
    2. Control file :  This file is automatically created when a playlist is
                       started and contains all the commands done to it.

    The first non-comment line in a control file must begin with
    "P:VERSION:DIR:FILE" where VERSION is the playlist control file version,
    DIR is the directory where the playlist is located and FILE is the
    playlist filename.  For dirplay, FILE will be empty.  An empty playlist
    will have both entries as null.

    Control file commands:
        a. Add track (A:<position>:<last position>:<path to track>)
            - Insert a track at the specified position in the current
              playlist.  Last position is used to specify where last insertion
              occurred.
        b. Queue track (Q:<position>:<last position>:<path to track>)
            - Queue a track at the specified position in the current
              playlist.  Queued tracks differ from added tracks in that they
              are deleted from the playlist as soon as they are played and
              they are not saved to disk as part of the playlist.
        c. Delete track (D:<position>)
            - Delete track from specified position in the current playlist.
        d. Shuffle playlist (S:<seed>:<index>)
            - Shuffle entire playlist with specified seed.  The index
              identifies the first index in the newly shuffled playlist
              (needed for repeat mode).
        e. Unshuffle playlist (U:<index>)
            - Unshuffle entire playlist.  The index identifies the first index
              in the newly unshuffled playlist.
        f. Reset last insert position (R)
            - Needed so that insertions work properly after resume

  Resume:
      The only resume info that needs to be saved is the current index in the
      playlist and the position in the track.  When resuming, all the commands
      in the control file will be reapplied so that the playlist indices are
      exactly the same as before shutdown.  To avoid unnecessary disk
      accesses, the shuffle mode settings are also saved in settings and only
      flushed to disk when required.
 */

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include "string-extra.h"
#include "playlist.h"
#include "ata_idle_notify.h"
#include "file.h"
#include "action.h"
#include "mv.h"
#include "debug.h"
#include "audio.h"
#include "lcd.h"
#include "kernel.h"
#include "settings.h"
#include "status.h"
#include "applimits.h"
#include "screens.h"
#include "core_alloc.h"
#include "misc.h"
#include "pathfuncs.h"
#include "button.h"
#include "filetree.h"
#include "abrepeat.h"
#include "thread.h"
#include "usb.h"
#include "filetypes.h"
#include "icons.h"
#include "system.h"

#include "lang.h"
#include "talk.h"
#include "splash.h"
#include "rbunicode.h"
#include "root_menu.h"
#include "plugin.h" /* To borrow a temp buffer to rewrite a .m3u8 file */
#include "logdiskf.h"
#ifdef HAVE_DIRCACHE
#include "dircache.h"
#endif

#if 0//def ROCKBOX_HAS_LOGDISKF
#warning LOGF enabled
#define LOGF_ENABLE
#include "logf.h"
#undef DEBUGF
#undef ERRORF
#undef WARNF
#undef NOTEF
#define DEBUGF logf
#define ERRORF DEBUGF
#define WARNF DEBUGF
#define NOTEF DEBUGF
//ERRORF
//WARNF
//NOTEF
#endif

/* default load buffer size (should be at least 1 KiB) */
#define PLAYLIST_LOAD_BUFLEN    (32*1024)

#define PLAYLIST_CONTROL_FILE_VERSION 2

#define PLAYLIST_COMMAND_SIZE (MAX_PATH+12)

/*
    Each playlist index has a flag associated with it which identifies what
    type of track it is.  These flags are stored in the 4 high order bits of
    the index.

    NOTE: This limits the playlist file size to a max of 256M.

    Bits 31-30:
        00 = Playlist track
        01 = Track was prepended into playlist
        10 = Track was inserted into playlist
        11 = Track was appended into playlist
    Bit 29:
        0 = Added track
        1 = Queued track
    Bit 28:
        0 = Track entry is valid
        1 = Track does not exist on disk and should be skipped
 */
#define PLAYLIST_SEEK_MASK              0x0FFFFFFF
#define PLAYLIST_INSERT_TYPE_MASK       0xC0000000
#define PLAYLIST_QUEUE_MASK             0x20000000

#define PLAYLIST_INSERT_TYPE_PREPEND    0x40000000
#define PLAYLIST_INSERT_TYPE_INSERT     0x80000000
#define PLAYLIST_INSERT_TYPE_APPEND     0xC0000000

#define PLAYLIST_QUEUED                 0x20000000
#define PLAYLIST_SKIPPED                0x10000000

struct directory_search_context {
    struct playlist_info* playlist;
    int position;
    bool queue;
    int count;
};

static struct playlist_info current_playlist;

#ifdef HAVE_DIRCACHE
#define PLAYLIST_LOAD_POINTERS 1
#define PLAYLIST_CLEAN_POINTERS 2
static bool dc_has_dirty_pointers = false;

static struct event_queue playlist_queue SHAREDBSS_ATTR;
static struct queue_sender_list playlist_queue_sender_list SHAREDBSS_ATTR;
static long playlist_stack[(DEFAULT_STACK_SIZE + 0x800)/sizeof(long)];
static const char dc_thread_playlist_name[] = "playlist cachectrl";

static void dc_copy_filerefs(struct dircache_fileref*,
                             const struct dircache_fileref*, int);
#endif

#if defined(PLAYLIST_DEBUG_MUTEX)
#define playlist_mutex_lock(m) {splashf(0, "%s lock", __func__); \
                                mutex_lock(m);}
#define playlist_mutex_unlock(m) {splashf(0, "%s unlock", __func__); \
                                  mutex_unlock(m);}
#else
static void playlist_mutex_lock(struct mutex *m) { mutex_lock(m); }
static void playlist_mutex_unlock(struct mutex *m) { mutex_unlock(m); }
#endif

#if defined(PLAYLIST_DEBUG_ACCESS_ERRORS)
#define notify_access_error() (splashf(HZ*2, "%s %s", \
                                    __func__, ID2P(LANG_PLAYLIST_ACCESS_ERROR)))
#define notify_control_access_error() (splashf(HZ*2, "%s %s", \
                            __func__, ID2P(LANG_PLAYLIST_CONTROL_ACCESS_ERROR)))
#else
static void notify_access_error(void) {
    splash(HZ*2, ID2P(LANG_PLAYLIST_ACCESS_ERROR));
}
static void notify_control_access_error(void) {
    splash(HZ*2, ID2P(LANG_PLAYLIST_CONTROL_ACCESS_ERROR));
}
#endif

/*
 * Display buffer full message
 */
static void notify_buffer_full(void)
{
    splash(HZ*2, ID2P(LANG_PLAYLIST_BUFFER_FULL));
}

static void dc_load_playlist_pointers(void)
{
#ifdef HAVE_DIRCACHE
    queue_post(&playlist_queue, PLAYLIST_LOAD_POINTERS, 0);
#endif
/* No-Op for non dircache targets */
}

static void dc_discard_playlist_pointers(void)
{
#ifdef HAVE_DIRCACHE
    /* dump any pointers currently waiting */
    if (dc_has_dirty_pointers)
        queue_send(&playlist_queue, PLAYLIST_CLEAN_POINTERS, 0);
#endif
/* No-Op for non dircache targets */
}

static void close_playlist_control_file(struct playlist_info *playlist)
{
    playlist_mutex_lock(&(playlist->mutex));
    if (playlist->control_fd >= 0)
    {
        close(playlist->control_fd);
        playlist->control_fd = -1;
    }
    playlist_mutex_unlock(&(playlist->mutex));
}

/* Check if the filename suggests M3U or M3U8 format. */
static bool is_m3u8_name(const char* filename)
{
    char *dot = strrchr(filename, '.');

    /* Default to M3U8 unless explicitly told otherwise. */
    return (!dot || strcasecmp(dot, ".m3u") != 0);
}

/* Convert a filename in an M3U playlist to UTF-8.
 *
 * buf     - the filename to convert; can contain more than one line from the
 *           playlist.
 * buf_len - amount of buf that is used.
 * buf_max - total size of buf.
 * temp    - temporary conversion buffer, at least buf_max bytes.
 *
 * Returns the length of the converted filename.
 */
static int convert_m3u_name(char* buf, int buf_len, int buf_max, char* temp)
{
    int i = 0;
    char* dest;

    /* Locate EOL. */
    while ((i < buf_len) && (buf[i] != '\n') && (buf[i] != '\r'))
    {
        i++;
    }

    /* Work back killing white space. */
    while ((i > 0) && isspace(buf[i - 1]))
    {
        i--;
    }

    buf_len = i;
    dest = temp;

    /* Convert char by char, so as to not overflow temp (iso_decode should
     * preferably handle this). No more than 4 bytes should be generated for
     * each input char.
     */
    for (i = 0; i < buf_len && dest < (temp + buf_max - 4); i++)
    {
        dest = iso_decode(&buf[i], dest, -1, 1);
    }

    *dest = 0;
    strcpy(buf, temp);
    return dest - temp;
}

/*
 * create control file for playlist
 */
static void create_control_unlocked(struct playlist_info* playlist)
{
    playlist->control_fd = open(playlist->control_filename,
                                O_CREAT|O_RDWR|O_TRUNC, 0666);

    playlist->control_created = (playlist->control_fd >= 0);

    if (!playlist->control_created)
    {
        if (!check_rockboxdir())
            return; /* No RB directory exists! */

        cond_talk_ids_fq(LANG_PLAYLIST_CONTROL_ACCESS_ERROR);
        int fd = playlist->control_fd;
        splashf(HZ*2, "%s (%d)", str(LANG_PLAYLIST_CONTROL_ACCESS_ERROR), fd);
    }
}

/*
 * Rotate indices such that first_index is index 0
 */
static int rotate_index(const struct playlist_info* playlist, int index)
{
    index -= playlist->first_index;
    if (index < 0)
        index += playlist->amount;

    return index;
}

/*
 * sync control file to disk
 */
static void sync_control(struct playlist_info* playlist, bool force)
{
#ifndef HAVE_DIRCACHE /*non dircache targets sync every time */
    force = true;
#endif

    if (playlist->started && force)
    {
        if (playlist->pending_control_sync)
        {
            playlist_mutex_lock(&(playlist->mutex));
            fsync(playlist->control_fd);
            playlist->pending_control_sync = false;
            playlist_mutex_unlock(&(playlist->mutex));
        }
    }
}

/*
 * Flush any cached control commands to disk.  Called when playlist is being
 * modified.  Returns 0 on success and -1 on failure.
 */
static int flush_cached_control(struct playlist_info* playlist)
{
    int result = 0;
    int i;

    if (playlist->num_cached <= 0)
        return 0;

    playlist_mutex_lock(&(playlist->mutex));

    lseek(playlist->control_fd, 0, SEEK_END);

    for (i=0; i<playlist->num_cached; i++)
    {
        struct playlist_control_cache* cache = &(playlist->control_cache[i]);

        switch (cache->command)
        {
            case PLAYLIST_COMMAND_PLAYLIST:
                result = fdprintf(playlist->control_fd, "P:%d:%s:%s\n",
                    cache->i1, cache->s1, cache->s2);
                break;
            case PLAYLIST_COMMAND_ADD:
            case PLAYLIST_COMMAND_QUEUE:
                result = fdprintf(playlist->control_fd, "%c:%d:%d:",
                    (cache->command == PLAYLIST_COMMAND_ADD)?'A':'Q',
                    cache->i1, cache->i2);
                if (result > 0)
                {
                    /* save the position in file where name is written */
                    int* seek_pos = (int *)cache->data;
                    *seek_pos = lseek(playlist->control_fd, 0, SEEK_CUR);
                    result = fdprintf(playlist->control_fd, "%s\n", cache->s1);
                }
                break;
            case PLAYLIST_COMMAND_DELETE:
                result = fdprintf(playlist->control_fd, "D:%d\n", cache->i1);
                break;
            case PLAYLIST_COMMAND_SHUFFLE:
                result = fdprintf(playlist->control_fd, "S:%d:%d\n",
                    cache->i1, cache->i2);
                break;
            case PLAYLIST_COMMAND_UNSHUFFLE:
                result = fdprintf(playlist->control_fd, "U:%d\n", cache->i1);
                break;
            case PLAYLIST_COMMAND_RESET:
                result = fdprintf(playlist->control_fd, "%s\n", "R");
                break;
            default:
                break;
        }

        if (result <= 0)
            break;
    }

    if (result > 0)
    {
        playlist->num_cached = 0;
        playlist->pending_control_sync = true;

        result = 0;
    }
    else
    {
        result = -1;
        splash(HZ*2, ID2P(LANG_PLAYLIST_CONTROL_UPDATE_ERROR));
    }

    playlist_mutex_unlock(&(playlist->mutex));
    return result;
}

/*
 * Update control data with new command.  Depending on the command, it may be
 * cached or flushed to disk.
 */
static int update_control(struct playlist_info* playlist,
                          enum playlist_command command, int i1, int i2,
                          const char* s1, const char* s2, void* data)
{
    int result = 0;
    struct playlist_control_cache* cache;
    bool flush = false;

    playlist_mutex_lock(&(playlist->mutex));

    cache = &(playlist->control_cache[playlist->num_cached++]);

    cache->command = command;
    cache->i1 = i1;
    cache->i2 = i2;
    cache->s1 = s1;
    cache->s2 = s2;
    cache->data = data;

    switch (command)
    {
        case PLAYLIST_COMMAND_PLAYLIST:
        case PLAYLIST_COMMAND_ADD:
        case PLAYLIST_COMMAND_QUEUE:
#ifndef HAVE_DIRCACHE
        case PLAYLIST_COMMAND_DELETE:
        case PLAYLIST_COMMAND_RESET:
#endif
            flush = true;
            break;
        case PLAYLIST_COMMAND_SHUFFLE:
        case PLAYLIST_COMMAND_UNSHUFFLE:
        default: /* only flush when needed */
            break;
    }

    if (flush || playlist->num_cached == PLAYLIST_MAX_CACHE)
        result = flush_cached_control(playlist);

    playlist_mutex_unlock(&(playlist->mutex));

    return result;
}

/*
 * store directory and name of playlist file
 */
static void update_playlist_filename_unlocked(struct playlist_info* playlist,
                                     const char *dir, const char *file)
{
    char *sep="";
    int dirlen = strlen(dir);

    playlist->utf8 = is_m3u8_name(file);

    /* If the dir does not end in trailing slash, we use a separator.
       Otherwise we don't. */
    if(!dirlen || '/' != dir[dirlen-1])
    {
        sep="/";
        dirlen++;
    }

    playlist->dirlen = dirlen;

    snprintf(playlist->filename, sizeof(playlist->filename),
        "%s%s%s", dir, sep, file);
}

/*
 * remove any files and indices associated with the playlist
 */
static void empty_playlist_unlocked(struct playlist_info* playlist, bool resume)
{
    dc_discard_playlist_pointers();

    if(playlist->fd >= 0) /* If there is an already open playlist, close it. */
    {
        close(playlist->fd);
    }

    if(playlist->control_fd >= 0)
    {
        close(playlist->control_fd);
    }

    playlist->filename[0] = '\0';

    chunk_alloc_free(&playlist->name_chunk_buffer);

    playlist->seed = 0;
    playlist->num_cached = 0;

    playlist->utf8 = true;
    playlist->control_created = false;
    playlist->in_ram = false;

    playlist->fd = -1;
    playlist->control_fd = -1;
    playlist->num_inserted_tracks = 0;

    playlist->index = 0;
    playlist->first_index = 0;
    playlist->amount = 0;
    playlist->last_insert_pos = -1;

    playlist->deleted = false;
    playlist->started = false;
    playlist->pending_control_sync = false;
    playlist->shuffle_modified = false;

    if (!resume && playlist->current)
    {
        /* start with fresh playlist control file when starting new
           playlist */
        create_control_unlocked(playlist);
    }
}

/* initializes the mutex for a new playlist and sets it as empty */
static void initalize_new_playlist(struct playlist_info* playlist, bool resume)
{
    mutex_init(&(playlist->mutex));
    empty_playlist_unlocked(playlist, resume);
}

/*
 * Returns absolute path of track
 *
 * dest: output buffer
 * src: the file name from the playlist
 * dir: the absolute path to the directory where the playlist resides
 *
 * The type of path in "src" determines what will be written to "dest":
 *
 * 1. UNIX-style absolute paths (/foo/bar) remain unaltered
 * 2. Windows-style absolute paths (C:/foo/bar) will be converted into an
 *    absolute path by replacing the drive letter with the volume that the
 *    *playlist* resides on, ie. the volume in "dir"
 * 3. Relative paths are converted to absolute paths by prepending "dir".
 *    This also applies to Windows-style relative paths "C:foo/bar" where
 *    the drive letter is accepted but ignored.
 */
static ssize_t format_track_path(char *dest, char *src, int buf_length,
                                 const char *dir)
{
    /* Look for the end of the string (includes NULL) */
    size_t len = strcspn(src, "\r\n");;

    /* Now work back killing white space */
    while (len > 0)
    {
        int c = src[len - 1];
        if (c != '\t' && c != ' ')
            break;
        len--;
    }

    src[len] = '\0';

    /* Replace backslashes with forward slashes */
    path_correct_separators(src, src);

    /* Handle Windows-style absolute paths */
    if (path_strip_drive(src, (const char **)&src, true) >= 0 &&
        src[-1] == PATH_SEPCH)
    {
    #ifdef HAVE_MULTIVOLUME
        const char *p;
        path_strip_last_volume(dir, &p, false);
        dir = strmemdupa(dir, p - dir); /* empty if no volspec on dir */
    #else
        dir = "";                       /* only volume is root */
    #endif
    }

    len = path_append(dest, *dir ? dir : PATH_ROOTSTR, src, buf_length);
    if (len >= (size_t)buf_length)
        return -1; /* buffer too small */

    path_remove_dot_segments (dest, dest);

    return strlen (dest);
}

/*
 * Initialize a new playlist for viewing/editing/playing.  dir is the
 * directory where the playlist is located and file is the filename.
 */
static void new_playlist_unlocked(struct playlist_info* playlist,
                                  const char *dir, const char *file)
{
    const char *fileused = file;
    const char *dirused = dir;

    initalize_new_playlist(playlist, false);

    if (!fileused)
    {
        fileused = "";

        if (dirused && playlist->current) /* !current cannot be in_ram */
            playlist->in_ram = true;
        else
            dirused = ""; /* empty playlist */
    }

    update_playlist_filename_unlocked(playlist, dirused, fileused);

    if (playlist->control_fd >= 0)
    {
        update_control(playlist, PLAYLIST_COMMAND_PLAYLIST,
            PLAYLIST_CONTROL_FILE_VERSION, -1, dirused, fileused, NULL);
        sync_control(playlist, false);
    }
}

/*
 * validate the control file.  This may include creating/initializing it if
 * necessary;
 */
static int check_control(struct playlist_info* playlist)
{
    int ret = 0;
    playlist_mutex_lock(&(playlist->mutex));
    if (!playlist->control_created)
    {
        create_control_unlocked(playlist);

        if (playlist->control_fd >= 0)
        {
            char* dir = playlist->filename;
            char* file = playlist->filename+playlist->dirlen;
            char c = playlist->filename[playlist->dirlen-1];

            playlist->filename[playlist->dirlen-1] = '\0';

            update_control(playlist, PLAYLIST_COMMAND_PLAYLIST,
                PLAYLIST_CONTROL_FILE_VERSION, -1, dir, file, NULL);
            sync_control(playlist, false);
            playlist->filename[playlist->dirlen-1] = c;
        }
    }

    if (playlist->control_fd < 0)
        ret = -1;

    playlist_mutex_unlock(&(playlist->mutex));

    return ret;
}


/*
 * Display splash message showing progress of playlist/directory insertion or
 * save.
 */
static void display_playlist_count(int count, const unsigned char *fmt,
                                   bool final)
{
    static long talked_tick = 0;
    long id = P2ID(fmt);

    if(id >= 0 && global_settings.talk_menu)
    {
        long next_tick = talked_tick + (HZ * 5);

        if (final || talked_tick == 0)
            next_tick = current_tick - 1;

        if(count && TIME_AFTER(current_tick, next_tick))
        {
            talked_tick = current_tick;
            talk_number(count, false);
            talk_id(id, true);
        }
    }

    splashf(0, P2STR(fmt), count, str(LANG_OFF_ABORT));
}

/*
 * recreate the control file based on current playlist entries
 */
static int recreate_control_unlocked(struct playlist_info* playlist)
{
    const char file_suffix[] = "_temp\0";
    char temp_file[MAX_PATH + sizeof(file_suffix)];
    int  temp_fd = -1;
    int  i;
    int  result = 0;

    temp_file[0] = 0;

    if(playlist->control_fd >= 0)
    {
        char* dir = playlist->filename;
        char* file = playlist->filename+playlist->dirlen;
        char c = playlist->filename[playlist->dirlen-1];

        close_playlist_control_file(playlist);

        snprintf(temp_file, sizeof(temp_file), "%s%s",
            playlist->control_filename, file_suffix);

        if (rename(playlist->control_filename, temp_file) < 0)
            return -1;

        temp_fd = open(temp_file, O_RDONLY);
        if (temp_fd < 0)
            return -1;

        playlist->control_fd = open(playlist->control_filename,
            O_CREAT|O_RDWR|O_TRUNC, 0666);
        if (playlist->control_fd < 0)
        {
            close(temp_fd);
            return -1;
        }

        playlist->filename[playlist->dirlen-1] = '\0';

        /* cannot call update_control() because of mutex */
        result = fdprintf(playlist->control_fd, "P:%d:%s:%s\n",
            PLAYLIST_CONTROL_FILE_VERSION, dir, file);

        playlist->filename[playlist->dirlen-1] = c;

        if (result < 0)
        {
            close(temp_fd);
            return result;
        }
    }

    playlist->seed = 0;
    playlist->shuffle_modified = false;
    playlist->deleted = false;
    playlist->num_inserted_tracks = 0;

    for (i=0; i<playlist->amount; i++)
    {
        if (playlist->indices[i] & PLAYLIST_INSERT_TYPE_MASK)
        {
            bool queue = playlist->indices[i] & PLAYLIST_QUEUE_MASK;
            char inserted_file[MAX_PATH+1];

            lseek(temp_fd, playlist->indices[i] & PLAYLIST_SEEK_MASK,
                SEEK_SET);
            read_line(temp_fd, inserted_file, sizeof(inserted_file));

            result = fdprintf(playlist->control_fd, "%c:%d:%d:",
                queue?'Q':'A', i, playlist->last_insert_pos);
            if (result > 0)
            {
                /* save the position in file where name is written */
                int seek_pos = lseek(playlist->control_fd, 0, SEEK_CUR);

                result = fdprintf(playlist->control_fd, "%s\n",
                    inserted_file);

                playlist->indices[i] =
                    (playlist->indices[i] & ~PLAYLIST_SEEK_MASK) | seek_pos;
            }

            if (result < 0)
                break;

            playlist->num_inserted_tracks++;
        }
    }

    close(temp_fd);
    remove(temp_file);
    fsync(playlist->control_fd);

    if (result < 0)
        return result;

    return 0;
}

/*
 * calculate track offsets within a playlist file
 */
static int add_indices_to_playlist(struct playlist_info* playlist,
                                   char* buffer, size_t buflen)
{
    ssize_t nread;
    unsigned int i = 0;
    unsigned int count = 0;
    bool store_index;
    unsigned char *p;
    int result = 0;
    /* get emergency buffer so we don't fail horribly */
    if (!buflen)
        buffer = alloca((buflen = 64));

    playlist_mutex_lock(&(playlist->mutex)); /* read can yield! */

    if(-1 == playlist->fd)
    {
        playlist->fd = open_utf8(playlist->filename, O_RDONLY);
        if(playlist->fd >= 0 && lseek(playlist->fd, 0, SEEK_CUR) > 0)
            playlist->utf8 = true; /* Override any earlier indication. */
    }

    if(playlist->fd < 0)
    {
        playlist_mutex_unlock(&(playlist->mutex));
        return -1; /* failure */
    }
    /* seek to the beginning of the file get_filename leaves it elsewhere */
    i = lseek(playlist->fd, playlist->utf8 ? BOM_UTF_8_SIZE : 0, SEEK_SET);

    splash(0, ID2P(LANG_WAIT));

    store_index = true;

    while(1)
    {
        nread = read(playlist->fd, buffer, buflen);
        /* Terminate on EOF */
        if(nread <= 0)
            break;

        p = (unsigned char *)buffer;

        for(count=0; count < (unsigned int)nread; count++,p++) {

            /* Are we on a new line? */
            if((*p == '\n') || (*p == '\r'))
            {
                store_index = true;
            }
            else if(store_index)
            {
                store_index = false;

                if(*p != '#')
                {
                    if ( playlist->amount >= playlist->max_playlist_size ) {
                        notify_buffer_full();
                        result = -1;
                        goto exit;
                    }

                    /* Store a new entry */
                    playlist->indices[ playlist->amount ] = i+count;
                #ifdef HAVE_DIRCACHE
                    dc_copy_filerefs(&playlist->dcfrefs[playlist->amount], NULL, 1);
                #endif
                    playlist->amount++;
                }
            }
        }

        i+= count;
    }

exit:

    playlist_mutex_unlock(&(playlist->mutex));

    return result;
}

/*
 * Checks if there are any music files in the dir or any of its
 * subdirectories.  May be called recursively.
 */
static int check_subdir_for_music(char *dir, const char *subdir, bool recurse)
{
    int result = -1;
    size_t dirlen = strlen(dir);
    int num_files = 0;
    int i;
    struct entry *files;
    bool has_music = false;
    bool has_subdir = false;
    struct tree_context* tc = tree_get_context();

    if (path_append(dir + dirlen, PA_SEP_HARD, subdir, MAX_PATH - dirlen) >=
            MAX_PATH - dirlen)
    {
        return 0;
    }

    if (ft_load(tc, dir) < 0)
    {
        return -2;
    }

    tree_lock_cache(tc);
    files = tree_get_entries(tc);
    num_files = tc->filesindir;

    for (i=0; i<num_files; i++)
    {
        if (files[i].attr & ATTR_DIRECTORY)
            has_subdir = true;
        else if ((files[i].attr & FILE_ATTR_MASK) == FILE_ATTR_AUDIO)
        {
            has_music = true;
            break;
        }
    }

    if (has_music)
    {
        tree_unlock_cache(tc);
        return 0;
    }

    if (has_subdir && recurse)
    {
        for (i=0; i<num_files; i++)
        {
            if (action_userabort(TIMEOUT_NOBLOCK))
            {
                result = -2;
                break;
            }

            if (files[i].attr & ATTR_DIRECTORY)
            {
                result = check_subdir_for_music(dir, files[i].name, true);
                if (!result)
                    break;
            }
        }
    }
    tree_unlock_cache(tc);

    if (result < 0)
    {
        if (dirlen)
        {
            dir[dirlen] = '\0';
        }
        else
        {
            strcpy(dir, PATH_ROOTSTR);
        }

        /* we now need to reload our current directory */
        if(ft_load(tc, dir) < 0)
            splash(HZ*2, ID2P(LANG_PLAYLIST_DIRECTORY_ACCESS_ERROR));
    }
    return result;
}

/*
 * search through all the directories (starting with the current) to find
 * one that has tracks to play
 */
static int get_next_dir(char *dir, bool is_forward)
{
    struct playlist_info* playlist = &current_playlist;
    int result = -1;
    char *start_dir = NULL;
    bool exit = false;
    struct tree_context* tc = tree_get_context();
    int saved_dirfilter = *(tc->dirfilter);
    unsigned int base_len;

    if (global_settings.constrain_next_folder)
    {
        /* constrain results to directories below user's start directory */
        strcpy(dir, global_settings.start_directory);
        base_len = strlen(dir);

        /* strip any trailing slash from base directory */
        if (base_len > 0 && dir[base_len - 1] == '/')
        {
            base_len--;
            dir[base_len] = '\0';
        }
    }
    else
    {
        /* start from root directory */
        dir[0] = '\0';
        base_len = 0;
    }

    /* process random folder advance */
    if (global_settings.next_folder == FOLDER_ADVANCE_RANDOM)
    {
        int fd = open(ROCKBOX_DIR "/folder_advance_list.dat", O_RDONLY);
        if (fd >= 0)
        {
            int folder_count = 0;
            ssize_t nread = read(fd,&folder_count,sizeof(int));
            if ((nread == sizeof(int)) && folder_count)
            {
                char buffer[MAX_PATH];
                /* give up looking for a directory after we've had four
                   times as many tries as there are directories. */
                unsigned long allowed_tries = folder_count * 4;
                int i;
                srand(current_tick);
                *(tc->dirfilter) = SHOW_MUSIC;
                tc->sort_dir = global_settings.sort_dir;
                while (!exit && allowed_tries--)
                {
                    i = rand() % folder_count;
                    lseek(fd, sizeof(int) + (MAX_PATH * i), SEEK_SET);
                    read(fd, buffer, MAX_PATH);
                    /* is the current dir within our base dir and has music? */
                    if ((base_len == 0 || !strncmp(buffer, dir, base_len))
                        && check_subdir_for_music(buffer, "", false) == 0)
                            exit = true;
                }
                close(fd);
                *(tc->dirfilter) = saved_dirfilter;
                tc->sort_dir = global_settings.sort_dir;
                reload_directory();
                if (exit)
                {
                    strcpy(dir,buffer);
                    return 0;
                }
            }
            else
                close(fd);
        }
    }

    /* if the current file is within our base dir, use its dir instead */
    if (base_len == 0 || !strncmp(playlist->filename, dir, base_len))
        strmemccpy(dir, playlist->filename, playlist->dirlen);

    /* use the tree browser dircache to load files */
    *(tc->dirfilter) = SHOW_ALL;

    /* set up sorting/direction */
    tc->sort_dir = global_settings.sort_dir;
    if (!is_forward)
    {
        static const char sortpairs[] =
        {
            [SORT_ALPHA] = SORT_ALPHA_REVERSED,
            [SORT_DATE] = SORT_DATE_REVERSED,
            [SORT_TYPE] = SORT_TYPE_REVERSED,
            [SORT_ALPHA_REVERSED] = SORT_ALPHA,
            [SORT_DATE_REVERSED] = SORT_DATE,
            [SORT_TYPE_REVERSED] = SORT_TYPE,
        };

        if ((unsigned)tc->sort_dir < sizeof(sortpairs))
            tc->sort_dir = sortpairs[tc->sort_dir];
    }

    while (!exit)
    {
        struct entry *files;
        int num_files = 0;
        int i;

        if (ft_load(tc, (dir[0]=='\0')?"/":dir) < 0)
        {
            exit = true;
            result = -1;
            break;
        }

        tree_lock_cache(tc);
        files = tree_get_entries(tc);
        num_files = tc->filesindir;

        for (i=0; i<num_files; i++)
        {
            /* user abort */
            if (action_userabort(TIMEOUT_NOBLOCK))
            {
                result = -1;
                exit = true;
                break;
            }

            if (files[i].attr & ATTR_DIRECTORY)
            {
                if (!start_dir)
                {
                    result = check_subdir_for_music(dir, files[i].name, true);
                    if (result != -1)
                    {
                        exit = true;
                        break;
                    }
                }
                else if (!strcmp(start_dir, files[i].name))
                    start_dir = NULL;
            }
        }
        tree_unlock_cache(tc);

        if (!exit)
        {
            /* we've already descended to the base dir with nothing found,
               check whether that contains music */
            if (strlen(dir) <= base_len)
            {
                result = check_subdir_for_music(dir, "", true);
                if (result == -1)
                    /* there's no music files in the base directory,
                       treat as a fatal error */
                    result = -2;
                break;
            }
            else
            {
                /* move down to parent directory.  current directory name is
                   stored as the starting point for the search in parent */
                start_dir = strrchr(dir, '/');
                if (start_dir)
                {
                    *start_dir = '\0';
                    start_dir++;
                }
                else
                    break;
            }
        }
    }

    /* restore dirfilter */
    *(tc->dirfilter) = saved_dirfilter;
    tc->sort_dir = global_settings.sort_dir;

    return result;
}

static int get_next_directory(char *dir){
    return get_next_dir(dir, true);
}

static int get_previous_directory(char *dir){
    return get_next_dir(dir, false);
}

/*
 * gets pathname for track at seek index
 */
static int get_track_filename(struct playlist_info* playlist, int index, int seek,
                              bool control_file, char *buf, int buf_length)
{
    int fd;
    int max = -1;
    char tmp_buf[MAX_PATH+1];
    char dir_buf[MAX_PATH+1];
    bool utf8 = playlist->utf8;

    if (buf_length > MAX_PATH+1)
        buf_length = MAX_PATH+1;

#ifdef HAVE_DIRCACHE
    if (playlist->dcfrefs)
    {
        max = dircache_get_fileref_path(&playlist->dcfrefs[index],
                                        tmp_buf, sizeof(tmp_buf));

        NOTEF("%s [in DCache]: 0x%x %s", __func__,
              playlist->dcfrefs[index], tmp_buf);
    }
#endif /* HAVE_DIRCACHE */

    if (playlist->in_ram && !control_file && max < 0)
    {
        char *namebuf = chunk_get_data(&playlist->name_chunk_buffer, seek);
        strmemccpy(tmp_buf, namebuf, sizeof(tmp_buf));
        chunk_put_data(&playlist->name_chunk_buffer, seek);
        NOTEF("%s [in Ram]: 0x%x %s", __func__, seek, tmp_buf);
    }
    else if (max < 0)
    {
        playlist_mutex_lock(&(playlist->mutex));

        if (control_file)
        {
            fd = playlist->control_fd;
            utf8 = true;
        }
        else
        {
            if(-1 == playlist->fd)
                playlist->fd = open(playlist->filename, O_RDONLY);

            fd = playlist->fd;
        }

        if(-1 != fd)
        {
            if (lseek(fd, seek, SEEK_SET) != seek)
                max = -1;
            else
            {
                max = read(fd, tmp_buf, MIN((size_t) buf_length, sizeof(tmp_buf)));

                if (max > 0)
                {
                    /* playlist file may end without a new line - terminate buffer */
                    tmp_buf[MIN(max, (int)sizeof(tmp_buf) - 1)] = '\0';

                    /* Use dir_buf as a temporary buffer. Note that dir_buf must
                     * be as large as tmp_buf.
                     */
                    if (!utf8)
                        max = convert_m3u_name(tmp_buf, max,
                                               sizeof(tmp_buf), dir_buf);

                    NOTEF("%s [in File]: 0x%x %s", __func__, seek, tmp_buf);
                }
            }
        }

        playlist_mutex_unlock(&(playlist->mutex));

        if (max < 0)
        {
            if (usb_detect() == USB_INSERTED)
                ; /* ignore error on usb plug */
            else if (control_file)
                notify_control_access_error();
            else
                notify_access_error();

            return max;
        }
    }

    strmemccpy(dir_buf, playlist->filename, playlist->dirlen);

    return format_track_path(buf, tmp_buf, buf_length, dir_buf);

    (void)index;
}

/*
 * Utility function to create a new playlist, fill it with the next or
 * previous directory, shuffle it if needed, and start playback.
 * If play_last is true and direction zero or negative, start playing
 * the last file in the directory, otherwise start playing the first.
 */
static int create_and_play_dir(int direction, bool play_last)
{
    char dir[MAX_PATH + 1];
    int res;
    int index = -1;

    if(direction > 0)
      res = get_next_directory(dir);
    else
      res = get_previous_directory(dir);

    if (res < 0) /* return the error encountered */
        return res;

    if (playlist_create(dir, NULL) != -1)
    {
        ft_build_playlist(tree_get_context(), 0);

        if (global_settings.playlist_shuffle)
             playlist_shuffle(current_tick, -1);

        if (play_last && direction <= 0)
            index = current_playlist.amount - 1;
        else
            index = 0;

        current_playlist.started = true;
    }

    /* we've overwritten the dircache when getting the next/previous dir,
       so the tree browser context will need to be reloaded */
    reload_directory();

    return index;
}

/*
 * Add track to playlist at specified position. There are seven special
 * positions that can be specified:
 *  PLAYLIST_PREPEND              - Add track at beginning of playlist
 *  PLAYLIST_INSERT               - Add track after current song.  NOTE: If
 *                                  there are already inserted tracks then track
 *                                  is added to the end of the insertion list
 *  PLAYLIST_INSERT_FIRST         - Add track immediately after current song, no
 *                                  matter what other tracks have been inserted
 *  PLAYLIST_INSERT_LAST          - Add track to end of playlist
 *  PLAYLIST_INSERT_SHUFFLED      - Add track at some random point between the
 *                                  current playing track and end of playlist
 *  PLAYLIST_INSERT_LAST_SHUFFLED - Add tracks in random order to the end of
 *                                  the playlist.
 *  PLAYLIST_REPLACE              - Erase current playlist, Cue the current track
 *                                  and inster this track at the end.
 */
static int add_track_to_playlist_unlocked(struct playlist_info* playlist,
                                          const char *filename, int position,
                                          bool queue, int seek_pos)
{
    int insert_position, orig_position;
    unsigned long flags = PLAYLIST_INSERT_TYPE_INSERT;
    int i;

    insert_position = orig_position = position;

    if (playlist->amount >= playlist->max_playlist_size)
    {
        notify_buffer_full();
        return -1;
    }

    switch (position)
    {
        case PLAYLIST_PREPEND:
            position = insert_position = playlist->first_index;
            break;
        case PLAYLIST_INSERT:
            /* if there are already inserted tracks then add track to end of
               insertion list else add after current playing track */
            if (playlist->last_insert_pos >= 0 &&
                playlist->last_insert_pos < playlist->amount &&
                (playlist->indices[playlist->last_insert_pos]&
                    PLAYLIST_INSERT_TYPE_MASK) == PLAYLIST_INSERT_TYPE_INSERT)
                position = insert_position = playlist->last_insert_pos+1;
            else if (playlist->amount > 0)
                position = insert_position = playlist->index + 1;
            else
                position = insert_position = 0;

            playlist->last_insert_pos = position;
            break;
        case PLAYLIST_INSERT_FIRST:
            if (playlist->amount > 0)
                position = insert_position = playlist->index + 1;
            else
                position = insert_position = 0;

            playlist->last_insert_pos = position;
            break;
        case PLAYLIST_INSERT_LAST:
            if (playlist->first_index > 0)
                position = insert_position = playlist->first_index;
            else
                position = insert_position = playlist->amount;

            playlist->last_insert_pos = position;
            break;
        case PLAYLIST_INSERT_SHUFFLED:
        {
            if (playlist->started)
            {
                int offset;
                int n = playlist->amount -
                    rotate_index(playlist, playlist->index);

                if (n > 0)
                    offset = rand() % n;
                else
                    offset = 0;

                position = playlist->index + offset + 1;
                if (position >= playlist->amount)
                    position -= playlist->amount;

                insert_position = position;
            }
            else
                position = insert_position = (rand() % (playlist->amount+1));
            break;
        }
        case PLAYLIST_INSERT_LAST_SHUFFLED:
        {
            int newpos = playlist->last_shuffled_start +
                rand() % (playlist->amount - playlist->last_shuffled_start + 1);
  
            position = insert_position = newpos;
            break;
        }
        case PLAYLIST_REPLACE:
            if (playlist_remove_all_tracks(playlist) < 0)
                return -1;
            int newpos = playlist->index + 1;
            playlist->last_insert_pos = position = insert_position = newpos;
            break;
    }

    if (queue)
        flags |= PLAYLIST_QUEUED;

    /* shift indices so that track can be added */
    for (i=playlist->amount; i>insert_position; i--)
    {
        playlist->indices[i] = playlist->indices[i-1];
#ifdef HAVE_DIRCACHE
        if (playlist->dcfrefs)
            playlist->dcfrefs[i] = playlist->dcfrefs[i-1];
#endif
    }

    /* update stored indices if needed */

    if (orig_position < 0)
    {
        if (playlist->amount > 0 && insert_position <= playlist->index &&
            playlist->started)
            playlist->index++;

        if (playlist->amount > 0 && insert_position <= playlist->first_index &&
            orig_position != PLAYLIST_PREPEND && playlist->started)
            playlist->first_index++;
    }

    if (insert_position < playlist->last_insert_pos ||
        (insert_position == playlist->last_insert_pos && position < 0))
        playlist->last_insert_pos++;

    if (seek_pos < 0 && playlist->control_fd >= 0)
    {
        int result = update_control(playlist,
            (queue?PLAYLIST_COMMAND_QUEUE:PLAYLIST_COMMAND_ADD), position,
            playlist->last_insert_pos, filename, NULL, &seek_pos);

        if (result < 0)
            return result;
    }

    playlist->indices[insert_position] = flags | seek_pos;

#ifdef HAVE_DIRCACHE
    dc_copy_filerefs(&playlist->dcfrefs[insert_position], NULL, 1);
#endif

    playlist->amount++;
    playlist->num_inserted_tracks++;

    return insert_position;
}

/*
 * Callback for playlist_directory_tracksearch to insert track into
 * playlist.
 */
static int directory_search_callback(char* filename, void* context)
{
    struct directory_search_context* c =
        (struct directory_search_context*) context;
    int insert_pos;

    insert_pos = add_track_to_playlist_unlocked(c->playlist, filename,
                                                c->position, c->queue, -1);

    if (insert_pos < 0)
        return -1;

    (c->count)++;

    /* After first INSERT_FIRST switch to INSERT so that all the
    rest of the tracks get inserted one after the other */
    if (c->position == PLAYLIST_INSERT_FIRST)
        c->position = PLAYLIST_INSERT;

    if (((c->count)%PLAYLIST_DISPLAY_COUNT) == 0)
    {
        unsigned char* count_str;

        if (c->queue)
            count_str = ID2P(LANG_PLAYLIST_QUEUE_COUNT);
        else
            count_str = ID2P(LANG_PLAYLIST_INSERT_COUNT);

        display_playlist_count(c->count, count_str, false);

        if ((c->count) == PLAYLIST_DISPLAY_COUNT &&
            (audio_status() & AUDIO_STATUS_PLAY) &&
            c->playlist->started)
            audio_flush_and_reload_tracks();
    }

    return 0;
}

/*
 * remove track at specified position
 */
static int remove_track_from_playlist(struct playlist_info* playlist,
                                      int position, bool write)
{
    int i;
    int result = 0;
    bool inserted;

    if (playlist->amount <= 0)
        return -1;

    playlist_mutex_lock(&(playlist->mutex));

    inserted = playlist->indices[position] & PLAYLIST_INSERT_TYPE_MASK;

    /* shift indices now that track has been removed */
    for (i=position; i<playlist->amount; i++)
    {
        playlist->indices[i] = playlist->indices[i+1];
#ifdef HAVE_DIRCACHE
        if (playlist->dcfrefs)
            playlist->dcfrefs[i] = playlist->dcfrefs[i+1];
#endif
    }

    playlist->amount--;

    if (inserted)
        playlist->num_inserted_tracks--;
    else
        playlist->deleted = true;

    /* update stored indices if needed */
    if (position < playlist->index)
        playlist->index--;

    if (position < playlist->first_index)
    {
        playlist->first_index--;
    }

    if (position <= playlist->last_insert_pos)
        playlist->last_insert_pos--;

    if (write && playlist->control_fd >= 0)
    {
        result = update_control(playlist, PLAYLIST_COMMAND_DELETE,
            position, -1, NULL, NULL, NULL);
        if (result >= 0)
            sync_control(playlist, false);
    }

    playlist_mutex_unlock(&(playlist->mutex));
    return result;
}

/*
 * Search for the seek track and set appropriate indices.  Used after shuffle
 * to make sure the current index is still pointing to correct track.
 */
static void find_and_set_playlist_index_unlocked(struct playlist_info* playlist,
                                                 unsigned int seek)
{
    int i;

    /* Set the index to the current song */
    for (i=0; i<playlist->amount; i++)
    {
        if (playlist->indices[i] == seek)
        {
            playlist->index = playlist->first_index = i;

            break;
        }
    }
}

/*
 * randomly rearrange the array of indices for the playlist.  If start_current
 * is true then update the index to the new index of the current playing track
 */
static int randomise_playlist(struct playlist_info* playlist,
                              unsigned int seed, bool start_current,
                              bool write)
{
    int count;
    int candidate;
    unsigned int current = playlist->indices[playlist->index];

    playlist_mutex_lock(&(playlist->mutex));

    dc_discard_playlist_pointers();

    /* seed 0 is used to identify sorted playlist for resume purposes */
    if (seed == 0)
        seed = 1;

    /* seed with the given seed */
    srand(seed);

    /* randomise entire indices list */
    for(count = playlist->amount - 1; count >= 0; count--)
    {
        /* the rand is from 0 to RAND_MAX, so adjust to our value range */
        candidate = rand() % (count + 1);

        /* now swap the values at the 'count' and 'candidate' positions */
        int indextmp = playlist->indices[candidate];
        playlist->indices[candidate] = playlist->indices[count];
        playlist->indices[count] = indextmp;
#ifdef HAVE_DIRCACHE
        if (playlist->dcfrefs)
        {
            struct dircache_fileref dcftmp = playlist->dcfrefs[candidate];
            playlist->dcfrefs[candidate] = playlist->dcfrefs[count];
            playlist->dcfrefs[count] = dcftmp;
        }
#endif
    }

    if (start_current)
        find_and_set_playlist_index_unlocked(playlist, current);

    /* indices have been moved so last insert position is no longer valid */
    playlist->last_insert_pos = -1;

    playlist->seed = seed;
    if (playlist->num_inserted_tracks > 0 || playlist->deleted)
        playlist->shuffle_modified = true;

    if (write)
    {
        update_control(playlist, PLAYLIST_COMMAND_SHUFFLE, seed,
            playlist->first_index, NULL, NULL, NULL);
    }

    playlist_mutex_unlock(&(playlist->mutex));

    return 0;
}

/*
 * used to sort track indices.  Sort order is as follows:
 * 1. Prepended tracks (in prepend order)
 * 2. Playlist/directory tracks (in playlist order)
 * 3. Inserted/Appended tracks (in insert order)
 */
static int sort_compare_fn(const void* p1, const void* p2)
{
    unsigned long* e1 = (unsigned long*) p1;
    unsigned long* e2 = (unsigned long*) p2;
    unsigned long flags1 = *e1 & PLAYLIST_INSERT_TYPE_MASK;
    unsigned long flags2 = *e2 & PLAYLIST_INSERT_TYPE_MASK;

    if (flags1 == flags2)
        return (*e1 & PLAYLIST_SEEK_MASK) - (*e2 & PLAYLIST_SEEK_MASK);
    else if (flags1 == PLAYLIST_INSERT_TYPE_PREPEND ||
        flags2 == PLAYLIST_INSERT_TYPE_APPEND)
        return -1;
    else if (flags1 == PLAYLIST_INSERT_TYPE_APPEND ||
        flags2 == PLAYLIST_INSERT_TYPE_PREPEND)
        return 1;
    else if (flags1 && flags2)
        return (*e1 & PLAYLIST_SEEK_MASK) - (*e2 & PLAYLIST_SEEK_MASK);
    else
        return *e1 - *e2;
}

/*
 * Sort the array of indices for the playlist. If start_current is true then
 * set the index to the new index of the current song.
 * Also while going to unshuffled mode set the first_index to 0.
 */
static int sort_playlist_unlocked(struct playlist_info* playlist,
                                  bool start_current, bool write)
{
    unsigned int current = playlist->indices[playlist->index];

    dc_discard_playlist_pointers();

    if (playlist->amount > 0)
        qsort((void*)playlist->indices, playlist->amount,
            sizeof(playlist->indices[0]), sort_compare_fn);

#ifdef HAVE_DIRCACHE
    /** We need to re-check the song names from disk because qsort can't
     * sort two arrays at once :/
     * FIXME: Please implement a better way to do this. */
    dc_copy_filerefs(playlist->dcfrefs, NULL, playlist->max_playlist_size);
    dc_load_playlist_pointers();
#endif

    if (start_current)
        find_and_set_playlist_index_unlocked(playlist, current);

    /* indices have been moved so last insert position is no longer valid */
    playlist->last_insert_pos = -1;

    if (!playlist->num_inserted_tracks && !playlist->deleted)
        playlist->shuffle_modified = false;
    if (write && playlist->control_fd >= 0)
    {
        playlist->first_index = 0;
        update_control(playlist, PLAYLIST_COMMAND_UNSHUFFLE,
            playlist->first_index, -1, NULL, NULL, NULL);
    }

    return 0;
}

/* Calculate how many steps we have to really step when skipping entries
 * marked as bad.
 */
static int calculate_step_count(const struct playlist_info *playlist, int steps)
{
    int i, count, direction;
    int index;
    int stepped_count = 0;

    if (steps < 0)
    {
        direction = -1;
        count = -steps;
    }
    else
    {
        direction = 1;
        count = steps;
    }

    index = playlist->index;
    i = 0;
    do {
        /* Boundary check */
        if (index < 0)
            index += playlist->amount;
        if (index >= playlist->amount)
            index -= playlist->amount;

        /* Check if we found a bad entry. */
        if (playlist->indices[index] & PLAYLIST_SKIPPED)
        {
            steps += direction;
            /* Are all entries bad? */
            if (stepped_count++ > playlist->amount)
                break ;
        }
        else
            i++;

        index += direction;
    } while (i <= count);

    return steps;
}

/*
 * returns the index of the track that is "steps" away from current playing
 * track.
 */
static int get_next_index(const struct playlist_info* playlist, int steps,
                          int repeat_mode)
{
    int current_index = playlist->index;
    int next_index    = -1;

    if (playlist->amount <= 0)
        return -1;

    if (repeat_mode == -1)
        repeat_mode = global_settings.repeat_mode;

    if (repeat_mode == REPEAT_SHUFFLE && playlist->amount <= 1)
        repeat_mode = REPEAT_ALL;

    steps = calculate_step_count(playlist, steps);
    switch (repeat_mode)
    {
        case REPEAT_SHUFFLE:
            /* Treat repeat shuffle just like repeat off.  At end of playlist,
               play will be resumed in playlist_next() */
        case REPEAT_OFF:
        {
            current_index = rotate_index(playlist, current_index);
            next_index = current_index+steps;
            if ((next_index < 0) || (next_index >= playlist->amount))
                next_index = -1;
            else
                next_index = (next_index+playlist->first_index) %
                    playlist->amount;

            break;
        }

        case REPEAT_ONE:
#ifdef AB_REPEAT_ENABLE
        case REPEAT_AB:
#endif
            next_index = current_index;
            break;

        case REPEAT_ALL:
        default:
        {
            next_index = (current_index+steps) % playlist->amount;
            while (next_index < 0)
                next_index += playlist->amount;

            if (steps >= playlist->amount)
            {
                int i, index;

                index = next_index;
                next_index = -1;

                /* second time around so skip the queued files */
                for (i=0; i<playlist->amount; i++)
                {
                    if (playlist->indices[index] & PLAYLIST_QUEUE_MASK)
                        index = (index+1) % playlist->amount;
                    else
                    {
                        next_index = index;
                        break;
                    }
                }
            }
            break;
        }
    }

    /* No luck if the whole playlist was bad. */
    if (next_index < 0 || next_index >= playlist->amount ||
        playlist->indices[next_index] & PLAYLIST_SKIPPED)
        return -1;

    return next_index;
}

#ifdef HAVE_DIRCACHE

static void dc_copy_filerefs(struct dircache_fileref *dcfto,
                              const struct dircache_fileref *dcffrom,
                              int count)
{
    if (!dcfto)
        return;

    if (dcffrom)
        memmove(dcfto, dcffrom, count * sizeof (*dcfto));
    else
    {
        /* just initialize the destination */
        for (int i = 0; i < count; i++, dcfto++)
            dircache_fileref_init(dcfto);
    }
}

static void dc_flush_playlist_callback(void)
{
    struct playlist_info *playlist;
    playlist = &current_playlist;
    if (playlist->control_fd >= 0)
    {
        flush_cached_control(playlist);
        sync_control(playlist, true);
    }
    else if (playlist->control_fd < 0 || playlist->num_cached <= 0)
        unregister_storage_idle_func(dc_flush_playlist_callback, false);
}

/**
 * Thread to update filename pointers to dircache on background
 * without affecting playlist load up performance.  This thread also flushes
 * any pending control commands when the disk spins up.
 */
static void dc_thread_playlist(void)
{
    struct queue_event ev;
    static char tmp[MAX_PATH+1];

    struct playlist_info *playlist;
    int index;
    int seek;
    bool control_file;

    int sleep_time = 5;

#ifdef HAVE_DISK_STORAGE
    if (global_settings.disk_spindown > 1 &&
        global_settings.disk_spindown <= 5)
        sleep_time = global_settings.disk_spindown - 1;
#endif

    while (1)
    {
        queue_wait_w_tmo(&playlist_queue, &ev, HZ*sleep_time);

        switch (ev.id)
        {
            case PLAYLIST_CLEAN_POINTERS:
                dc_has_dirty_pointers = false;
                queue_reply(&playlist_queue, 0);
                break;

            case PLAYLIST_LOAD_POINTERS:
                dc_has_dirty_pointers = true;
                break ;

            /* Start the background scanning after either the disk spindown
               timeout or 5s, whichever is less */
            case SYS_TIMEOUT:
            {
                playlist = &current_playlist;
                if (playlist->control_fd >= 0)
                {
                    if (playlist->num_cached > 0)
                        register_storage_idle_func(dc_flush_playlist_callback);
                }

                if (!playlist->dcfrefs || playlist->amount <= 0)
                    break ;

                /* Check if previously loaded pointers are intact. */
                if (!dc_has_dirty_pointers)
                    break ;

                struct dircache_info info;
                dircache_get_info(&info);

                if (info.status != DIRCACHE_READY)
                    break ;

                trigger_cpu_boost();

                for (index = 0; index < playlist->amount
                     && queue_empty(&playlist_queue); index++)
                {
                    /* Process only pointers that are superficially stale. */
                    if (dircache_search(DCS_FILEREF, &playlist->dcfrefs[index], NULL) > 0)
                        continue ;

                    control_file = playlist->indices[index] & PLAYLIST_INSERT_TYPE_MASK;
                    seek = playlist->indices[index] & PLAYLIST_SEEK_MASK;

                    /* Load the filename from playlist file. */
                    if (get_track_filename(playlist, index, seek,
                                           control_file, tmp, sizeof(tmp)) < 0)
                    {
                        break ;
                    }

                    /* Obtain the dircache file entry cookie. */
                    dircache_search(DCS_CACHED_PATH | DCS_UPDATE_FILEREF,
                                    &playlist->dcfrefs[index], tmp);

                    /* And be on background so user doesn't notice any delays. */
                    yield();
                }

                cancel_cpu_boost();

                if (index == playlist->amount)
                    dc_has_dirty_pointers = false;

                break ;
            }

            case SYS_USB_CONNECTED:
                usb_acknowledge(SYS_USB_CONNECTED_ACK);
                usb_wait_for_disconnect(&playlist_queue);
                break ;
        }
    }
}
#endif

/*
 * Allocate name chunk buffer header for in-ram playlists
 */
static void alloc_namebuffer(void)
{
#if MEMORYSIZE >= 16
# define NAME_CHUNK_SZ (200 << 10) /*200K*/
#elif MEMORYSIZE >= 8
# define NAME_CHUNK_SZ (100 << 10) /*100K*/
#else
# define NAME_CHUNK_SZ (50 << 10) /*50K*/
#endif
    struct playlist_info* playlist = &current_playlist;
    size_t namebufsz = (AVERAGE_FILENAME_LENGTH * global_settings.max_files_in_dir);
    size_t name_chunks = (namebufsz + NAME_CHUNK_SZ - 1) / NAME_CHUNK_SZ;
    core_chunk_alloc_init(&playlist->name_chunk_buffer, NAME_CHUNK_SZ, name_chunks);
#undef NAME_CHUNK_SZ
}

/*
 * Allocate a temporary buffer for loading playlists
 */
static int alloc_tempbuf(size_t* buflen)
{
    /* request a reasonable size first */
    int handle = core_alloc_ex(PLAYLIST_LOAD_BUFLEN, &buflib_ops_locked);
    if (handle > 0)
    {
        *buflen = PLAYLIST_LOAD_BUFLEN;
        return handle;
    }

    /* otherwise, try being unreasonable */
    return core_alloc_maximum(buflen, &buflib_ops_locked);
}

/*
 * Need no movement protection since all 3 allocations are not passed to
 * other functions which can yield().
 */
static int move_callback(int handle, void* current, void* new)
{
    (void)handle;
    struct playlist_info* playlist = &current_playlist;
    if (current == playlist->indices)
        playlist->indices = new;
#ifdef HAVE_DIRCACHE
    else if (current == playlist->dcfrefs)
        playlist->dcfrefs = new;
#endif /* HAVE_DIRCACHE */
    return BUFLIB_CB_OK;
}


static struct buflib_callbacks ops = {
    .move_callback = move_callback,
    .shrink_callback = NULL,
};

/******************************************************************************/
/******************************************************************************/
/* ************************************************************************** */
/* * PUBLIC INTERFACE FUNCTIONS * *********************************************/
/* ************************************************************************** */
/******************************************************************************/
/******************************************************************************/
/*
 * Initialize playlist entries at startup
 */
void playlist_init(void)
{
    int handle;
    struct playlist_info* playlist = &current_playlist;

    playlist->current = true;
    strmemccpy(playlist->control_filename, PLAYLIST_CONTROL_FILE,
            sizeof(playlist->control_filename));
    playlist->fd = -1;
    playlist->control_fd = -1;
    playlist->max_playlist_size = global_settings.max_files_in_playlist;

    handle = core_alloc_ex(playlist->max_playlist_size * sizeof(*playlist->indices), &ops);
    playlist->indices = core_get_data(handle);

    initalize_new_playlist(playlist, true);

#ifdef HAVE_DIRCACHE
    handle = core_alloc_ex(
        playlist->max_playlist_size * sizeof(*playlist->dcfrefs), &ops);
    playlist->dcfrefs = core_get_data(handle);
    dc_copy_filerefs(playlist->dcfrefs, NULL, playlist->max_playlist_size);
    unsigned int playlist_thread_id =
        create_thread(dc_thread_playlist, playlist_stack, sizeof(playlist_stack),
                      0, dc_thread_playlist_name IF_PRIO(, PRIORITY_BACKGROUND)
                      IF_COP(, CPU));

    queue_init(&playlist_queue, true);
    queue_enable_queue_send(&playlist_queue,
                            &playlist_queue_sender_list, playlist_thread_id);
#endif /* HAVE_DIRCACHE */
}

/*
 * Clean playlist at shutdown
 */
void playlist_shutdown(void)
{
    struct playlist_info* playlist = &current_playlist;

    if (playlist->control_fd >= 0)
    {
        flush_cached_control(playlist);

        close_playlist_control_file(playlist);
    }
}

/*
 * Add track to in_ram playlist.  Used when playing directories.
 */
int playlist_add(const char *filename)
{
    size_t indice = CHUNK_ALLOC_INVALID;
    struct playlist_info* playlist = &current_playlist;
    int len = strlen(filename);

    if (!chunk_alloc_is_initialized(&playlist->name_chunk_buffer))
        alloc_namebuffer();

    if (chunk_alloc_is_initialized(&playlist->name_chunk_buffer))
        indice = chunk_alloc(&playlist->name_chunk_buffer, len + 1);

    if(indice == CHUNK_ALLOC_INVALID)
    {

        notify_buffer_full();
        return -2;
    }

    if(playlist->amount >= playlist->max_playlist_size)
    {
        notify_buffer_full();
        return -1;
    }

    playlist_mutex_lock(&(playlist->mutex));

    char *namebuf = (char*)chunk_get_data(&playlist->name_chunk_buffer, indice);
    strcpy(namebuf, filename);

    namebuf += len;
    namebuf[0] = '\0';

    chunk_put_data(&playlist->name_chunk_buffer, indice);
    playlist->indices[playlist->amount] = indice;

#ifdef HAVE_DIRCACHE
    dc_copy_filerefs(&playlist->dcfrefs[playlist->amount], NULL, 1);
#endif

    playlist->amount++;

    playlist_mutex_unlock(&(playlist->mutex));

    return 0;
}

/* returns number of tracks in playlist (includes queued/inserted tracks) */
int playlist_amount_ex(const struct playlist_info* playlist)
{
    if (!playlist)
        playlist = &current_playlist;

    return playlist->amount;
}

/* returns number of tracks in current playlist */
int playlist_amount(void)
{
    return playlist_amount_ex(NULL);
}

/*
 * Create a new playlist  If playlist is not NULL then we're loading a
 * playlist off disk for viewing/editing.  The index_buffer is used to store
 * playlist indices (required for and only used if !current playlist).  The
 * temp_buffer (if not NULL) is used as a scratchpad when loading indices.
 */
int playlist_create_ex(struct playlist_info* playlist,
                       const char* dir, const char* file,
                       void* index_buffer, int index_buffer_size,
                       void* temp_buffer, int temp_buffer_size)
{
    if (!playlist)
    {
        playlist = &current_playlist;
        playlist_mutex_lock(&(playlist->mutex));
        playlist->last_shuffled_start = playlist->amount;
        playlist_mutex_unlock(&(playlist->mutex));
    }
    else
    {
        /* Initialize playlist structure */
        int r = rand() % 10;
        playlist->current = false;

        /* Use random name for control file */
        snprintf(playlist->control_filename, sizeof(playlist->control_filename),
            "%s.%d", PLAYLIST_CONTROL_FILE, r);
        playlist->fd = -1;
        playlist->control_fd = -1;

        if (index_buffer)
        {
            int num_indices = index_buffer_size /
                              playlist_get_required_bufsz(playlist, false, 1);

            if (num_indices > global_settings.max_files_in_playlist)
                num_indices = global_settings.max_files_in_playlist;

            playlist->max_playlist_size = num_indices;
            playlist->indices = index_buffer;
#ifdef HAVE_DIRCACHE
            playlist->dcfrefs = (void *)&playlist->indices[num_indices];
#endif
        }
        else
        {
            playlist->max_playlist_size = current_playlist.max_playlist_size;
            playlist->indices = current_playlist.indices;
#ifdef HAVE_DIRCACHE
            playlist->dcfrefs = current_playlist.dcfrefs;
#endif
        }

        chunk_alloc_free(&playlist->name_chunk_buffer);
    }

    new_playlist_unlocked(playlist, dir, file);

    if (file)
    {
        /* load the playlist file */
        add_indices_to_playlist(playlist, temp_buffer, temp_buffer_size);
        dc_load_playlist_pointers();
    }
    return 0;
}

/*
 * Create new playlist
 */
int playlist_create(const char *dir, const char *file)
{
    struct playlist_info* playlist = &current_playlist;

    new_playlist_unlocked(playlist, dir, file);

    if (file)
    {
        size_t buflen;
        int handle = alloc_tempbuf(&buflen);
        if (handle > 0)
        {
            /* align for faster load times */
            void* buf = core_get_data(handle);
            STORAGE_ALIGN_BUFFER(buf, buflen);
            buflen = ALIGN_DOWN(buflen, 512); /* to avoid partial sector I/O */
            /* load the playlist file */
            add_indices_to_playlist(playlist, buf, buflen);
            dc_load_playlist_pointers();
            core_free(handle);
        }
        else
        {
            /* should not happen -- happens if plugin takes audio buffer */
            splashf(HZ * 2, "%s(): OOM", __func__);
            return -1;
        }
    }

    return 0;
}

/* Returns false if 'steps' is out of bounds, else true */
bool playlist_check(int steps)
{
    struct playlist_info* playlist = &current_playlist;

    /* always allow folder navigation */
    if (global_settings.next_folder && playlist->in_ram)
        return true;

    int index = get_next_index(playlist, steps, -1);

    if (index < 0 && steps >= 0 && global_settings.repeat_mode == REPEAT_SHUFFLE)
        index = get_next_index(playlist, steps, REPEAT_ALL);

    return (index >= 0);
}

/*
 * Close files and delete control file for non-current playlist.
 */
void playlist_close(struct playlist_info* playlist)
{
    if (!playlist)
        return;

    if (playlist->fd >= 0)
    {
        close(playlist->fd);
        playlist->fd = -1;
    }

    close_playlist_control_file(playlist);

    if (playlist->control_created)
    {
        remove(playlist->control_filename);
        playlist->control_created = false;
    }
}

/*
 * Delete track at specified index.  If index is PLAYLIST_DELETE_CURRENT then
 * we want to delete the current playing track.
 */
int playlist_delete(struct playlist_info* playlist, int index)
{
    int result = 0;

    if (!playlist)
        playlist = &current_playlist;

    if (check_control(playlist) < 0)
    {
        notify_control_access_error();
        return -1;
    }

    dc_discard_playlist_pointers();

    if (index == PLAYLIST_DELETE_CURRENT)
        index = playlist->index;

    result = remove_track_from_playlist(playlist, index, true);

    if (result != -1 && (audio_status() & AUDIO_STATUS_PLAY) &&
        playlist->started)
        audio_flush_and_reload_tracks();

    return result;
}

/*
 * Search specified directory for tracks and notify via callback.  May be
 * called recursively.
 */
int playlist_directory_tracksearch(const char* dirname, bool recurse,
                                   int (*callback)(char*, void*),
                                   void* context)
{
    char buf[MAX_PATH+1];
    int result = 0;
    int num_files = 0;
    int i;;
    struct tree_context* tc = tree_get_context();
    struct tree_cache* cache = &tc->cache;
    int old_dirfilter = *(tc->dirfilter);

    if (!callback)
        return -1;

    /* use the tree browser dircache to load files */
    *(tc->dirfilter) = SHOW_ALL;

    if (ft_load(tc, dirname) < 0)
    {
        splash(HZ*2, ID2P(LANG_PLAYLIST_DIRECTORY_ACCESS_ERROR));
        *(tc->dirfilter) = old_dirfilter;
        return -1;
    }

    num_files = tc->filesindir;

    /* we've overwritten the dircache so tree browser will need to be
       reloaded */
    reload_directory();

    for (i=0; i<num_files; i++)
    {
        /* user abort */
        if (action_userabort(TIMEOUT_NOBLOCK))
        {
            result = -1;
            break;
        }

        struct entry *files = core_get_data(cache->entries_handle);
        if (files[i].attr & ATTR_DIRECTORY)
        {
            if (recurse)
            {
                /* recursively add directories */
                if (path_append(buf, dirname, files[i].name, sizeof(buf))
                        >= sizeof(buf))
                {
                    continue;
                }

                result = playlist_directory_tracksearch(buf, recurse,
                    callback, context);
                if (result < 0)
                    break;

                /* we now need to reload our current directory */
                if(ft_load(tc, dirname) < 0)
                {
                    result = -1;
                    break;
                }

                num_files = tc->filesindir;
                if (!num_files)
                {
                    result = -1;
                    break;
                }
            }
            else
                continue;
        }
        else if ((files[i].attr & FILE_ATTR_MASK) == FILE_ATTR_AUDIO)
        {
            if (path_append(buf, dirname, files[i].name, sizeof(buf))
                    >= sizeof(buf))
            {
                continue;
            }

            if (callback(buf, context) != 0)
            {
                result = -1;
                break;
            }

            /* let the other threads work */
            yield();
        }
    }

    /* restore dirfilter */
    *(tc->dirfilter) = old_dirfilter;

    return result;
}


struct playlist_info *playlist_get_current(void)
{
    return &current_playlist;
}

/* Returns index of current playing track for display purposes.  This value
   should not be used for resume purposes as it doesn't represent the actual
   index into the playlist */
int playlist_get_display_index(void)
{
    struct playlist_info* playlist = &current_playlist;

    /* first_index should always be index 0 for display purposes */
    int index = rotate_index(playlist, playlist->index);

    return (index+1);
}

/* returns the crc32 of the filename of the track at the specified index */
unsigned int playlist_get_filename_crc32(struct playlist_info *playlist,
                                         int index)
{
    struct playlist_track_info track_info;
    if (playlist_get_track_info(playlist, index, &track_info) == -1)
        return -1;
    const char *basename;
#ifdef HAVE_MULTIVOLUME
    /* remove the volume identifier it might change just use the relative part*/
    path_strip_volume(track_info.filename, &basename, false);
    if (basename == NULL)
#endif
        basename = track_info.filename;
    NOTEF("%s: %s", __func__, basename);
    return crc_32(basename, strlen(basename), -1);
}

/* returns index of first track in playlist */
int playlist_get_first_index(const struct playlist_info* playlist)
{
    if (!playlist)
        playlist = &current_playlist;

    return playlist->first_index;
}

/* returns the playlist filename */
char *playlist_get_name(const struct playlist_info* playlist, char *buf,
                        int buf_size)
{
    if (!playlist)
        playlist = &current_playlist;

    strmemccpy(buf, playlist->filename, buf_size);

    if (!buf[0])
        return NULL;

    return buf;
}

/* return size of buffer needed for playlist to initialize num_indices entries */
size_t playlist_get_required_bufsz(struct playlist_info* playlist,
                                             bool include_namebuf,
                                                   int num_indices)
{
    size_t namebuf = 0;

    if (!playlist)
        playlist = &current_playlist;

    size_t unit_size = sizeof (*playlist->indices);
    #ifdef HAVE_DIRCACHE
            unit_size += sizeof (*playlist->dcfrefs);
    #endif
    if (include_namebuf)
        namebuf = AVERAGE_FILENAME_LENGTH * global_settings.max_files_in_dir;

    return (num_indices * unit_size) + namebuf;
}

/* Get resume info for current playing song.  If return value is -1 then
   settings shouldn't be saved. */
int playlist_get_resume_info(int *resume_index)
{
    struct playlist_info* playlist = &current_playlist;

    *resume_index = playlist->index;

    return 0;
}

/* returns shuffle seed of playlist */
int playlist_get_seed(const struct playlist_info* playlist)
{
    if (!playlist)
        playlist = &current_playlist;

    return playlist->seed;
}

/* Fills info structure with information about track at specified index.
   Returns 0 on success and -1 on failure */
int playlist_get_track_info(struct playlist_info* playlist, int index,
                            struct playlist_track_info* info)
{
    int seek;
    bool control_file;

    if (!playlist)
        playlist = &current_playlist;

    if (index < 0 || index >= playlist->amount)
        return -1;

    control_file = playlist->indices[index] & PLAYLIST_INSERT_TYPE_MASK;
    seek = playlist->indices[index] & PLAYLIST_SEEK_MASK;

    if (get_track_filename(playlist, index, seek, control_file,
                           info->filename, sizeof(info->filename)) < 0)
        return -1;

    info->attr = 0;

    if (control_file)
    {
        if (playlist->indices[index] & PLAYLIST_QUEUE_MASK)
            info->attr |= PLAYLIST_ATTR_QUEUED;
        else
            info->attr |= PLAYLIST_ATTR_INSERTED;

    }

    if (playlist->indices[index] & PLAYLIST_SKIPPED)
        info->attr |= PLAYLIST_ATTR_SKIPPED;

    info->index = index;
    info->display_index = rotate_index(playlist, index) + 1;

    return 0;
}

/*
 * Insert all tracks from specified directory into playlist.
 */
int playlist_insert_directory(struct playlist_info* playlist,
                              const char *dirname, int position, bool queue,
                              bool recurse)
{
    int result;
    unsigned char *count_str;
    struct directory_search_context context;

    if (!playlist)
        playlist = &current_playlist;

    if (check_control(playlist) < 0)
    {
        notify_control_access_error();
        return -1;
    }

    if (position == PLAYLIST_REPLACE)
    {
        if (playlist_remove_all_tracks(playlist) == 0)
            position = PLAYLIST_INSERT_LAST;
        else
            return -1;
    }

    dc_discard_playlist_pointers();

    if (queue)
        count_str = ID2P(LANG_PLAYLIST_QUEUE_COUNT);
    else
        count_str = ID2P(LANG_PLAYLIST_INSERT_COUNT);

    display_playlist_count(0, count_str, false);

    context.playlist = playlist;
    context.position = position;
    context.queue = queue;
    context.count = 0;

    cpu_boost(true);

    result = playlist_directory_tracksearch(dirname, recurse,
        directory_search_callback, &context);

    sync_control(playlist, false);

    cpu_boost(false);

    display_playlist_count(context.count, count_str, true);

    if ((audio_status() & AUDIO_STATUS_PLAY) && playlist->started)
        audio_flush_and_reload_tracks();

    dc_load_playlist_pointers();

    return result;
}

/*
 * Insert all tracks from specified playlist into dynamic playlist.
 */
int playlist_insert_playlist(struct playlist_info* playlist, const char *filename,
                             int position, bool queue)
{
    int fd;
    int max;
    char *dir;
    unsigned char *count_str;
    char temp_buf[MAX_PATH+1];
    char trackname[MAX_PATH+1];
    int count = 0;
    int result = -1;
    bool utf8 = is_m3u8_name(filename);

    if (!playlist)
        playlist = &current_playlist;

    playlist_mutex_lock(&(playlist->mutex));

    dc_discard_playlist_pointers();

    cpu_boost(true);

    if (check_control(playlist) < 0)
    {
        notify_control_access_error();
        goto out;
    }

    fd = open_utf8(filename, O_RDONLY);
    if (fd < 0)
    {
        notify_access_error();
        goto out;
    }

    /* we need the directory name for formatting purposes */
    size_t dirlen = path_dirname(filename, (const char **)&dir);
    dir = strmemdupa(dir, dirlen);

    if (queue)
        count_str = ID2P(LANG_PLAYLIST_QUEUE_COUNT);
    else
        count_str = ID2P(LANG_PLAYLIST_INSERT_COUNT);

    display_playlist_count(count, count_str, false);

    if (position == PLAYLIST_REPLACE)
    {
        if (playlist_remove_all_tracks(playlist) == 0)
            position = PLAYLIST_INSERT_LAST;
        else
        {
            close(fd);
            goto out;
        }
    }

    while ((max = read_line(fd, temp_buf, sizeof(temp_buf))) > 0)
    {
        /* user abort */
        if (action_userabort(TIMEOUT_NOBLOCK))
            break;

        if (temp_buf[0] != '#' && temp_buf[0] != '\0')
        {
            int insert_pos;

            if (!utf8)
            {
                /* Use trackname as a temporay buffer. Note that trackname must
                 * be as large as temp_buf.
                 */
                max = convert_m3u_name(temp_buf, max, sizeof(temp_buf), trackname);
            }

            /* we need to format so that relative paths are correctly
               handled */
            if (format_track_path(trackname, temp_buf, sizeof(trackname), dir) < 0)
            {
                goto out;
            }

            insert_pos = add_track_to_playlist_unlocked(playlist, trackname,
                                                        position, queue, -1);

            if (insert_pos < 0)
            {
                goto out;
            }

            /* After first INSERT_FIRST switch to INSERT so that all the
            rest of the tracks get inserted one after the other */
            if (position == PLAYLIST_INSERT_FIRST)
                position = PLAYLIST_INSERT;

            count++;

            if ((count%PLAYLIST_DISPLAY_COUNT) == 0)
            {
                display_playlist_count(count, count_str, false);

                if (count == PLAYLIST_DISPLAY_COUNT &&
                    (audio_status() & AUDIO_STATUS_PLAY) &&
                    playlist->started)
                {
                    audio_flush_and_reload_tracks();
                }
            }
        }

        /* let the other threads work */
        yield();
    }

    close(fd);

    sync_control(playlist, false);

    display_playlist_count(count, count_str, true);

    if ((audio_status() & AUDIO_STATUS_PLAY) && playlist->started)
        audio_flush_and_reload_tracks();

    dc_load_playlist_pointers();
    result = 0;

out:
    cpu_boost(false);

    playlist_mutex_unlock(&(playlist->mutex));

    return result;
}

/*
 * Insert track into playlist at specified position (or one of the special
 * positions).  Returns position where track was inserted or -1 if error.
 */
int playlist_insert_track(struct playlist_info* playlist, const char *filename,
                          int position, bool queue, bool sync)
{
    int result;

    if (!playlist)
        playlist = &current_playlist;

    playlist_mutex_lock(&(playlist->mutex));

    dc_discard_playlist_pointers();

    if (check_control(playlist) < 0)
    {
        notify_control_access_error();
        return -1;
    }

    result = add_track_to_playlist_unlocked(playlist, filename,
                                            position, queue, -1);

    /* Check if we want manually sync later. For example when adding
     * bunch of files from tagcache, syncing after every file wouldn't be
     * a good thing to do. */
    if (sync && result >= 0)
    {
        playlist_sync(playlist);
    }

    playlist_mutex_unlock(&(playlist->mutex));

    return result;
}

/* returns true if playlist has been modified */
bool playlist_modified(const struct playlist_info* playlist)
{
    if (!playlist)
        playlist = &current_playlist;

    if (playlist->shuffle_modified ||
        playlist->deleted ||
        playlist->num_inserted_tracks > 0)
    {
        return true;
    }

    return false;
}

/*
 * Move track at index to new_index.  Tracks between the two are shifted
 * appropriately.  Returns 0 on success and -1 on failure.
 */
int playlist_move(struct playlist_info* playlist, int index, int new_index)
{
    int result = -1;
    int seek;
    bool control_file;
    bool queue;
    bool current = false;
    int r;
    struct playlist_track_info info;
    int idx_cur; /* display index of the currently playing track */
    int idx_from; /* display index of the track we're moving */
    int idx_to; /* display index of the position we're moving to */
    bool displace_current = false;
    char filename[MAX_PATH];

    if (!playlist)
        playlist = &current_playlist;

    playlist_mutex_lock(&(playlist->mutex));

    if (check_control(playlist) < 0)
    {
        notify_control_access_error();
        goto out;;
    }

    if (index == new_index)
        goto out;

    if (index == playlist->index)
    {
        /* Moving the current track */
        current = true;
    }
    else
    {
        /* Get display index of the currently playing track */
        if (playlist_get_track_info(playlist, playlist->index, &info) != -1)
        {
            idx_cur = info.display_index;
            /* Get display index of the position we're moving to */
            if (playlist_get_track_info(playlist, new_index, &info) != -1)
            {
                idx_to = info.display_index;
                /* Get display index of the track we're trying to move */
                if (playlist_get_track_info(playlist, index, &info) != -1)
                {
                    idx_from = info.display_index;
                    /* Check if moving will displace the current track.
                       Displace happens when moving from after current to
                       before, but also when moving from before to before
                       due to the removal from the original position */
                    if ( ((idx_from > idx_cur) && (idx_to <= idx_cur)) ||
                         ((idx_from < idx_cur) && (idx_to < idx_cur)) )
                        displace_current = true;
                }
            }
        }
    }

    control_file = playlist->indices[index] & PLAYLIST_INSERT_TYPE_MASK;
    queue = playlist->indices[index] & PLAYLIST_QUEUE_MASK;
    seek = playlist->indices[index] & PLAYLIST_SEEK_MASK;

    if (get_track_filename(playlist, index, seek,
                           control_file, filename, sizeof(filename)) < 0)
    {
        goto out;
    }

    dc_discard_playlist_pointers();

    /* We want to insert the track at the position that was specified by
       new_index.  This may be different then new_index because of the
       shifting that will occur after the delete.
       We calculate this before we do the remove as it depends on the
       size of the playlist before the track removal */
    r = rotate_index(playlist, new_index);

    /* Delete track from original position */
    result = remove_track_from_playlist(playlist, index, true);

    if (result != -1)
    {
        if (r == 0)/* First index */
        {
            new_index = PLAYLIST_PREPEND;
        }
        else if (r == playlist->amount)
        {
            /* Append */
            new_index = PLAYLIST_INSERT_LAST;
        }
        else /* Calculate index of desired position */
        {
            new_index = (r+playlist->first_index)%playlist->amount;
        }

        result = add_track_to_playlist_unlocked(playlist, filename,
                                                new_index, queue, -1);

        if (result != -1)
        {
            if (current)
            {
                /* Moved the current track */
                switch (new_index)
                {
                    case PLAYLIST_PREPEND:
                        playlist->index = playlist->first_index;
                        break;
                    case PLAYLIST_INSERT_LAST:
                        playlist->index = playlist->first_index - 1;
                        if (playlist->index < 0)
                            playlist->index += playlist->amount;
                        break;
                    default:
                        playlist->index = new_index;
                        break;
                }
            }
            else if ((displace_current) && (new_index != PLAYLIST_PREPEND))
            {
                    /* make the index point to the currently playing track */
                    playlist->index++;
            }

            playlist_mutex_unlock(&(playlist->mutex));
            if ((audio_status() & AUDIO_STATUS_PLAY) && playlist->started)
                audio_flush_and_reload_tracks();
        }
        else
        {
            playlist_mutex_unlock(&(playlist->mutex));
        }
    }

    dc_load_playlist_pointers();
    return result;

out:
    playlist_mutex_unlock(&(playlist->mutex));

    return result;
}

/* returns full path of playlist (minus extension) */
char *playlist_name(const struct playlist_info* playlist, char *buf,
                    int buf_size)
{
    char *sep;

    if (!playlist)
        playlist = &current_playlist;

    strmemccpy(buf, playlist->filename+playlist->dirlen, buf_size);

    if (!buf[0])
        return NULL;

    /* Remove extension */
    sep = strrchr(buf, '.');
    if (sep)
        *sep = 0;

    return buf;
}

/*
 * Update indices as track has changed
 */
int playlist_next(int steps)
{
    struct playlist_info* playlist = &current_playlist;

    playlist_mutex_lock(&(playlist->mutex));

    int index;

    if ( (steps > 0)
#ifdef AB_REPEAT_ENABLE
    && (global_settings.repeat_mode != REPEAT_AB)
#endif
    && (global_settings.repeat_mode != REPEAT_ONE) )
    {
        int i, j;

        dc_discard_playlist_pointers();

        /* We need to delete all the queued songs */
        for (i=0, j=steps; i<j; i++)
        {
            index = get_next_index(playlist, i, -1);

            if (index >= 0 && playlist->indices[index] & PLAYLIST_QUEUE_MASK)
            {
                remove_track_from_playlist(playlist, index, true);
                steps--; /* one less track */
            }
        }
    }

    index = get_next_index(playlist, steps, -1);

    if (index < 0)
    {
        /* end of playlist... or is it */
        if (global_settings.repeat_mode == REPEAT_SHUFFLE &&
            playlist->amount > 1)
        {
            /* Repeat shuffle mode.  Re-shuffle playlist and resume play */
            playlist->first_index = 0;
            sort_playlist_unlocked(playlist, false, false);
            randomise_playlist(playlist, current_tick, false, true);

            playlist->started = true;
            playlist->index = 0;
            index = 0;
        }
        else if (playlist->in_ram && global_settings.next_folder)
        {
            /* we switch playlists here */
            playlist_mutex_unlock(&(playlist->mutex));
            index = create_and_play_dir(steps, true);
            playlist_mutex_lock(&(playlist->mutex));
            if (index >= 0)
            {
                playlist->index = index;
            }
        }
        goto out;
    }

    playlist->index = index;

    if (playlist->last_insert_pos >= 0 && steps > 0)
    {
        /* check to see if we've gone beyond the last inserted track */
        int cur = rotate_index(playlist, index);
        int last_pos = rotate_index(playlist, playlist->last_insert_pos);

        if (cur > last_pos)
        {
            /* reset last inserted track */
            playlist->last_insert_pos = -1;
            if (playlist->control_fd >= 0)
            {
                int result = update_control(playlist, PLAYLIST_COMMAND_RESET,
                    -1, -1, NULL, NULL, NULL);

                if (result < 0)
                {
                    index = result;
                    goto out;
                }
                sync_control(playlist, false);
            }
        }
    }

out:
    playlist_mutex_unlock(&(playlist->mutex));

    return index;
}

/* try playing next or previous folder */
bool playlist_next_dir(int direction)
{
    /* not to mess up real playlists */
    if(!current_playlist.in_ram)
       return false;

    playlist_mutex_lock(&(current_playlist.mutex));
    playlist_mutex_unlock(&(current_playlist.mutex));

    return create_and_play_dir(direction, false) >= 0;
}

/* get trackname of track that is "steps" away from current playing track.
   NULL is used to identify end of playlist */
const char* playlist_peek(int steps, char* buf, size_t buf_size)
{
    struct playlist_info* playlist = &current_playlist;
    int seek;
    char *temp_ptr;
    int index;
    bool control_file;

    index = get_next_index(playlist, steps, -1);
    if (index < 0)
        return NULL;

    /* Just testing - don't care about the file name */
    if (!buf || !buf_size)
        return "";

    control_file = playlist->indices[index] & PLAYLIST_INSERT_TYPE_MASK;
    seek = playlist->indices[index] & PLAYLIST_SEEK_MASK;

    if (get_track_filename(playlist, index, seek,
                           control_file, buf, buf_size) < 0)
        return NULL;

    temp_ptr = buf;

    if (!playlist->in_ram || control_file)
    {
        /* remove bogus dirs from beginning of path
           (workaround for buggy playlist creation tools) */
        while (temp_ptr)
        {
            if (file_exists(temp_ptr))
                break;

            temp_ptr = strchr(temp_ptr+1, '/');
        }

        if (!temp_ptr)
        {
            /* Even though this is an invalid file, we still need to pass a
               file name to the caller because NULL is used to indicate end
               of playlist */
            return buf;
        }
    }

    return temp_ptr;
}

/* shuffle currently playing playlist */
int playlist_randomise(struct playlist_info* playlist, unsigned int seed,
                       bool start_current)
{
    int result;

    if (!playlist)
        playlist = &current_playlist;

    playlist_mutex_lock(&(playlist->mutex));

    check_control(playlist);

    result = randomise_playlist(playlist, seed, start_current, true);

    if (result != -1 && (audio_status() & AUDIO_STATUS_PLAY) &&
        playlist->started)
    {
        audio_flush_and_reload_tracks();
    }

    playlist_mutex_unlock(&(playlist->mutex));

    return result;
}

/*
 * Removes all tracks, from the playlist, leaving the presently playing
 * track queued.
 */
int playlist_remove_all_tracks(struct playlist_info *playlist)
{
    int result;

    if (playlist == NULL)
        playlist = &current_playlist;

    dc_discard_playlist_pointers();

    while (playlist->index > 0)
        if ((result = remove_track_from_playlist(playlist, 0, true)) < 0)
            return result;

    while (playlist->amount > 1)
        if ((result = remove_track_from_playlist(playlist, 1, true)) < 0)
            return result;

    if (playlist->amount == 1) {
        playlist->indices[0] |= PLAYLIST_QUEUED;
    }

    return 0;
}

/*
 * Restore the playlist state based on control file commands.  Called to
 * resume playback after shutdown.
 */
int playlist_resume(void)
{
    char *buffer;
    size_t buflen;
    size_t readsize;
    int handle;
    int nread;
    int total_read = 0;
    int control_file_size = 0;
    bool first = true;
    bool sorted = true;
    int result = -1;

    splash(0, ID2P(LANG_WAIT));

    struct playlist_info* playlist = &current_playlist;
    playlist_mutex_lock(&(playlist->mutex));

    if (core_allocatable() < (1 << 10))
        talk_buffer_set_policy(TALK_BUFFER_LOOSE); /* back off voice buffer */

#ifdef HAVE_DIRCACHE
    dircache_wait(); /* we need the dircache to use the files in the playlist */
#endif

    handle = alloc_tempbuf(&buflen);
    if (handle < 0)
    {
        splashf(HZ * 2, "%s(): OOM", __func__);
        goto out;
    }

    /* align buffer for faster load times */
    buffer = core_get_data(handle);
    STORAGE_ALIGN_BUFFER(buffer, buflen);
    buflen = ALIGN_DOWN(buflen, 512); /* to avoid partial sector I/O */

    playlist_shutdown(); /* flush any cached control commands to disk */
    empty_playlist_unlocked(playlist, true);

    playlist->control_fd = open(playlist->control_filename, O_RDWR);
    if (playlist->control_fd < 0)
    {
        notify_control_access_error();
        goto out;
    }
    playlist->control_created = true;

    control_file_size = filesize(playlist->control_fd);
    if (control_file_size <= 0)
    {
        notify_control_access_error();
        goto out;
    }

    /* read a small amount first to get the header */
    readsize = (PLAYLIST_COMMAND_SIZE<buflen?PLAYLIST_COMMAND_SIZE:buflen);
    nread = read(playlist->control_fd, buffer, readsize);
    if(nread <= 0)
    {
        notify_control_access_error();
        goto out;
    }

    playlist->started = true;

    while (1)
    {
        result = 0;
        int count;
        enum playlist_command current_command = PLAYLIST_COMMAND_COMMENT;
        int last_newline = 0;
        int str_count = -1;
        bool newline = true;
        bool exit_loop = false;
        char *p = buffer;
        char *str1 = NULL;
        char *str2 = NULL;
        char *str3 = NULL;

        unsigned long last_tick = current_tick;
        splash_progress_set_delay(HZ / 2); /* wait 1/2 sec before progress */
        bool useraborted = false;

        for(count=0; count<nread && !exit_loop; count++,p++)
        {
            /* Show a splash while we are loading. */
            splash_progress((total_read + count), control_file_size,
                         "%s (%s)", str(LANG_WAIT), str(LANG_OFF_ABORT));
            if (TIME_AFTER(current_tick, last_tick + HZ/4))
            {
                if (action_userabort(TIMEOUT_NOBLOCK))
                {
                    useraborted = true;
                    exit_loop = true;
                    break;
                }
                last_tick = current_tick;
            }
            /* Are we on a new line? */
            if((*p == '\n') || (*p == '\r'))
            {
                *p = '\0';

                switch (current_command)
                {
                    case PLAYLIST_COMMAND_PLAYLIST:
                    {
                        /* str1=version str2=dir str3=file */
                        int version;

                        if (!str1)
                        {
                            result = -2;
                            exit_loop = true;
                            break;
                        }

                        if (!str2)
                            str2 = "";

                        if (!str3)
                            str3 = "";

                        version = atoi(str1);

                        if (version != PLAYLIST_CONTROL_FILE_VERSION)
                        {
                            result = -3;
                            goto out;
                        }

                        update_playlist_filename_unlocked(playlist, str2, str3);

                        if (str3[0] != '\0')
                        {
                            /* NOTE: add_indices_to_playlist() overwrites the
                               audiobuf so we need to reload control file
                               data */
                            add_indices_to_playlist(playlist, buffer, buflen);
                        }
                        else if (str2[0] != '\0')
                        {
                            playlist->in_ram = true;
                            resume_directory(str2);
                        }

                        /* load the rest of the data */
                        first = false;
                        exit_loop = true;
                        readsize = buflen;
                        break;
                    }
                    case PLAYLIST_COMMAND_ADD:
                    case PLAYLIST_COMMAND_QUEUE:
                    {
                        /* str1=position str2=last_position str3=file */
                        int position, last_position;
                        bool queue;

                        if (!str1 || !str2 || !str3)
                        {
                            result = -4;
                            exit_loop = true;
                            break;
                        }

                        position = atoi(str1);
                        last_position = atoi(str2);

                        queue = (current_command == PLAYLIST_COMMAND_ADD)?
                            false:true;

                        /* seek position is based on str3's position in
                           buffer */
                        if (add_track_to_playlist_unlocked(playlist, str3,
                                position, queue, total_read+(str3-buffer)) < 0)
                        {
                            result = -5;
                            goto out;
                        }

                        playlist->last_insert_pos = last_position;

                        break;
                    }
                    case PLAYLIST_COMMAND_DELETE:
                    {
                        /* str1=position */
                        int position;

                        if (!str1)
                        {
                            result = -6;
                            exit_loop = true;
                            break;
                        }

                        position = atoi(str1);

                        if (remove_track_from_playlist(playlist, position,
                                false) < 0)
                        {
                            result = -7;
                            goto out;
                        }

                        break;
                    }
                    case PLAYLIST_COMMAND_SHUFFLE:
                    {
                        /* str1=seed str2=first_index */
                        int seed;

                        if (!str1 || !str2)
                        {
                            result = -8;
                            exit_loop = true;
                            break;
                        }

                        if (!sorted)
                        {
                            /* Always sort list before shuffling */
                            sort_playlist_unlocked(playlist, false, false);
                        }

                        seed = atoi(str1);
                        playlist->first_index = atoi(str2);

                        if (randomise_playlist(playlist, seed, false,
                                false) < 0)
                        {
                            result = -9;
                            goto out;
                        }
                        sorted = false;

                        break;
                    }
                    case PLAYLIST_COMMAND_UNSHUFFLE:
                    {
                        /* str1=first_index */
                        if (!str1)
                        {
                            result = -10;
                            exit_loop = true;
                            break;
                        }

                        playlist->first_index = atoi(str1);

                        if (sort_playlist_unlocked(playlist, false, false) < 0)
                        {
                            result = -11;
                            goto out;
                        }

                        sorted = true;
                        break;
                    }
                    case PLAYLIST_COMMAND_RESET:
                    {
                        playlist->last_insert_pos = -1;
                        break;
                    }
                    case PLAYLIST_COMMAND_COMMENT:
                    default:
                        break;
                }

                /* save last_newline in case we need to load more data */
                last_newline = count;
                newline = true;

                /* to ignore any extra newlines */
                current_command = PLAYLIST_COMMAND_COMMENT;
            }
            else if(newline)
            {
                newline = false;

                switch (*p)
                {
                    case 'P':
                        /* playlist can only be specified once */
                        if (!first)
                        {
                            result = -13;
                            exit_loop = true;
                            break;
                        }

                        current_command = PLAYLIST_COMMAND_PLAYLIST;
                        break;
                    case 'A':
                        current_command = PLAYLIST_COMMAND_ADD;
                        break;
                    case 'Q':
                        current_command = PLAYLIST_COMMAND_QUEUE;
                        break;
                    case 'D':
                        current_command = PLAYLIST_COMMAND_DELETE;
                        break;
                    case 'S':
                        current_command = PLAYLIST_COMMAND_SHUFFLE;
                        break;
                    case 'U':
                        current_command = PLAYLIST_COMMAND_UNSHUFFLE;
                        break;
                    case 'R':
                        current_command = PLAYLIST_COMMAND_RESET;
                        break;
                    case '#':
                        current_command = PLAYLIST_COMMAND_COMMENT;
                        break;
                    default:
                        result = -14;
                        exit_loop = true;
                        break;
                }

                /* first non-comment line must always specify playlist */
                if (first &&
                    (current_command != PLAYLIST_COMMAND_PLAYLIST) &&
                    (current_command != PLAYLIST_COMMAND_COMMENT))
                {
                    result = -12;
                    exit_loop = true;
                    break;
                }

                str_count = -1;
                str1 = NULL;
                str2 = NULL;
                str3 = NULL;
            }
            else if(current_command != PLAYLIST_COMMAND_COMMENT)
            {
                /* all control file strings are separated with a colon.
                   Replace the colon with 0 to get proper strings that can be
                   used by commands above */
                if (*p == ':')
                {
                    *p = '\0';
                    str_count++;

                    if ((count+1) < nread)
                    {
                        switch (str_count)
                        {
                        case 0:
                            str1 = p+1;
                            break;
                        case 1:
                            str2 = p+1;
                            break;
                        case 2:
                            str3 = p+1;
                            break;
                        default:
                            /* allow last string to contain colons */
                            *p = ':';
                            break;
                        }
                    }
                }
            }
        }

        if (result < 0)
        {
            splashf(HZ*2, "Err: %d, %s", result, str(LANG_PLAYLIST_CONTROL_INVALID));
            goto out;
        }

        if (useraborted)
        {
            splash(HZ*2, ID2P(LANG_CANCEL));
            result = -1;
            goto out;
        }

        if (!newline || (exit_loop && count<nread))
        {
            if ((total_read + count) >= control_file_size)
            {
                /* no newline at end of control file */
                splashf(HZ*2, "Err: EOF, %s", str(LANG_PLAYLIST_CONTROL_INVALID));
                result = -15;
                goto out;
            }

            /* We didn't end on a newline or we exited loop prematurely.
               Either way, re-read the remainder. */
            count = last_newline;
            lseek(playlist->control_fd, total_read+count, SEEK_SET);
        }

        total_read += count;

        nread = read(playlist->control_fd, buffer, readsize);

        /* Terminate on EOF */
        if(nread <= 0)
        {
            break;
        }
    }

    dc_load_playlist_pointers();

out:
    playlist_mutex_unlock(&(playlist->mutex));

    talk_buffer_set_policy(TALK_BUFFER_DEFAULT);
    core_free(handle);
    return result;
}

/* resume a playlist track with the given crc_32 of the track name. */
void playlist_resume_track(int start_index, unsigned int crc,
                           unsigned long elapsed, unsigned long offset)
{
    int i;
    unsigned int tmp_crc;
    struct playlist_info* playlist = &current_playlist;

    tmp_crc = playlist_get_filename_crc32(playlist, start_index);

    if (tmp_crc == crc)
    {
        playlist_start(start_index, elapsed, offset);
        return;
    }

    for (i = 0 ; i < playlist->amount; i++)
    {
        tmp_crc = playlist_get_filename_crc32(playlist, i);
        if (tmp_crc == crc)
        {
            playlist_start(i, elapsed, offset);
            return;
        }
    }

    /* If we got here the file wasnt found, so start from the beginning */
    playlist_start(0, 0, 0);
}

/* save the current dynamic playlist to specified file. The
 * temp_buffer (if not NULL) is used as a scratchpad when loading indices
 * (slow if not used). */
int playlist_save(struct playlist_info* playlist, char *filename,
                       void* temp_buffer, size_t temp_buffer_size)
{
    int fd;
    int i, index;
    int count = 0;
    char path[MAX_PATH+1];
    char tmp_buf[MAX_PATH+1];
    int result = 0;
    int *seek_buf;
    bool reparse;
    ssize_t pathlen;

    ALIGN_BUFFER(temp_buffer, temp_buffer_size, sizeof(int));
    seek_buf = temp_buffer;

    /* without temp_buffer, or when it's depleted, and we overwrite the current
     * playlist then the newly saved playlist has to be reparsed. With
     * sufficient temp_buffer the indicies be remembered and added without
     * reparsing */
    reparse = temp_buffer_size == 0;

    if (!playlist)
        playlist = &current_playlist;

    if (playlist->amount <= 0)
        return -1;

    /* use current working directory as base for pathname */
    pathlen = format_track_path(path, filename, sizeof(path), PATH_ROOTSTR);
    if (pathlen < 0)
        return -1;

    /* Use temporary pathname and overwrite/rename later */
    if (strlcat(path, "_temp", sizeof(path)) >= sizeof (path))
        return -1;

    if (is_m3u8_name(path))
    {
        fd = open_utf8(path, O_CREAT|O_WRONLY|O_TRUNC);
    }
    else
    {
        /* some applications require a BOM to read the file properly */
        fd = open(path, O_CREAT|O_WRONLY|O_TRUNC, 0666);
    }

    if (fd < 0)
    {
        notify_access_error();
        return -1;
    }

    display_playlist_count(count, ID2P(LANG_PLAYLIST_SAVE_COUNT), false);

    cpu_boost(true);

    index = playlist->first_index;
    for (i=0; i<playlist->amount; i++)
    {
        bool control_file;
        bool queue;
        int seek;

        /* user abort */
        if (action_userabort(TIMEOUT_NOBLOCK))
        {
            result = -1;
            break;
        }

        control_file = playlist->indices[index] & PLAYLIST_INSERT_TYPE_MASK;
        queue = playlist->indices[index] & PLAYLIST_QUEUE_MASK;
        seek = playlist->indices[index] & PLAYLIST_SEEK_MASK;

        /* Don't save queued files */
        if (!queue)
        {
            if (get_track_filename(playlist, index, seek,
                                   control_file, tmp_buf, MAX_PATH+1) < 0)
            {
                result = -1;
                break;
            }

            if (!reparse)
                seek_buf[count] = filesize(fd);

            if (fdprintf(fd, "%s\n", tmp_buf) < 0)
            {
                notify_access_error();
                result = -1;
                break;
            }

            count++;
            /* when our temp buffer is depleted we have to fall
             * back to reparsing the playlist (slow) */
            if (count*sizeof(int) >= temp_buffer_size)
                reparse = true;

            if ((count % PLAYLIST_DISPLAY_COUNT) == 0)
                display_playlist_count(count, ID2P(LANG_PLAYLIST_SAVE_COUNT),
                                       false);

            yield();
        }

        index = (index+1)%playlist->amount;
    }

    close(fd);
    fd = -1;

    display_playlist_count(count, ID2P(LANG_PLAYLIST_SAVE_COUNT), true);

    if (result >= 0)
    {
        strmemcpy(tmp_buf, path, pathlen); /* remove "_temp" */

        playlist_mutex_lock(&(playlist->mutex));

        if (!rename(path, tmp_buf))
        {
            fd = open_utf8(tmp_buf, O_RDONLY);
            if (fd >= 0 && fsamefile(fd, playlist->fd) > 0)
            {
                /* Replace the current playlist with the new one and update
                   indices */
                close(playlist->fd);
                playlist->fd = fd;
                fd = -1;
                dc_discard_playlist_pointers();

                if (!reparse)
                {
                    index = playlist->first_index;
                    for (i=0, count=0; i<playlist->amount; i++)
                    {
                        if (!(playlist->indices[index] & PLAYLIST_QUEUE_MASK))
                        {
                            playlist->indices[index] = seek_buf[count];
                            count++;
                        }
                        index = (index+1)%playlist->amount;
                    }
                }
                else
                {
                    NOTEF("reparsing current playlist (slow)");
                    playlist->amount = 0;
                    add_indices_to_playlist(playlist, temp_buffer,
                                            temp_buffer_size);
                }

                /* we need to recreate control because inserted tracks are
                   now part of the playlist and shuffle has been invalidated */
                result = recreate_control_unlocked(playlist);
                dc_load_playlist_pointers();
            }
        }

        playlist_mutex_unlock(&(playlist->mutex));
    }

    if (fd >= 0)
        close(fd);

    cpu_boost(false);

    return result;
}

/*
 * Set the specified playlist as the current.
 * NOTE: You will get undefined behaviour if something is already playing so
 *       remember to stop before calling this.  Also, this call will
 *       effectively close your playlist, making it unusable.
 */
int playlist_set_current(struct playlist_info* playlist)
{
    int result = -1;

    if (!playlist || (check_control(playlist) < 0))
        return result;

    playlist_mutex_lock(&(current_playlist.mutex));

    empty_playlist_unlocked(&current_playlist, false);

    strmemccpy(current_playlist.filename, playlist->filename,
        sizeof(current_playlist.filename));

    current_playlist.utf8 = playlist->utf8;
    current_playlist.fd = playlist->fd;

    close_playlist_control_file(playlist);
    close_playlist_control_file(&current_playlist);

    remove(current_playlist.control_filename);
    current_playlist.control_created = false;

    if (rename(playlist->control_filename, current_playlist.control_filename) < 0)
        goto out;

    current_playlist.control_fd = open(current_playlist.control_filename,
        O_RDWR);

    if (current_playlist.control_fd < 0)
        goto out;

    current_playlist.control_created = true;
    current_playlist.dirlen = playlist->dirlen;

    if (playlist->indices && playlist->indices != current_playlist.indices)
    {
        memcpy((void*)current_playlist.indices, (void*)playlist->indices,
               playlist->max_playlist_size*sizeof(*playlist->indices));
#ifdef HAVE_DIRCACHE
        dc_copy_filerefs(current_playlist.dcfrefs, playlist->dcfrefs,
                         playlist->max_playlist_size);
#endif
    }

    current_playlist.first_index = playlist->first_index;
    current_playlist.amount = playlist->amount;
    current_playlist.last_insert_pos = playlist->last_insert_pos;
    current_playlist.seed = playlist->seed;
    current_playlist.shuffle_modified = playlist->shuffle_modified;
    current_playlist.deleted = playlist->deleted;
    current_playlist.num_inserted_tracks = playlist->num_inserted_tracks;

    memcpy(current_playlist.control_cache, playlist->control_cache,
        sizeof(current_playlist.control_cache));

    current_playlist.num_cached = playlist->num_cached;
    current_playlist.pending_control_sync = playlist->pending_control_sync;
    result = 0;

out:
    playlist_mutex_unlock(&(current_playlist.mutex));

    return result;
}

/* set playlist->last_shuffle_start to playlist->amount for
   PLAYLIST_INSERT_LAST_SHUFFLED command purposes*/
void playlist_set_last_shuffled_start(void)
{
    struct playlist_info* playlist = &current_playlist;
    playlist_mutex_lock(&(playlist->mutex));
    playlist->last_shuffled_start = playlist->amount;
    playlist_mutex_unlock(&(playlist->mutex));
}

/* shuffle newly created playlist using random seed. */
int playlist_shuffle(int random_seed, int start_index)
{
    struct playlist_info* playlist = &current_playlist;
    playlist_mutex_lock(&(playlist->mutex));
    bool start_current = false;

    if (start_index >= 0 && global_settings.play_selected)
    {
        /* store the seek position before the shuffle */
        playlist->index = playlist->first_index = start_index;
        start_current = true;
    }

    randomise_playlist(playlist, random_seed, start_current, true);
    playlist_mutex_unlock(&(playlist->mutex));
    return playlist->index;
}

/* Marks the index of the track to be skipped that is "steps" away from
 * current playing track.
 */
void playlist_skip_entry(struct playlist_info *playlist, int steps)
{
    int index;

    if (playlist == NULL)
        playlist = &current_playlist;
    playlist_mutex_lock(&(playlist->mutex));

    /* need to account for already skipped tracks */
    steps = calculate_step_count(playlist, steps);

    index = playlist->index + steps;
    if (index < 0)
        index += playlist->amount;
    else if (index >= playlist->amount)
        index -= playlist->amount;

    playlist->indices[index] |= PLAYLIST_SKIPPED;
    playlist_mutex_unlock(&(playlist->mutex));
}

/* sort currently playing playlist */
int playlist_sort(struct playlist_info* playlist, bool start_current)
{
    int result;

    if (!playlist)
        playlist = &current_playlist;

    playlist_mutex_lock(&(playlist->mutex));

    check_control(playlist);
    result = sort_playlist_unlocked(playlist, start_current, true);

    if (result != -1 && (audio_status() & AUDIO_STATUS_PLAY) && playlist->started)
        audio_flush_and_reload_tracks();

    playlist_mutex_unlock(&(playlist->mutex));
    return result;
}

/* start playing current playlist at specified index/offset */
void playlist_start(int start_index, unsigned long elapsed,
                    unsigned long offset)
{
    struct playlist_info* playlist = &current_playlist;

    playlist_mutex_lock(&(playlist->mutex));

    playlist->index = start_index;
    playlist->started = true;

    sync_control(playlist, false);

    playlist_mutex_unlock(&(playlist->mutex));

    audio_play(elapsed, offset);
    audio_resume();
}

void playlist_sync(struct playlist_info* playlist)
{
    if (!playlist)
        playlist = &current_playlist;

    sync_control(playlist, false);
    if ((audio_status() & AUDIO_STATUS_PLAY) && playlist->started)
        audio_flush_and_reload_tracks();

    dc_load_playlist_pointers();
}

/* Update resume info for current playing song.  Returns -1 on error. */
int playlist_update_resume_info(const struct mp3entry* id3)
{
    struct playlist_info* playlist = &current_playlist;

    if (id3)
    {
        if (global_status.resume_index  != playlist->index ||
            global_status.resume_elapsed != id3->elapsed ||
            global_status.resume_offset != id3->offset)
        {
            unsigned int crc = playlist_get_filename_crc32(playlist,
                                                           playlist->index);
            global_status.resume_index  = playlist->index;
            global_status.resume_crc32 = crc;
            global_status.resume_elapsed = id3->elapsed;
            global_status.resume_offset = id3->offset;
            status_save();
        }
    }
    else
    {
        global_status.resume_index  = -1;
        global_status.resume_crc32 = -1;
        global_status.resume_elapsed = -1;
        global_status.resume_offset = -1;
        status_save();
        return -1;
    }

    return 0;
}