/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 Daniel Stenberg
 *
 * 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.
 *
 ****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <sys/stat.h>
#include <time.h>
#include <errno.h>
#include "config.h"

#define HAVE_STATVFS (!defined(WIN32))
#define HAVE_LSTAT   (!defined(WIN32))

#if HAVE_STATVFS
#include <sys/statvfs.h>
#endif

#ifdef WIN32
#include <windows.h>
#endif

#ifndef _MSC_VER
#include <dirent.h>
#include <unistd.h>
#else
#include "dir-win32.h"
#endif

#include <fcntl.h>
#ifdef HAVE_SDL_THREADS
#include "thread-sdl.h"
#else
#define sim_thread_unlock() NULL
#define sim_thread_lock(a)
#endif
#include "thread.h"
#include "kernel.h"
#include "debug.h"
#include "ata.h" /* for IF_MV2 et al. */
#include "rbpaths.h"
#include "load_code.h"

/* keep this in sync with file.h! */
#undef MAX_PATH /* this avoids problems when building simulator */
#define MAX_PATH 260
#define MAX_OPEN_FILES 11

/* Windows (and potentially other OSes) distinguish binary and text files.
 * Define a dummy for the others. */
#ifndef O_BINARY
#define O_BINARY 0
#endif

/* Unicode compatibility for win32 */
#if defined __MINGW32__
/* Rockbox unicode functions */
extern const unsigned char* utf8decode(const unsigned char *utf8,
                                       unsigned short *ucs);
extern unsigned char* utf8encode(unsigned long ucs, unsigned char *utf8);

/* Static buffers for the conversion results. This isn't thread safe,
 * but it's sufficient for rockbox. */
static unsigned char convbuf1[3*MAX_PATH];
static unsigned char convbuf2[3*MAX_PATH];

static wchar_t* utf8_to_ucs2(const unsigned char *utf8, void *buffer)
{
    wchar_t *ucs = buffer;

    while (*utf8)
        utf8 = utf8decode(utf8, ucs++);

    *ucs = 0;
    return buffer;
}
static unsigned char *ucs2_to_utf8(const wchar_t *ucs, unsigned char *buffer)
{
    unsigned char *utf8 = buffer;

    while (*ucs)
        utf8 = utf8encode(*ucs++, utf8);

    *utf8 = 0;
    return buffer;
}

#define UTF8_TO_OS(a)  utf8_to_ucs2(a,convbuf1)
#define OS_TO_UTF8(a)  ucs2_to_utf8(a,convbuf1)
#define DIR_T       _WDIR
#define DIRENT_T    struct _wdirent
#define STAT_T      struct _stat
extern int _wmkdir(const wchar_t*);
extern int _wrmdir(const wchar_t*);
#define MKDIR(a,b)  (_wmkdir)(UTF8_TO_OS(a))
#define RMDIR(a)    (_wrmdir)(UTF8_TO_OS(a))
#define OPENDIR(a)  (_wopendir)(UTF8_TO_OS(a))
#define READDIR(a)  (_wreaddir)(a)
#define CLOSEDIR(a) (_wclosedir)(a)
#define STAT(a,b)   (_wstat)(UTF8_TO_OS(a),b)
/* empty variable parameter list doesn't work for variadic macros,
 * so pretend the second parameter is variable too */
#define OPEN(a,...) (_wopen)(UTF8_TO_OS(a), __VA_ARGS__)
#define CLOSE(a)    (close)(a)
#define REMOVE(a)   (_wremove)(UTF8_TO_OS(a))
#define RENAME(a,b) (_wrename)(UTF8_TO_OS(a),utf8_to_ucs2(b,convbuf2))

#else  /* !__MINGW32__ */

#define UTF8_TO_OS(a) (a)
#define OS_TO_UTF8(a) (a)
#define DIR_T       DIR
#define DIRENT_T    struct dirent
#define STAT_T      struct stat
#define MKDIR(a,b)  (mkdir)(a,b)
#define RMDIR(a)    (rmdir)(a)
#define OPENDIR(a)  (opendir)(a)
#define READDIR(a)  (readdir)(a)
#define CLOSEDIR(a) (closedir)(a)
#define STAT(a,b)   (stat)(a,b)
/* empty variable parameter list doesn't work for variadic macros,
 * so pretend the second parameter is variable too */
#define OPEN(a, ...) (open)(a, __VA_ARGS__)
#define CLOSE(x)    (close)(x)
#define REMOVE(a)   (remove)(a)
#define RENAME(a,b) (rename)(a,b)

#endif /* !__MINGW32__ */


#ifdef HAVE_DIRCACHE
int dircache_get_entry_id(const char *filename);
void dircache_add_file(const char *name, long startcluster);
void dircache_remove(const char *name);
void dircache_rename(const char *oldname, const char *newname);
#endif


#define SIMULATOR_DEFAULT_ROOT "simdisk"
extern const char *sim_root_dir;

static int num_openfiles = 0;

/* from dir.h */
struct dirinfo {
    int attribute;
    long size;
    unsigned short wrtdate;
    unsigned short wrttime;
};

struct sim_dirent {
    unsigned char d_name[MAX_PATH];
    struct dirinfo info;
    long startcluster;
};

struct dirstruct {
    void *dir; /* actually a DIR* dir */
    char *name;
} SIM_DIR;

struct mydir {
    DIR_T *dir;
    char *name;
};

typedef struct mydir MYDIR;

static unsigned int rockbox2sim(int opt)
{
#if 0
/* this shouldn't be needed since we use the host's versions */
    int newopt = O_BINARY;

    if(opt & 1)
        newopt |= O_WRONLY;
    if(opt & 2)
        newopt |= O_RDWR;
    if(opt & 4)
        newopt |= O_CREAT;
    if(opt & 8)
        newopt |= O_APPEND;
    if(opt & 0x10)
        newopt |= O_TRUNC;

    return newopt;
#else
    return opt|O_BINARY;
#endif
}

/** Simulator I/O engine routines **/
#define IO_YIELD_THRESHOLD 512

enum io_dir
{
    IO_READ,
    IO_WRITE,
};

struct sim_io
{
    struct mutex sim_mutex; /* Rockbox mutex */
    int cmd; /* The command to perform */
    int ready; /* I/O ready flag - 1= ready */
    int fd; /* The file to read/write */
    void *buf; /* The buffer to read/write */
    size_t count; /* Number of bytes to read/write */
    size_t accum; /* Acculated bytes transferred */
};

static struct sim_io io;

int ata_init(void)
{
    /* Initialize the rockbox kernel objects on a rockbox thread */
    mutex_init(&io.sim_mutex);
    io.accum = 0;
    return 1;
}

int ata_spinup_time(void)
{
    return HZ;
}

static ssize_t io_trigger_and_wait(enum io_dir cmd)
{
    void *mythread = NULL;
    ssize_t result;

    if (io.count > IO_YIELD_THRESHOLD ||
        (io.accum += io.count) >= IO_YIELD_THRESHOLD)
    {
        /* Allow other rockbox threads to run */
        io.accum = 0;
        mythread = sim_thread_unlock();
    }

    switch (cmd)
    {
    case IO_READ:
        result = read(io.fd, io.buf, io.count);
        break;
    case IO_WRITE:
        result = write(io.fd, io.buf, io.count);
        break;
        /* shut up gcc */
    default:
        result = -1;
    }

    /* Regain our status as current */
    if (mythread != NULL)
    {
        sim_thread_lock(mythread);
    }

    return result;
}

#if !defined(__PCTOOL__) && !defined(APPLICATION)
static const char *get_sim_pathname(const char *name)
{
    static char buffer[MAX_PATH]; /* sufficiently big */

    if(name[0] == '/')
    {
        snprintf(buffer, sizeof(buffer), "%s%s", 
            sim_root_dir != NULL ? sim_root_dir : SIMULATOR_DEFAULT_ROOT, name);
        return buffer;
    }
    fprintf(stderr, "WARNING, bad file name lacks slash: %s\n", name);
    return name;
}
#else
#define get_sim_pathname(name) name
#endif

MYDIR *sim_opendir(const char *name)
{
    DIR_T *dir;
    dir = (DIR_T *) OPENDIR(get_sim_pathname(name));

    if (dir)
    {
        MYDIR *my = (MYDIR *)malloc(sizeof(MYDIR));
        my->dir = dir;
        my->name = (char *)malloc(strlen(name)+1);
        strcpy(my->name, name);

        return my;
    }
    /* failed open, return NULL */
    return (MYDIR *)0;
}

#if defined(WIN32)
static inline struct tm* localtime_r (const time_t *clock, struct tm *result) {
       if (!clock || !result) return NULL;
       memcpy(result,localtime(clock),sizeof(*result));
       return result;
}
#endif

struct sim_dirent *sim_readdir(MYDIR *dir)
{
    char buffer[MAX_PATH]; /* sufficiently big */
    static struct sim_dirent secret;
    STAT_T s;
    struct tm tm;
    DIRENT_T *x11;

#ifdef EOVERFLOW
read_next:
#endif
    x11 = READDIR(dir->dir);

    if(!x11)
        return (struct sim_dirent *)0;

    strcpy((char *)secret.d_name, OS_TO_UTF8(x11->d_name));

    /* build file name */
    snprintf(buffer, sizeof(buffer), "%s/%s", 
        get_sim_pathname(dir->name), secret.d_name);

    if (STAT(buffer, &s)) /* get info */
    {
#ifdef EOVERFLOW
        /* File size larger than 2 GB? */
        if (errno == EOVERFLOW)
        {
            DEBUGF("stat() overflow for %s. Skipping\n", buffer);
            goto read_next;
        }
#endif

        return NULL;
    }

#define ATTR_DIRECTORY 0x10

    secret.info.attribute = 0;

    if (S_ISDIR(s.st_mode))
        secret.info.attribute = ATTR_DIRECTORY;

    secret.info.size = s.st_size;
    
    if (localtime_r(&(s.st_mtime), &tm) == NULL)
        return NULL;
    secret.info.wrtdate = ((tm.tm_year - 80) << 9) |
                        ((tm.tm_mon + 1) << 5) |
                        tm.tm_mday;
    secret.info.wrttime = (tm.tm_hour << 11) |
                        (tm.tm_min << 5) |
                        (tm.tm_sec >> 1);

#if HAVE_LSTAT
#define ATTR_LINK      0x80
    if (!lstat(buffer, &s) && S_ISLNK(s.st_mode))
    {
        secret.info.attribute |= ATTR_LINK;
    }
#endif

    return &secret;
}

void sim_closedir(MYDIR *dir)
{
    free(dir->name);
    CLOSEDIR(dir->dir);

    free(dir);
}

int sim_open(const char *name, int o, ...)
{
    int opts = rockbox2sim(o);
    int ret;
    if (num_openfiles >= MAX_OPEN_FILES)
        return -2;

    if (opts & O_CREAT)
    {
        va_list ap;
        va_start(ap, o);
        mode_t mode = va_arg(ap, unsigned int);
        ret = OPEN(get_sim_pathname(name), opts, mode);
#ifdef HAVE_DIRCACHE
        if (ret >= 0 && (dircache_get_entry_id(name) < 0))
            dircache_add_file(name, 0);
#endif
        va_end(ap);
    }
    else
        ret = OPEN(get_sim_pathname(name), opts);

    if (ret >= 0)
        num_openfiles++;
    return ret;
}

int sim_close(int fd)
{
    int ret;
    ret = CLOSE(fd);
    if (ret == 0)
        num_openfiles--;
    return ret;
}

int sim_creat(const char *name, mode_t mode)
{
    int ret = OPEN(get_sim_pathname(name),
                   O_BINARY | O_WRONLY | O_CREAT | O_TRUNC, mode);
#ifdef HAVE_DIRCACHE
    if (ret >= 0 && (dircache_get_entry_id(name) < 0))
        dircache_add_file(name, 0);
#endif
    return ret;
}

ssize_t sim_read(int fd, void *buf, size_t count)
{
    ssize_t result;

    mutex_lock(&io.sim_mutex);

    /* Setup parameters */
    io.fd = fd;
    io.buf = buf;
    io.count = count;

    result = io_trigger_and_wait(IO_READ);

    mutex_unlock(&io.sim_mutex);

    return result;
}

ssize_t sim_write(int fd, const void *buf, size_t count)
{
    ssize_t result;

    mutex_lock(&io.sim_mutex);

    io.fd = fd;
    io.buf = (void*)buf;
    io.count = count;

    result = io_trigger_and_wait(IO_WRITE);

    mutex_unlock(&io.sim_mutex);

    return result;
}

int sim_mkdir(const char *name)
{
    return MKDIR(get_sim_pathname(name), 0777);
}

int sim_rmdir(const char *name)
{
    return RMDIR(get_sim_pathname(name));
}

int sim_remove(const char *name)
{
    int ret = REMOVE(get_sim_pathname(name));
#ifdef HAVE_DIRCACHE
    if (ret >= 0)
        dircache_remove(name);
#endif
    return ret;
}

int sim_rename(const char *oldname, const char *newname)
{
    char sim_old[MAX_PATH];
    char sim_new[MAX_PATH];
#ifdef HAVE_DIRCACHE
    dircache_rename(oldname, newname);
#endif
    // This is needed as get_sim_pathname() has a static buffer
    strncpy(sim_old, get_sim_pathname(oldname), MAX_PATH);
    strncpy(sim_new, get_sim_pathname(newname), MAX_PATH);
    return RENAME(sim_old, sim_new);
}

/* rockbox off_t may be different from system off_t */
long sim_lseek(int fildes, long offset, int whence)
{
    return lseek(fildes, offset, whence);
}

long filesize(int fd)
{
#ifdef WIN32
    return _filelength(fd);
#else
    struct stat buf;

    if (!fstat(fd, &buf))
        return buf.st_size;
    else
        return -1;
#endif
}

void fat_size(IF_MV2(int volume,) unsigned long* size, unsigned long* free)
{
#ifdef HAVE_MULTIVOLUME
    if (volume != 0) {
        /* debugf("io.c: fat_size(volume=%d); simulator only supports volume 0\n",volume); */

        if (size) *size = 0;
        if (free) *free = 0;
        return;
    }
#endif

#ifdef WIN32
    long secperclus, bytespersec, free_clusters, num_clusters;

    if (GetDiskFreeSpace(NULL, &secperclus, &bytespersec, &free_clusters,
                     &num_clusters)) {
        if (size)
            *size = num_clusters * secperclus / 2 * (bytespersec / 512);
        if (free)
            *free = free_clusters * secperclus / 2 * (bytespersec / 512);
    } else
#elif HAVE_STATVFS
    struct statvfs vfs;

    if (!statvfs(".", &vfs)) {
        DEBUGF("statvfs: frsize=%d blocks=%ld free=%ld\n",
               (int)vfs.f_frsize, (long)vfs.f_blocks, (long)vfs.f_bfree);
        if (size)
            *size = vfs.f_blocks / 2 * (vfs.f_frsize / 512);
        if (free)
            *free = vfs.f_bfree / 2 * (vfs.f_frsize / 512);
    } else
#endif
    {
        if (size)
            *size = 0;
        if (free)
            *free = 0;
    }
}

int sim_fsync(int fd)
{
#ifdef WIN32
    return _commit(fd);
#else
    return fsync(fd);
#endif
}

#ifndef __PCTOOL__

void *lc_open(const char *filename, unsigned char *buf, size_t buf_size)
{
    const char *sim_path = get_sim_pathname(filename);
    void *handle = _lc_open(UTF8_TO_OS(sim_path), buf, buf_size);

    if (handle == NULL)
    {
        DEBUGF("failed to load %s\n", filename);
        DEBUGF("lc_open(%s): %s\n", filename, lc_last_error());
    }
    return handle;
}

void *lc_get_header(void *handle)
{
    return _lc_get_header(handle);
}

void lc_close(void *handle)
{
    _lc_close(handle);
}

#endif /* __PCTOOL__ */

/* rockbox off_t may be different from system off_t */
int sim_ftruncate(int fd, long length)
{
#ifdef WIN32
    return _chsize(fd, length);
#else
    return ftruncate(fd, length);
#endif
}