#include <m_pd.h>
#include <m_fixed.h>
#include "delay.h"

extern int ugen_getsortno(void);

#define DEFDELVS 64	    	/* LATER get this from canvas at DSP time */
static int delread_zero = 0;	/* four bytes of zero for delread~, vd~ */

static t_class *sigdelread_class;

typedef struct _sigdelread
{
    t_object x_obj;
    t_symbol *x_sym;
    t_float x_deltime;	/* delay in msec */
    int x_delsamps; 	/* delay in samples */
    t_float x_sr;   	/* samples per msec */
    t_float x_n;   	/* vector size */
    int x_zerodel;  	/* 0 or vecsize depending on read/write order */
} t_sigdelread;

static void sigdelread_float(t_sigdelread *x, t_float f);

static void *sigdelread_new(t_symbol *s, t_floatarg f)
{
    t_sigdelread *x = (t_sigdelread *)pd_new(sigdelread_class);
    x->x_sym = s;
    x->x_sr = 1;
    x->x_n = 1;
    x->x_zerodel = 0;
    sigdelread_float(x, f);
    outlet_new(&x->x_obj, &s_signal);
    return (x);
}

static void sigdelread_float(t_sigdelread *x, t_float f)
{
    int samps;
    t_sigdelwrite *delwriter =
    	(t_sigdelwrite *)pd_findbyclass(x->x_sym, sigdelwrite_class);
    x->x_deltime = f;
    if (delwriter)
    {
    	int delsize = delwriter->x_cspace.c_n;
    	x->x_delsamps = (int)(0.5 + x->x_sr * x->x_deltime)
    	    + x->x_n - x->x_zerodel;
    	if (x->x_delsamps < x->x_n) x->x_delsamps = x->x_n;
    	else if (x->x_delsamps > delwriter->x_cspace.c_n - DEFDELVS)
    	    x->x_delsamps = delwriter->x_cspace.c_n - DEFDELVS;
    }
}

static t_int *sigdelread_perform(t_int *w)
{
    t_sample *out = (t_sample *)(w[1]);
    t_delwritectl *c = (t_delwritectl *)(w[2]);
    int delsamps = *(int *)(w[3]);
    int n = (int)(w[4]);
    int phase = c->c_phase - delsamps, nsamps = c->c_n;
    t_sample *vp = c->c_vec, *bp, *ep = vp + (c->c_n + XTRASAMPS);

    if (phase < 0) phase += nsamps;
    bp = vp + phase;
    while (n--)
    {
    	*out++ = *bp++;
    	if (bp == ep) bp -= nsamps;
    }
    return (w+5);
}

static void sigdelread_dsp(t_sigdelread *x, t_signal **sp)
{
    t_sigdelwrite *delwriter =
    	(t_sigdelwrite *)pd_findbyclass(x->x_sym, sigdelwrite_class);
    x->x_sr = sp[0]->s_sr * 0.001;
    x->x_n = sp[0]->s_n;
    if (delwriter)
    {
    	sigdelwrite_checkvecsize(delwriter, sp[0]->s_n);
    	x->x_zerodel = (delwriter->x_sortno == ugen_getsortno() ?
    	    0 : delwriter->x_vecsize);
    	sigdelread_float(x, x->x_deltime);
    	dsp_add(sigdelread_perform, 4,
    	    sp[0]->s_vec, &delwriter->x_cspace, &x->x_delsamps, sp[0]->s_n);
    }
    else if (*x->x_sym->s_name)
    	error("delread~: %s: no such delwrite~",x->x_sym->s_name);
}

void delread_tilde_setup(void)
{
    sigdelread_class = class_new(gensym("delread~"),
    	(t_newmethod)sigdelread_new, 0,
    	sizeof(t_sigdelread), 0, A_DEFSYM, A_DEFFLOAT, 0);
    class_addmethod(sigdelread_class, (t_method)sigdelread_dsp,
    	gensym("dsp"), 0);
    class_addfloat(sigdelread_class, (t_method)sigdelread_float);
}