#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "config.h"
#include "mp_msg.h"

#include "img_format.h"
#include "mp_image.h"
#include "vf.h"

#include "libvo/fastmemcpy.h"

struct metrics {
	int even;
	int odd;
	int noise;
	int temp;
};

struct vf_priv_s {
	int frame;
	int drop, lastdrop;
	struct metrics pm;
	int thres[5];
	int inframes, outframes;
	int mode;
	int (*analyze)(struct vf_priv_s *, mp_image_t *, mp_image_t *);
	int needread;
};

#define COMPE(a,b,e) (abs((a)-(b)) < (((a)+(b))>>(e)))
#define COMPARABLE(a,b) COMPE((a),(b),2)
#define VERYCLOSE(a,b) COMPE((a),(b),3)

#define OUTER_TC_NBHD(s) ( \
 COMPARABLE((s)[-1].m.even,(s)[-1].m.odd) && \
 COMPARABLE((s)[1].m.even,(s)[0].m.odd) && \
 COMPARABLE((s)[2].m.even,(s)[1].m.odd) && \
 COMPARABLE((s)[-1].m.noise,(s)[0].m.temp) && \
 COMPARABLE((s)[2].m.noise,(s)[2].m.temp) )

#define INNER_TC_NBHD(s,l,h) ( \
 COMPARABLE((s)[0].m.even,(l)) && \
 COMPARABLE((s)[2].m.odd,(l)) && ( \
 COMPARABLE((s)[0].m.noise,(h)) || \
 COMPARABLE((s)[1].m.noise,(h)) ) )

enum {
	TC_DROP,
	TC_PROG,
	TC_IL1,
	TC_IL2
};

static void block_diffs(struct metrics *m, unsigned char *old, unsigned char *new, int os, int ns)
{
	int x, y, even=0, odd=0, noise, temp;
	unsigned char *oldp, *newp;
	m->noise = m->temp = 0;
	for (x = 8; x; x--) {
		oldp = old++;
		newp = new++;
		noise = temp = 0;
		for (y = 4; y; y--) {
			even += abs(newp[0]-oldp[0]);
			odd += abs(newp[ns]-oldp[os]);
			noise += newp[ns]-newp[0];
			temp += oldp[os]-newp[0];
			oldp += os<<1;
			newp += ns<<1;
		}
		m->noise += abs(noise);
		m->temp += abs(temp);
	}
	m->even = even;
	m->odd = odd;
}

static void diff_planes(struct metrics *m, unsigned char *old, unsigned char *new, int w, int h, int os, int ns)
{
	int x, y, me=0, mo=0, mn=0, mt=0;
	struct metrics l;
	for (y = 0; y < h-7; y += 8) {
		for (x = 0; x < w-7; x += 8) {
			block_diffs(&l, old+x+y*os, new+x+y*ns, os, ns);
			if (l.even > me) me = l.even;
			if (l.odd > mo) mo = l.odd;
			if (l.noise > mn) mn = l.noise;
			if (l.temp > mt) mt = l.temp;
		}
	}
	m->even = me;
	m->odd = mo;
	m->noise = mn;
	m->temp = mt;
}

static void diff_fields(struct metrics *metr, mp_image_t *old, mp_image_t *new)
{
	struct metrics m, mu, mv;
	diff_planes(&m, old->planes[0], new->planes[0],
		new->w, new->h, old->stride[0], new->stride[0]);
	if (new->flags & MP_IMGFLAG_PLANAR) {
		diff_planes(&mu, old->planes[1], new->planes[1],
			new->chroma_width, new->chroma_height,
			old->stride[1], new->stride[1]);
		diff_planes(&mv, old->planes[2], new->planes[2],
			new->chroma_width, new->chroma_height,
			old->stride[2], new->stride[2]);
		if (mu.even > m.even) m.even = mu.even;
		if (mu.odd > m.odd) m.odd = mu.odd;
		if (mu.noise > m.noise) m.noise = mu.noise;
		if (mu.temp > m.temp) m.temp = mu.temp;
		if (mv.even > m.even) m.even = mv.even;
		if (mv.odd > m.odd) m.odd = mv.odd;
		if (mv.noise > m.noise) m.noise = mv.noise;
		if (mv.temp > m.temp) m.temp = mv.temp;
	}
	*metr = m;
}

static void status(int f, struct metrics *m)
{
	mp_msg(MSGT_VFILTER, MSGL_V, "frame %d: e=%d o=%d n=%d t=%d\n",
		f, m->even, m->odd, m->noise, m->temp);
}

static int analyze_fixed_pattern(struct vf_priv_s *p, mp_image_t *new, mp_image_t *old)
{
	if (p->frame >= 0) p->frame = (p->frame+1)%5;
	mp_msg(MSGT_VFILTER, MSGL_V, "frame %d\n", p->frame);
	switch (p->frame) {
	case -1: case 0: case 1: case 2:
		return TC_PROG;
	case 3:
		return TC_IL1;
	case 4:
		return TC_IL2;
	}
	return 0;
}

static int analyze_aggressive(struct vf_priv_s *p, mp_image_t *new, mp_image_t *old)
{
	struct metrics m, pm;
	
	if (p->frame >= 0) p->frame = (p->frame+1)%5;
	
	diff_fields(&m, old, new);
	
	status(p->frame, &m);

	pm = p->pm;
	p->pm = m;

	if (p->frame == 4) {
		/* We need to break at scene changes, but is this a valid test? */
		if ((m.even > p->thres[2]) && (m.odd > p->thres[2]) && (m.temp > p->thres[3])
			&& (m.temp > 5*pm.temp) && (m.temp*2 > m.noise)) {
			mp_msg(MSGT_VFILTER, MSGL_V, "scene change breaking telecine!\n");
			p->frame = -1;
			return TC_DROP;
		}
		/* Thres. is to compensate for quantization errors when noise is low */
		if (m.noise - m.temp > -p->thres[4]) {
			if (COMPARABLE(m.even, pm.odd)) {
				//mp_msg(MSGT_VFILTER, MSGL_V, "confirmed field match!\n");
				return TC_IL2;
			} else if ((m.even < p->thres[0]) && (m.odd < p->thres[0]) && VERYCLOSE(m.even, m.odd)
				&& VERYCLOSE(m.noise,m.temp) && VERYCLOSE(m.noise,pm.noise)) {
				mp_msg(MSGT_VFILTER, MSGL_V, "interlaced frame appears in duplicate!!!\n");
				p->pm = pm; /* hack :) */
				p->frame = 3;
				return TC_IL1;
			} 
		} else {
			mp_msg(MSGT_VFILTER, MSGL_V, "mismatched telecine fields!\n");
			p->frame = -1;
		}
	}

	if (2*m.even*m.temp < m.odd*m.noise) {
		mp_msg(MSGT_VFILTER, MSGL_V, "caught telecine sync!\n");
		p->frame = 3;
		return TC_IL1;
	}

	if (p->frame < 3) {
		if (m.noise > p->thres[3]) {
			if (m.noise > 2*m.temp) {
				mp_msg(MSGT_VFILTER, MSGL_V, "merging fields out of sequence!\n");
				return TC_IL2;
			}
			if ((m.noise > 2*pm.noise) && (m.even > p->thres[2]) && (m.odd > p->thres[2])) {
				mp_msg(MSGT_VFILTER, MSGL_V, "dropping horrible interlaced frame!\n");
				return TC_DROP;
			}
		}
	}

	switch (p->frame) {
	case -1:
		if (4*m.noise > 5*m.temp) {
			mp_msg(MSGT_VFILTER, MSGL_V, "merging fields out of sequence!\n");
			return TC_IL2;
		}
	case 0:
	case 1:
	case 2:
		return TC_PROG;
	case 3:
		if ((m.even > p->thres[1]) && (m.even > m.odd) && (m.temp > m.noise)) {
			mp_msg(MSGT_VFILTER, MSGL_V, "lost telecine tracking!\n");
			p->frame = -1;
			return TC_PROG;
		}
		return TC_IL1;
	case 4:
		return TC_IL2;
	}
	return 0;
}

static void copy_image(mp_image_t *dmpi, mp_image_t *mpi, int field)
{
	switch (field) {
	case 0:
		my_memcpy_pic(dmpi->planes[0], mpi->planes[0], mpi->w, mpi->h/2,
			dmpi->stride[0]*2, mpi->stride[0]*2);
		if (mpi->flags & MP_IMGFLAG_PLANAR) {
			my_memcpy_pic(dmpi->planes[1], mpi->planes[1],
				mpi->chroma_width, mpi->chroma_height/2,
				dmpi->stride[1]*2, mpi->stride[1]*2);
			my_memcpy_pic(dmpi->planes[2], mpi->planes[2],
				mpi->chroma_width, mpi->chroma_height/2,
				dmpi->stride[2]*2, mpi->stride[2]*2);
		}
		break;
	case 1:
		my_memcpy_pic(dmpi->planes[0]+dmpi->stride[0],
			mpi->planes[0]+mpi->stride[0], mpi->w, mpi->h/2,
			dmpi->stride[0]*2, mpi->stride[0]*2);
		if (mpi->flags & MP_IMGFLAG_PLANAR) {
			my_memcpy_pic(dmpi->planes[1]+dmpi->stride[1],
				mpi->planes[1]+mpi->stride[1],
				mpi->chroma_width, mpi->chroma_height/2,
				dmpi->stride[1]*2, mpi->stride[1]*2);
			my_memcpy_pic(dmpi->planes[2]+dmpi->stride[2],
				mpi->planes[2]+mpi->stride[2],
				mpi->chroma_width, mpi->chroma_height/2,
				dmpi->stride[2]*2, mpi->stride[2]*2);
		}
		break;
	case 2:
		memcpy_pic(dmpi->planes[0], mpi->planes[0], mpi->w, mpi->h,
			dmpi->stride[0], mpi->stride[0]);
		if (mpi->flags & MP_IMGFLAG_PLANAR) {
			memcpy_pic(dmpi->planes[1], mpi->planes[1],
				mpi->chroma_width, mpi->chroma_height,
				dmpi->stride[1], mpi->stride[1]);
			memcpy_pic(dmpi->planes[2], mpi->planes[2],
				mpi->chroma_width, mpi->chroma_height,
				dmpi->stride[2], mpi->stride[2]);
		}
		break;
	}
}

static int do_put_image(struct vf_instance* vf, mp_image_t *dmpi)
{
	struct vf_priv_s *p = vf->priv;
	int dropflag;

	switch (p->drop) {
	default:
		dropflag = 0;
		break;
	case 1:
		dropflag = (++p->lastdrop >= 5);
		break;
	case 2:
		dropflag = (++p->lastdrop >= 5) && (4*p->inframes <= 5*p->outframes);
		break;
	}
	
	if (dropflag) {
		mp_msg(MSGT_VFILTER, MSGL_V, "drop! [%d/%d=%g]\n",
			p->outframes, p->inframes, (float)p->outframes/p->inframes);
		p->lastdrop = 0;
		return 0;
	}

	p->outframes++;
	return vf_next_put_image(vf, dmpi, MP_NOPTS_VALUE);
}

static int put_image(struct vf_instance* vf, mp_image_t *mpi, double pts)
{
	int ret=0;
	mp_image_t *dmpi;
	struct vf_priv_s *p = vf->priv;

	p->inframes++;

	if (p->needread) dmpi = vf_get_image(vf->next, mpi->imgfmt,
		MP_IMGTYPE_STATIC, MP_IMGFLAG_ACCEPT_STRIDE |
		MP_IMGFLAG_PRESERVE | MP_IMGFLAG_READABLE,
		mpi->width, mpi->height);
	/* FIXME: is there a good way to get rid of static type? */
	else dmpi = vf_get_image(vf->next, mpi->imgfmt,
		MP_IMGTYPE_STATIC, MP_IMGFLAG_ACCEPT_STRIDE |
		MP_IMGFLAG_PRESERVE, mpi->width, mpi->height);
		
	switch (p->analyze(p, mpi, dmpi)) {
	case TC_DROP:
		/* Don't copy anything unless we'll need to read it. */
		if (p->needread) copy_image(dmpi, mpi, 2);
		p->lastdrop = 0;
		break;
	case TC_PROG:
		/* Copy and display the whole frame. */
		copy_image(dmpi, mpi, 2);
		ret = do_put_image(vf, dmpi);
		break;
	case TC_IL1:
		/* Only copy bottom field unless we need to read. */
		if (p->needread) copy_image(dmpi, mpi, 2);
		else copy_image(dmpi, mpi, 1);
		p->lastdrop = 0;
		break;
	case TC_IL2:
		/* Copy top field and show frame, then copy bottom if needed. */
		copy_image(dmpi, mpi, 0);
		ret = do_put_image(vf, dmpi);
		if (p->needread) copy_image(dmpi, mpi, 1);
		break;
	}
	return ret;
}

static int query_format(struct vf_instance* vf, unsigned int fmt)
{
	/* FIXME - figure out which other formats work */
	switch (fmt) {
	case IMGFMT_YV12:
	case IMGFMT_IYUV:
	case IMGFMT_I420:
		return vf_next_query_format(vf, fmt);
	}
	return 0;
}

static int config(struct vf_instance* vf,
        int width, int height, int d_width, int d_height,
	unsigned int flags, unsigned int outfmt)
{
	return vf_next_config(vf,width,height,d_width,d_height,flags,outfmt);
}

static void uninit(struct vf_instance* vf)
{
	free(vf->priv);
}

static struct {
	char *name;
	int (*func)(struct vf_priv_s *p, mp_image_t *new, mp_image_t *old);
	int needread;
} anal_funcs[] = {
	{ "fixed", analyze_fixed_pattern, 0 },
	{ "aggressive", analyze_aggressive, 1 },
	{ NULL, NULL, 0 }
};

#define STARTVARS if (0)
#define GETVAR(str, name, out, func) \
 else if (!strncmp((str), name "=", sizeof(name))) \
 (out) = (func)((str) + sizeof(name))

static void parse_var(struct vf_priv_s *p, char *var)
{
	STARTVARS;
	GETVAR(var, "dr", p->drop, atoi);
	GETVAR(var, "t0", p->thres[0], atoi);
	GETVAR(var, "t1", p->thres[1], atoi);
	GETVAR(var, "t2", p->thres[2], atoi);
	GETVAR(var, "t3", p->thres[3], atoi);
	GETVAR(var, "t4", p->thres[4], atoi);
	GETVAR(var, "fr", p->frame, atoi);
	GETVAR(var, "am", p->mode, atoi);
}

static void parse_args(struct vf_priv_s *p, char *args)
{
	char *next, *orig;
	for (args=orig=strdup(args); args; args=next) {
		next = strchr(args, ':');
		if (next) *next++ = 0;
		parse_var(p, args);
	}
	free(orig);
}

static int open(vf_instance_t *vf, char* args)
{
	struct vf_priv_s *p;
	vf->config = config;
	vf->put_image = put_image;
	vf->query_format = query_format;
	vf->uninit = uninit;
	vf->default_reqs = VFCAP_ACCEPT_STRIDE;
	vf->priv = p = calloc(1, sizeof(struct vf_priv_s));
	p->frame = -1;
	p->thres[0] = 440;
	p->thres[1] = 720;
	p->thres[2] = 2500;
	p->thres[3] = 2500;
	p->thres[4] = 800;
	p->drop = 0;
	p->mode = 1;
	if (args) parse_args(p, args);
	p->analyze = anal_funcs[p->mode].func;
	p->needread = anal_funcs[p->mode].needread;
	return 1;
}

const vf_info_t vf_info_detc = {
    "de-telecine filter",
    "detc",
    "Rich Felker",
    "",
    open,
    NULL
};