/*
  * Copyright (c) 2015 Paul B Mahol
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "float.h"
 
 #include "libavutil/eval.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/opt.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 
 typedef struct DrawGraphContext {
     const AVClass *class;
 
     char          *key[4];
     float         min, max;
     char          *fg_str[4];
     AVExpr        *fg_expr[4];
     uint8_t       bg[4];
     int           mode;
     int           slide;
     int           w, h;
 
     AVFrame       *out;
     int           x;
     int           prev_y[4];
     int           first;

     float         *values[4];
     int           values_size[4];
     int           nb_values;

 } DrawGraphContext;
 
 #define OFFSET(x) offsetof(DrawGraphContext, x)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 
 static const AVOption drawgraph_options[] = {
     { "m1", "set 1st metadata key", OFFSET(key[0]), AV_OPT_TYPE_STRING, {.str=""}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "fg1", "set 1st foreground color expression", OFFSET(fg_str[0]), AV_OPT_TYPE_STRING, {.str="0xffff0000"}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "m2", "set 2nd metadata key", OFFSET(key[1]), AV_OPT_TYPE_STRING, {.str=""}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "fg2", "set 2nd foreground color expression", OFFSET(fg_str[1]), AV_OPT_TYPE_STRING, {.str="0xff00ff00"}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "m3", "set 3rd metadata key", OFFSET(key[2]), AV_OPT_TYPE_STRING, {.str=""}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "fg3", "set 3rd foreground color expression", OFFSET(fg_str[2]), AV_OPT_TYPE_STRING, {.str="0xffff00ff"}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "m4", "set 4th metadata key", OFFSET(key[3]), AV_OPT_TYPE_STRING, {.str=""}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "fg4", "set 4th foreground color expression", OFFSET(fg_str[3]), AV_OPT_TYPE_STRING, {.str="0xffffff00"}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "bg", "set background color", OFFSET(bg), AV_OPT_TYPE_COLOR, {.str="white"}, CHAR_MIN, CHAR_MAX, FLAGS },
     { "min", "set minimal value", OFFSET(min), AV_OPT_TYPE_FLOAT, {.dbl=-1.}, INT_MIN, INT_MAX, FLAGS },
     { "max", "set maximal value", OFFSET(max), AV_OPT_TYPE_FLOAT, {.dbl=1.}, INT_MIN, INT_MAX, FLAGS },
     { "mode", "set graph mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=2}, 0, 2, FLAGS, "mode" },
         {"bar", "draw bars", OFFSET(mode), AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "mode"},
         {"dot", "draw dots", OFFSET(mode), AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "mode"},
         {"line", "draw lines", OFFSET(mode), AV_OPT_TYPE_CONST, {.i64=2}, 0, 0, FLAGS, "mode"},

     { "slide", "set slide mode", OFFSET(slide), AV_OPT_TYPE_INT, {.i64=0}, 0, 4, FLAGS, "slide" },

         {"frame", "draw new frames", OFFSET(slide), AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "slide"},
         {"replace", "replace old columns with new", OFFSET(slide), AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "slide"},
         {"scroll", "scroll from right to left", OFFSET(slide), AV_OPT_TYPE_CONST, {.i64=2}, 0, 0, FLAGS, "slide"},

         {"rscroll", "scroll from left to right", OFFSET(slide), AV_OPT_TYPE_CONST, {.i64=3}, 0, 0, FLAGS, "slide"},

         {"picture", "display graph in single frame", OFFSET(slide), AV_OPT_TYPE_CONST, {.i64=4}, 0, 0, FLAGS, "slide"},

     { "size", "set graph size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="900x256"}, 0, 0, FLAGS },
     { "s", "set graph size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="900x256"}, 0, 0, FLAGS },
     { NULL }
 };
 
 static const char *const var_names[] = {   "MAX",   "MIN",   "VAL", NULL };
 enum                                   { VAR_MAX, VAR_MIN, VAR_VAL, VAR_VARS_NB };
 
 static av_cold int init(AVFilterContext *ctx)
 {
     DrawGraphContext *s = ctx->priv;
     int ret, i;
 
     if (s->max <= s->min) {
         av_log(ctx, AV_LOG_ERROR, "max is same or lower than min\n");
         return AVERROR(EINVAL);
     }
 
     for (i = 0; i < 4; i++) {
         if (s->fg_str[i]) {
             ret = av_expr_parse(&s->fg_expr[i], s->fg_str[i], var_names,
                                 NULL, NULL, NULL, NULL, 0, ctx);
 
             if (ret < 0)
                 return ret;
         }
     }
 
     s->first = 1;
 

     if (s->slide == 4) {
         s->values[0] = av_fast_realloc(NULL, &s->values_size[0], 2000);
         s->values[1] = av_fast_realloc(NULL, &s->values_size[1], 2000);
         s->values[2] = av_fast_realloc(NULL, &s->values_size[2], 2000);
         s->values[3] = av_fast_realloc(NULL, &s->values_size[3], 2000);
 
         if (!s->values[0] || !s->values[1] ||
             !s->values[2] || !s->values[3]) {
             return AVERROR(ENOMEM);
         }
     }
 

     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterLink *outlink = ctx->outputs[0];
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_RGBA,
         AV_PIX_FMT_NONE
     };

     int ret;

 
     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);

     if ((ret = ff_formats_ref(fmts_list, &outlink->in_formats)) < 0)
         return ret;

 
     return 0;
 }
 
 static void clear_image(DrawGraphContext *s, AVFrame *out, AVFilterLink *outlink)
 {
     int i, j;
     int bg = AV_RN32(s->bg);
 
     for (i = 0; i < out->height; i++)
         for (j = 0; j < out->width; j++)
             AV_WN32(out->data[0] + i * out->linesize[0] + j * 4, bg);
 }
 
 static inline void draw_dot(int fg, int x, int y, AVFrame *out)
 {
     AV_WN32(out->data[0] + y * out->linesize[0] + x * 4, fg);
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;
     DrawGraphContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     AVDictionary *metadata;
     AVDictionaryEntry *e;
     AVFrame *out = s->out;
     int i;
 

     if (s->slide == 4 && s->nb_values >= s->values_size[0] / sizeof(float)) {
         float *ptr;
 
         ptr = av_fast_realloc(s->values[0], &s->values_size[0], s->values_size[0] * 2);
         if (!ptr)

             return AVERROR(ENOMEM);

         s->values[0] = ptr;
 
         ptr = av_fast_realloc(s->values[1], &s->values_size[1], s->values_size[1] * 2);
         if (!ptr)
             return AVERROR(ENOMEM);
         s->values[1] = ptr;
 
         ptr = av_fast_realloc(s->values[2], &s->values_size[2], s->values_size[2] * 2);
         if (!ptr)
             return AVERROR(ENOMEM);
         s->values[2] = ptr;

         ptr = av_fast_realloc(s->values[3], &s->values_size[3], s->values_size[3] * 2);
         if (!ptr)
             return AVERROR(ENOMEM);
         s->values[3] = ptr;
     }
 
     if (s->slide != 4 || s->nb_values == 0) {
         if (!s->out || s->out->width  != outlink->w ||
                        s->out->height != outlink->h) {
             av_frame_free(&s->out);
             s->out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
             out = s->out;
             if (!s->out) {
                 av_frame_free(&in);
                 return AVERROR(ENOMEM);
             }
 
             clear_image(s, out, outlink);
         }
         av_frame_copy_props(out, in);

     }
 

     metadata = in->metadata;

 
     for (i = 0; i < 4; i++) {
         double values[VAR_VARS_NB];

         int j, y, x, old;
         uint32_t fg, bg;

         float vf;
 

         if (s->slide == 4)
             s->values[i][s->nb_values] = NAN;
 

         e = av_dict_get(metadata, s->key[i], NULL, 0);
         if (!e || !e->value)
             continue;
 
         if (sscanf(e->value, "%f", &vf) != 1)
             continue;
 
         vf = av_clipf(vf, s->min, s->max);
 

         if (s->slide == 4) {
             s->values[i][s->nb_values] = vf;
             continue;
         }
 

         values[VAR_MIN] = s->min;
         values[VAR_MAX] = s->max;
         values[VAR_VAL] = vf;
 
         fg = av_expr_eval(s->fg_expr[i], values, NULL);
         bg = AV_RN32(s->bg);
 

         if (i == 0 && (s->x >= outlink->w || s->slide == 3)) {

             if (s->slide == 0 || s->slide == 1)
                 s->x = 0;
 
             if (s->slide == 2) {
                 s->x = outlink->w - 1;
                 for (j = 0; j < outlink->h; j++) {
                     memmove(out->data[0] + j * out->linesize[0] ,
                             out->data[0] + j * out->linesize[0] + 4,
                             (outlink->w - 1) * 4);
                 }

             } else if (s->slide == 3) {
                 s->x = 0;
                 for (j = 0; j < outlink->h; j++) {
                     memmove(out->data[0] + j * out->linesize[0] + 4,
                             out->data[0] + j * out->linesize[0],
                             (outlink->w - 1) * 4);
                 }

             } else if (s->slide == 0) {
                 clear_image(s, out, outlink);
             }
         }
 
         x = s->x;
         y = (outlink->h - 1) * (1 - ((vf - s->min) / (s->max - s->min)));
 
         switch (s->mode) {
         case 0:

             if (i == 0 && (s->slide > 0))

                 for (j = 0; j < outlink->h; j++)
                     draw_dot(bg, x, j, out);
 
             old = AV_RN32(out->data[0] + y * out->linesize[0] + x * 4);
             for (j = y; j < outlink->h; j++) {
                 if (old != bg &&
                     (AV_RN32(out->data[0] + j * out->linesize[0] + x * 4) != old) ||
                     AV_RN32(out->data[0] + FFMIN(j+1, outlink->h - 1) * out->linesize[0] + x * 4) != old) {
                     draw_dot(fg, x, j, out);
                     break;
                 }
                 draw_dot(fg, x, j, out);
             }
             break;
         case 1:

             if (i == 0 && (s->slide > 0))

                 for (j = 0; j < outlink->h; j++)
                     draw_dot(bg, x, j, out);
             draw_dot(fg, x, y, out);
             break;
         case 2:
             if (s->first) {
                 s->first = 0;
                 s->prev_y[i] = y;
             }
 

             if (i == 0 && (s->slide > 0)) {

                 for (j = 0; j < y; j++)
                     draw_dot(bg, x, j, out);
                 for (j = outlink->h - 1; j > y; j--)
                     draw_dot(bg, x, j, out);
             }
             if (y <= s->prev_y[i]) {
                 for (j = y; j <= s->prev_y[i]; j++)
                     draw_dot(fg, x, j, out);
             } else {
                 for (j = s->prev_y[i]; j <= y; j++)
                     draw_dot(fg, x, j, out);
             }
             s->prev_y[i] = y;
             break;
         }
     }
 

     s->nb_values++;

     s->x++;
 
     av_frame_free(&in);

 
     if (s->slide == 4)
         return 0;
 

     return ff_filter_frame(outlink, av_frame_clone(s->out));
 }
 

 static int request_frame(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     DrawGraphContext *s = ctx->priv;
     AVFrame *out = s->out;
     int ret, i, k, step, l;
 
     ret = ff_request_frame(ctx->inputs[0]);
 
     if (s->slide == 4 && ret == AVERROR_EOF && s->nb_values > 0) {
         s->x = l = 0;
         step = ceil(s->nb_values / (float)s->w);
 
         for (k = 0; k < s->nb_values; k++) {
             for (i = 0; i < 4; i++) {
                 double values[VAR_VARS_NB];
                 int j, y, x, old;
                 uint32_t fg, bg;
                 float vf = s->values[i][k];
 
                 if (isnan(vf))
                     continue;
 
                 values[VAR_MIN] = s->min;
                 values[VAR_MAX] = s->max;
                 values[VAR_VAL] = vf;
 
                 fg = av_expr_eval(s->fg_expr[i], values, NULL);
                 bg = AV_RN32(s->bg);
 
                 x = s->x;
                 y = (outlink->h - 1) * (1 - ((vf - s->min) / (s->max - s->min)));
 
                 switch (s->mode) {
                 case 0:
                     old = AV_RN32(out->data[0] + y * out->linesize[0] + x * 4);
                     for (j = y; j < outlink->h; j++) {
                         if (old != bg &&
                             (AV_RN32(out->data[0] + j * out->linesize[0] + x * 4) != old) ||
                             AV_RN32(out->data[0] + FFMIN(j+1, outlink->h - 1) * out->linesize[0] + x * 4) != old) {
                             draw_dot(fg, x, j, out);
                             break;
                         }
                         draw_dot(fg, x, j, out);
                     }
                     break;
                 case 1:
                     draw_dot(fg, x, y, out);
                     break;
                 case 2:
                     if (s->first) {
                         s->first = 0;
                         s->prev_y[i] = y;
                     }
 
                     if (y <= s->prev_y[i]) {
                         for (j = y; j <= s->prev_y[i]; j++)
                             draw_dot(fg, x, j, out);
                     } else {
                         for (j = s->prev_y[i]; j <= y; j++)
                             draw_dot(fg, x, j, out);
                     }
                     s->prev_y[i] = y;
                     break;
                 }
             }
 
             l++;
             if (l >= step) {
                 l = 0;
                 s->x++;
             }
         }
 
         s->nb_values = 0;
         out->pts = 0;
         ret = ff_filter_frame(ctx->outputs[0], s->out);
     }
 
     return ret;
 }
 

 static int config_output(AVFilterLink *outlink)
 {
     DrawGraphContext *s = outlink->src->priv;
 
     outlink->w = s->w;
     outlink->h = s->h;
     outlink->sample_aspect_ratio = (AVRational){1,1};
 
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     DrawGraphContext *s = ctx->priv;
     int i;
 
     for (i = 0; i < 4; i++)
         av_expr_free(s->fg_expr[i]);

 
     if (s->slide != 4)
         av_frame_free(&s->out);
 
     av_freep(&s->values[0]);
     av_freep(&s->values[1]);
     av_freep(&s->values[2]);
     av_freep(&s->values[3]);

 }
 
 #if CONFIG_DRAWGRAPH_FILTER
 
 AVFILTER_DEFINE_CLASS(drawgraph);
 
 static const AVFilterPad drawgraph_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad drawgraph_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_output,

         .request_frame = request_frame,

     },
     { NULL }
 };
 
 AVFilter ff_vf_drawgraph = {
     .name          = "drawgraph",
     .description   = NULL_IF_CONFIG_SMALL("Draw a graph using input video metadata."),
     .priv_size     = sizeof(DrawGraphContext),
     .priv_class    = &drawgraph_class,
     .query_formats = query_formats,
     .init          = init,
     .uninit        = uninit,
     .inputs        = drawgraph_inputs,
     .outputs       = drawgraph_outputs,
 };
 
 #endif // CONFIG_DRAWGRAPH_FILTER
 
 #if CONFIG_ADRAWGRAPH_FILTER
 
 #define adrawgraph_options drawgraph_options
 AVFILTER_DEFINE_CLASS(adrawgraph);
 
 static const AVFilterPad adrawgraph_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_AUDIO,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad adrawgraph_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_output,

         .request_frame = request_frame,

     },
     { NULL }
 };
 
 AVFilter ff_avf_adrawgraph = {
     .name          = "adrawgraph",
     .description   = NULL_IF_CONFIG_SMALL("Draw a graph using input audio metadata."),
     .priv_size     = sizeof(DrawGraphContext),
     .priv_class    = &adrawgraph_class,
     .query_formats = query_formats,
     .init          = init,
     .uninit        = uninit,
     .inputs        = adrawgraph_inputs,
     .outputs       = adrawgraph_outputs,
 };
 #endif // CONFIG_ADRAWGRAPH_FILTER