#include "cell.h"
#include <string.h>
#include <stdlib.h>
#include "stb_image_common.h"

// GIF decoding via stb_image - handles animated GIFs
// Returns an object with:
//   .width, .height - dimensions
//   .frames - array of frame objects, each with:
//     .width, .height, .format, .pitch, .pixels, .depth, .hdr
//     .duration - frame duration in milliseconds (for animated GIFs)
//   .frame_count - number of frames
JSValue js_gif_decode(JSContext *js, JSValue this_val, int argc, JSValueConst *argv)
{
  size_t len;
  void *raw = js_get_blob_data(js, &len, argv[0]);
  if (raw == NULL) return JS_EXCEPTION;
  if (!raw) return JS_ThrowReferenceError(js, "could not get GIF data from blob");

  int n, width, height, frames_count;
  int *delays = NULL;
  void *data = stbi_load_gif_from_memory(raw, len, &delays, &width, &height, &frames_count, &n, 4);

  if (!data)
    return JS_ThrowReferenceError(js, "failed to decode GIF: %s", stbi_failure_reason());

  if (width <= 0 || height <= 0) {
    stbi_image_free(data);
    if (delays) stbi_image_free(delays);
    return JS_ThrowReferenceError(js, "decoded GIF has invalid size: %dx%d", width, height);
  }

  int pitch = width * 4;
  size_t frame_size = pitch * height;

  // Create frames array
  JSValue frames_array = JS_NewArray(js);
  
  for (int i = 0; i < frames_count; i++) {
    JSValue frame = JS_NewObject(js);
    JS_SetPropertyStr(js, frame, "width", JS_NewInt32(js, width));
    JS_SetPropertyStr(js, frame, "height", JS_NewInt32(js, height));
    JS_SetPropertyStr(js, frame, "format", JS_NewString(js, "rgba32"));
    JS_SetPropertyStr(js, frame, "pitch", JS_NewInt32(js, pitch));
    
    void *frame_pixels = (unsigned char*)data + (frame_size * i);
    JS_SetPropertyStr(js, frame, "pixels", js_new_blob_stoned_copy(js, frame_pixels, frame_size));
    JS_SetPropertyStr(js, frame, "depth", JS_NewInt32(js, 8));
    JS_SetPropertyStr(js, frame, "hdr", JS_NewBool(js, 0));
    
    // Add duration in milliseconds (delays are in centiseconds, i.e. 1/100th of a second)
    int duration_ms = delays ? delays[i] * 10 : 100;
    JS_SetPropertyStr(js, frame, "duration", JS_NewInt32(js, duration_ms));
    
    JS_SetPropertyUint32(js, frames_array, i, frame);
  }

  // Create result object
  JSValue result = JS_NewObject(js);
  JS_SetPropertyStr(js, result, "width", JS_NewInt32(js, width));
  JS_SetPropertyStr(js, result, "height", JS_NewInt32(js, height));
  JS_SetPropertyStr(js, result, "frames", frames_array);
  JS_SetPropertyStr(js, result, "frame_count", JS_NewInt32(js, frames_count));

  stbi_image_free(data);
  if (delays) stbi_image_free(delays);
  return result;
}

static const JSCFunctionListEntry js_gif_funcs[] = {
  MIST_FUNC_DEF(gif, decode, 1)
};

CELL_USE_FUNCS(js_gif_funcs)