#include <SDL2/SDL_image.h>
#include <stdlib.h>
#include "opengl.h"
#include "FrameSheet.h"
#include "fifo.h"
#include "report.h"
#include "string.h"

struct FrameSheet *newFrameSheet() {
  struct FrameSheet *sheet = malloc(sizeof(struct FrameSheet));
  sheet->textures = NULL;
  sheet->surfaces = NULL;
  sheet->count = 0;
  sheet->state = 0;
  return sheet;
}

struct FrameSheet *loadFrameSheet(const char *name, const char *framedir) {
  if (framedir == NULL) return NULL;
  struct Dir *dir = openDir(framedir, 0);
  if (dir == NULL) {
    report(ERROR, "loadFrameSheet", "dir %s does not exist", framedir);
    return NULL;
  }
  struct FrameSheet *sheet = newFrameSheet();
  struct DirEntry *entry;
  while ((entry = readDir(dir)) != NULL) {
    if (entry->d_type != F_REG) continue;
    char *filename = NULL;
    filename = setStringF(filename, "%s/%s", framedir, entry->d_name);
    SDL_Surface *surface = NULL;
    if ((surface = IMG_Load(filename)) == NULL) {
      report(ERROR, "loadFrameSheet", "error loading surface: %s", SDL_GetError());
      free(filename);
      continue;
    }
    free(filename);
    // seems valid, let's add it as a frame
    sheet->count++;
    sheet->surfaces = realloc(sheet->surfaces, sheet->count*sizeof(SDL_Surface*));
    if (sheet->surfaces == NULL) {
      report(ERROR, "loadFrameSheet", "could not realloc surfaces");
      freeFrameSheet(sheet);
      return NULL;
    }
    sheet->surfaces[sheet->count-1] = surface;
  }
  sheet->textures = realloc(sheet->textures, sheet->count*sizeof(GLuint));
  closeDir(dir);
  return sheet;
}
int freeFrameSheet(struct FrameSheet *sheet) {
  if (sheet == NULL) return 1;
  int i;
  if (sheet->surfaces != NULL) {
    for (i = 0; i < sheet->count; i++) {
      SDL_FreeSurface(sheet->surfaces[i]);
    }
    free(sheet->surfaces);
  }
  // clean up textures if open
  if (sheet->textures != NULL) {
    closeFrameSheet(sheet);
    free(sheet->textures);
  }
  free(sheet);
  return 0;
}
int openFrameSheet(struct FrameSheet *sheet) {
  if (sheet == NULL) return 1;
  if (sheet->state == 0) {
    int i;
    for (i = 0; i < sheet->count; i++) {
      sheet->textures[i] = createTexture(sheet->surfaces[i]);
    }
  }
  sheet->state = 1;
  return 0;
}
int closeFrameSheet(struct FrameSheet *sheet) {
  if (sheet == NULL) return 1;
  if (sheet->state == 1) {
    int i;
    for (i = 0; i < sheet->count; i++) {
      glDeleteTextures(1, &sheet->textures[i]);
    }
  }
  sheet->state = 0;
  return 0;
}
int renderFrame(struct FrameSheet *sheet, int frame, int x, int y) {
  if (sheet == NULL) return 1;
  if (frame < 0 || frame >= sheet->count) return 2;
  if (sheet->state == 0) {
    openFrameSheet(sheet);
  }
  x -= sheet->surfaces[frame]->w/2;
  y -= sheet->surfaces[frame]->h/2;
  float sx = sheet->surfaces[frame]->w;
  float sy = sheet->surfaces[frame]->h;
  // bind our texture
  glBindTexture(GL_TEXTURE_2D, sheet->textures[frame]);
  // make sure we're rendering textures
  glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
  // reset view
  glLoadIdentity();
  // translate to a quad
  glTranslated(x, y, 1.0f);
  // draw !
  glBegin(GL_QUADS);
    // top left
    glTexCoord2d(0.0f, 0.0f); glVertex2f(0.0f, 0.0f);
    // top right
    glTexCoord2d(1.0, 0.0f); glVertex2f(sx, 0.0f);
    // bottom right
    glTexCoord2d(1.0f, 1.0f); glVertex2f(sx, sy);
    // bottom left
    glTexCoord2d(0.0f, 1.0f); glVertex2f(0.0f, sy);
  glEnd();
  return 0;
}