/*
 * Copyright 2022 Frederico de Oliveira Linhares
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "texture.h"

#include "color.h"
#include "core.h"
#include "font.h"
#include "palette.h"
#include "pgm_image.h"
#include "point.h"

void
cg_free_texture(mrb_state *mrb, void* obj)
{
  struct cg_texture *ptr = obj;

  SDL_DestroyTexture(ptr->data);
  mrb_free(mrb, ptr);
}

const struct mrb_data_type cg_texture_type = {
  "CG_Texture", cg_free_texture };

static mrb_value
texture_alloc(mrb_state *mrb, mrb_value class)
{
  struct RClass *cg_cTexture = mrb_class_ptr(class);
  enum mrb_vtype ttype = MRB_INSTANCE_TT(cg_cTexture);

  // I do not know if I need this. If things break, try uncomment this line.
  // if (ttype == 0) ttype = MRB_TT_OBJECT;
  return mrb_obj_value(
    (struct RObject*)mrb_obj_alloc(mrb, ttype, cg_cTexture));
}

static mrb_value
cg_cTexture_from_image(mrb_state *mrb, mrb_value self)
{
  PGMImage pgm_img;

  struct mrb_value texture = texture_alloc(mrb, self);
  const char *file_path;
  struct cg_palette *palette;
  struct cg_texture *ptr;
  mrb_bool palette_given;
  SDL_Surface *surface = NULL;

  mrb_get_args(
    mrb, "z|d?", &file_path, &palette, &cg_palette_type, &palette_given);
  ptr = (struct cg_texture *)DATA_PTR(texture);
  if(ptr) mrb_free(mrb, ptr);
  ptr = (struct cg_texture *)mrb_malloc(mrb, sizeof(struct cg_texture));
  if(palette_given)
  {
    if(!PGMImage_constructor(&pgm_img, file_path))
      mrb_raise(mrb, E_RUNTIME_ERROR, pgm_img.error);

    // Depth = 8 bits image.
    // Pitch = 1 byte (8 bits) * image width.
    surface = SDL_CreateRGBSurfaceWithFormatFrom(
      pgm_img.data, pgm_img.width, pgm_img.height, 8, pgm_img.width,
      SDL_PIXELFORMAT_INDEX8);
    if(!surface) mrb_raise(mrb, E_RUNTIME_ERROR, SDL_GetError());
    SDL_SetPaletteColors(surface->format->palette, palette->colors, 0, 256);
  }
  else
  {
    surface = IMG_Load(file_path);
    if(!surface) mrb_raise(mrb, E_RUNTIME_ERROR, IMG_GetError());
  }

  ptr->data = SDL_CreateTextureFromSurface(cg_core.renderer, surface);
  SDL_SetTextureBlendMode(ptr->data, SDL_BLENDMODE_BLEND);
  SDL_FreeSurface(surface);
  if(palette_given) PGMImage_destructor(&pgm_img);
  if(ptr->data == NULL) mrb_raise(mrb, E_RUNTIME_ERROR, SDL_GetError());

  SDL_QueryTexture(ptr->data, NULL, NULL, &ptr->width, &ptr->height);

  mrb_data_init(texture, ptr, &cg_texture_type);
  return texture;
}

mrb_value
cg_cText_from_text(mrb_state *mrb, mrb_value self)
{
  char *text;
  SDL_Surface *surface = NULL;
  mrb_bool background;
  struct mrb_value texture = texture_alloc(mrb, self);
  struct cg_color *tx_color_ptr, *bg_color_ptr;
  struct cg_font *font_ptr;
  struct cg_texture *ptr;

  mrb_get_args(
      mrb, "zdd|d?", &text, &font_ptr, &cg_font_type,
      &tx_color_ptr, &cg_color_type, &bg_color_ptr, &cg_color_type,
      &background);

  ptr = (struct cg_texture *)DATA_PTR(texture);
  if(ptr) mrb_free(mrb, ptr);
  ptr = (struct cg_texture *)mrb_malloc(mrb, sizeof(struct cg_texture));

  // Create surface.
  if(background)
    surface = TTF_RenderUTF8_Shaded(
        font_ptr->data, text, tx_color_ptr->data, bg_color_ptr->data);
  else
    surface = TTF_RenderUTF8_Solid(font_ptr->data, text, tx_color_ptr->data);
  if(surface == NULL) mrb_raise(mrb, E_RUNTIME_ERROR, TTF_GetError());

  // Convert the surface to a texture.
  ptr->data = SDL_CreateTextureFromSurface(cg_core.renderer, surface);
  SDL_FreeSurface(surface);
  if(ptr->data == NULL) mrb_raise(mrb, E_RUNTIME_ERROR, SDL_GetError());

  SDL_QueryTexture(ptr->data, NULL, NULL, &ptr->width, &ptr->height);
  mrb_data_init(texture, ptr, &cg_texture_type);
  return texture;
}

static mrb_value
cg_cTexture_width(mrb_state *mrb, mrb_value self)
{
  struct cg_texture *ptr;

  ptr = (struct cg_texture *)DATA_PTR(self);

  return mrb_int_value(mrb, ptr->width);
}

static mrb_value
cg_cTexture_height(mrb_state *mrb, mrb_value self)
{
  struct cg_texture *ptr;

  ptr = (struct cg_texture *)DATA_PTR(self);

  return mrb_int_value(mrb, ptr->height);
}

static mrb_value
cg_cTexture_draw(mrb_state *mrb, mrb_value self)
{
  SDL_Rect dst_rect;

  struct cg_texture *ptr;
  struct cg_point *point;

  mrb_get_args(mrb, "d", &point, &cg_point_type);
  ptr = (struct cg_texture *)DATA_PTR(self);

  dst_rect.x = point->data.x;
  dst_rect.y = point->data.y;
  dst_rect.w = ptr->width;
  dst_rect.h = ptr->height;

  SDL_RenderCopy(cg_core.renderer, ptr->data, NULL, &dst_rect);

  return self;
}

static mrb_value
cg_cTexture_draw_xy(mrb_state *mrb, mrb_value self)
{
  SDL_Rect dst_rect;

  struct cg_texture *ptr;
  mrb_int x, y;

  mrb_get_args(mrb, "ii", &x, &y);
  ptr = (struct cg_texture *)DATA_PTR(self);

  dst_rect.x = x;
  dst_rect.y = y;
  dst_rect.w = ptr->width;
  dst_rect.h = ptr->height;

  SDL_RenderCopy(cg_core.renderer, ptr->data, NULL, &dst_rect);

  return self;
}

void
cg_texture_init(mrb_state *mrb)
{
  struct RClass *cg_m, *cg_cTexture;

  cg_m = mrb_module_get(mrb, "CandyGear");
  cg_cTexture = mrb_define_class_under(
    mrb, cg_m, "Texture", mrb->object_class);
  MRB_SET_INSTANCE_TT(cg_cTexture, MRB_TT_DATA);

  mrb_undef_class_method(mrb, cg_cTexture, "new");
  mrb_define_class_method(
    mrb, cg_cTexture, "from_image", cg_cTexture_from_image,
    MRB_ARGS_REQ(1) | MRB_ARGS_OPT(1));
  mrb_define_class_method(
    mrb, cg_cTexture, "from_text", cg_cText_from_text,
    MRB_ARGS_REQ(3)|MRB_ARGS_OPT(1));
  mrb_define_method(
    mrb, cg_cTexture, "width", cg_cTexture_width, MRB_ARGS_NONE());
  mrb_define_method(
    mrb, cg_cTexture, "height", cg_cTexture_height, MRB_ARGS_NONE());
  mrb_define_method(
    mrb, cg_cTexture, "draw", cg_cTexture_draw, MRB_ARGS_REQ(1));
  mrb_define_method(
    mrb, cg_cTexture, "draw_xy", cg_cTexture_draw_xy, MRB_ARGS_REQ(2));
}