/**
 * Copyright (c) 2026 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "display/texture/texture.h"
#include "assert/assert.h"
#include "error/errorgl.h"
#include "util/memory.h"

errorret_t textureInitGL(
  texturegl_t *texture,
  const int32_t width,
  const int32_t height,
  const textureformatgl_t format,
  const texturedata_t data
) {
  glGenTextures(1, &texture->id);
  errorChain(errorGLCheck());
  glBindTexture(GL_TEXTURE_2D, texture->id);
  errorChain(errorGLCheck());

  switch(format) {
    case TEXTURE_FORMAT_RGBA:
      glTexImage2D(
        GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
        GL_RGBA, GL_UNSIGNED_BYTE, (void*)data.rgbaColors
      );
      errorChain(errorGLCheck());
      break;

    case TEXTURE_FORMAT_PALETTE:
      texture->palette = data.paletted.palette;
      assertTrue(
        texture->palette == &PALETTES[0],
        "Only the first palette is supported in legacy opengl."
      );

      #ifdef DUSK_OPENGL_LEGACY
        glColorTableEXT(
          GL_TEXTURE_2D, GL_RGBA, texture->palette->count, GL_RGBA,
          GL_UNSIGNED_BYTE, (const void*)texture->palette->colors
        );
        errorChain(errorGLCheck());
        glTexImage2D(
          GL_TEXTURE_2D,
          0, GL_COLOR_INDEX8_EXT,
          width, height,
          0, GL_COLOR_INDEX8_EXT,
          GL_UNSIGNED_BYTE, (void*)data.paletted.indices
        );
        errorChain(errorGLCheck());
      #else
        // For modern systems we send to only the R channel and the shader does
        // the rest.
        glTexImage2D(
          GL_TEXTURE_2D, 0, GL_RED, width, height, 0,
          GL_RED, GL_UNSIGNED_BYTE, (void*)data.paletted.indices
        );
        errorChain(errorGLCheck());
      #endif
      break;

    default:
      assertUnreachable("Unknown texture format");
      break;
  }
  errorChain(errorGLCheck());

  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  errorChain(errorGLCheck());
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  errorChain(errorGLCheck());
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
  errorChain(errorGLCheck());
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
  errorChain(errorGLCheck());
  
  glBindTexture(GL_TEXTURE_2D, 0);
  errorChain(errorGLCheck());

  errorOk();
}

errorret_t textureDisposeGL(texturegl_t *texture) {
  assertNotNull(texture, "Texture cannot be NULL");
  assertTrue(texture->id != 0, "Texture ID must be valid");

  glDeleteTextures(1, &texture->id);
  errorChain(errorGLCheck());

  errorOk();
}