#include <assets/loaders/shader_loader.h>
#include <renderer/shader.h>
#include <utils/logger.h>

namespace extra2d {

ShaderLoader::ShaderLoader(AssetFileSystem fileSystem)
    : fileSystem_(std::move(fileSystem)) {}

Ptr<Shader> ShaderLoader::load(const std::string &path) {
  std::string basePath = path;

  std::string::size_type dotPos = basePath.rfind('.');
  if (dotPos != std::string::npos) {
    basePath = basePath.substr(0, dotPos);
  }

  std::string vertPath = basePath + ".vert";
  std::string fragPath = basePath + ".frag";

  if (!fileSystem_.exists(vertPath)) {
    vertPath = basePath + ".vs";
  }
  if (!fileSystem_.exists(fragPath)) {
    fragPath = basePath + ".fs";
  }

  return load(vertPath, fragPath);
}

Ptr<Shader> ShaderLoader::load(const std::string &vertPath,
                               const std::string &fragPath) {
  // 读取顶点着色器文件
  std::string vsSource = fileSystem_.readString(vertPath);
  if (vsSource.empty()) {
    E2D_ERROR("ShaderLoader: 读取顶点着色器失败: {}", vertPath);
    return Ptr<Shader>();
  }

  // 读取片段着色器文件
  std::string fsSource = fileSystem_.readString(fragPath);
  if (fsSource.empty()) {
    E2D_ERROR("ShaderLoader: 读取片段着色器失败: {}", fragPath);
    return Ptr<Shader>();
  }

  // 从源码加载着色器
  Ptr<Shader> shader = makePtr<Shader>();
  if (!shader->loadFromSource(vsSource, fsSource)) {
    E2D_ERROR("ShaderLoader: 编译着色器失败 {} + {}", vertPath, fragPath);
    return Ptr<Shader>();
  }

  E2D_DEBUG("ShaderLoader: 已加载着色器 {} + {}", vertPath, fragPath);
  return shader;
}

Ptr<Shader> ShaderLoader::loadFromMemory(const uint8_t *data, size_t size) {
  E2D_ERROR("ShaderLoader: loadFromMemory 不支持着色器");
  return Ptr<Shader>();
}

Ptr<Shader> ShaderLoader::loadFromSource(const std::string &vsSource,
                                         const std::string &fsSource) {
  Ptr<Shader> shader = makePtr<Shader>();

  if (!shader->loadFromSource(vsSource, fsSource)) {
    E2D_ERROR("ShaderLoader: 从源码编译着色器失败");
    return Ptr<Shader>();
  }

  E2D_DEBUG("ShaderLoader: 已从源码编译着色器");
  return shader;
}

} // namespace extra2d