#ifndef ARE_INCLUDE_RESOURCE_SHADER_H
#define ARE_INCLUDE_RESOURCE_SHADER_H

#include "basic/types.h"
#include <string>
#include <unordered_map>

namespace are {

/// @brief Shader program resource
class Shader {
public:
    /// @brief Constructor
    Shader();

	Shader(const Shader&) = delete;
    Shader& operator=(const Shader&) = delete;

    Shader(Shader&& other) noexcept;
    Shader& operator=(Shader&& other) noexcept;
    
    /// @brief Destructor
    ~Shader();
    
    /// @brief Load and compile shader from files
    /// @param vertex_path Vertex shader path
    /// @param fragment_path Fragment shader path
    /// @return True if compilation succeeded
    bool load(const std::string& vertex_path, const std::string& fragment_path);
    
    /// @brief Load and compile compute shader
    /// @param compute_path Compute shader path
    /// @return True if compilation succeeded
    bool load_compute(const std::string& compute_path);
    
    /// @brief Compile shader from source strings
    /// @param vertex_source Vertex shader source
    /// @param fragment_source Fragment shader source
    /// @return True if compilation succeeded
    bool compile(const std::string& vertex_source, const std::string& fragment_source);
    
    /// @brief Compile compute shader from source
    /// @param compute_source Compute shader source
    /// @return True if compilation succeeded
    bool compile_compute(const std::string& compute_source);
    
    /// @brief Use/activate shader program
    void use() const;  // 改为const
    
    /// @brief Release shader resources
    void release();
    
    /// @brief Set uniform boolean
    /// @param name Uniform name
    /// @param value Value
    void set_bool(const std::string& name, bool value) const;  // 新增，const
    
    /// @brief Set uniform integer
    /// @param name Uniform name
    /// @param value Value
    void set_int(const std::string& name, int value) const;  // 改为const
    
    /// @brief Set uniform unsigned integer
    /// @param name Uniform name
    /// @param value Value
    void set_uint(const std::string& name, uint value) const;  // 改为const
    
    /// @brief Set uniform float
    /// @param name Uniform name
    /// @param value Value
    void set_float(const std::string& name, float value) const;  // 改为const
    
    /// @brief Set uniform vec2
    /// @param name Uniform name
    /// @param value Value
    void set_vec2(const std::string& name, const Vec2& value) const;  // 改为const
    
    /// @brief Set uniform vec3
    /// @param name Uniform name
    /// @param value Value
    void set_vec3(const std::string& name, const Vec3& value) const;  // 改为const
    
    /// @brief Set uniform vec4
    /// @param name Uniform name
    /// @param value Value
    void set_vec4(const std::string& name, const Vec4& value) const;  // 改为const
    
    /// @brief Set uniform mat3
    /// @param name Uniform name
    /// @param value Value
    void set_mat3(const std::string& name, const Mat3& value) const;  // 改为const
    
    /// @brief Set uniform mat4
    /// @param name Uniform name
    /// @param value Value
    void set_mat4(const std::string& name, const Mat4& value) const;  // 改为const
    
    /// @brief Get shader program handle
    /// @return Shader handle
    ShaderHandle get_handle() const { return handle_; }
    
    /// @brief Check if shader is valid
    /// @return True if valid
    bool is_valid() const { return handle_ != INVALID_HANDLE; }

private:
    ShaderHandle handle_;
    mutable std::unordered_map<std::string, int> uniform_cache_;  // 改为mutable
    
    /// @brief Get uniform location (with caching)
    /// @param name Uniform name
    /// @return Uniform location
    int get_uniform_location_(const std::string& name) const;  // 改为const
    
    /// @brief Compile shader stage
    /// @param source Shader source code
    /// @param type Shader type (GL_VERTEX_SHADER, etc.)
    /// @return Shader object handle (0 on failure)
    uint compile_shader_(const std::string& source, uint type);
    
    /// @brief Link shader program
    /// @param shaders Array of shader object handles
    /// @param count Number of shaders
    /// @return True if linking succeeded
    bool link_program_(const uint* shaders, uint count);
    
    /// @brief Read file content
    /// @param path File path
    /// @return File content
    std::string read_file_(const std::string& path);
};

} // namespace are

#endif // ARE_INCLUDE_RESOURCE_SHADER_H