#pragma once
#include "hd2d/GL.h"

#include <glm/glm.hpp>
#include <string>
#include <unordered_map>

namespace hd2d {

// GLSL program loaded from files. Supports `#include "file.glsl"` (resolved
// relative to the including file) and hot reload: a failed reload keeps the
// previous working program.
class Shader {
public:
    Shader() = default;
    Shader(const Shader&) = delete;
    Shader& operator=(const Shader&) = delete;
    ~Shader();

    bool load(const std::string& vertPath, const std::string& fragPath);
    bool reload();
    void use() const { glUseProgram(program_); }
    GLuint id() const { return program_; }

    void set(const char* name, int v);
    void set(const char* name, float v);
    void set(const char* name, const glm::vec2& v);
    void set(const char* name, const glm::vec3& v);
    void set(const char* name, const glm::vec4& v);
    void set(const char* name, const glm::ivec2& v);
    void set(const char* name, const glm::ivec4& v);
    void set(const char* name, const glm::mat4& v);

private:
    GLint location(const char* name);

    GLuint program_ = 0;
    std::string vertPath_, fragPath_;
    std::unordered_map<std::string, GLint> locations_;
};

}  // namespace hd2d