// Copyright 2011 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#pragma once

#include <atomic>
#include <memory>
#include <mutex>
#include <tuple>
#include <unordered_map>

#include "Common/GL/GLUtil.h"

namespace OGL
{
class OGLShader;
class GLVertexFormat;
class StreamBuffer;

struct SHADER
{
  void Destroy()
  {
    DestroyShaders();
    if (glprogid)
    {
      glDeleteProgram(glprogid);
      glprogid = 0;
    }
  }

  GLuint vsid = 0;
  GLuint gsid = 0;
  GLuint psid = 0;
  GLuint glprogid = 0;

  void SetProgramVariables();
  void SetProgramBindings(bool is_compute);
  void Bind() const;
  void DestroyShaders();
};

struct PipelineProgramKey
{
  const OGLShader* vertex_shader;
  const OGLShader* geometry_shader;
  const OGLShader* pixel_shader;

  bool operator==(const PipelineProgramKey& rhs) const;
  bool operator!=(const PipelineProgramKey& rhs) const;
  bool operator<(const PipelineProgramKey& rhs) const;
};

struct PipelineProgramKeyHash
{
  std::size_t operator()(const PipelineProgramKey& key) const;
};

struct PipelineProgram
{
  PipelineProgramKey key;
  SHADER shader;
  std::atomic_size_t reference_count{1};
};

class ProgramShaderCache
{
public:
  static void BindVertexFormat(const GLVertexFormat* vertex_format);
  static void InvalidateVertexFormat();
  static void InvalidateLastProgram();

  static bool CompileShader(SHADER& shader, const std::string& vcode, const std::string& pcode,
                            const std::string& gcode = "");
  static bool CompileComputeShader(SHADER& shader, const std::string& code);
  static GLuint CompileSingleShader(GLenum type, const std::string& code);
  static bool CheckShaderCompileResult(GLuint id, GLenum type, const std::string& code);
  static bool CheckProgramLinkResult(GLuint id, const std::string& vcode, const std::string& pcode,
                                     const std::string& gcode);
  static StreamBuffer* GetUniformBuffer();
  static u32 GetUniformBufferAlignment();
  static void InvalidateConstants();
  static void UploadConstants();

  static void Init();
  static void Shutdown();
  static void CreateHeader();

  static const PipelineProgram* GetPipelineProgram(const OGLShader* vertex_shader,
                                                   const OGLShader* geometry_shader,
                                                   const OGLShader* pixel_shader);
  static void ReleasePipelineProgram(const PipelineProgram* prog);

private:
  typedef std::unordered_map<PipelineProgramKey, std::unique_ptr<PipelineProgram>,
                             PipelineProgramKeyHash>
      PipelineProgramMap;

  static void CreateAttributelessVAO();

  static PipelineProgramMap pipelineprograms;
  static std::mutex pipelineprogramlock;

  static u32 s_ubo_buffer_size;
  static s32 s_ubo_align;

  static GLuint s_attributeless_VBO;
  static GLuint s_attributeless_VAO;
  static GLuint s_last_VAO;
};

}  // namespace OGL