/**
 ******************************************************************************
 * Xenia : Xbox 360 Emulator Research Project                                 *
 ******************************************************************************
 * Copyright 2022 Ben Vanik. All rights reserved.                             *
 * Released under the BSD license - see LICENSE in the root for more details. *
 ******************************************************************************
 */

#ifndef XENIA_GPU_GRAPHICS_SYSTEM_H_
#define XENIA_GPU_GRAPHICS_SYSTEM_H_

#include <atomic>
#include <cstdint>
#include <functional>
#include <memory>
#include <mutex>
#include <string>
#include <thread>

#include "xenia/cpu/processor.h"
#include "xenia/gpu/register_file.h"
#include "xenia/kernel/xthread.h"
#include "xenia/memory.h"
#include "xenia/ui/graphics_provider.h"
#include "xenia/ui/presenter.h"
#include "xenia/ui/windowed_app_context.h"
#include "xenia/xbox.h"

namespace xe {
class Emulator;
}  // namespace xe

namespace xe {
namespace gpu {

class CommandProcessor;

class GraphicsSystem {
 public:
  virtual ~GraphicsSystem();

  virtual std::string name() const = 0;

  Memory* memory() const { return memory_; }
  cpu::Processor* processor() const { return processor_; }
  kernel::KernelState* kernel_state() const { return kernel_state_; }
  ui::GraphicsProvider* provider() const { return provider_.get(); }
  ui::Presenter* presenter() const { return presenter_.get(); }

  virtual X_STATUS Setup(cpu::Processor* processor,
                         kernel::KernelState* kernel_state,
                         ui::WindowedAppContext* app_context,
                         bool with_presentation);
  virtual void Shutdown();

  // May be called from any thread any number of times, even during recovery
  // from a device loss.
  void OnHostGpuLossFromAnyThread(bool is_responsible);

  RegisterFile* register_file() { return register_file_; }
  CommandProcessor* command_processor() const {
    return command_processor_.get();
  }

  virtual void InitializeRingBuffer(uint32_t ptr, uint32_t size_log2);
  virtual void EnableReadPointerWriteBack(uint32_t ptr,
                                          uint32_t block_size_log2);

  virtual void SetInterruptCallback(uint32_t callback, uint32_t user_data);
  void DispatchInterruptCallback(uint32_t source, uint32_t cpu);

  virtual void ClearCaches();

  void InitializeShaderStorage(
      const std::filesystem::path& cache_root, uint32_t title_id, bool blocking,
      std::function<void()> completion_callback = nullptr);

  void RequestFrameTrace();
  void BeginTracing();
  void EndTracing();

  bool is_paused() const { return paused_; }
  void Pause();
  void Resume();

  bool Save(ByteStream* stream);
  bool Restore(ByteStream* stream);

  std::pair<uint32_t, uint32_t> GetResolution() const;

  std::pair<uint32_t, uint32_t> GetScaledAspectRatio() const {
    return {scaled_aspect_x_, scaled_aspect_y_};
  };
  void SetScaledAspectRatio(uint32_t x, uint32_t y) {
    scaled_aspect_x_ = x;
    scaled_aspect_y_ = y;
  };

 protected:
  GraphicsSystem();

  virtual std::unique_ptr<CommandProcessor> CreateCommandProcessor() = 0;

  static uint32_t ReadRegisterThunk(void* ppc_context, GraphicsSystem* gs,
                                    uint32_t addr);
  static void WriteRegisterThunk(void* ppc_context, GraphicsSystem* gs,
                                 uint32_t addr, uint32_t value);
  uint32_t ReadRegister(uint32_t addr);
  void WriteRegister(uint32_t addr, uint32_t value);

  void MarkVblank();

  Memory* memory_ = nullptr;
  cpu::Processor* processor_ = nullptr;
  kernel::KernelState* kernel_state_ = nullptr;
  ui::WindowedAppContext* app_context_ = nullptr;
  std::unique_ptr<ui::GraphicsProvider> provider_;

  uint32_t interrupt_callback_ = 0;
  uint32_t interrupt_callback_data_ = 0;

  std::atomic<bool> frame_limiter_worker_running_;
  kernel::object_ref<kernel::XHostThread> frame_limiter_worker_thread_;

  RegisterFile* register_file_;
  std::unique_ptr<CommandProcessor> command_processor_;

  bool paused_ = false;

  uint32_t scaled_aspect_x_ = 0;
  uint32_t scaled_aspect_y_ = 0;

 private:
  std::unique_ptr<ui::Presenter> presenter_;

  std::atomic_flag host_gpu_loss_reported_;
};

}  // namespace gpu
}  // namespace xe

#endif  // XENIA_GPU_GRAPHICS_SYSTEM_H_
