// Copyright 2019 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include "DolphinNoGUI/Platform.h"

#include "Common/MsgHandler.h"
#include "Core/Config/MainSettings.h"
#include "Core/ConfigManager.h"
#include "Core/Core.h"
#include "Core/State.h"

#include <Windows.h>
#include <climits>
#include <cstdio>

#include "VideoCommon/RenderBase.h"
#include "resource.h"

namespace
{
class PlatformWin32 : public Platform
{
public:
  ~PlatformWin32() override;

  bool Init() override;
  void SetTitle(const std::string& string) override;
  void MainLoop() override;

  WindowSystemInfo GetWindowSystemInfo() const;

private:
  static constexpr TCHAR WINDOW_CLASS_NAME[] = _T("DolphinNoGUI");

  static LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

  bool RegisterRenderWindowClass();
  bool CreateRenderWindow();
  void UpdateWindowPosition();
  void ProcessEvents();

  HWND m_hwnd{};

  int m_window_x = Config::Get(Config::MAIN_RENDER_WINDOW_XPOS);
  int m_window_y = Config::Get(Config::MAIN_RENDER_WINDOW_YPOS);
  int m_window_width = Config::Get(Config::MAIN_RENDER_WINDOW_WIDTH);
  int m_window_height = Config::Get(Config::MAIN_RENDER_WINDOW_HEIGHT);
};

PlatformWin32::~PlatformWin32()
{
  if (m_hwnd)
    DestroyWindow(m_hwnd);
}

bool PlatformWin32::RegisterRenderWindowClass()
{
  WNDCLASSEX wc = {};
  wc.cbSize = sizeof(WNDCLASSEX);
  wc.style = 0;
  wc.lpfnWndProc = WndProc;
  wc.cbClsExtra = 0;
  wc.cbWndExtra = 0;
  wc.hInstance = GetModuleHandle(nullptr);
  wc.hIcon = LoadIcon(NULL, IDI_ICON1);
  wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
  wc.lpszMenuName = NULL;
  wc.lpszClassName = WINDOW_CLASS_NAME;
  wc.hIconSm = LoadIcon(NULL, IDI_ICON1);

  if (!RegisterClassEx(&wc))
  {
    MessageBox(nullptr, _T("Window registration failed."), _T("Error"), MB_ICONERROR | MB_OK);
    return false;
  }

  return true;
}

bool PlatformWin32::CreateRenderWindow()
{
  m_hwnd = CreateWindowEx(WS_EX_CLIENTEDGE, WINDOW_CLASS_NAME, _T("Dolphin"), WS_OVERLAPPEDWINDOW,
                          m_window_x < 0 ? CW_USEDEFAULT : m_window_x,
                          m_window_y < 0 ? CW_USEDEFAULT : m_window_y, m_window_width,
                          m_window_height, nullptr, nullptr, GetModuleHandle(nullptr), this);
  if (!m_hwnd)
  {
    MessageBox(nullptr, _T("CreateWindowEx failed."), _T("Error"), MB_ICONERROR | MB_OK);
    return false;
  }

  ShowWindow(m_hwnd, SW_SHOW);
  UpdateWindow(m_hwnd);
  return true;
}

bool PlatformWin32::Init()
{
  if (!RegisterRenderWindowClass() || !CreateRenderWindow())
    return false;

  // TODO: Enter fullscreen if enabled.
  if (Config::Get(Config::MAIN_FULLSCREEN))
  {
    ProcessEvents();
  }

  UpdateWindowPosition();
  return true;
}

void PlatformWin32::SetTitle(const std::string& string)
{
  SetWindowTextW(m_hwnd, UTF8ToUTF16(string).c_str());
}

void PlatformWin32::MainLoop()
{
  while (IsRunning())
  {
    UpdateRunningFlag();
    Core::HostDispatchJobs();
    ProcessEvents();
    UpdateWindowPosition();

    // TODO: Is this sleep appropriate?
    std::this_thread::sleep_for(std::chrono::milliseconds(1));
  }
}

WindowSystemInfo PlatformWin32::GetWindowSystemInfo() const
{
  WindowSystemInfo wsi;
  wsi.type = WindowSystemType::Windows;
  wsi.render_window = reinterpret_cast<void*>(m_hwnd);
  wsi.render_surface = reinterpret_cast<void*>(m_hwnd);
  return wsi;
}

void PlatformWin32::UpdateWindowPosition()
{
  if (m_window_fullscreen)
    return;

  RECT rc = {};
  if (!GetWindowRect(m_hwnd, &rc))
    return;

  m_window_x = rc.left;
  m_window_y = rc.top;
  m_window_width = rc.right - rc.left;
  m_window_height = rc.bottom - rc.top;
}

void PlatformWin32::ProcessEvents()
{
  MSG msg;
  while (PeekMessage(&msg, m_hwnd, 0, 0, PM_REMOVE))
  {
    TranslateMessage(&msg);
    DispatchMessage(&msg);
  }
}

LRESULT PlatformWin32::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
  PlatformWin32* platform = reinterpret_cast<PlatformWin32*>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
  switch (msg)
  {
  case WM_NCCREATE:
  {
    platform =
        reinterpret_cast<PlatformWin32*>(reinterpret_cast<CREATESTRUCT*>(lParam)->lpCreateParams);
    SetWindowLongPtr(hwnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(platform));
    return DefWindowProc(hwnd, msg, wParam, lParam);
  }

  case WM_SIZE:
  {
    if (g_renderer)
      g_renderer->ResizeSurface();
  }
  break;

  case WM_CLOSE:
    platform->RequestShutdown();
    break;

  default:
    return DefWindowProc(hwnd, msg, wParam, lParam);
  }

  return 0;
}
}  // namespace

std::unique_ptr<Platform> Platform::CreateWin32Platform()
{
  return std::make_unique<PlatformWin32>();
}