/*  PCSX2 - PS2 Emulator for PCs
 *  Copyright (C) 2002-2022  PCSX2 Dev Team
 *
 *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU Lesser General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with PCSX2.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include <chrono>
#include <csignal>
#include <condition_variable>
#include <mutex>
#include <thread>

#ifdef _WIN32
#include "common/RedtapeWindows.h"
#endif

#include "fmt/core.h"

#include "common/Assertions.h"
#include "common/Console.h"
#include "common/Exceptions.h"
#include "common/FileSystem.h"
#include "common/MemorySettingsInterface.h"
#include "common/Path.h"
#include "common/SettingsWrapper.h"
#include "common/StringUtil.h"

#include "pcsx2/PrecompiledHeader.h"

#include "pcsx2/CDVD/CDVD.h"
#include "pcsx2/Frontend/CommonHost.h"
#include "pcsx2/Frontend/InputManager.h"
#include "pcsx2/Frontend/ImGuiManager.h"
#include "pcsx2/Frontend/LogSink.h"
#include "pcsx2/GS.h"
#include "pcsx2/GS/GS.h"
#include "pcsx2/GSDumpReplayer.h"
#include "pcsx2/HostDisplay.h"
#include "pcsx2/HostSettings.h"
#include "pcsx2/INISettingsInterface.h"
#include "pcsx2/PerformanceMetrics.h"
#include "pcsx2/VMManager.h"

#ifdef ENABLE_ACHIEVEMENTS
#include "pcsx2/Frontend/Achievements.h"
#endif

#include "svnrev.h"

namespace GSRunner
{
	static bool InitializeConfig();
	static bool SetCriticalFolders();

	static bool CreatePlatformWindow();
	static void DestroyPlatformWindow();
	static std::optional<WindowInfo> GetPlatformWindowInfo();
	static void PumpPlatformMessages();
} // namespace GSRunner

static constexpr u32 WINDOW_WIDTH = 640;
static constexpr u32 WINDOW_HEIGHT = 480;

static MemorySettingsInterface s_settings_interface;
alignas(16) static SysMtgsThread s_mtgs_thread;

static std::string s_output_prefix;
static s32 s_loop_count = 1;
static std::optional<bool> s_use_window;

bool GSRunner::SetCriticalFolders()
{
	EmuFolders::AppRoot = Path::Canonicalize(Path::GetDirectory(FileSystem::GetProgramPath()));
	EmuFolders::Resources = Path::Combine(EmuFolders::AppRoot, "resources");
	EmuFolders::DataRoot = EmuFolders::AppRoot;

	// allow SetDataDirectory() to change settings directory (if we want to split config later on)
	if (EmuFolders::Settings.empty())
		EmuFolders::Settings = Path::Combine(EmuFolders::DataRoot, "inis");

	// the resources directory should exist, bail out if not
	if (!FileSystem::DirectoryExists(EmuFolders::Resources.c_str()))
	{
		Console.Error("Resources directory is missing, your installation is incomplete.");
		return false;
	}

	return true;
}

bool GSRunner::InitializeConfig()
{
	if (!CommonHost::InitializeCriticalFolders())
		return false;

	// don't provide an ini path, or bother loading. we'll store everything in memory.
	MemorySettingsInterface& si = s_settings_interface;
	Host::Internal::SetBaseSettingsLayer(&si);

	CommonHost::SetDefaultSettings(si, true, true, true, true, true);

	// complete as quickly as possible
	si.SetBoolValue("EmuCore/GS", "FrameLimitEnable", false);
	si.SetIntValue("EmuCore/GS", "VsyncEnable", static_cast<int>(VsyncMode::Off));

	// ensure all input sources are disabled, we're not using them
	si.SetBoolValue("InputSources", "SDL", false);
	si.SetBoolValue("InputSources", "XInput", false);

	// we don't need any sound output
	si.SetStringValue("SPU2/Output", "OutputModule", "nullout");

	// force logging
	si.SetBoolValue("Logging", "EnableSystemConsole", true);
	si.SetBoolValue("Logging", "EnableTimestamps", true);
	si.SetBoolValue("Logging", "EnableVerbose", true);

	// and show some stats :)
	si.SetBoolValue("EmuCore/GS", "OsdShowFPS", true);
	si.SetBoolValue("EmuCore/GS", "OsdShowResolution", true);
	si.SetBoolValue("EmuCore/GS", "OsdShowGSStats", true);

	CommonHost::LoadStartupSettings();
	return true;
}

void Host::CommitBaseSettingChanges()
{
	// nothing to save, we're all in memory
}

void Host::LoadSettings(SettingsInterface& si, std::unique_lock<std::mutex>& lock)
{
	CommonHost::LoadSettings(si, lock);
}

void Host::CheckForSettingsChanges(const Pcsx2Config& old_config)
{
	CommonHost::CheckForSettingsChanges(old_config);
}

bool Host::RequestResetSettings(bool folders, bool core, bool controllers, bool hotkeys, bool ui)
{
	// not running any UI, so no settings requests will come in
	return false;
}

void Host::SetDefaultUISettings(SettingsInterface& si)
{
	// nothing
}

std::optional<std::vector<u8>> Host::ReadResourceFile(const char* filename)
{
	const std::string path(Path::Combine(EmuFolders::Resources, filename));
	std::optional<std::vector<u8>> ret(FileSystem::ReadBinaryFile(path.c_str()));
	if (!ret.has_value())
		Console.Error("Failed to read resource file '%s'", filename);
	return ret;
}

std::optional<std::string> Host::ReadResourceFileToString(const char* filename)
{
	const std::string path(Path::Combine(EmuFolders::Resources, filename));
	std::optional<std::string> ret(FileSystem::ReadFileToString(path.c_str()));
	if (!ret.has_value())
		Console.Error("Failed to read resource file to string '%s'", filename);
	return ret;
}

std::optional<std::time_t> Host::GetResourceFileTimestamp(const char* filename)
{
	const std::string path(Path::Combine(EmuFolders::Resources, filename));
	FILESYSTEM_STAT_DATA sd;
	if (!FileSystem::StatFile(filename, &sd))
		return std::nullopt;

	return sd.ModificationTime;
}

void Host::ReportErrorAsync(const std::string_view& title, const std::string_view& message)
{
	if (!title.empty() && !message.empty())
	{
		Console.Error(
			"ReportErrorAsync: %.*s: %.*s", static_cast<int>(title.size()), title.data(), static_cast<int>(message.size()), message.data());
	}
	else if (!message.empty())
	{
		Console.Error("ReportErrorAsync: %.*s", static_cast<int>(message.size()), message.data());
	}
}

bool Host::ConfirmMessage(const std::string_view& title, const std::string_view& message)
{
	if (!title.empty() && !message.empty())
	{
		Console.Error(
			"ConfirmMessage: %.*s: %.*s", static_cast<int>(title.size()), title.data(), static_cast<int>(message.size()), message.data());
	}
	else if (!message.empty())
	{
		Console.Error("ConfirmMessage: %.*s", static_cast<int>(message.size()), message.data());
	}

	return true;
}

void Host::OpenURL(const std::string_view& url)
{
	// noop
}

bool Host::CopyTextToClipboard(const std::string_view& text)
{
	return false;
}

void Host::BeginTextInput()
{
	// noop
}

void Host::EndTextInput()
{
	// noop
}

std::optional<WindowInfo> Host::GetTopLevelWindowInfo()
{
	return GSRunner::GetPlatformWindowInfo();
}

void Host::OnInputDeviceConnected(const std::string_view& identifier, const std::string_view& device_name)
{
}

void Host::OnInputDeviceDisconnected(const std::string_view& identifier)
{
}

bool Host::AcquireHostDisplay(RenderAPI api)
{
	const std::optional<WindowInfo> wi(GSRunner::GetPlatformWindowInfo());
	if (!wi.has_value())
		return false;

	g_host_display = HostDisplay::CreateForAPI(api);
	if (!g_host_display)
		return false;

	if (!g_host_display->CreateDevice(wi.value()) || !g_host_display->MakeCurrent() || !g_host_display->SetupDevice() || !ImGuiManager::Initialize())
	{
		ReleaseHostDisplay();
		return false;
	}

	Console.WriteLn(Color_StrongGreen, "%s Graphics Driver Info:", HostDisplay::RenderAPIToString(g_host_display->GetRenderAPI()));
	Console.Indent().WriteLn(g_host_display->GetDriverInfo());

	return g_host_display.get();
}

void Host::ReleaseHostDisplay()
{
	if (!g_host_display)
		return;

	ImGuiManager::Shutdown();
	g_host_display.reset();
}

VsyncMode Host::GetEffectiveVSyncMode()
{
	// Never vsync! We want to finish as quickly as possible.
	return VsyncMode::Off;
}

bool Host::BeginPresentFrame(bool frame_skip)
{
	return g_host_display->BeginPresent(frame_skip);
}

void Host::EndPresentFrame()
{
	if (GSDumpReplayer::IsReplayingDump())
		GSDumpReplayer::RenderUI();

	ImGuiManager::RenderOSD();
	g_host_display->EndPresent();
	ImGuiManager::NewFrame();
}

void Host::ResizeHostDisplay(u32 new_window_width, u32 new_window_height, float new_window_scale)
{
}

void Host::UpdateHostDisplay()
{
}

void Host::RequestResizeHostDisplay(s32 width, s32 height)
{
}

void Host::OnVMStarting()
{
}

void Host::OnVMStarted()
{
}

void Host::OnVMDestroyed()
{
}

void Host::OnVMPaused()
{
}

void Host::OnVMResumed()
{
}

void Host::OnGameChanged(const std::string& disc_path, const std::string& game_serial, const std::string& game_name, u32 game_crc)
{
}

void Host::OnPerformanceMetricsUpdated()
{
}

void Host::OnSaveStateLoading(const std::string_view& filename)
{
}

void Host::OnSaveStateLoaded(const std::string_view& filename, bool was_successful)
{
}

void Host::OnSaveStateSaved(const std::string_view& filename)
{
}

void Host::InvalidateSaveStateCache()
{
}

void Host::RunOnCPUThread(std::function<void()> function, bool block /* = false */)
{
	pxFailRel("Not implemented");
}

void Host::RefreshGameListAsync(bool invalidate_cache)
{
}

void Host::CancelGameListRefresh()
{
}

bool Host::IsFullscreen()
{
	return false;
}

void Host::SetFullscreen(bool enabled)
{
}

void Host::RequestExit(bool save_state_if_running)
{
}

void Host::RequestVMShutdown(bool allow_confirm, bool allow_save_state, bool default_save_state)
{
	VMManager::SetState(VMState::Stopping);
}

#ifdef ENABLE_ACHIEVEMENTS
void Host::OnAchievementsRefreshed()
{
	// noop
}
#endif

std::optional<u32> InputManager::ConvertHostKeyboardStringToCode(const std::string_view& str)
{
	return std::nullopt;
}

std::optional<std::string> InputManager::ConvertHostKeyboardCodeToString(u32 code)
{
	return std::nullopt;
}

SysMtgsThread& GetMTGS()
{
	return s_mtgs_thread;
}

//////////////////////////////////////////////////////////////////////////
// Interface Stuff
//////////////////////////////////////////////////////////////////////////

const IConsoleWriter* PatchesCon = &Console;
BEGIN_HOTKEY_LIST(g_host_hotkeys)
END_HOTKEY_LIST()

static void PrintCommandLineVersion()
{
	std::fprintf(stderr, "PCSX2 GS Runner Version %s\n", GIT_REV);
	std::fprintf(stderr, "https://pcsx2.net/\n");
	std::fprintf(stderr, "\n");
}

static void PrintCommandLineHelp(const char* progname)
{
	PrintCommandLineVersion();
	std::fprintf(stderr, "Usage: %s [parameters] [--] [filename]\n", progname);
	std::fprintf(stderr, "\n");
	std::fprintf(stderr, "  -help: Displays this information and exits.\n");
	std::fprintf(stderr, "  -version: Displays version information and exits.\n");
	std::fprintf(stderr, "  -dumpdir <dir>: Frame dump directory (will be dumped as filename_frameN.png).\n");
	std::fprintf(stderr, "  -loop <count>: Loops dump playback N times. Defaults to 1. 0 will loop infinitely.\n");
	std::fprintf(stderr, "  -renderer <renderer>: Sets the graphics renderer. Defaults to Auto.\n");
	std::fprintf(stderr, "  -window: Forces a window to be displayed.\n");
	std::fprintf(stderr, "  -surfaceless: Disables showing a window.\n");
	std::fprintf(stderr, "  --: Signals that no more arguments will follow and the remaining\n"
						 "    parameters make up the filename. Use when the filename contains\n"
						 "    spaces or starts with a dash.\n");
	std::fprintf(stderr, "\n");
}

static bool ParseCommandLineArgs(int argc, char* argv[], VMBootParameters& params)
{
	bool no_more_args = false;
	for (int i = 1; i < argc; i++)
	{
		if (!no_more_args)
		{
#define CHECK_ARG(str) !std::strcmp(argv[i], str)
#define CHECK_ARG_PARAM(str) (!std::strcmp(argv[i], str) && ((i + 1) < argc))

			if (CHECK_ARG("-help"))
			{
				PrintCommandLineHelp(argv[0]);
				return false;
			}
			else if (CHECK_ARG("-version"))
			{
				PrintCommandLineVersion();
				return false;
			}
			else if (CHECK_ARG_PARAM("-dumpdir"))
			{
				s_output_prefix = StringUtil::StripWhitespace(argv[++i]);
				if (s_output_prefix.empty())
				{
					Console.Error("Invalid dump directory specified.");
					return false;
				}

				if (!FileSystem::DirectoryExists(s_output_prefix.c_str()) && !FileSystem::CreateDirectoryPath(s_output_prefix.c_str(), false))
				{
					Console.Error("Failed to create output directory");
					return false;
				}

				continue;
			}
			else if (CHECK_ARG_PARAM("-loop"))
			{
				s_loop_count = StringUtil::FromChars<s32>(argv[++i]).value_or(0);
				Console.WriteLn("Looping dump playback %d times.", s_loop_count);
				continue;
			}
			else if (CHECK_ARG_PARAM("-renderer"))
			{
				const char* rname = argv[++i];

				GSRendererType type = GSRendererType::Auto;
				if (StringUtil::Strcasecmp(rname, "Auto") == 0)
					type = GSRendererType::Auto;
#ifdef _WIN32
				else if (StringUtil::Strcasecmp(rname, "dx11") == 0)
					type = GSRendererType::DX11;
				else if (StringUtil::Strcasecmp(rname, "dx12") == 0)
					type = GSRendererType::DX12;
#endif
#ifdef ENABLE_OPENGL
				else if (StringUtil::Strcasecmp(rname, "gl") == 0)
					type = GSRendererType::OGL;
#endif
#ifdef ENABLE_VULKAN
				else if (StringUtil::Strcasecmp(rname, "vulkan") == 0)
					type = GSRendererType::VK;
#endif
#ifdef __APPLE__
				else if (StringUtil::Strcasecmp(rname, "metal") == 0)
					type = GSRendererType::Metal;
#endif
				else if (StringUtil::Strcasecmp(rname, "sw") == 0)
					type = GSRendererType::SW;
				else
				{
					Console.Error("Unknown renderer '%s'", rname);
					return false;
				}

				Console.WriteLn("Using %s renderer.", Pcsx2Config::GSOptions::GetRendererName(type));
				s_settings_interface.SetIntValue("EmuCore/GS", "Renderer", static_cast<int>(type));
				continue;
			}
			else if (CHECK_ARG("-window"))
			{
				Console.WriteLn("Creating window");
				s_use_window = true;
				continue;
			}
			else if (CHECK_ARG("-surfaceless"))
			{
				Console.WriteLn("Running surfaceless");
				s_use_window = false;
				continue;
			}
			else if (CHECK_ARG("--"))
			{
				no_more_args = true;
				continue;
			}
			else if (argv[i][0] == '-')
			{
				Console.Error("Unknown parameter: '%s'", argv[i]);
				return false;
			}

#undef CHECK_ARG
#undef CHECK_ARG_PARAM
		}

		if (!params.filename.empty())
			params.filename += ' ';
		params.filename += argv[i];
	}

	if (params.filename.empty())
	{
		Console.Error("No dump filename provided.");
		return false;
	}

	if (!VMManager::IsGSDumpFileName(params.filename))
	{
		Console.Error("Provided filename is not a GS dump.");
		return false;
	}

	// set up the frame dump directory
	if (!s_output_prefix.empty())
	{
		// strip off all extensions
		std::string_view title(Path::GetFileTitle(params.filename));
		if (StringUtil::EndsWithNoCase(title, ".gs"))
			title = Path::GetFileTitle(title);

		s_output_prefix = Path::Combine(s_output_prefix, StringUtil::StripWhitespace(title));
		Console.WriteLn(fmt::format("Saving dumps as {}_frameN.png", s_output_prefix));
	}

	return true;
}

int main(int argc, char* argv[])
{
	CommonHost::InitializeEarlyConsole();

	if (!GSRunner::InitializeConfig())
	{
		Console.Error("Failed to initialize config.");
		return false;
	}

	VMBootParameters params;
	if (!ParseCommandLineArgs(argc, argv, params))
		return false;

	PerformanceMetrics::SetCPUThread(Threading::ThreadHandle::GetForCallingThread());
	if (!VMManager::Internal::InitializeGlobals() || !VMManager::Internal::InitializeMemory())
	{
		Console.Error("Failed to allocate globals/memory.");
		return false;
	}

	if (s_use_window.value_or(false) && !GSRunner::CreatePlatformWindow())
	{
		Console.Error("Failed to create window.");
		return false;
	}

	VMManager::ApplySettings();

	if (VMManager::Initialize(params))
	{
		// run until end
		GSDumpReplayer::SetLoopCount(s_loop_count);
		VMManager::SetState(VMState::Running);
		while (VMManager::GetState() == VMState::Running)
			VMManager::Execute();
		VMManager::Shutdown(false);
	}

	InputManager::CloseSources();
	VMManager::Internal::ReleaseMemory();
	PerformanceMetrics::SetCPUThread(Threading::ThreadHandle());
	GSRunner::DestroyPlatformWindow();

	return EXIT_SUCCESS;
}

void Host::CPUThreadVSync()
{
	if (!s_output_prefix.empty())
	{
		// wait for the previous frame to complete (and thus dump)
		GetMTGS().WaitGS(false, false, false);

		// queue dumping of this frame
		std::string dump_path(fmt::format("{}_frame{}.png", s_output_prefix, GSDumpReplayer::GetFrameNumber()));
		GetMTGS().RunOnGSThread([dump_path = std::move(dump_path)]() { GSQueueSnapshot(dump_path); });
	}

	// process any window messages (but we shouldn't really have any)
	GSRunner::PumpPlatformMessages();
}

//////////////////////////////////////////////////////////////////////////
// Platform specific code
//////////////////////////////////////////////////////////////////////////

#ifdef _WIN32

static constexpr LPCWSTR WINDOW_CLASS_NAME = L"PCSX2GSRunner";
static HWND s_hwnd = NULL;

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

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

	if (!RegisterClassExW(&wc))
	{
		Console.Error("Window registration failed.");
		return false;
	}

	s_hwnd = CreateWindowExW(WS_EX_CLIENTEDGE, WINDOW_CLASS_NAME, L"PCSX2 GS Runner",
		WS_OVERLAPPEDWINDOW | WS_CAPTION | WS_MINIMIZEBOX | WS_SYSMENU | WS_SIZEBOX, CW_USEDEFAULT, CW_USEDEFAULT, WINDOW_WIDTH,
		WINDOW_HEIGHT, nullptr, nullptr, GetModuleHandleW(nullptr), nullptr);
	if (!s_hwnd)
	{
		Console.Error("CreateWindowEx failed.");
		return false;
	}

	ShowWindow(s_hwnd, SW_SHOW);
	UpdateWindow(s_hwnd);

	// make sure all messages are processed before returning
	PumpPlatformMessages();
	return true;
}

void GSRunner::DestroyPlatformWindow()
{
	if (!s_hwnd)
		return;

	PumpPlatformMessages();
	DestroyWindow(s_hwnd);
	s_hwnd = {};
}

std::optional<WindowInfo> GSRunner::GetPlatformWindowInfo()
{
	WindowInfo wi;

	if (s_hwnd)
	{
		RECT rc = {};
		GetWindowRect(s_hwnd, &rc);
		wi.surface_width = static_cast<u32>(rc.right - rc.left);
		wi.surface_height = static_cast<u32>(rc.bottom - rc.top);
		wi.surface_scale = 1.0f;
		wi.type = WindowInfo::Type::Win32;
		wi.window_handle = s_hwnd;
	}
	else
	{
		wi.type = WindowInfo::Type::Surfaceless;
	}

	return wi;
}

void GSRunner::PumpPlatformMessages()
{
	MSG msg;
	while (PeekMessageW(&msg, NULL, 0, 0, PM_REMOVE))
	{
		TranslateMessage(&msg);
		DispatchMessageW(&msg);
	}
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
	return DefWindowProcW(hwnd, msg, wParam, lParam);
}

#endif // _WIN32