/*  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 "PrecompiledHeader.h"

#include <csignal>

#include <QtCore/QTimer>
#include <QtWidgets/QMessageBox>

#ifdef _WIN32
#include "common/RedtapeWindows.h"
#include <KnownFolders.h>
#include <ShlObj.h>
#endif

#include "common/Assertions.h"
#include "common/Console.h"
#include "common/CrashHandler.h"
#include "common/FileSystem.h"
#include "common/SettingsWrapper.h"
#include "common/StringUtil.h"

#include "pcsx2/Frontend/GameList.h"
#include "pcsx2/Frontend/INISettingsInterface.h"
#include "pcsx2/HostSettings.h"
#include "pcsx2/PAD/Host/PAD.h"

#include "EmuThread.h"
#include "GameList/GameListWidget.h"
#include "MainWindow.h"
#include "QtHost.h"

#include "pcsx2/DebugTools/Debug.h"

static constexpr u32 SETTINGS_VERSION = 1;
static constexpr u32 SETTINGS_SAVE_DELAY = 1000;

//////////////////////////////////////////////////////////////////////////
// Local function declarations
//////////////////////////////////////////////////////////////////////////
namespace QtHost {
static void InitializeWxRubbish();
static bool InitializeConfig();
static bool ShouldUsePortableMode();
static void SetResourcesDirectory();
static void SetDataDirectory();
static void HookSignals();
static bool SetCriticalFolders();
static void SetDefaultConfig();
static void SaveSettings();
}

//////////////////////////////////////////////////////////////////////////
// Local variable declarations
//////////////////////////////////////////////////////////////////////////
static std::unique_ptr<QTimer> s_settings_save_timer;
static std::unique_ptr<INISettingsInterface> s_base_settings_interface;

//////////////////////////////////////////////////////////////////////////
// Initialization/Shutdown
//////////////////////////////////////////////////////////////////////////

bool QtHost::Initialize()
{
	qRegisterMetaType<std::optional<bool>>();
	qRegisterMetaType<std::function<void()>>();
	qRegisterMetaType<std::shared_ptr<VMBootParameters>>();
	qRegisterMetaType<GSRendererType>();
	qRegisterMetaType<InputBindingKey>();
	qRegisterMetaType<const GameList::Entry*>();

	InitializeWxRubbish();
	if (!InitializeConfig())
	{
		Console.WriteLn("Failed to initialize config.");
		return false;
	}

	if (!VMManager::Internal::InitializeGlobals())
		return false;

	HookSignals();
	return true;
}

void QtHost::Shutdown()
{
	EmuThread::stop();
	if (g_main_window)
	{
		g_main_window->close();
		delete g_main_window;
	}
}

bool QtHost::SetCriticalFolders()
{
	std::string program_path(FileSystem::GetProgramPath());
	EmuFolders::AppRoot = wxDirName(wxFileName(StringUtil::UTF8StringToWxString(program_path)));
	SetResourcesDirectory();
	SetDataDirectory();

	// allow SetDataDirectory() to change settings directory (if we want to split config later on)
	if (!EmuFolders::Settings.IsOk())
		EmuFolders::Settings = EmuFolders::DataRoot.Combine(wxDirName(L"inis"));

	// Write crash dumps to the data directory, since that'll be accessible for certain.
	CrashHandler::SetWriteDirectory(EmuFolders::DataRoot.ToUTF8().data());

	// the resources directory should exist, bail out if not
	if (!EmuFolders::Resources.Exists())
	{
		QMessageBox::critical(nullptr, QStringLiteral("Error"),
			QStringLiteral("Resources directory is missing, your installation is incomplete."));
		return false;
	}

	return true;
}

bool QtHost::ShouldUsePortableMode()
{
	// Check whether portable.ini exists in the program directory.
	return FileSystem::FileExists(Path::CombineStdString(EmuFolders::AppRoot, "portable.ini").c_str());
}

void QtHost::SetResourcesDirectory()
{
	// On Windows/Linux, these are in the binary directory.
	EmuFolders::Resources = EmuFolders::AppRoot.Combine(wxDirName(L"resources"));
}

void QtHost::SetDataDirectory()
{
	if (ShouldUsePortableMode())
	{
		EmuFolders::DataRoot = EmuFolders::AppRoot;
		return;
	}

#if defined(_WIN32)
	// On Windows, use My Documents\PCSX2 to match old installs.
	PWSTR documents_directory;
	if (SUCCEEDED(SHGetKnownFolderPath(FOLDERID_Documents, 0, NULL, &documents_directory)))
	{
		if (std::wcslen(documents_directory) > 0)
			EmuFolders::DataRoot = wxDirName(Path::Combine(wxString(documents_directory), L"PCSX2"));
		CoTaskMemFree(documents_directory);
	}
#elif defined(__linux__)
	// Check for $HOME/PCSX2 first, for legacy installs.
	const char* home_dir = getenv("HOME");
	const std::string legacy_dir(home_dir ? Path::CombineStdString(home_dir, "PCSX2") : std::string());
	if (!legacy_dir.empty() && FileSystem::DirectoryExists(legacy_dir.c_str()))
	{
		EmuFolders::DataRoot = wxDirName(StringUtil::UTF8StringToWxString(legacy_dir));
	}
	else
	{
		// otherwise, use $XDG_CONFIG_HOME/PCSX2.
		const char* xdg_config_home = getenv("XDG_CONFIG_HOME");
		if (xdg_config_home && xdg_config_home[0] == '/' && FileSystem::DirectoryExists(xdg_config_home))
		{
			EmuFolders::DataRoot = wxDirName(StringUtil::UTF8StringToWxString(Path::CombineStdString(xdg_config_home, "PCSX2")));
		}
		else if (!legacy_dir.empty())
		{
			// fall back to the legacy PCSX2-in-home.
			EmuFolders::DataRoot = wxDirName(StringUtil::UTF8StringToWxString(legacy_dir));
		}
	}
#elif defined(__APPLE__)
	static constexpr char MAC_DATA_DIR[] = "Library/Application Support/PCSX2";
	const char* home_dir = getenv("HOME");
	if (home_dir)
		EmuFolders::DataRoot = wxDirName(StringUtil::UTF8StringToWxString(Path::CombineStdString(home_dir, MAC_DATA_DIR)));
#endif

	// make sure it exists
	if (EmuFolders::DataRoot.IsOk() && !EmuFolders::DataRoot.Exists())
	{
		// we're in trouble if we fail to create this directory... but try to hobble on with portable
		if (!EmuFolders::DataRoot.Mkdir())
			EmuFolders::DataRoot.Clear();
	}

	// couldn't determine the data directory? fallback to portable.
	if (!EmuFolders::DataRoot.IsOk())
		EmuFolders::DataRoot = EmuFolders::AppRoot;
}

void QtHost::UpdateFolders()
{
	// TODO: This should happen with the VM thread paused.
	auto lock = Host::GetSettingsLock();
	EmuFolders::LoadConfig(*s_base_settings_interface.get());
	EmuFolders::EnsureFoldersExist();
}

bool QtHost::InitializeConfig()
{
	if (!SetCriticalFolders())
		return false;

	const std::string path(Path::CombineStdString(EmuFolders::Settings, "PCSX2.ini"));
	s_base_settings_interface = std::make_unique<INISettingsInterface>(std::move(path));
	Host::Internal::SetBaseSettingsLayer(s_base_settings_interface.get());

	uint settings_version;
	if (!s_base_settings_interface->Load() ||
		!s_base_settings_interface->GetUIntValue("UI", "SettingsVersion", &settings_version) ||
		settings_version != SETTINGS_VERSION)
	{
		QMessageBox::critical(
			g_main_window, qApp->translate("QtHost", "Settings Reset"),
			qApp->translate("QtHost", "Settings do not exist or are the incorrect version, resetting to defaults."));
		SetDefaultConfig();
		s_base_settings_interface->Save();
	}

	// TODO: Handle reset to defaults if load fails.
	EmuFolders::LoadConfig(*s_base_settings_interface.get());
	EmuFolders::EnsureFoldersExist();
	QtHost::UpdateLogging();
	return true;
}

void QtHost::SetDefaultConfig()
{
	EmuConfig = Pcsx2Config();
	EmuFolders::SetDefaults();

	SettingsInterface& si = *s_base_settings_interface.get();
	si.SetUIntValue("UI", "SettingsVersion", SETTINGS_VERSION);

	{
		SettingsSaveWrapper wrapper(si);
		EmuConfig.LoadSave(wrapper);
	}

	EmuFolders::Save(si);
	PAD::SetDefaultConfig(si);
}

SettingsInterface* QtHost::GetBaseSettingsInterface()
{
	return s_base_settings_interface.get();
}

std::string QtHost::GetBaseStringSettingValue(const char* section, const char* key, const char* default_value /*= ""*/)
{
	auto lock = Host::GetSettingsLock();
	return s_base_settings_interface->GetStringValue(section, key, default_value);
}

bool QtHost::GetBaseBoolSettingValue(const char* section, const char* key, bool default_value /*= false*/)
{
	auto lock = Host::GetSettingsLock();
	return s_base_settings_interface->GetBoolValue(section, key, default_value);
}

int QtHost::GetBaseIntSettingValue(const char* section, const char* key, int default_value /*= 0*/)
{
	auto lock = Host::GetSettingsLock();
	return s_base_settings_interface->GetIntValue(section, key, default_value);
}

float QtHost::GetBaseFloatSettingValue(const char* section, const char* key, float default_value /*= 0.0f*/)
{
	auto lock = Host::GetSettingsLock();
	return s_base_settings_interface->GetFloatValue(section, key, default_value);
}

std::vector<std::string> QtHost::GetBaseStringListSetting(const char* section, const char* key)
{
	auto lock = Host::GetSettingsLock();
	return s_base_settings_interface->GetStringList(section, key);
}

void QtHost::SetBaseBoolSettingValue(const char* section, const char* key, bool value)
{
	auto lock = Host::GetSettingsLock();
	s_base_settings_interface->SetBoolValue(section, key, value);
	QueueSettingsSave();
}

void QtHost::SetBaseIntSettingValue(const char* section, const char* key, int value)
{
	auto lock = Host::GetSettingsLock();
	s_base_settings_interface->SetIntValue(section, key, value);
	QueueSettingsSave();
}

void QtHost::SetBaseFloatSettingValue(const char* section, const char* key, float value)
{
	auto lock = Host::GetSettingsLock();
	s_base_settings_interface->SetFloatValue(section, key, value);
	QueueSettingsSave();
}

void QtHost::SetBaseStringSettingValue(const char* section, const char* key, const char* value)
{
	auto lock = Host::GetSettingsLock();
	s_base_settings_interface->SetStringValue(section, key, value);
	QueueSettingsSave();
}

void QtHost::SetBaseStringListSettingValue(const char* section, const char* key, const std::vector<std::string>& values)
{
	auto lock = Host::GetSettingsLock();
	s_base_settings_interface->SetStringList(section, key, values);
	QueueSettingsSave();
}

bool QtHost::AddBaseValueToStringList(const char* section, const char* key, const char* value)
{
	auto lock = Host::GetSettingsLock();
	if (!s_base_settings_interface->AddToStringList(section, key, value))
		return false;

	QueueSettingsSave();
	return true;
}

bool QtHost::RemoveBaseValueFromStringList(const char* section, const char* key, const char* value)
{
	auto lock = Host::GetSettingsLock();
	if (!s_base_settings_interface->RemoveFromStringList(section, key, value))
		return false;

	QueueSettingsSave();
	return true;
}

void QtHost::RemoveBaseSettingValue(const char* section, const char* key)
{
	auto lock = Host::GetSettingsLock();
	s_base_settings_interface->DeleteValue(section, key);
	QueueSettingsSave();
}

void QtHost::SaveSettings()
{
	pxAssertRel(!g_emu_thread->isOnEmuThread(), "Saving should happen on the UI thread.");

	{
		auto lock = Host::GetSettingsLock();
		if (!s_base_settings_interface->Save())
			Console.Error("Failed to save settings.");
	}

	s_settings_save_timer->deleteLater();
	s_settings_save_timer.release();
}

void QtHost::QueueSettingsSave()
{
	if (s_settings_save_timer)
		return;

	s_settings_save_timer = std::make_unique<QTimer>();
	s_settings_save_timer->connect(s_settings_save_timer.get(), &QTimer::timeout, SaveSettings);
	s_settings_save_timer->setSingleShot(true);
	s_settings_save_timer->start(SETTINGS_SAVE_DELAY);
}

void QtHost::RunOnUIThread(const std::function<void()>& func, bool block /*= false*/)
{
	// main window always exists, so it's fine to attach it to that.
	QMetaObject::invokeMethod(g_main_window, "runOnUIThread",
		block ? Qt::BlockingQueuedConnection : Qt::QueuedConnection,
		Q_ARG(const std::function<void()>&, func));
}

std::optional<std::vector<u8>> Host::ReadResourceFile(const char* filename)
{
	const std::string path(Path::CombineStdString(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::CombineStdString(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;
}

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());
	}

	QMetaObject::invokeMethod(g_main_window, "reportError", Qt::QueuedConnection,
		Q_ARG(const QString&, title.empty() ? QString() : QString::fromUtf8(title.data(), title.size())),
		Q_ARG(const QString&, message.empty() ? QString() : QString::fromUtf8(message.data(), message.size())));
}

void Host::OnInputDeviceConnected(const std::string_view& identifier, const std::string_view& device_name)
{
	emit g_emu_thread->onInputDeviceConnected(
		identifier.empty() ? QString() : QString::fromUtf8(identifier.data(), identifier.size()),
		device_name.empty() ? QString() : QString::fromUtf8(device_name.data(), device_name.size()));
}

void Host::OnInputDeviceDisconnected(const std::string_view& identifier)
{
	emit g_emu_thread->onInputDeviceDisconnected(
		identifier.empty() ? QString() : QString::fromUtf8(identifier.data(), identifier.size()));
}

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

const IConsoleWriter* PatchesCon = &Console;

void LoadAllPatchesAndStuff(const Pcsx2Config& cfg)
{
	// FIXME
}

void PatchesVerboseReset()
{
	// FIXME
}

static void SignalHandler(int signal)
{
	// First try the normal (graceful) shutdown/exit.
	static bool graceful_shutdown_attempted = false;
	if (!graceful_shutdown_attempted && g_main_window)
	{
		std::fprintf(stderr, "Received CTRL+C, attempting graceful shutdown. Press CTRL+C again to force.\n");
		graceful_shutdown_attempted = true;

		// This could be a bit risky invoking from a signal handler... hopefully it's okay.
		QMetaObject::invokeMethod(g_main_window, &MainWindow::requestExit, Qt::QueuedConnection);
		return;
	}

	std::signal(signal, SIG_DFL);

	// MacOS is missing std::quick_exit() despite it being C++11...
#ifndef __APPLE__
	std::quick_exit(1);
#else
	_Exit(1);
#endif
}

void QtHost::HookSignals()
{
	std::signal(SIGINT, SignalHandler);
	std::signal(SIGTERM, SignalHandler);
}

// Replacement for Console so we actually get output to our console window on Windows.
#ifdef _WIN32

static bool s_debugger_attached = false;
static bool s_console_handle_set = false;
static HANDLE s_console_handle = nullptr;

static void __concall ConsoleWinQt_SetTitle(const wxString& title)
{
	SetConsoleTitleW(title.wc_str());
}

static void __concall ConsoleWinQt_DoSetColor(ConsoleColors color)
{
	if (!s_console_handle)
		return;

	static constexpr WORD colors[ConsoleColors_Count] = {
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE, // default
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE, // black
		FOREGROUND_GREEN, // green
		FOREGROUND_RED, // red
		FOREGROUND_BLUE, // blue
		FOREGROUND_RED | FOREGROUND_BLUE, // magenta
		FOREGROUND_RED | FOREGROUND_GREEN, // orange
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE, // gray
		FOREGROUND_BLUE | FOREGROUND_INTENSITY, // cyan
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_INTENSITY, // yellow
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY, // white
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE, // strong black
		FOREGROUND_RED | FOREGROUND_INTENSITY, // strong red
		FOREGROUND_GREEN | FOREGROUND_INTENSITY, // strong green
		FOREGROUND_BLUE | FOREGROUND_INTENSITY, // strong blue
		FOREGROUND_RED | FOREGROUND_BLUE | FOREGROUND_INTENSITY, // strong magenta
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_INTENSITY, // strong orange
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE, // strong gray
		FOREGROUND_BLUE | FOREGROUND_INTENSITY, // strong cyan
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_INTENSITY, // strong yellow
		FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY, // strong white
	};

	SetConsoleTextAttribute(s_console_handle, colors[static_cast<u32>(color)]);
}

static void __concall ConsoleWinQt_Newline()
{
	if (!s_console_handle)
		return;

	if (s_debugger_attached)
		OutputDebugStringW(L"\n");

	DWORD written;
	WriteConsoleW(s_console_handle, L"\n", 1, &written, nullptr);
}

static void __concall ConsoleWinQt_DoWrite(const wxString& fmt)
{
	if (!s_console_handle)
		return;

	if (s_debugger_attached)
		OutputDebugStringW(fmt.wc_str());

	DWORD written;
	WriteConsoleW(s_console_handle, fmt.wc_str(), static_cast<DWORD>(fmt.size()), &written, nullptr);
}

static void __concall ConsoleWinQt_DoWriteLn(const wxString& fmt)
{
	if (!s_console_handle)
		return;

	if (s_debugger_attached)
	{
		OutputDebugStringW(fmt.wc_str());
		OutputDebugStringW(L"\n");
	}

	DWORD written;
	WriteConsoleW(s_console_handle, fmt.wc_str(), static_cast<DWORD>(fmt.size()), &written, nullptr);
	WriteConsoleW(s_console_handle, L"\n", 1, &written, nullptr);
}

static const IConsoleWriter ConsoleWriter_WinQt =
	{
		ConsoleWinQt_DoWrite,
		ConsoleWinQt_DoWriteLn,
		ConsoleWinQt_DoSetColor,

		ConsoleWinQt_DoWrite,
		ConsoleWinQt_Newline,
		ConsoleWinQt_SetTitle,
};

static BOOL WINAPI ConsoleCtrlHandler(DWORD dwCtrlType)
{
	Console.WriteLn("Handler %u", dwCtrlType);
	if (dwCtrlType != CTRL_C_EVENT)
		return FALSE;

	SignalHandler(SIGTERM);
	return TRUE;
}

#endif

void QtHost::UpdateLogging()
{
	// TODO: Make this an actual option.
	const bool system_console_enabled = QtHost::GetBaseBoolSettingValue("Logging", "EnableSystemConsole", false);

	const bool any_logging_sinks = system_console_enabled;
	DevConWriterEnabled = any_logging_sinks && QtHost::GetBaseBoolSettingValue("Logging", "EnableVerbose", false);
	SysConsole.eeConsole.Enabled = any_logging_sinks && QtHost::GetBaseBoolSettingValue("Logging", "EnableEEConsole", true);
	SysConsole.iopConsole.Enabled = any_logging_sinks && QtHost::GetBaseBoolSettingValue("Logging", "EnableIOPConsole", true);

#ifdef _WIN32
	if (system_console_enabled)
	{
		s_debugger_attached = IsDebuggerPresent();
		if (!s_console_handle_set)
		{
			bool handle_valid = (GetConsoleWindow() != NULL);
			if (!handle_valid)
			{
				AllocConsole();
				handle_valid = (freopen("CONIN$", "r", stdin) != nullptr);
				handle_valid = (freopen("CONOUT$", "w", stdout) != nullptr);
				handle_valid = (freopen("CONOUT$", "w", stderr) != nullptr);
			}

			if (handle_valid)
			{
				s_console_handle = GetStdHandle(STD_OUTPUT_HANDLE);
				s_console_handle_set = true;
			}
		}

		if (!s_console_handle && !s_debugger_attached)
		{
			Console_SetActiveHandler(ConsoleWriter_Null);
			SetConsoleCtrlHandler(ConsoleCtrlHandler, FALSE);
		}
		else
		{
			Console_SetActiveHandler(ConsoleWriter_WinQt);
			SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
		}
	}
	else
	{
		Console_SetActiveHandler(ConsoleWriter_Null);
		SetConsoleCtrlHandler(ConsoleCtrlHandler, FALSE);
	}
#else
	if (system_console_enabled)
	{
		Console_SetActiveHandler(ConsoleWriter_Stdout);
	}
	else
	{
		Console_SetActiveHandler(ConsoleWriter_Null);
	}
#endif
}

#include <wx/module.h>

#ifdef _WIN32
extern "C" HINSTANCE wxGetInstance();
extern void wxSetInstance(HINSTANCE hInst);
#endif

void QtHost::InitializeWxRubbish()
{
	wxLog::DoCreateOnDemand();
	wxLog::GetActiveTarget();

#ifdef _WIN32
	if (!wxGetInstance())
		wxSetInstance(::GetModuleHandle(NULL));
#endif // _WIN32

	wxModule::RegisterModules();
	wxModule::InitializeModules();
}