
#include <cstring>
#include <cassert>
#include <thread>
#include <atomic>
#include <vector>

#include "base/timeutil.h"
#include "Common/ChunkFile.h"
#include "Core/Config.h"
#include "Core/ConfigValues.h"
#include "Core/Core.h"
#include "Core/HLE/sceCtrl.h"
#include "Core/HLE/sceUtility.h"
#include "Core/HLE/__sceAudio.h"
#include "Core/HW/MemoryStick.h"
#include "Core/Host.h"
#include "Core/MemMap.h"
#include "Core/System.h"
#include "Log.h"
#include "LogManager.h"
#include "ConsoleListener.h"
#include "file/vfs.h"
#include "file/zip_read.h"
#include "GPU/GPUState.h"
#include "GPU/GPUInterface.h"
#include "GPU/Common/FramebufferCommon.h"
#include "GPU/Common/TextureScalerCommon.h"
#include "input/input_state.h"
#include "base/NativeApp.h"
#include "thread/threadutil.h"

#include "libretro/libretro.h"
#include "libretro/LibretroGraphicsContext.h"

#define DIR_SEP "/"
#ifdef _WIN32
#define DIR_SEP_CHRS "/\\"
#else
#define DIR_SEP_CHRS "/"
#endif

#define SAMPLERATE 44100

namespace Libretro {
LibretroGraphicsContext *ctx;
retro_environment_t environ_cb;
static retro_audio_sample_batch_t audio_batch_cb;
static retro_input_poll_t input_poll_cb;
static retro_input_state_t input_state_cb;
} // namespace Libretro

using namespace Libretro;

class LibretroHost : public Host {
public:
	LibretroHost() {}
	bool InitGraphics(std::string *error_message, GraphicsContext **ctx) override { return true; }
	void ShutdownGraphics() override {}
	void InitSound() override {}
	void UpdateSound() override {
		extern int hostAttemptBlockSize;
		const int blockSizeMax = 512;
		static int16_t audio[blockSizeMax * 2];
		assert(hostAttemptBlockSize <= blockSizeMax);

		int samples = __AudioMix(audio, hostAttemptBlockSize, SAMPLERATE);
		audio_batch_cb(audio, samples);
	}
	void ShutdownSound() override {}
	bool IsDebuggingEnabled() override { return false; }
	bool AttemptLoadSymbolMap() override { return false; }
};

class PrintfLogger : public LogListener {
public:
	PrintfLogger(retro_log_callback log) : log_(log.log) {}
	void Log(const LogMessage &message) {
		switch (message.level) {
		case LogTypes::LVERBOSE:
		case LogTypes::LDEBUG:
			log_(RETRO_LOG_DEBUG, "[%s] %s", message.log, message.msg.c_str());
			return;

		case LogTypes::LERROR:
			log_(RETRO_LOG_ERROR, "[%s] %s", message.log, message.msg.c_str());
			return;

		case LogTypes::LNOTICE:
		case LogTypes::LWARNING:
			log_(RETRO_LOG_WARN, "[%s] %s", message.log, message.msg.c_str());
			return;

		case LogTypes::LINFO:
		default:
			log_(RETRO_LOG_INFO, "[%s] %s", message.log, message.msg.c_str());
			return;
		}
	}

private:
	retro_log_printf_t log_;
};
static PrintfLogger *printfLogger;

template <typename T> class RetroOption {
public:
	RetroOption(const char *id, const char *name, std::initializer_list<std::pair<const char *, T>> list) : id_(id), name_(name), list_(list.begin(), list.end()) {}
	RetroOption(const char *id, const char *name, std::initializer_list<const char *> list) : id_(id), name_(name) {
		for (auto option : list)
			list_.push_back({ option, (T)list_.size() });
	}
	RetroOption(const char *id, const char *name, T first, std::initializer_list<const char *> list) : id_(id), name_(name) {
		for (auto option : list)
			list_.push_back({ option, first + (int)list_.size() });
	}
	RetroOption(const char *id, const char *name, T first, int count, int step = 1) : id_(id), name_(name) {
		for (T i = first; i < first + count; i += step)
			list_.push_back({ std::to_string(i), i });
	}
	RetroOption(const char *id, const char *name, bool initial) : id_(id), name_(name) {
		list_.push_back({ initial ? "enabled" : "disabled", initial });
		list_.push_back({ !initial ? "enabled" : "disabled", !initial });
	}
	retro_variable GetOptions() {
		if (options_.empty()) {
			options_ = name_;
			options_.push_back(';');
			for (auto &option : list_) {
				if (option.first == list_.begin()->first)
					options_ += std::string(" ") + option.first;
				else
					options_ += std::string("|") + option.first;
			}
		}
		return { id_, options_.c_str() };
	}
	bool Update(T *dest) {
		retro_variable var{ id_ };
		T val = list_.front().second;

		if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
			for (auto option : list_) {
				if (option.first == var.value) {
					val = option.second;
					break;
				}
			}
		}

		if (*dest != val) {
			*dest = val;
			return true;
		}

		return false;
	}

private:
	const char *id_;
	const char *name_;
	std::string options_;
	std::vector<std::pair<std::string, T>> list_;
};

static RetroOption<CPUCore> ppsspp_cpu_core("ppsspp_cpu_core", "CPU Core", { { "jit", CPUCore::JIT }, { "IR jit", CPUCore::IR_JIT }, { "interpreter", CPUCore::INTERPRETER } });
static RetroOption<int> ppsspp_locked_cpu_speed("ppsspp_locked_cpu_speed", "Locked CPU Speed", { { "off", 0 }, { "222MHz", 222 }, { "266MHz", 266 }, { "333MHz", 333 } });
static RetroOption<int> ppsspp_language("ppsspp_language", "Language", { { "automatic", -1 }, { "english", PSP_SYSTEMPARAM_LANGUAGE_ENGLISH }, { "japanese", PSP_SYSTEMPARAM_LANGUAGE_JAPANESE }, { "french", PSP_SYSTEMPARAM_LANGUAGE_FRENCH }, { "spanish", PSP_SYSTEMPARAM_LANGUAGE_SPANISH }, { "german", PSP_SYSTEMPARAM_LANGUAGE_GERMAN }, { "italian", PSP_SYSTEMPARAM_LANGUAGE_ITALIAN }, { "dutch", PSP_SYSTEMPARAM_LANGUAGE_DUTCH }, { "portuguese", PSP_SYSTEMPARAM_LANGUAGE_PORTUGUESE }, { "russian", PSP_SYSTEMPARAM_LANGUAGE_RUSSIAN }, { "korean", PSP_SYSTEMPARAM_LANGUAGE_KOREAN }, { "chinese_traditional", PSP_SYSTEMPARAM_LANGUAGE_CHINESE_TRADITIONAL }, { "chinese_simplified", PSP_SYSTEMPARAM_LANGUAGE_CHINESE_SIMPLIFIED } });
static RetroOption<int> ppsspp_rendering_mode("ppsspp_rendering_mode", "Rendering Mode", { { "buffered", FB_BUFFERED_MODE }, { "nonbuffered", FB_NON_BUFFERED_MODE } });
static RetroOption<bool> ppsspp_auto_frameskip("ppsspp_auto_frameskip", "Auto Frameskip", false);
static RetroOption<int> ppsspp_frameskip("ppsspp_frameskip", "Frameskip", 0, 10);
static RetroOption<int> ppsspp_frameskiptype("ppsspp_frameskiptype", "Frameskip Type", 0, 10);
static RetroOption<int> ppsspp_audio_latency("ppsspp_audio_latency", "Audio latency", { "low", "medium", "high" });
static RetroOption<int> ppsspp_internal_resolution("ppsspp_internal_resolution", "Internal Resolution (restart)", 1, { "480x272", "960x544", "1440x816", "1920x1088", "2400x1360", "2880x1632", "3360x1904", "3840x2176", "4320x2448", "4800x2720" });
static RetroOption<int> ppsspp_button_preference("ppsspp_button_preference", "Confirmation Button", { { "cross", PSP_SYSTEMPARAM_BUTTON_CROSS }, { "circle", PSP_SYSTEMPARAM_BUTTON_CIRCLE } });
static RetroOption<bool> ppsspp_fast_memory("ppsspp_fast_memory", "Fast Memory (Speedhack)", true);
static RetroOption<bool> ppsspp_block_transfer_gpu("ppsspp_block_transfer_gpu", "Block Transfer GPU", true);
static RetroOption<int> ppsspp_texture_scaling_level("ppsspp_texture_scaling_level", "Texture Scaling Level", { { "1", 1 }, { "2", 2 }, { "3", 3 }, { "4", 4 }, { "5", 5 }, { "0", 0 } });
static RetroOption<int> ppsspp_texture_scaling_type("ppsspp_texture_scaling_type", "Texture Scaling Type", { { "xbrz", TextureScalerCommon::XBRZ }, { "hybrid", TextureScalerCommon::HYBRID }, { "bicubic", TextureScalerCommon::BICUBIC }, { "hybrid_bicubic", TextureScalerCommon::HYBRID_BICUBIC } });
static RetroOption<int> ppsspp_texture_filtering("ppsspp_texture_filtering", "Texture Filtering", { { "auto", 1 }, { "nearest", 2 }, { "linear", 3 }, { "linear(FMV)", 4 } });
static RetroOption<int> ppsspp_texture_anisotropic_filtering("ppsspp_texture_anisotropic_filtering", "Anisotropic Filtering", { "off", "1x", "2x", "4x", "8x", "16x" });
static RetroOption<bool> ppsspp_texture_deposterize("ppsspp_texture_deposterize", "Texture Deposterize", false);
static RetroOption<bool> ppsspp_texture_replacement("ppsspp_texture_replacement", "Texture Replacement", false);
static RetroOption<bool> ppsspp_gpu_hardware_transform("ppsspp_gpu_hardware_transform", "GPU Hardware T&L", true);
static RetroOption<bool> ppsspp_vertex_cache("ppsspp_vertex_cache", "Vertex Cache (Speedhack)", true);
static RetroOption<bool> ppsspp_unsafe_func_replacements("ppsspp_unsafe_func_replacements", "Unsafe FuncReplacements", true);
static RetroOption<bool> ppsspp_cheats("ppsspp_cheats", "Internal Cheats Support", false);
static RetroOption<IOTimingMethods> ppsspp_io_timing_method("ppsspp_io_timing_method", "IO Timing Method", { { "Fast", IOTimingMethods::IOTIMING_FAST }, { "Host", IOTimingMethods::IOTIMING_HOST }, { "Simulate UMD delays", IOTimingMethods::IOTIMING_REALISTIC } });

void retro_set_environment(retro_environment_t cb) {
	std::vector<retro_variable> vars;
	vars.push_back(ppsspp_cpu_core.GetOptions());
	vars.push_back(ppsspp_locked_cpu_speed.GetOptions());
	vars.push_back(ppsspp_language.GetOptions());
	vars.push_back(ppsspp_rendering_mode.GetOptions());
	vars.push_back(ppsspp_auto_frameskip.GetOptions());
	vars.push_back(ppsspp_frameskip.GetOptions());
	vars.push_back(ppsspp_frameskiptype.GetOptions());
	vars.push_back(ppsspp_audio_latency.GetOptions());
	vars.push_back(ppsspp_internal_resolution.GetOptions());
	vars.push_back(ppsspp_button_preference.GetOptions());
	vars.push_back(ppsspp_fast_memory.GetOptions());
	vars.push_back(ppsspp_block_transfer_gpu.GetOptions());
	vars.push_back(ppsspp_texture_scaling_level.GetOptions());
	vars.push_back(ppsspp_texture_scaling_type.GetOptions());
	vars.push_back(ppsspp_texture_filtering.GetOptions());
	vars.push_back(ppsspp_texture_anisotropic_filtering.GetOptions());
	vars.push_back(ppsspp_texture_deposterize.GetOptions());
	vars.push_back(ppsspp_texture_replacement.GetOptions());
	vars.push_back(ppsspp_gpu_hardware_transform.GetOptions());
	vars.push_back(ppsspp_vertex_cache.GetOptions());
	vars.push_back(ppsspp_unsafe_func_replacements.GetOptions());
	vars.push_back(ppsspp_cheats.GetOptions());
	vars.push_back(ppsspp_io_timing_method.GetOptions());
	vars.push_back({});

	environ_cb = cb;

	cb(RETRO_ENVIRONMENT_SET_VARIABLES, (void *)vars.data());
}

static int get_language_auto(void) {
	retro_language val = RETRO_LANGUAGE_ENGLISH;
	environ_cb(RETRO_ENVIRONMENT_GET_LANGUAGE, &val);

	switch (val) {
	default:
	case RETRO_LANGUAGE_ENGLISH:
		return PSP_SYSTEMPARAM_LANGUAGE_ENGLISH;
	case RETRO_LANGUAGE_JAPANESE:
		return PSP_SYSTEMPARAM_LANGUAGE_JAPANESE;
	case RETRO_LANGUAGE_FRENCH:
		return PSP_SYSTEMPARAM_LANGUAGE_FRENCH;
	case RETRO_LANGUAGE_GERMAN:
		return PSP_SYSTEMPARAM_LANGUAGE_GERMAN;
	case RETRO_LANGUAGE_SPANISH:
		return PSP_SYSTEMPARAM_LANGUAGE_SPANISH;
	case RETRO_LANGUAGE_ITALIAN:
		return PSP_SYSTEMPARAM_LANGUAGE_ITALIAN;
	case RETRO_LANGUAGE_PORTUGUESE_BRAZIL:
	case RETRO_LANGUAGE_PORTUGUESE_PORTUGAL:
		return PSP_SYSTEMPARAM_LANGUAGE_PORTUGUESE;
	case RETRO_LANGUAGE_RUSSIAN:
		return PSP_SYSTEMPARAM_LANGUAGE_RUSSIAN;
	case RETRO_LANGUAGE_DUTCH:
		return PSP_SYSTEMPARAM_LANGUAGE_DUTCH;
	case RETRO_LANGUAGE_KOREAN:
		return PSP_SYSTEMPARAM_LANGUAGE_KOREAN;
	case RETRO_LANGUAGE_CHINESE_TRADITIONAL:
		return PSP_SYSTEMPARAM_LANGUAGE_CHINESE_TRADITIONAL;
	case RETRO_LANGUAGE_CHINESE_SIMPLIFIED:
		return PSP_SYSTEMPARAM_LANGUAGE_CHINESE_SIMPLIFIED;
	}
}

static void check_variables(CoreParameter &coreParam) {
	bool updated = false;

	if (coreState != CORE_POWERUP && environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) && !updated)
		return;

	ppsspp_button_preference.Update(&g_Config.iButtonPreference);
	ppsspp_fast_memory.Update(&g_Config.bFastMemory);
	ppsspp_vertex_cache.Update(&g_Config.bVertexCache);
	ppsspp_gpu_hardware_transform.Update(&g_Config.bHardwareTransform);
	ppsspp_frameskip.Update(&g_Config.iFrameSkip);
	ppsspp_frameskiptype.Update(&g_Config.iFrameSkipType);
	ppsspp_audio_latency.Update(&g_Config.iAudioLatency);
	ppsspp_auto_frameskip.Update(&g_Config.bAutoFrameSkip);
	ppsspp_block_transfer_gpu.Update(&g_Config.bBlockTransferGPU);
	ppsspp_texture_filtering.Update(&g_Config.iTexFiltering);
	ppsspp_texture_anisotropic_filtering.Update(&g_Config.iAnisotropyLevel);
	ppsspp_texture_deposterize.Update(&g_Config.bTexDeposterize);
	ppsspp_texture_replacement.Update(&g_Config.bReplaceTextures);
	ppsspp_unsafe_func_replacements.Update(&g_Config.bFuncReplacements);
	ppsspp_cheats.Update(&g_Config.bEnableCheats);
	ppsspp_locked_cpu_speed.Update(&g_Config.iLockedCPUSpeed);
	ppsspp_rendering_mode.Update(&g_Config.iRenderingMode);
	ppsspp_cpu_core.Update((CPUCore *)&g_Config.iCpuCore);
	ppsspp_io_timing_method.Update((IOTimingMethods *)&g_Config.iIOTimingMethod);

	ppsspp_language.Update(&g_Config.iLanguage);
	if (g_Config.iLanguage < 0) {
		g_Config.iLanguage = get_language_auto();
	}

	if (!PSP_IsInited() && ppsspp_internal_resolution.Update(&g_Config.iInternalResolution)) {
		coreParam.pixelWidth = coreParam.renderWidth = g_Config.iInternalResolution * 480;
		coreParam.pixelHeight = coreParam.renderHeight = g_Config.iInternalResolution * 272;
		if (gpu) {
			retro_system_av_info av_info;
			retro_get_system_av_info(&av_info);
			environ_cb(RETRO_ENVIRONMENT_SET_SYSTEM_AV_INFO, &av_info);
			gpu->Resized();
		}
	}

	if (ppsspp_texture_scaling_type.Update(&g_Config.iTexScalingType) && gpu) {
		gpu->ClearCacheNextFrame();
	}

	if (ppsspp_texture_scaling_level.Update(&g_Config.iTexScalingLevel) && gpu) {
		gpu->ClearCacheNextFrame();
	}
}

void retro_set_audio_sample_batch(retro_audio_sample_batch_t cb) { audio_batch_cb = cb; }
void retro_set_audio_sample(retro_audio_sample_t cb) { (void)cb; }
void retro_set_input_poll(retro_input_poll_t cb) { input_poll_cb = cb; }
void retro_set_input_state(retro_input_state_t cb) { input_state_cb = cb; }

void retro_init(void) {
#if 0
	g_Config.Load("");
#endif

	g_Config.bEnableLogging = true;
	g_Config.bFrameSkipUnthrottle = false;
	g_Config.bMemStickInserted = PSP_MEMORYSTICK_STATE_INSERTED;
	g_Config.iGlobalVolume = VOLUME_MAX - 1;
	g_Config.iAltSpeedVolume = -1;
	g_Config.bEnableSound = true;
	g_Config.bAudioResampler = false;
	g_Config.iCwCheatRefreshRate = 60;
	
	g_Config.iFirmwareVersion = PSP_DEFAULT_FIRMWARE;
	g_Config.iPSPModel = PSP_MODEL_SLIM;
	
	LogManager::Init();

	host = new LibretroHost;

	struct retro_log_callback log;
	if (environ_cb(RETRO_ENVIRONMENT_GET_LOG_INTERFACE, &log)) {
		printfLogger = new PrintfLogger(log);
		LogManager *logman = LogManager::GetInstance();
		logman->RemoveListener(logman->GetConsoleListener());
		logman->RemoveListener(logman->GetDebuggerListener());
		logman->ChangeFileLog(nullptr);
		logman->AddListener(printfLogger);
#if 1
		logman->SetAllLogLevels(LogTypes::LINFO);
#endif
	}
}

void retro_deinit(void) {
	LogManager::Shutdown();

	delete printfLogger;
	printfLogger = nullptr;

	delete host;
	host = nullptr;
}

void retro_set_controller_port_device(unsigned port, unsigned device) {
	(void)port;
	(void)device;
}

void retro_get_system_info(struct retro_system_info *info) {
	*info = {};
	info->library_name = "PPSSPP";
	info->library_version = PPSSPP_GIT_VERSION;
	info->need_fullpath = true;
	info->valid_extensions = "elf|iso|cso|prx|pbp";
}

void retro_get_system_av_info(struct retro_system_av_info *info) {
	*info = {};
	info->timing.fps = 60.0f / 1.001f;
	info->timing.sample_rate = SAMPLERATE;

	info->geometry.base_width = g_Config.iInternalResolution * 480;
	info->geometry.base_height = g_Config.iInternalResolution * 272;
	info->geometry.max_width = g_Config.iInternalResolution * 480;
	info->geometry.max_height = g_Config.iInternalResolution * 272;
	info->geometry.aspect_ratio = 16.0 / 9.0;
}

unsigned retro_api_version(void) { return RETRO_API_VERSION; }
namespace Libretro {

bool useEmuThread = false;
std::atomic<EmuThreadState> emuThreadState(EmuThreadState::DISABLED);

static std::thread emuThread;
static void EmuFrame() {
	ctx->SetRenderTarget();
	if (ctx->GetDrawContext()) {
		ctx->GetDrawContext()->BeginFrame();
	}

	gpu->BeginHostFrame();

	coreState = CORE_RUNNING;
	PSP_RunLoopUntil(UINT64_MAX);

	gpu->EndHostFrame();

	if (ctx->GetDrawContext()) {
		ctx->GetDrawContext()->EndFrame();
	}
}

static void EmuThreadFunc() {
	setCurrentThreadName("Emu");

	while (true) {
		switch ((EmuThreadState)emuThreadState) {
		case EmuThreadState::START_REQUESTED:
			emuThreadState = EmuThreadState::RUNNING;
			/* fallthrough */
		case EmuThreadState::RUNNING:
			EmuFrame();
			break;
		case EmuThreadState::PAUSE_REQUESTED:
			emuThreadState = EmuThreadState::PAUSED;
			/* fallthrough */
		case EmuThreadState::PAUSED:
			sleep_ms(1);
			break;
		default:
		case EmuThreadState::QUIT_REQUESTED:
			emuThreadState = EmuThreadState::STOPPED;
			ctx->StopThread();
			return;
		}
	}
}

void EmuThreadStart() {
	bool wasPaused = emuThreadState == EmuThreadState::PAUSED;
	emuThreadState = EmuThreadState::START_REQUESTED;

	if (!wasPaused) {
		ctx->ThreadStart();
		emuThread = std::thread(&EmuThreadFunc);
	}
}

void EmuThreadStop() {
	if (emuThreadState != EmuThreadState::RUNNING) {
		return;
	}

	emuThreadState = EmuThreadState::QUIT_REQUESTED;

	while (ctx->ThreadFrame()) {
		// Need to keep eating frames to allow the EmuThread to exit correctly.
		continue;
	}

	emuThread.join();
	emuThread = std::thread();
	ctx->ThreadEnd();
}

void EmuThreadPause() {
	if (emuThreadState != EmuThreadState::RUNNING) {
		return;
	}

	emuThreadState = EmuThreadState::PAUSE_REQUESTED;

	ctx->ThreadFrame(); // Eat 1 frame

	while (emuThreadState != EmuThreadState::PAUSED) {
		sleep_ms(1);
	}
}

} // namespace Libretro

bool retro_load_game(const struct retro_game_info *game) {
	struct retro_input_descriptor desc[] = {
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT, "D-Pad Left" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP, "D-Pad Up" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN, "D-Pad Down" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "D-Pad Right" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B, "Cross" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A, "Circle" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_X, "Triangle" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_Y, "Square" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L, "L" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R, "R" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT, "Select" },
		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START, "Start" },
		{ 0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_X, "Right Analog X" },
		{ 0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_Y, "Right Analog Y" },
		{ 0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_X, "Left Analog X" },
		{ 0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_Y, "Left Analog Y" },
		{ 0 },
	};
	environ_cb(RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS, desc);

	enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_XRGB8888;
	if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt)) {
		ERROR_LOG(SYSTEM, "XRGB8888 is not supported.\n");
		return false;
	}

	const char *nickname = NULL;
	if (environ_cb(RETRO_ENVIRONMENT_GET_USERNAME, &nickname) && nickname) {
		g_Config.sNickName = std::string(nickname);
	}

	const char *dir_ptr = NULL;
	static std::string retro_base_dir;
	static std::string retro_save_dir;

	if (environ_cb(RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY, &dir_ptr) && dir_ptr) {
		retro_base_dir = dir_ptr;
		// Make sure that we don't have any lingering slashes, etc, as they break Windows.
		size_t last = retro_base_dir.find_last_not_of(DIR_SEP_CHRS);
		if (last != std::string::npos)
			last++;

		retro_base_dir = retro_base_dir.substr(0, last) + DIR_SEP;
	}

	if (environ_cb(RETRO_ENVIRONMENT_GET_SAVE_DIRECTORY, &dir_ptr) && dir_ptr) {
		retro_save_dir = dir_ptr;
		// Make sure that we don't have any lingering slashes, etc, as they break Windows.
		size_t last = retro_save_dir.find_last_not_of(DIR_SEP_CHRS);
		if (last != std::string::npos)
			last++;

		retro_save_dir = retro_save_dir.substr(0, last) + DIR_SEP;
	}

	if (retro_base_dir.empty()) {
		retro_base_dir = File::GetDir(game->path);
	}

	retro_base_dir += "PPSSPP" DIR_SEP;

	if (retro_save_dir.empty()) {
		retro_save_dir = File::GetDir(game->path);
	}

	g_Config.currentDirectory = retro_base_dir;
	g_Config.externalDirectory = retro_base_dir;
	g_Config.memStickDirectory = retro_save_dir;
	g_Config.flash0Directory = retro_base_dir + "flash0" DIR_SEP;
	g_Config.internalDataDirectory = retro_base_dir;

	VFSRegister("", new DirectoryAssetReader(retro_base_dir.c_str()));

	coreState = CORE_POWERUP;
	ctx = LibretroGraphicsContext::CreateGraphicsContext();
	INFO_LOG(SYSTEM, "Using %s backend", ctx->Ident());

	Core_SetGraphicsContext(ctx);
	SetGPUBackend((GPUBackend)g_Config.iGPUBackend);

	useEmuThread = ctx->GetGPUCore() == GPUCORE_GLES;

	CoreParameter coreParam = {};
	coreParam.enableSound = true;
	coreParam.fileToStart = std::string(game->path);
	coreParam.mountIso = "";
	coreParam.startBreak = false;
	coreParam.printfEmuLog = true;
	coreParam.headLess = true;
	coreParam.unthrottle = true;
	coreParam.graphicsContext = ctx;
	coreParam.gpuCore = ctx->GetGPUCore();
	coreParam.cpuCore = CPUCore::JIT;
	check_variables(coreParam);

#if 0
	g_Config.bVertexDecoderJit = (coreParam.cpuCore == CPU_JIT) ? true : false;
#endif

	std::string error_string;
	if (!PSP_InitStart(coreParam, &error_string)) {
		ERROR_LOG(BOOT, "%s", error_string.c_str());
		return false;
	}

	return true;
}

void retro_unload_game(void) {
	if (Libretro::useEmuThread) {
		Libretro::EmuThreadStop();
	}

	PSP_Shutdown();
	VFSShutdown();

	delete ctx;
	ctx = nullptr;
	PSP_CoreParameter().graphicsContext = nullptr;
}

void retro_reset(void) {
	std::string error_string;

	PSP_Shutdown();

#if 0
	coreState = CORE_POWERUP;
	if (!PSP_InitStart(PSP_CoreParameter(), &error_string))
	{
		ERROR_LOG(BOOT, "%s", error_string.c_str());
		environ_cb(RETRO_ENVIRONMENT_SHUTDOWN, nullptr);
	}
#else
	if (!PSP_Init(PSP_CoreParameter(), &error_string)) {
		ERROR_LOG(BOOT, "%s", error_string.c_str());
		environ_cb(RETRO_ENVIRONMENT_SHUTDOWN, nullptr);
	}
#endif
}

static void retro_input(void) {
	// clang-format off
	static struct
	{
		u32 retro;
		u32 sceCtrl;
	} map[] = {
		{ RETRO_DEVICE_ID_JOYPAD_UP,     CTRL_UP },
		{ RETRO_DEVICE_ID_JOYPAD_DOWN,   CTRL_DOWN },
		{ RETRO_DEVICE_ID_JOYPAD_LEFT,   CTRL_LEFT },
		{ RETRO_DEVICE_ID_JOYPAD_RIGHT,  CTRL_RIGHT },
		{ RETRO_DEVICE_ID_JOYPAD_X,      CTRL_TRIANGLE },
		{ RETRO_DEVICE_ID_JOYPAD_A,      CTRL_CIRCLE },
		{ RETRO_DEVICE_ID_JOYPAD_B,      CTRL_CROSS },
		{ RETRO_DEVICE_ID_JOYPAD_Y,      CTRL_SQUARE },
		{ RETRO_DEVICE_ID_JOYPAD_L,      CTRL_LTRIGGER },
		{ RETRO_DEVICE_ID_JOYPAD_R,      CTRL_RTRIGGER },
		{ RETRO_DEVICE_ID_JOYPAD_START,  CTRL_START },
		{ RETRO_DEVICE_ID_JOYPAD_SELECT, CTRL_SELECT },
	};
	// clang-format on

	input_poll_cb();

	for (int i = 0; i < sizeof(map) / sizeof(*map); i++) {
		if (input_state_cb(0, RETRO_DEVICE_JOYPAD, 0, map[i].retro)) {
			__CtrlButtonDown(map[i].sceCtrl);
		} else {
			__CtrlButtonUp(map[i].sceCtrl);
		}
	}

	__CtrlSetAnalogX(input_state_cb(0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_X) / 32768.0f, CTRL_STICK_LEFT);
	__CtrlSetAnalogY(input_state_cb(0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_LEFT, RETRO_DEVICE_ID_ANALOG_Y) / -32768.0f, CTRL_STICK_LEFT);
	__CtrlSetAnalogX(input_state_cb(0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_X) / 32768.0f, CTRL_STICK_RIGHT);
	__CtrlSetAnalogY(input_state_cb(0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT, RETRO_DEVICE_ID_ANALOG_Y) / -32768.0f, CTRL_STICK_RIGHT);
}

void retro_run(void) {
	if (PSP_IsIniting()) {
		std::string error_string;
#if 0
		if (!PSP_InitUpdate(&error_string))
		{
			graphics_context->SwapBuffers();
			return;
		}
#else
		while (!PSP_InitUpdate(&error_string)) {
			sleep_ms(4);
		}
#endif

		if (!PSP_IsInited()) {
			ERROR_LOG(BOOT, "%s", error_string.c_str());
			environ_cb(RETRO_ENVIRONMENT_SHUTDOWN, nullptr);
			return;
		}
	}

	check_variables(PSP_CoreParameter());

	retro_input();

	if (useEmuThread) {
		if(emuThreadState == EmuThreadState::PAUSED || emuThreadState == EmuThreadState::PAUSE_REQUESTED) {
			ctx->SwapBuffers();
			return;
		}

		if (emuThreadState != EmuThreadState::RUNNING) {
			EmuThreadStart();
		}

		if (!ctx->ThreadFrame()) {
			return;
		}
	} else {
		EmuFrame();
	}

	ctx->SwapBuffers();
}

unsigned retro_get_region(void) { return RETRO_REGION_NTSC; }

bool retro_load_game_special(unsigned type, const struct retro_game_info *info, size_t num) {
	(void)type;
	(void)info;
	(void)num;
	return false;
}

namespace SaveState {
struct SaveStart {
	void DoState(PointerWrap &p);
};
} // namespace SaveState

size_t retro_serialize_size(void) {
	// TODO: Libretro API extension to use the savestate queue
	if (useEmuThread) {
		EmuThreadPause();
	}

	SaveState::SaveStart state;
	return (CChunkFileReader::MeasurePtr(state) + 0x800000) & ~0x7FFFFF; // We don't unpause intentionally
}

bool retro_serialize(void *data, size_t size) {
	// TODO: Libretro API extension to use the savestate queue
	if (useEmuThread) {
		EmuThreadPause(); // Does nothing if already paused
	}
	
	SaveState::SaveStart state;
	assert(CChunkFileReader::MeasurePtr(state) <= size);
	bool retVal = CChunkFileReader::SavePtr((u8 *)data, state) == CChunkFileReader::ERROR_NONE;

	if (useEmuThread) {
		EmuThreadStart();
		sleep_ms(4);
	}
	
	return retVal;
}

bool retro_unserialize(const void *data, size_t size) {
	// TODO: Libretro API extension to use the savestate queue
	if (useEmuThread) {
		EmuThreadPause(); // Does nothing if already paused
	}

	SaveState::SaveStart state;
	bool retVal = CChunkFileReader::LoadPtr((u8 *)data, state) == CChunkFileReader::ERROR_NONE;

	if (useEmuThread) {
		EmuThreadStart();
		sleep_ms(4);
	}

	return retVal;
}

void *retro_get_memory_data(unsigned id) {
	if ( id == RETRO_MEMORY_SYSTEM_RAM ) {
		return Memory::GetPointerUnchecked(PSP_GetKernelMemoryBase()) ;
	}
	return NULL;
}

size_t retro_get_memory_size(unsigned id) {
	if ( id == RETRO_MEMORY_SYSTEM_RAM ) {
		return Memory::g_MemorySize ;
	}
	return 0;
}

void retro_cheat_reset(void) {}

void retro_cheat_set(unsigned index, bool enabled, const char *code) {
	(void)index;
	(void)enabled;
	(void)code;
}

int System_GetPropertyInt(SystemProperty prop) {
	switch (prop) {
	case SYSPROP_AUDIO_SAMPLE_RATE:
		return SAMPLERATE;
	case SYSPROP_DISPLAY_REFRESH_RATE:
		return 60000;
	default:
		return -1;
	}
}

std::string System_GetProperty(SystemProperty prop) { return ""; }
void System_SendMessage(const char *command, const char *parameter) {}
void NativeUpdate() {}
void NativeRender(GraphicsContext *graphicsContext) {}
void NativeResized() {}
bool System_InputBoxGetWString(const wchar_t *title, const std::wstring &defaultvalue, std::wstring &outvalue) { return false; }
