// Copyright 2009 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include "LogManager.h"

#include <algorithm>
#include <cstdarg>
#include <cstring>
#include <locale>
#include <mutex>
#include <ostream>
#include <string>
#include <fstream>

#include "ConsoleListener.h"
#include "Log.h"
#include "StringUtil.h"
#include "cfg/cfg.h"
#include "oslib/oslib.h"

constexpr size_t MAX_MSGLEN = 1024;

template <typename T>
void OpenFStream(T& fstream, const std::string& filename, std::ios_base::openmode openmode)
{
#ifdef _WIN32
	fstream.open(UTF8ToTStr(filename).c_str(), openmode);
#else
	fstream.open(filename.c_str(), openmode);
#endif
}

class FileLogListener : public LogListener
{
public:
	FileLogListener(const std::string& filename)
	{
		OpenFStream(m_logfile, filename, std::ios::app);
		SetEnable(true);
	}

	void Log(LogTypes::LOG_LEVELS, const char* msg) override
	{
		if (!IsEnabled() || !IsValid())
			return;

		std::lock_guard<std::mutex> lk(m_log_lock);
		m_logfile << msg << std::flush;
	}

	bool IsValid() const { return m_logfile.good(); }
	bool IsEnabled() const { return m_enable; }
	void SetEnable(bool enable) { m_enable = enable; }

private:
	std::mutex m_log_lock;
	std::ofstream m_logfile;
	bool m_enable;
};

void GenericLog(LogTypes::LOG_LEVELS level, LogTypes::LOG_TYPE type, const char* file, int line,
		const char* fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	if (LogManager::GetInstance())
		LogManager::GetInstance()->Log(level, type, file, line, fmt, args);
	va_end(args);
}

static size_t DeterminePathCutOffPoint()
{
	constexpr const char* pattern = "/core/";
#ifdef _WIN32
	constexpr const char* pattern2 = "\\core\\";
#endif
	std::string path = __FILE__;
	std::transform(path.begin(), path.end(), path.begin(),
			[](char c) { return std::tolower(c, std::locale::classic()); });
	size_t pos = path.find(pattern);
#ifdef _WIN32
	if (pos == std::string::npos)
		pos = path.find(pattern2);
#endif
	if (pos != std::string::npos)
		return pos + strlen(pattern);
	return 0;
}

LogManager::LogManager()
{
	// create log containers
	m_log[LogTypes::AICA] = {"AICA", "AICA Audio Emulation"};
	m_log[LogTypes::AICA_ARM] = {"AICA_ARM", "AICA ARM Emulation"};
	m_log[LogTypes::AUDIO] = {"AUDIO", "Audio Ouput Interface"};
	m_log[LogTypes::BOOT] = {"BOOT", "Boot"};
	m_log[LogTypes::COMMON] = {"COMMON", "Common"};
	m_log[LogTypes::DYNAREC] = {"DYNAREC", "Dynamic Recompiler"};
	m_log[LogTypes::FLASHROM] = {"FLASHROM", "FlashROM / EEPROM"};
	m_log[LogTypes::GDROM] = {"GDROM", "GD-Rom Drive"};
	m_log[LogTypes::HOLLY] = {"HOLLY", "Holly Chipset"};
	m_log[LogTypes::INPUT] = {"INPUT", "Input Peripherals"};
	m_log[LogTypes::JVS] = {"JVS", "Naomi JVS Protocol"};
	m_log[LogTypes::MAPLE] = {"MAPLE", "Maple Bus and Peripherals"};
	m_log[LogTypes::INTERPRETER] = {"INTERPRETER", "SH4 Interpreter"};
	m_log[LogTypes::MEMORY] = {"MEMORY", "Memory Management"};
	m_log[LogTypes::VMEM] = {"VMEM", "Virtual Memory Management"};
	m_log[LogTypes::MODEM] = {"MODEM", "Modem and Network"};
	m_log[LogTypes::NAOMI] = {"NAOMI", "Naomi"};
	m_log[LogTypes::PVR] = {"PVR", "PowerVR GPU"};
	m_log[LogTypes::REIOS] = {"REIOS", "HLE BIOS"};
	m_log[LogTypes::RENDERER] = {"RENDERER", "OpenGL Renderer"};
	m_log[LogTypes::SAVESTATE] = {"SAVESTATE", "Save States"};
	m_log[LogTypes::SH4] = {"SH4", "SH4 Modules"};

	RegisterListener(LogListener::FILE_LISTENER, new FileLogListener("flycast.log"));
	RegisterListener(LogListener::CONSOLE_LISTENER, new ConsoleListener());

	// Set up log listeners
	int verbosity = cfgLoadInt("log", "Verbosity", LogTypes::LDEBUG);

	// Ensure the verbosity level is valid
	if (verbosity < 1)
		verbosity = 1;
	if (verbosity > MAX_LOGLEVEL)
		verbosity = MAX_LOGLEVEL;

	SetLogLevel(static_cast<LogTypes::LOG_LEVELS>(verbosity));
	EnableListener(LogListener::FILE_LISTENER, cfgLoadBool("log", "LogToFile", false));
	EnableListener(LogListener::CONSOLE_LISTENER, cfgLoadBool("log", "LogToConsole", true));
	//  EnableListener(LogListener::LOG_WINDOW_LISTENER, Config::Get(LOGGER_WRITE_TO_WINDOW));

	for (LogContainer& container : m_log)
	{
		container.m_enable = cfgLoadBool("log", container.m_short_name, true);
	}

	m_path_cutoff_point = DeterminePathCutOffPoint();
}

LogManager::~LogManager()
{
	// The log window listener pointer is owned by the GUI code.
	delete m_listeners[LogListener::CONSOLE_LISTENER];
	delete m_listeners[LogListener::FILE_LISTENER];
}

// Return the current time formatted as Minutes:Seconds:Milliseconds
// in the form 00:00:000.
static std::string GetTimeFormatted()
{
	double now = os_GetSeconds();
	u32 minutes = (u32)now / 60;
	u32 seconds = (u32)now % 60;
	u32 ms = (now - (u32)now) * 1000;
	return StringFromFormat("%02d:%02d:%03d", minutes, seconds, ms);
}

void LogManager::Log(LogTypes::LOG_LEVELS level, LogTypes::LOG_TYPE type, const char* file,
		int line, const char* format, va_list args)
{
	return LogWithFullPath(level, type, file + m_path_cutoff_point, line, format, args);
}

void LogManager::LogWithFullPath(LogTypes::LOG_LEVELS level, LogTypes::LOG_TYPE type,
		const char* file, int line, const char* format, va_list args)
{
	if (!IsEnabled(type, level) || !static_cast<bool>(m_listener_ids))
		return;

	char temp[MAX_MSGLEN];
	CharArrayFromFormatV(temp, MAX_MSGLEN, format, args);

	std::string msg =
			StringFromFormat("%s %s:%u %c[%s]: %s\n", GetTimeFormatted().c_str(), file,
					line, LogTypes::LOG_LEVEL_TO_CHAR[(int)level], GetShortName(type), temp);

	for (auto listener_id : m_listener_ids)
		if (m_listeners[listener_id])
			m_listeners[listener_id]->Log(level, msg.c_str());
}

LogTypes::LOG_LEVELS LogManager::GetLogLevel() const
{
	return m_level;
}

void LogManager::SetLogLevel(LogTypes::LOG_LEVELS level)
{
	m_level = level;
}

void LogManager::SetEnable(LogTypes::LOG_TYPE type, bool enable)
{
	m_log[type].m_enable = enable;
}

bool LogManager::IsEnabled(LogTypes::LOG_TYPE type, LogTypes::LOG_LEVELS level) const
{
	return m_log[type].m_enable && GetLogLevel() >= level;
}

const char* LogManager::GetShortName(LogTypes::LOG_TYPE type) const
{
	return m_log[type].m_short_name;
}

const char* LogManager::GetFullName(LogTypes::LOG_TYPE type) const
{
	return m_log[type].m_full_name;
}

void LogManager::RegisterListener(LogListener::LISTENER id, LogListener* listener)
{
	m_listeners[id] = listener;
}

void LogManager::EnableListener(LogListener::LISTENER id, bool enable)
{
	m_listener_ids[id] = enable;
}

bool LogManager::IsListenerEnabled(LogListener::LISTENER id) const
{
	return m_listener_ids[id];
}

// Singleton. Ugh.
static LogManager* s_log_manager;

LogManager* LogManager::GetInstance()
{
	return s_log_manager;
}

void LogManager::Init()
{
	s_log_manager = new LogManager();
}

void LogManager::Shutdown()
{
	delete s_log_manager;
	s_log_manager = nullptr;
}
