// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <cinttypes>
#include <ctime>
#include <string>

#ifdef _WIN32
#include <mmsystem.h>
#include <sys/timeb.h>
#include <windows.h>
#else
#include <sys/time.h>
#endif

#include "Common/CommonTypes.h"
#include "Common/StringUtil.h"
#include "Common/Timer.h"

namespace Common
{

u32 Timer::GetTimeMs()
{
#ifdef _WIN32
	return timeGetTime();
#elif defined __APPLE__
	struct timeval t;
	(void)gettimeofday(&t, nullptr);
	return ((u32)(t.tv_sec * 1000 + t.tv_usec / 1000));
#else
	struct timespec t;
	(void)clock_gettime(CLOCK_MONOTONIC, &t);
	return ((u32)(t.tv_sec * 1000 + t.tv_nsec / 1000000));
#endif
}

#ifdef _WIN32
double GetFreq()
{
	LARGE_INTEGER freq;
	QueryPerformanceFrequency(&freq);
	return 1000000.0 / double(freq.QuadPart);
}
#endif

u64 Timer::GetTimeUs()
{
#ifdef _WIN32
	LARGE_INTEGER time;
	static double freq = GetFreq();
	QueryPerformanceCounter(&time);
	return u64(double(time.QuadPart) * freq);
#elif defined __APPLE__
	struct timeval t;
	(void)gettimeofday(&t, nullptr);
	return ((u64)(t.tv_sec * 1000000 + t.tv_usec));
#else
	struct timespec t;
	(void)clock_gettime(CLOCK_MONOTONIC, &t);
	return ((u64)(t.tv_sec * 1000000 + t.tv_nsec / 1000));
#endif
}

// --------------------------------------------
// Initiate, Start, Stop, and Update the time
// --------------------------------------------

// Set initial values for the class
Timer::Timer()
	: m_LastTime(0), m_StartTime(0), m_Running(false)
{
	Update();
}

// Write the starting time
void Timer::Start()
{
	m_StartTime = GetTimeMs();
	m_Running = true;
}

// Stop the timer
void Timer::Stop()
{
	// Write the final time
	m_LastTime = GetTimeMs();
	m_Running = false;
}

// Update the last time variable
void Timer::Update()
{
	m_LastTime = GetTimeMs();
	//TODO(ector) - QPF
}

// -------------------------------------
// Get time difference and elapsed time
// -------------------------------------

// Get the number of milliseconds since the last Update()
u64 Timer::GetTimeDifference()
{
	return GetTimeMs() - m_LastTime;
}

// Add the time difference since the last Update() to the starting time.
// This is used to compensate for a paused game.
void Timer::AddTimeDifference()
{
	m_StartTime += GetTimeDifference();
}

// Get the time elapsed since the Start()
u64 Timer::GetTimeElapsed()
{
	// If we have not started yet, return 1 (because then I don't
	// have to change the FPS calculation in CoreRerecording.cpp .
	if (m_StartTime == 0) return 1;

	// Return the final timer time if the timer is stopped
	if (!m_Running) return (m_LastTime - m_StartTime);

	return (GetTimeMs() - m_StartTime);
}

// Get the formatted time elapsed since the Start()
std::string Timer::GetTimeElapsedFormatted() const
{
	// If we have not started yet, return zero
	if (m_StartTime == 0)
		return "00:00:00:000";

	// The number of milliseconds since the start.
	// Use a different value if the timer is stopped.
	u64 Milliseconds;
	if (m_Running)
		Milliseconds = GetTimeMs() - m_StartTime;
	else
		Milliseconds = m_LastTime - m_StartTime;
	// Seconds
	u32 Seconds = (u32)(Milliseconds / 1000);
	// Minutes
	u32 Minutes = Seconds / 60;
	// Hours
	u32 Hours = Minutes / 60;

	std::string TmpStr = StringFromFormat("%02i:%02i:%02i:%03" PRIu64,
		Hours, Minutes % 60, Seconds % 60, Milliseconds % 1000);
	return TmpStr;
}

// Get current time
void Timer::IncreaseResolution()
{
#ifdef _WIN32
	timeBeginPeriod(1);
#endif
}

void Timer::RestoreResolution()
{
#ifdef _WIN32
	timeEndPeriod(1);
#endif
}

// Get the number of seconds since January 1 1970
u64 Timer::GetTimeSinceJan1970()
{
	time_t ltime;
	time(&ltime);
	return((u64)ltime);
}

u64 Timer::GetLocalTimeSinceJan1970()
{
	time_t sysTime, tzDiff, tzDST;
	struct tm * gmTime;

	time(&sysTime);

	// Account for DST where needed
	gmTime = localtime(&sysTime);
	if (gmTime->tm_isdst == 1)
		tzDST = 3600;
	else
		tzDST = 0;

	// Lazy way to get local time in sec
	gmTime = gmtime(&sysTime);
	tzDiff = sysTime - mktime(gmTime);

	return (u64)(sysTime + tzDiff + tzDST);
}

// Return the current time formatted as Minutes:Seconds:Milliseconds
// in the form 00:00:000.
std::string Timer::GetTimeFormatted()
{
	time_t sysTime;
	time(&sysTime);

	struct tm * gmTime = localtime(&sysTime);

	char tmp[13];
	strftime(tmp, 6, "%M:%S", gmTime);

	// Now tack on the milliseconds
#ifdef _WIN32
	struct timeb tp;
	(void)::ftime(&tp);
	return StringFromFormat("%s:%03i", tmp, tp.millitm);
#elif defined __APPLE__
	struct timeval t;
	(void)gettimeofday(&t, nullptr);
	return StringFromFormat("%s:%03d", tmp, (int)(t.tv_usec / 1000));
#else
	struct timespec t;
	(void)clock_gettime(CLOCK_MONOTONIC, &t);
	return StringFromFormat("%s:%03d", tmp, (int)(t.tv_nsec / 1000000));
#endif
}

// Returns a timestamp with decimals for precise time comparisons
double Timer::GetDoubleTime()
{
#ifdef _WIN32
	struct timeb tp;
	(void)::ftime(&tp);
#elif defined __APPLE__
	struct timeval t;
	(void)gettimeofday(&t, nullptr);
#else
	struct timespec t;
	(void)clock_gettime(CLOCK_MONOTONIC, &t);
#endif
	// Get continuous timestamp
	u64 TmpSeconds = Common::Timer::GetTimeSinceJan1970();

	// Remove a few years. We only really want enough seconds to make
	// sure that we are detecting actual actions, perhaps 60 seconds is
	// enough really, but I leave a year of seconds anyway, in case the
	// user's clock is incorrect or something like that.
	TmpSeconds = TmpSeconds - DOUBLE_TIME_OFFSET;

	// Make a smaller integer that fits in the double
	u32 Seconds = (u32)TmpSeconds;
#ifdef _WIN32
	double ms = tp.millitm / 1000.0 / 1000.0;
#elif defined __APPLE__
	double ms = t.tv_usec / 1000000.0;
#else
	double ms = t.tv_nsec / 1000000000.0;
#endif
	double TmpTime = Seconds + ms;

	return TmpTime;
}

// Formats a timestamp from GetDoubleTime() into a date and time string
std::string Timer::GetDateTimeFormatted(double time)
{
	// revert adjustments from GetDoubleTime() to get a normal Unix timestamp again
	time_t seconds = (time_t)time + DOUBLE_TIME_OFFSET;
	tm* localTime = localtime(&seconds);

	char tmp[32] = {};
	strftime(tmp, sizeof(tmp), "%x %X", localTime);
	return tmp;
}

} // Namespace Common
