// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.

#include <time.h>

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

#include "common/common.h"
#include "common/timer.h"
#include "common/string_util.h"

namespace Common
{

u32 Timer::GetTimeMs()
{
#ifdef _WIN32
    return timeGetTime();
#else
    struct timeval t;
    (void)gettimeofday(&t, nullptr);
    return ((u32)(t.tv_sec * 1000 + t.tv_usec / 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:%03i",
        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;
    struct tm * gmTime;
    char tmp[13];

    time(&sysTime);
    gmTime = localtime(&sysTime);

    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);
#else
    struct timeval t;
    (void)gettimeofday(&t, nullptr);
    return StringFromFormat("%s:%03d", tmp, (int)(t.tv_usec / 1000));
#endif
}

// Returns a timestamp with decimals for precise time comparisons
// ----------------
double Timer::GetDoubleTime()
{
#ifdef _WIN32
    struct timeb tp;
    (void)::ftime(&tp);
#else
    struct timeval t;
    (void)gettimeofday(&t, nullptr);
#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 - (38 * 365 * 24 * 60 * 60);

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

    return TmpTime;
}

} // Namespace Common
