/*

* Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  This is a project specific include file for building the 

*                clock related functions as part of libc library.

*

*/

#include <e32base.h>

#include <e32cons.h>

#include <tz.h>

#include <tzconverter.h>

#include "tzlocalizer.h" 

#include "tzlocalizationdatatypes.h"

#include "vtzrules.h"

#include "utf.h" 

#include "timefuncs.h"

#include "lposix.h"

#include "sysif.h"

#include "libc_wsd_defs.h"

// This represents the base EpochTime in microseconds, 

// which happens to be January 1, 1970 (midnight UTC/GMT), 

// not counting leap seconds. This effectively represents 

// the number of microseconds in 1970 years.    

static const TInt64 KEpochTime = 62168256000000000;

#ifndef EMULATOR

struct tm cachetm;

time_t prevchange;

time_t nextchange;

#else //EMULATOR

GET_GLOBAL_VAR_FROM_TLS(cachetm, struct tm)

#define cachetm (*GET_WSD_VAR_NAME(cachetm, g)())

GET_GLOBAL_VAR_FROM_TLS(prevchange, time_t)

#define prevchange (*GET_WSD_VAR_NAME(prevchange, g)())

GET_GLOBAL_VAR_FROM_TLS(nextchange, time_t)

#define nextchange (*GET_WSD_VAR_NAME(nextchange, g)())

#endif //EMULATOR

#if !defined(__SERIES60_30__) 

TTzTimeReference FindChangeBracket(TTime& aTime ,TTime& aUTime, CVTzActualisedRules& aRule,TBool& aDstOn)

    {

    TInt cnt = aRule.Count();

    TInt lowestOffset = -1, curOffset=-1;

    TBool isInit = EFalse;

    TTime CurTime(aTime);

    TTime Previous(-1), Next(-1);

    TTzTimeReference ref(ETzWallTimeReference);

//datetime to be created from the UTC time.    

    TDateTime dateTime = aUTime.DateTime();

// Initially set aDstOn to False

    aDstOn = EFalse;

// Loop to find the lowest time offset applicable in the year.    

    for(TInt idx=0; idx<cnt; idx++)

        {

        TVTzActualisedRule& Actual = aRule[idx];  

        if (Actual.iTimeOfChange.DateTime().Year() == dateTime.Year())

            {

            if (!isInit)

                {

                lowestOffset = Actual.iNewOffset;

                isInit = ETrue;    

                }

            if (isInit && Actual.iNewOffset < lowestOffset)

                {

                lowestOffset = Actual.iNewOffset;

                }   

            }

        }

//    Loop to find the current offset, previous time of change and the next time of change.

    for(TInt idx=0; idx<cnt; idx++)

        {

        TVTzActualisedRule& Actual = aRule[idx];

        if(Actual.iTimeReference == ETzUtcTimeReference && CurTime != aUTime)

            {

            CurTime = aUTime;

            ref = ETzUtcTimeReference;

            }

        //  Rules are arranged in increasing order of iTimeofChange

        if(CurTime >= Actual.iTimeOfChange)

            {

            Previous = Actual.iTimeOfChange;

            curOffset = Actual.iNewOffset;

            }

        else

            {

            Next = Actual.iTimeOfChange;

            break;

            }

       }

/*

 * If the Next and Previous were not set due to some reason,

 * Set them to one year after and one year before the time passed.

 */     

    if(Next == -1)

        {

        /* Next year */

        Next = CurTime + (TTimeIntervalSeconds)(365*86400);

        }

    if (Previous == -1)

        {

        /* Prev Year */

        Previous = CurTime - (TTimeIntervalSeconds)(365*86400);

        }

    aTime = Previous;

    aUTime = Next;

    if(lowestOffset != -1 && curOffset > lowestOffset)

        {

        aDstOn = ETrue;

        }

    return ref;

    }

#endif

void UpdateDstAndTznameL(RTz &aServer,CTzId& aId,struct tm* aTmStruct, TTime aTime, TTime aUTime, TDateTime aDate, TTzTimeReference aReference)

    {

#if !defined(__SERIES60_30__) 

    CTzRules* zonerules = aServer.GetTimeZoneRulesL(aId, aTime, aTime, aReference);

    CleanupStack::PushL(zonerules);

    CVTzActualisedRules* actual = CVTzActualisedRules::NewL(aDate.Year()-1, aDate.Year()+1);

    CleanupStack::PushL(actual);

    zonerules->GetActualisedRulesL(*actual);

    TTime PrevTime(aTime), NextTime(aUTime);

    TBool IsDstOn;

    /* Send local TTimes */

    if(FindChangeBracket(PrevTime, NextTime, *actual, IsDstOn)== ETzWallTimeReference)

        {

        aServer.ConvertToUniversalTime(PrevTime,aId);

        aServer.ConvertToUniversalTime(NextTime,aId);

        }

    prevchange = (PrevTime.Int64() - KEpochTime)/1000000;

    nextchange = (NextTime.Int64() - KEpochTime)/1000000;

    aTmStruct->tm_isdst = IsDstOn;

    CleanupStack::PopAndDestroy(actual);

    CleanupStack::PopAndDestroy(zonerules);

#else // __SERIES60_30__ defined

    aServer;

    aTime;

    aUTime;

    aDate;

    aReference;

#endif

/*  //This part has been commented out because of performance issue. Also this requires capability.

    if(RProcess().HasCapability(ECapabilityReadUserData,ECapabilityWriteUserData,NULL))

        {

        //          tm_zone updated only in this case. Otherwise always has UTC.

        CTzLocalizer *localizer = CTzLocalizer::NewL();

        CleanupStack::PushL(localizer);

        CTzLocalizedTimeZone* timezone = localizer->GetLocalizedTimeZoneL(aId.TimeZoneNumericID());

        CleanupStack::PushL(timezone);

        TPtrC zoneNameDesc;

        if (aTmStruct->tm_isdst)

            {

            zoneNameDesc.Set(timezone->ShortDaylightName());

            }

        else            

            {

            zoneNameDesc.Set(timezone->ShortStandardName());

            }

        //TODO: Value should not be hardcoded here. Get it from the struct state again.

        TPtr8 ptr((unsigned char*)tzname[0],zoneNameDesc.Size());

        CnvUtfConverter::ConvertFromUnicodeToUtf8(ptr,zoneNameDesc);

        CleanupStack::PopAndDestroy(timezone);  

        CleanupStack::PopAndDestroy(localizer);

        } 

    aTmStruct->tm_zone = tzname[0]; */

    aTmStruct->tm_zone = "WILDABBR";

    }  

void ConvertUtcToLocalTimeL(const time_t* aUTCTime, struct tm* const atmStruct)

    {

    if(!aUTCTime)

        {

        User::Leave(KErrArgument);

        }

    TTime   time(KEpochTime + (*aUTCTime) * (TInt64)1000000);

    TTime   Utime(time);

    // Cache Logic.

    TTimeIntervalSeconds UtcOffset = User::UTCOffset();

    if( cachetm.tm_gmtoff == UtcOffset.Int() && prevchange <= *aUTCTime && *aUTCTime<= nextchange)

        {

        time += UtcOffset;         // Convert to local time.

        TDateTime tdt = time.DateTime();

        cachetm.tm_sec = tdt.Second();

        cachetm.tm_min = tdt.Minute();

        cachetm.tm_hour = tdt.Hour();    

        cachetm.tm_mday = tdt.Day() + 1;

        cachetm.tm_mon = tdt.Month();

        cachetm.tm_year = tdt.Year() - 1900;    // This is as per the tm structure format.  

        cachetm.tm_wday = (time.DayNoInWeek()+1)%7; // Note: first day of the week is considered as Monday, so adding +1. 

        cachetm.tm_yday = time.DayNoInYear()-1; // Note: first day of the year is considered as 1, so

        *atmStruct = cachetm;

        return;

        }

    TDateTime tdt = time.DateTime();

    //enable the cache

	TInt status = KErrNone;

	RTz& rtzServer = Backend()->TZServer(status);

	if(status != KErrNone)

		User::Leave(status);

    CTzConverter* ctzConverter = CTzConverter::NewL(rtzServer);

    CleanupStack::PushL(ctzConverter);

    if(ctzConverter->ConvertToLocalTime(time) == KErrNone)      

        {

        tdt = time.DateTime();

        atmStruct->tm_sec = tdt.Second();

        atmStruct->tm_min = tdt.Minute();

        atmStruct->tm_hour = tdt.Hour();

        atmStruct->tm_mday = tdt.Day() + 1;

        atmStruct->tm_mon = tdt.Month();

        atmStruct->tm_year = tdt.Year() - 1900;    // This is as per the tm structure format.  

        atmStruct->tm_wday = (time.DayNoInWeek()+1)%7; // Note: first day of the week is considered as Monday, so adding +1. 

        atmStruct->tm_yday = time.DayNoInYear()-1; // Note: first day of the year is considered as 1, so 

        atmStruct->tm_gmtoff = (time.Int64() - Utime.Int64())/1000000;

        TInt timeZoneId = ctzConverter->CurrentTzId();

        CTzId* zoneid = CTzId::NewL((TUint)timeZoneId);

        CleanupStack::PushL(zoneid);

        atmStruct->tm_isdst  = -1;

        UpdateDstAndTznameL(rtzServer, *zoneid, atmStruct, time, Utime, tdt, ETzWallTimeReference);

        CleanupStack::PopAndDestroy(zoneid);

        }   

    CleanupStack::PopAndDestroy(1);

    cachetm = *atmStruct;

    }

void ConvertLocalToUtcTimeL(time_t* aUTCTime, struct tm* const aTmStruct)

    {

    if(!aTmStruct || aTmStruct->tm_year < 0 || aTmStruct->tm_mon < 0 || aTmStruct->tm_mday < 1 || aTmStruct->tm_hour < 0 || aTmStruct->tm_min < 0 || aTmStruct->tm_sec < 0 )

        {

        User::Leave(KErrArgument);

        }

    TDateTime tdt(aTmStruct->tm_year + 1900, (TMonth)aTmStruct->tm_mon, aTmStruct->tm_mday-1, 

                    aTmStruct->tm_hour, aTmStruct->tm_min, aTmStruct->tm_sec, 0);

    TTime   time(tdt);

    TTime   oldTime(time);

//  Cache Logic 

    TTimeIntervalSeconds UtcOffset = User::UTCOffset();

    if(cachetm.tm_gmtoff == UtcOffset.Int() && cachetm.tm_year == aTmStruct->tm_year && cachetm.tm_mon == aTmStruct->tm_mon && cachetm.tm_mday == aTmStruct->tm_mday)

        {

        aTmStruct->tm_gmtoff = cachetm.tm_gmtoff;

        aTmStruct->tm_isdst = cachetm.tm_isdst;

        aTmStruct->tm_zone = cachetm.tm_zone;    

        aTmStruct->tm_wday = (time.DayNoInWeek()+1)%7; // Note: first day of the week is considered as Monday, so adding +1. 

        aTmStruct->tm_yday = time.DayNoInYear()-1; // Note: first day of the year is considered as 1, so

        time -= UtcOffset;                 // Converting to UTC time.

        TInt64 utcTimeMicroSec = time.Int64();

        TInt64 epochRefTime = utcTimeMicroSec - KEpochTime;

        (*aUTCTime) = (TInt) (epochRefTime / 1000000);

        return;

        }

	TInt status = KErrNone;

	RTz& rtzServer = Backend()->TZServer(status);

	if(status != KErrNone)

		User::Leave(status);

    CTzConverter* ctzConverter = CTzConverter::NewL(rtzServer);      

    CleanupStack::PushL(ctzConverter);

 /* Following fields are updated if successful:

  * tm_wday

  * tm_yday

  * tm_isdst

  * tm_gmtoffset

  * tm_zone ( Conditional on capabilities available)

  */

    if(ctzConverter->ConvertToUniversalTime(time) == KErrNone)

        {

        //conversion successful

        TInt64 utcTimeMicroSec = time.Int64();

        TInt64 epochRefTime = utcTimeMicroSec - KEpochTime;

        (*aUTCTime) = (TInt) (epochRefTime / 1000000);

        aTmStruct->tm_wday = (oldTime.DayNoInWeek()+1)%7; // Note: first day of the week is considered as Monday, so adding +1. 

        aTmStruct->tm_yday = oldTime.DayNoInYear()-1; // Note: first day of the year is considered as 1, so

        aTmStruct->tm_gmtoff = (oldTime.Int64() - utcTimeMicroSec)/1000000;

        TInt timeZoneId = ctzConverter->CurrentTzId();

        CTzId* zoneid = CTzId::NewL((TUint)timeZoneId);

        CleanupStack::PushL(zoneid);

        aTmStruct->tm_isdst  = -1;

        UpdateDstAndTznameL(rtzServer, *zoneid, aTmStruct, oldTime, time, tdt, ETzUtcTimeReference);

        CleanupStack::PopAndDestroy(zoneid);

        }

    cachetm = *aTmStruct;

    CleanupStack::PopAndDestroy(1);

    }

// converts a UTC time to local time, or, local time to UTC time.  

TInt ConvertTime(const TInt atimeConverFlg, time_t *aUTCTime, struct tm *const atmStruct)

    {

    TInt err = 0;

    CActiveScheduler* oldAs = CActiveScheduler::Current();

    RHeap* oldHeap = User::SwitchHeap(Backend()->Heap());

    CActiveScheduler* newAs = new CActiveScheduler();

    User::SwitchHeap(oldHeap);

    if(!newAs)

        {

        errno = ENOMEM;

        return ENOMEM;

        }

    if(oldAs)

        {

        (void)CActiveScheduler::Replace(newAs);

        }

    else

        {

        CActiveScheduler::Install(newAs);

        }

    oldHeap = User::SwitchHeap(Backend()->Heap());

    // Cleanup stack needed

    CTrapCleanup* cleanup=CTrapCleanup::New();

    if (cleanup)

        {

        if(EUtcToLocal == atimeConverFlg)

            {

            TRAP(err, ConvertUtcToLocalTimeL(aUTCTime, atmStruct));

            }

        else if(ELocalToUtc == atimeConverFlg)

            {

            TRAP(err, ConvertLocalToUtcTimeL(aUTCTime, atmStruct));

            }

        delete cleanup;

        }

    else

        {

        err = ENOMEM;

        }

    if(oldAs)

        {

        (void)CActiveScheduler::Replace(oldAs);

        }

    delete newAs;

    User::SwitchHeap(oldHeap);

    return MapError(err,errno);

    }