/*
* Copyright (c) 2002-2004 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 : Class looking after alarm fields for forms.
*
*/

//debug
#include "calendarui_debug.h"

//user includes
#include "CalenSolarTerms.h"
#include "CalenLunarPaths.h"

//system includes
#include <f32file.h>
#include <s32file.h>


// CONSTANTS
_LIT( KSolarTermsFile, "KoreanSolarItems" );
const TInt KFirstSolarTermYear( 1900 );
const TInt KLastSolarTermYear( 2100 );


// ======== MEMBER FUNCTIONS ========


// ---------------------------------------------------------------------------
// CCalenSolarTerms::NewL()
// ---------------------------------------------------------------------------
//
CCalenSolarTerms* CCalenSolarTerms::NewL( RFs& aFs )
    {
    TRACE_ENTRY_POINT;
    
    CCalenSolarTerms* self = new (ELeave) CCalenSolarTerms(aFs);
    CleanupStack::PushL( self );
    self->ConstructL();
    CleanupStack::Pop( self );
    
    TRACE_EXIT_POINT;
    return self;
    }

// ---------------------------------------------------------------------------
// CCalenSolarTerms::~CCalenSolarTerms()
// ---------------------------------------------------------------------------
//
CCalenSolarTerms::~CCalenSolarTerms()
    {
    TRACE_ENTRY_POINT;
    TRACE_EXIT_POINT;
    }

// ---------------------------------------------------------------------------
// CCalenSolarTerms::CheckSolarTermDateL()
// ---------------------------------------------------------------------------
//
TInt CCalenSolarTerms::CheckSolarTermDateL( const TDateTime& aDate )
    {
    TRACE_ENTRY_POINT;
    
    ReadSolarTermsL( aDate );
    if ( HasSolarTermDataAvailable( aDate ) )
        {
        // Solar festival data is available for this date 
        for ( TInt i( 0 ); i < KSolarTermCount; i++ )
            {
            TDateTime date = iSolarTermDates[i];
            if ( aDate.Month() == date.Month() && aDate.Day() == date.Day() )
                {
                // First item in iSolarTermNames is LiChun ("Spring begins")
                // occuring around 4.2 in western year. 
                // It is first solar term in Chinese Lunar year, but it's 
                // third term in western year.
                // 
                // iSolarTermDates list terms from beginning of western year,
                // that's why we subtract 2 and take modulo 24 here, to convert
                // order from 
                // Xiao Han (~ 6.1.), Da Han (~22.1), Li Chun (~4.2)...
                // to 
                // Li Chun (~4.2.), ..., ..., Da Han (~22.1)
                i += KSolarTermCount - 2;
                TInt foundIndex = i % KSolarTermCount;
                
                TRACE_EXIT_POINT;
                return foundIndex;
                }
            }
        TRACE_EXIT_POINT;
        return KErrNotFound;
        }
    else
        {
        // Solar festival data is NOT available for this date 
        TRACE_EXIT_POINT;
        return KErrNotSupported;
        }
    }

// ---------------------------------------------------------------------------
// CCalenSolarTerms::CCalenSolarTerms()
// ---------------------------------------------------------------------------
//
CCalenSolarTerms::CCalenSolarTerms( RFs& aFs ) : iFs( aFs )
    {
    TRACE_ENTRY_POINT;
    TRACE_EXIT_POINT;
    }

// ---------------------------------------------------------------------------
// CCalenSolarTerms::ConstructL()
// ---------------------------------------------------------------------------
//
void CCalenSolarTerms::ConstructL()
    {
    TRACE_ENTRY_POINT;
    TRACE_EXIT_POINT;
    }

// ---------------------------------------------------------------------------
// CCalenSolarTerms::HasSolarTermDataAvailable()
// ---------------------------------------------------------------------------
//
TBool CCalenSolarTerms::HasSolarTermDataAvailable( const TDateTime& aDate ) const
    {
    TRACE_ENTRY_POINT;
    
    // Note: day parameter for TDateTime starts from 0, not from 1
    const TDateTime KMinAvailable( KFirstSolarTermYear, EJanuary, 0, 0, 0, 0, 0 );
    const TDateTime KMaxAvailable( KLastSolarTermYear, EDecember, 31 - 1, 23, 59, 59, 0 );
    
    TRACE_EXIT_POINT;
    return TTime( KMinAvailable ) <= TTime( aDate ) &&
           TTime( aDate ) <= TTime( KMaxAvailable );
    }

// ---------------------------------------------------------
// CCalenSolarTerms::ReadSolarTermsL()
// Reads and caches 24 solar term dates for one year
// from "SolarItems" file
// ---------------------------------------------------------
//
void CCalenSolarTerms::ReadSolarTermsL( TDateTime aDate )
    {
    TRACE_ENTRY_POINT;
    
    // Caches one year of solar items
    if ( ! HasSolarTermDataAvailable( aDate ) )
        {
        return;
        }

    TInt year = aDate.Year();

    if ( iCachedYear != year )
        {
        RFile file;
        RFs& fs = iFs;
        TFindFile ffile( fs );
        User::LeaveIfError( ffile.FindByDir( KSolarTermsFile, KSolarTermsPath ) );
        User::LeaveIfError( file.Open( fs, ffile.File(), EFileRead ) );
        CleanupClosePushL( file );

        TInt seekPos = 
            ( year - KFirstSolarTermYear ) * sizeof( TUint8 ) * KSolarTermCount;

        RFileReadStream readStream( file, seekPos );
        readStream.PushL();

         for ( TInt i( 0 ); i < KSolarTermCount; i++ )
             {
             TMonth month = static_cast<TMonth>( EJanuary + (i / 2) );
             TInt day = readStream.ReadUint8L();
             TDateTime dt( year, month, day-1, 0, 0, 0, 0 );
             iSolarTermDates[i] = dt;
             }

        CleanupStack::PopAndDestroy( 2 ); // readStream, file
        iCachedYear = year;
        }
    
    TRACE_EXIT_POINT;
    }

// End of file