//
// C++ Implementation: fmkernfeat
//
// Description: try to make it the more compact & simple as possible
//
//
// Author: Pierre Marchand <pierremarc@oep-h.com>, (C) 2009
//
// Copyright: See COPYING file that comes with this distribution
//
//

#include "fmkernfeat.h"

#include FT_TRUETYPE_TABLES_H
#include FT_TRUETYPE_TAGS_H

#include <QStringList>
#include <QDebug>


FMKernFeature::FMKernFeature ( FT_Face face )
		:p_face ( face )
{
	FT_ULong length = 0;
	if ( !FT_Load_Sfnt_Table ( face, TTAG_GPOS , 0, NULL, &length ) )
	{
		if ( length > 32 )
		{
			GPOSTableRaw.resize ( length );
			FT_Load_Sfnt_Table ( face, TTAG_GPOS, 0, ( FT_Byte * ) GPOSTableRaw.data (), &length );

			makeCoverage();
		}
		else
			GPOSTableRaw.clear();
	}
}

FMKernFeature::~ FMKernFeature()
{
}


void FMKernFeature::makeCoverage()
{
	if ( GPOSTableRaw.isEmpty() )
		return;

	bool out ( true );
	quint16 FeatureList_Offset= toUint16 ( 6 );
	quint16 LookupList_Offset = toUint16 ( 8 );

	// Find the offsets of the kern feature tables
	quint16 FeatureCount = toUint16 ( FeatureList_Offset );;
	QList<quint16> FeatureKern_Offset;
	for ( quint16 FeatureRecord ( 0 ); FeatureRecord < FeatureCount; ++ FeatureRecord )
	{
		int rawIdx ( FeatureList_Offset + 2 + ( 6 * FeatureRecord ) );
		quint32 tag ( FT_MAKE_TAG ( GPOSTableRaw.at ( rawIdx ),
		                            GPOSTableRaw.at ( rawIdx + 1 ),
		                            GPOSTableRaw.at ( rawIdx + 2 ),
		                            GPOSTableRaw.at ( rawIdx + 3 ) ) );
		if ( tag == TTAG_kern )
		{
			FeatureKern_Offset << ( toUint16 ( rawIdx + 4 ) + FeatureList_Offset );
			if ( out )
			{
				qDebug() <<"KERN"<<FeatureKern_Offset;
			}

		}
	}

	// Extract indices of lookups for feture kern
	QList<quint16> LookupListIndex;
	foreach ( quint16 kern, FeatureKern_Offset )
	{
		quint16 LookupCount ( toUint16 ( kern + 2 ) );
		if ( out )
		{
			qDebug() <<"\tParams"<<toUint16 ( kern );
			qDebug() <<"\tLookupCount"<<LookupCount;
		}
		for ( int llio ( 0 ) ; llio < LookupCount; ++llio )
		{
			quint16 Idx ( toUint16 ( kern + 4 + ( llio * 2 ) ) );
			if ( !LookupListIndex.contains ( Idx ) )
			{
				LookupListIndex <<Idx ;
			}
		}
		if ( out )
			qDebug() <<"\tLookupIndex"<<LookupListIndex;
	}


	// Extract offsets of lookup tables for feature kern
	QList<quint16> LookupTables;
	QList<quint16> PairAdjustmentSubTables;
	for ( int i ( 0 ); i < LookupListIndex.size(); ++i )
	{
		int rawIdx ( LookupList_Offset + 2 + ( LookupListIndex[i] * 2 ) );
		quint16 Lookup ( toUint16 ( rawIdx )  + LookupList_Offset );
		quint16 SubTableCount ( toUint16 ( Lookup + 4 ) );
		for ( int stIdx ( 0 ); stIdx < SubTableCount; ++ stIdx )
		{
			quint16 SubTable ( toUint16 ( Lookup + 6 + ( 2 * stIdx ) ) + Lookup );

			quint16 PosFormat ( toUint16 ( SubTable ) );
			quint16 Coverage_Offset ( toUint16 ( SubTable + 2 ) + SubTable );
			quint16 CoverageFormat ( toUint16 ( Coverage_Offset ) );

			if ( out )
			{
				qDebug() <<"\t\tPosFormat"<<PosFormat;
				qDebug() <<"\t\tCoverageFormat"<<CoverageFormat;
			}
			if ( 1 == CoverageFormat ) // glyph indices based
			{
				quint16 GlyphCount ( toUint16 ( Coverage_Offset + 2 ) );
				quint16 GlyphID ( Coverage_Offset + 4 );
				if ( out )
					qDebug() <<"\t\t\tGlyphCount"<<GlyphCount;
				for ( unsigned int gl ( 0 ); gl < GlyphCount; ++gl )
				{
					coverages[SubTable] << toUint16 ( GlyphID + ( gl * 2 ) );
				}
			}
			else if ( 2 == CoverageFormat ) // Coverage Format2 => ranges based
			{
				quint16 RangeCount ( toUint16 ( Coverage_Offset + 2 ) );
				if ( out )
					qDebug() <<"\t\t\tRangeCount" <<RangeCount;
				int gl_base ( 0 );
				for ( int r ( 0 ); r < RangeCount; ++r )
				{
					quint16 rBase ( Coverage_Offset + 4 + ( r * 6 ) );
					quint16 Start ( toUint16 ( rBase ) );
					quint16 End ( toUint16 ( rBase + 2 ) );
					quint16 StartCoverageIndex ( toUint16 ( rBase + 4 ) );
					if(out)
						qDebug()<<"\t\t\t\tRange"<<Start<<End<<StartCoverageIndex;
					for ( unsigned int gl ( Start ); gl <= End; ++gl )
						coverages[SubTable]  << gl;
				}
			}
			else
				qDebug() <<"Unknow Coverage Format:"<<CoverageFormat;

			if(out)
				qDebug()<<"\t\t**Built a coverage array of length:"<<coverages[SubTable].size();
			makePairs ( SubTable );
		}

	}

}


void FMKernFeature::makePairs ( quint16 subtableOffset )
{
	/*
	Lookup Type 2:
	Pair Adjustment Positioning Subtable
	*/

	quint16 PosFormat ( toUint16 ( subtableOffset ) );

	if ( PosFormat == 1 )
	{
		quint16 ValueFormat1 ( toUint16 ( subtableOffset +4 ) );
		quint16 ValueFormat2 ( toUint16 ( subtableOffset +6 ) );
		quint16 PairSetCount ( toUint16 ( subtableOffset +8 ) );
		if ( ValueFormat1 && ValueFormat2 )
		{
			for ( int psIdx ( 0 ); psIdx < PairSetCount; ++ psIdx )
			{
				unsigned int FirstGlyph ( coverages[subtableOffset][psIdx] );
				quint16 PairSetOffset ( toUint16 ( subtableOffset +10 + ( 2 * psIdx ) ) +  subtableOffset );
				quint16 PairValueCount ( toUint16 ( PairSetOffset ) );
				quint16 PairValueRecord ( PairSetOffset + 2 );
				for ( int pvIdx ( 0 );pvIdx < PairValueCount; ++pvIdx )
				{
					quint16 recordBase ( PairValueRecord + ( ( 2 + 2 + 2 ) * pvIdx ) );
					quint16 SecondGlyph ( toUint16 ( recordBase ) );
					qint16 Value1 ( toInt16 ( recordBase + 2 ) );
					pairs[FirstGlyph][SecondGlyph] = double ( Value1 );

				}

			}
		}
		else if ( ValueFormat1 && ( !ValueFormat2 ) )
		{
			for ( int psIdx ( 0 ); psIdx < PairSetCount; ++ psIdx )
			{
				unsigned int FirstGlyph ( coverages[subtableOffset][psIdx] );
				quint16 PairSetOffset ( toUint16 ( subtableOffset +10 + ( 2 * psIdx ) ) +  subtableOffset );
				quint16 PairValueCount ( toUint16 ( PairSetOffset ) );
				quint16 PairValueRecord ( PairSetOffset + 2 );
				for ( int pvIdx ( 0 );pvIdx < PairValueCount; ++pvIdx )
				{
					quint16 recordBase ( PairValueRecord + ( ( 2 + 2 ) * pvIdx ) );
					quint16 SecondGlyph ( toUint16 ( recordBase ) );
					qint16 Value1 ( toInt16 ( recordBase + 2 ) );
					pairs[FirstGlyph][SecondGlyph] = double ( Value1 );

				}

			}
		}
		else
		{
			qDebug() <<"ValueFormat1 is null or both ValueFormat1 and ValueFormat2 are null";
		}

	}
	else if ( PosFormat == 2 )
	{
		quint16 ValueFormat1 ( toUint16 ( subtableOffset +4 ) );
		quint16 ValueFormat2 ( toUint16 ( subtableOffset +6 ) );
		quint16 ClassDef1 ( toUint16 ( subtableOffset +8 )  + subtableOffset );
		quint16 ClassDef2 ( toUint16 ( subtableOffset +10 ) + subtableOffset );
		quint16 Class1Count ( toUint16 ( subtableOffset +12 ) );
		quint16 Class2Count ( toUint16 ( subtableOffset +14 ) );
		quint16 Class1Record ( subtableOffset +16 );

		// first extract classses
		ClassDefTable Class1Data ( getClass ( ClassDef1 , subtableOffset ) );
		ClassDefTable Class2Data ( getClass ( ClassDef2 , subtableOffset ) );

		if ( ValueFormat1 && ValueFormat2 )
		{
			for ( quint16 C1 ( 0 );C1 < Class1Count; ++C1 )
			{
				QList<quint16> Class1 ( Class1Data[C1] );
				quint16 Class2Record ( Class1Record + ( C1 * ( 2 * 2 * Class2Count ) ) );
				for ( quint16 C2 ( 0 );C2 < Class2Count; ++C2 )
				{
					qint16 Value1 ( toInt16 ( Class2Record + ( C2 * ( 2 * 2 ) ) ) );
					QList<quint16> Class2 ( Class2Data[C2] );
					// keep it barbarian :D
					foreach ( quint16 FirstGlyph, Class1 )
					{
						foreach ( quint16 SecondGlyph, Class2 )
						{
							if ( Value1 )
								pairs[FirstGlyph][SecondGlyph] = double ( Value1 );
						}
					}
				}
			}
		}
		else if ( ValueFormat1 && ( !ValueFormat2 ) )
		{
			for ( quint16 C1 ( 0 );C1 < Class1Count; ++C1 )
			{
				QString cdbg ( QString::number ( C1 ).rightJustified ( 5,QChar ( 32 ) ) );
				QList<quint16> Class1 ( Class1Data[C1] );
				quint16 Class2Record ( Class1Record + ( C1 * ( 2 * Class2Count ) ) );
				for ( quint16 C2 ( 0 );C2 < Class2Count; ++C2 )
				{
					qint16 Value1 ( toInt16 ( Class2Record + ( C2 * 2 ) ) );
					QList<quint16> Class2 ( Class2Data[C2] );

					foreach ( quint16 FirstGlyph, Class1 )
					{
						foreach ( quint16 SecondGlyph, Class2 )
						{
							if ( Value1 )
								pairs[FirstGlyph][SecondGlyph] = double ( Value1 );
						}
					}
				}
			}
		}
		else
		{
			qDebug() <<"ValueFormat1 is null or both ValueFormat1 and ValueFormat2 are null";
		}

	}
	else
		qDebug() <<"unknown PosFormat"<<PosFormat;
}

quint16 FMKernFeature::toUint16 ( quint16 index )
{
	if ( ( index + 2 ) >= GPOSTableRaw.size() )
	{
		return 0;
	}
	quint16 c1 ( GPOSTableRaw.at ( index ) );
	quint16 c2 ( GPOSTableRaw.at ( index + 1 ) );
	c1 &= 0xFF;
	c2 &= 0xFF;
	quint16 ret ( ( c1 << 8 ) | c2 );
// 	qDebug()<<"**"<<index<<"("<<c1 << c2 <<")"<<ret;
	return ret;
}

qint16 FMKernFeature::toInt16 ( quint16 index )
{
	if ( ( index + 2 ) > GPOSTableRaw.size() )
	{
		return 0;
	}
	// FIXME I just do not know how it has to be done *properly*
	quint16 c1 ( GPOSTableRaw.at ( index ) );
	quint16 c2 ( GPOSTableRaw.at ( index + 1 ) );
	c1 &= 0xFF;
	c2 &= 0xFF;
	qint16 ret ( ( c1 << 8 ) | c2 );
	return ret;
}


QString FMKernFeature::glyphname ( int index )
{
	QByteArray key ( 1001,0 );
	if ( FT_HAS_GLYPH_NAMES ( p_face ) )
	{
		FT_Get_Glyph_Name ( p_face, index, key.data() , 1000 );
		if ( key[0] == char ( 0 ) )
		{
			key = "noname";
		}
	}
	else
	{
		key = "noname";
	}
	return QString ( key );
}

FMKernFeature::ClassDefTable FMKernFeature::getClass ( quint16 classDefOffset, quint16 coverageId )
{
	ClassDefTable ret;
	ret[0] = coverages[coverageId];
// 	ret[0] = QList<quint16>();
	quint16 ClassFormat ( toUint16 ( classDefOffset ) );
	if ( ClassFormat == 1 )
	{
// 		qDebug()<<"ClassFormat1";
		quint16 StartGlyph ( toUint16 ( classDefOffset +2 ) );
		quint16 GlyphCount ( toUint16 ( classDefOffset +4 ) );
		quint16 ClassValueArray ( classDefOffset + 6 );
		for ( quint16 CV ( 0 );CV < GlyphCount; ++CV )
		{
			ret[0].removeAll(StartGlyph + CV);
			ret[ toUint16 ( ClassValueArray + ( CV * 2 ) ) ] << StartGlyph + CV;
		}
	}
	else if ( ClassFormat == 2 )
	{
// 		qDebug()<<"ClassFormat2";
		quint16 ClassRangeCount ( toUint16 ( classDefOffset + 2 ) );
		quint16 ClassRangeRecord ( classDefOffset + 4 );
		for ( int CRR ( 0 ); CRR < ClassRangeCount; ++CRR )
		{
			quint16 Start ( toUint16 ( ClassRangeRecord + ( CRR * 6 ) ) );
			quint16 End ( toUint16 ( ClassRangeRecord + ( CRR * 6 ) + 2 ) );
			quint16 Class ( toUint16 ( ClassRangeRecord + ( CRR * 6 ) + 4 ) );
// 			qDebug()<<"CRC"<<Start<<End<<Class;
			for ( quint16 gl ( Start ); gl <= End; ++gl )
			{
				ret[0].removeAll(gl);
				ret[Class] << gl;
			}
		}
	}
	else
		qDebug() <<"Unknown Class Table type";
	
// 	foreach(quint16 c, ret.keys())
// 	{
// 		if(c>0)
// 		{
// 			QStringList dl;
// 			foreach(quint16 lg, ret[c])
// 			{
// 				dl << glyphname(lg);
// 			}
// 			if(!dl.contains("noname"))
// 				qDebug()<<"\t"<< c <<dl.join(";");
// 			else
// 				qDebug()<<"ERROR nonames"<<dl.size();
// 		}
// 		else
// 			qDebug()<<"\t"<< c <<ret[c].size();
// 	}

	return ret;
}

