#include "font.h"

#include <stdio.h>
#include <string.h>

#include <exception>

#define fh (( (FILE *)rawfh ))

Font::Font( const char *sSrcFile ) :
    iTableTop( 0 ),
    pTable( NULL )
{
    iTableTop = 128;
    pTable = new Glyph*[iTableTop];
    memset( pTable, 0, sizeof(Glyph*)*iTableTop );
    Parser p( sSrcFile, *this );
    p.parse();
}

Font::~Font()
{
}

Font::Parser::Parser( const char *sSrcFile, Font &rFont ) :
    rFont( rFont ),
    rawfh( NULL ),
    sLine( NULL ),
    bDone( false )
{
    sLine = new char[1024];
    rawfh = fopen( sSrcFile, "rt" );
}

Font::Parser::~Parser()
{
    delete[] sLine;
    fclose( fh );
}

void Font::Parser::parse()
{
    header();
    characters();
    if( strncasecmp("ENDFONT", sLine, 7 ) )
    {
        printf("End of file reached, but no end marker.\n");
        throw std::exception();
    }
}

void Font::Parser::getLine()
{
    for(;;)
    {
        if( fgets( sLine, 1024, fh ) == NULL )
        {
            sLine[0] = '\0';
            bDone = true;
            printf("Premature end of file.\n");
            throw std::exception();
            return;
        }

        if( strncasecmp("COMMENT ", sLine, 8 ) )
        {
            return;
        }
    }
}

void Font::Parser::header()
{
    getLine();
    if( strncasecmp("STARTFONT 2.1", sLine, 13 ) )
    {
        printf("Bad format: %s\n", sLine);
        throw std::exception();
    }

    for(;;)
    {
        getLine();
        if( strncasecmp("SIZE ", sLine, 5 ) == 0 )
        {
        }
        else if( strncasecmp("FONTBOUNDINGBOX ", sLine, 16 ) == 0 )
        {
        }
        else if( strncasecmp("STARTPROPERTIES ", sLine, 16 ) == 0 )
        {
            properties();
        }
        else if( strncasecmp("CHARS ", sLine, 6 ) == 0 )
        {
            return;
        }
    }
}

void Font::Parser::properties()
{
    for(;;)
    {
        getLine();
        if( strncasecmp("ENDPROPERTIES", sLine, 13 ) == 0 )
            return;
    }
}

void Font::Parser::characters()
{
    for(;;)
    {
        getLine();
        if( strncasecmp("STARTCHAR ", sLine, 10 ) == 0 )
            character();
        else
            return;
    }
}

uint8_t hex2byte( const char *str )
{
    uint8_t ret = 0;

    ret |= ((*str >= '0' && *str <= '9')?(*str-'0'):(
           (*str >= 'a' && *str <= 'f')?(*str-'a'+10):(
           (*str >= 'A' && *str <= 'F')?(*str-'A'+10):0
           )))<<4;
    str++;
    ret |= (*str >= '0' && *str <= '9')?(*str-'0'):(
           (*str >= 'a' && *str <= 'f')?(*str-'a'+10):(
           (*str >= 'A' && *str <= 'F')?(*str-'A'+10):0
           ));
    return ret;
}

void Font::Parser::character()
{
    char sName[1024];
    int32_t iIdx = -1;
    strcpy( sName, sLine+10 );
    Glyph *pChar = new Glyph();

    for(;;)
    {
        getLine();
        if( strncasecmp("ENCODING ", sLine, 9 ) == 0 )
        {
            sscanf( sLine+9, "%d", &iIdx );
        }
        else if( strncasecmp("DWIDTH ", sLine, 7 ) == 0 )
        {
            sscanf( sLine+7, "%d %d", &pChar->pDevOff.x, &pChar->pDevOff.y );
        }
        else if( strncasecmp("BBX ", sLine, 4 ) == 0 )
        {
            sscanf( sLine+4, "%d %d %d %d",
                &pChar->pBox.x, &pChar->pBox.y,
                &pChar->pOff.x, &pChar->pOff.y
                );
        }
        else if( strncasecmp("BITMAP", sLine, 6 ) == 0 )
        {
            pChar->iRowBytes = pChar->pBox.x/8 + ((pChar->pBox.x%8)==0?0:1);

            pChar->pData = new uint8_t[pChar->iRowBytes*pChar->pBox.y];
            // Read bitmap
            for( int y = 0; y < pChar->pBox.y; y++ )
            {
                getLine();
                for( int x = 0; x < pChar->iRowBytes; x++ )
                {
                    pChar->pData[x+y*pChar->iRowBytes] = hex2byte( sLine+(2*x) );
                }
            }
        }
        else if( strncasecmp("ENDCHAR", sLine, 7 ) == 0 )
        {
            if( iIdx >= 0 && iIdx < rFont.iTableTop )
            {
                rFont.pTable[iIdx] = pChar;
                //printf("Char %d: %s\n", iIdx, sName );
            }
            else
                delete pChar;
            return;
        }
    }
}