/*
 * Copyright (C) 2007-2023 Xagasoft, All rights reserved.
 *
 * This file is part of the libbu++ library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#include "bu/taf.h"
#include "bu/string.h"
#include "bu/stream.h"

#include <stdlib.h>

using namespace Bu;

Bu::TafReader::TafReader( Bu::Stream &sIn ) :
    c( 0 ),
    la( 0 ),
    sIn( sIn ),
    iLine( 1 ), iCol( -1 )
{
    next(); next();
}

Bu::TafReader::~TafReader()
{

}

Bu::TafGroup *Bu::TafReader::readGroup()
{
    ws();
    if( c != '{' )
        throw TafException("%d:%d: Expected '{' got '%c'.", iLine, iCol, c );
    next();
    ws();
    String sName = readStr();
    TafGroup *pGroup = new TafGroup( sName );
    try
    {
        ws();
        if( c != ':' )
            throw TafException("%d:%d: Expected ':' got '%c'.",
                iLine, iCol, c );
        next();
        //printf("Node[%s]:\n", sName.getStr() );

        groupContent( pGroup );

        if( c != '}' )
            throw TafException("%d:%d: Expected '}' got '%c'.",
                iLine, iCol, c );

        //next();

        return pGroup;
    }
    catch(...)
    {
        delete pGroup;
        throw;
    }
}

void Bu::TafReader::groupContent( Bu::TafGroup *pGroup )
{
    for(;;)
    {
        ws();
        if( c == '{' )
        {
            pGroup->addChild( readGroup() );
            next();
        }
        else if( c == '}' )
            return;
        else if( c == '/' && la == '*' )
            pGroup->addChild( readComment() );
        else if( c == '/' && la == '/' )
            pGroup->addChild( readComment( true ) );
        else if( c == ':' )
            throw TafException("%d:%d: Encountered stray ':' in taf stream.",
                iLine, iCol );
        else
            pGroup->addChild( readProperty() );
    }
}

Bu::TafProperty *Bu::TafReader::readProperty()
{
    String sName = readStr();
    ws();
    if( c != '=' )
    {
        //printf("  %s (true)\n", sName.getStr() );
        return new Bu::TafProperty( "", sName );
    }
    next();
    String sValue = readStr();
    return new Bu::TafProperty( sName, sValue );
    //printf("  %s = %s\n", sName.getStr(), sValue.getStr() );
}

Bu::TafComment *Bu::TafReader::readComment( bool bEOL )
{
    String sCmnt;
    next();
    if( bEOL )
    {
        for(;;)
        {
            next();
            if( c == '\n' && la == '\r' )
            {
                next(); next();
                break;
            }
            else if( c == '\n' || c == '\r' )
            {
                next();
                break;
            }
            sCmnt += c;
        }
    }
    else
    {
        for(;;)
        {
            next();
            if( c == '*' && la == '/' )
            {
                next(); next();
                break;
            }
            sCmnt += c;
        }
    }

    return new TafComment( sCmnt, bEOL );
}

Bu::String Bu::TafReader::readStr()
{
    ws();
    String s;
    if( c == '"' )
	{
		next();
		for(;;)
		{
			if( c == '\\' )
			{
				next();
				if( c == 'x' )
				{
					char code[3]={'\0','\0','\0'};
					next();
					code[0] = c;
					next();
					code[1] = c;
					c = (unsigned char)strtol( code, NULL, 16 );
				}
				else if( c == '"' )
                    c = '"';
				else if( c == '\\' )
					c = '\\';
				else if( c == 'n' )
					c = '\n';
				else if( c == 't' )
					c = '\t';
				else
					throw TafException("%d:%d: Invalid escape sequence '\\%c'.",
						iLine, iCol, c );
			}
			else if( c == '"' )
                break;
            s += c;
            next();
        }
        next();
    }
    else
    {
        for(;;)
        {
            if( isws() || c == '}' || c == '{' || c == ':' || c == '=' )
                break;
            s += c;
            next();
        }
    }

    return s;
}

void Bu::TafReader::ws()
{
    for(;;)
    {
        if( !isws() )
            return;

        next();
    }
}

bool Bu::TafReader::isws()
{
    return (c == ' ' || c == '\t' || c == '\n' || c == '\r');
}

void Bu::TafReader::next()
{
    if( c == '\n' )
    {
        iLine++;
        iCol = 1;
    }
    else
        iCol++;
    if( c == '}' )
    {
        rawread( &c );
        if( c != '}' )
            rawread( &la );
    }
    else
    {
        c = la;
        if( c != '}' )
            rawread( &la );
    }
}

void Bu::TafReader::rawread( char *c )
{
    if( sIn.read( c, 1 ) < 1 )
    {
        if( sIn.isEos() )
        {
            throw TafException("%d:%d: Premature end of stream.",
                iLine, iCol, c );
        }
        else
        {
            throw TafException("%d:%d: No data read, but not end of stream?",
                iLine, iCol, c );
        }
    }
}