// $Revision: 1.2 $
//Copyright (C) 1995 Taligent, Inc. All rights reserved.

#ifndef TaligentSamples_DECODEXBM
#include "DecodeXBM.h"
#endif
#ifndef TaligentSamples_XBM
#include "XBM.h"
#endif
#ifndef Taligent_RGBTRANSFERMODES
#include <Taligent/RGBTransferModes.h>
#endif
#ifndef Taligent_RGBCOLOR
#include <Taligent/RGBColor.h>
#endif
#ifndef Taligent_GRAPHICIMAGE
#include <Taligent/GraphicImage.h>
#endif
#ifndef Taligent_IMAGE
#include <Taligent/Image.h>
#endif
#ifndef Taligent_KERNEL
#include <Taligent/Kernel.h>
#endif
#ifndef Taligent_RUNTIME
#include <Taligent/RunTime.h>
#endif
extern "C" {
#include <stdlib.h>
}

TXBMDecoder::TXBMDecoder(TStream& inputStream)
{
    fImage = NIL;
	fStream = &inputStream;
	
	ParseHeader();
	ParseBody();
}


TXBMDecoder::~TXBMDecoder()
{
    delete fImage;
}


unsigned char
TXBMDecoder::GetNextByte()
{
    unsigned char byte;
	do {
		byte <<= *fStream;
	} while (byte == ' ' || byte == '\t' || byte == '\n' || byte == '\r');
    return byte;
}


TXBMDecoder::XBMCode
TXBMDecoder::ReadOneCode()
{
 	char hexCode[5];
	for (int codeIndex = 0 ; codeIndex < 4 ; codeIndex++) {
		hexCode[codeIndex] = GetNextByte();
	};
	if ((hexCode[0] == '0') && (hexCode[1] == 'x')) {
		TXBMDecoder::XBMCode result;
		hexCode[4] = '\0';
		return (TXBMDecoder::XBMCode)strtoul(hexCode, NIL, 16);
	}
	ThrowBadData("Invalid hexidecimal data found in stream");
	return 0;
}

unsigned short
TXBMDecoder::GetImageSize()
{
	unsigned char charBlock[256];
	unsigned char* blockPtr = &charBlock[0];
	for (int filled = 0 ; filled<256 ; filled++) {
		*blockPtr <<= *fStream;
		switch (*blockPtr) {
		  case '0': case '1': case '2': case '3': case '4':
		  case '5': case '6': case '7': case '8': case '9':
			blockPtr++;
			break;
		  case '\n':
		  case '\r':
			*blockPtr = '\0';
			return atoi((const char*)charBlock);
		  default:
			blockPtr = &charBlock[0];
			break;
		}
	}
	ThrowBadData("Invalid header line");
	return 0;
}

void
TXBMDecoder::ParseHeader()
{
	if (GetNextByte() == '#') {
		fImageWidth = GetImageSize();
		if (GetNextByte() == '#') {
			fImageHeight = GetImageSize();

			TGrafBundle *tBundle = NIL;
			tBundle = new TGrafBundle();
			tBundle->AdoptImageTransferMode(
						   new TRGBTransparentTransferMode(TRGBColor(1,1,1)));

			TIndexedImage::TRGBColorArray colorArray(2);
			fImage = new TIndexedImage(TGPoint(0,0), fImageWidth, fImageHeight,
									   colorArray, TGImage::k72DPI, tBundle);
			return;
		}
	}
	ThrowBadData("Invalid header data");
}


void
TXBMDecoder::ParseBody()
{
	while (GetNextByte() != '{') ;

	TGModifiableImage* pixels = fImage->GetModifiableImage();
	unsigned short column = 0;
	unsigned short row = 0;
	while (row < fImageHeight) {
		TXBMDecoder::XBMCode xbmCode = ReadOneCode();

		for (short bits=0 ; bits<8 ; bits++, column++) {
			if (column < fImageWidth) {
				if ((xbmCode >> bits) & 0x1) {
					pixels->SetPixel(column, row, TRGBColor(1,1,1));
				} else {
					pixels->SetPixel(column, row, TRGBColor(0,0,0));
				}
			}
		}
		if (column >= fImageWidth) {
			column = 0;
			if (++row == fImageHeight) {
				break;
			}
		}
		unsigned char byte = GetNextByte();
		if (byte != ',') {
			qprintf("Bad Byte at row %i -- %i:  %c\n", row, (int)byte, byte);
			ThrowBadData("Expected image size doesn't match data");
		}
	}
}

TModifiableImage*
TXBMDecoder::OrphanImage()
{
    TModifiableImage* result = fImage;
    fImage = NIL;
    return result;
}

void
TXBMDecoder::ThrowBadData(const char* reason)
{
    qprintf("TXBMDecoder::ThrowBadData: %s\n", reason);
    
    throw TXBMConverter::TXBMConverterException(
	  TXBMConverter::TXBMConverterException::kBadData);
}