/*
 * binpatch 0.0.1, testing binary patching utility.
 *
 * Copyright (C) 2006 Jindrich Novy (jnovy@users.sourceforge.net)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>

#include <inttypes.h>

uint8_t *b1;
off_t patchsize;

void *check_malloc( size_t s ) {
	void *p = malloc(s);
    
	if ( !p ) {
		printf("Can't allocate %llu bytes, exiting...\n", s);
		exit(1);
	}

	return p;
}

uint32_t gc( FILE *f ) {
	uint32_t c;
	
	if ( !patchsize ) {
		fprintf(stderr, "Read request at EOF!");
		exit(1);
	}
	
	if ( (c=fgetc(f)) == EOF ) {
		fprintf(stderr,"Unexpected EOF!\n");
		exit(1);
	}
	
	patchsize--;
	
	return c;
}

uint32_t gn( FILE *f ) {
	return gc(f)|(gc(f)<<8)|(gc(f)<<16);
}

void pc( int c, FILE *f ) {
	if ( fputc(c,f) == EOF ) {
		fprintf(stderr,"Error in writing!\n");
		exit(1);
	}
}

int main( int argc, char **argv ) {
	FILE *fi, *fp, *fo;
	struct stat s1, s2;

	if ( argc != 4 ) {
		fprintf(stderr,"%s <binfile> <binpatch> <newfile>\n", argv[0]);
		exit(1);
	}

        if ( stat(argv[1], &s1 ) ) {
	        perror("");
		exit(1);
	}
	if ( stat(argv[2], &s2 ) ) {
	        perror("");
	        exit(1);
	}
	
	patchsize = s2.st_size;
	printf("%d\n", patchsize);

	fp = fopen(argv[2],"rb");
	fo = fopen(argv[3],"wb");

	fi = fopen(argv[1],"rb");	
	b1 = check_malloc(s1.st_size);
	fread(b1, 1, s1.st_size, fi);
	fclose(fi);
	
	{
		uint32_t unmatched, i;

		unmatched = gn(fp);

		for ( i=0; i<unmatched; i++ )
			pc(gc(fp), fo);

		while ( patchsize ) {
			uint32_t b1pos, size;

			unmatched = gn(fp);
			b1pos     = gn(fp);
			size      = gn(fp);

			printf("%5d == %5d, %8d\n", b1pos, ftell(fo), size);

			for ( i=b1pos; i<b1pos+size; i++ )
				pc(b1[i],fo);

			for ( i=0; i<unmatched; i++ )
				pc(gc(fp),fo);
		}
	}
	
	free(b1);
	
	fclose(fo);
	fclose(fp);

	return 0;
}