/* -------------------------------------------------------------------------------

   Copyright (C) 1999-2007 id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

   -------------------------------------------------------------------------------

   This code has been altered significantly from its original form, to support
   several games based on the Quake III Arena engine, in the form of "Q3Map2."

   ------------------------------------------------------------------------------- */



/* dependencies */
#include "q3map2.h"



/*
   MD4BlockChecksum()
   calculates an md4 checksum for a block of data
 */

static int MD4BlockChecksum( void * buffer, int length ) {
	unsigned char digest[16];
	int checksum;

	md4_get_digest( buffer, length, digest );
	/* I suppose it has to be done that way for legacy reasons? */
	checksum = digest[0] & ( digest[1] << 8 ) & ( digest[2] << 16 ) & ( digest[3] << 24 );
	checksum ^= digest[4] & ( digest[5] << 8 ) & ( digest[6] << 16 ) & ( digest[7] << 24 );
	checksum ^= digest[8] & ( digest[9] << 8 ) & ( digest[10] << 16 ) & ( digest[11] << 24 );
	checksum ^= digest[12] & ( digest[13] << 8 ) & ( digest[14] << 16 ) & ( digest[15] << 24 );
	return checksum;
}

/*
   FixAASMain()
   resets an aas checksum to match the given BSP
 */

int FixAASMain( int argc, char **argv ){
	int length, checksum;
	void        *buffer;
	FILE        *file;
	char aas[ 1024 ], **ext;
	char        *exts[] =
	{
		".aas",
		"_b0.aas",
		"_b1.aas",
		NULL
	};


	/* arg checking */
	if ( argc < 2 ) {
		Sys_Printf( "Usage: q3map -fixaas [-v] <mapname>\n" );
		return 0;
	}

	/* do some path mangling */
	strcpy( source, ExpandArg( argv[ argc - 1 ] ) );
	StripExtension( source );
	DefaultExtension( source, ".bsp" );

	/* note it */
	Sys_Printf( "--- FixAAS ---\n" );

	/* load the bsp */
	Sys_Printf( "Loading %s\n", source );
	length = LoadFile( source, &buffer );

	/* create bsp checksum */
	Sys_Printf( "Creating checksum...\n" );
	checksum = LittleLong( MD4BlockChecksum( buffer, length ) );

	/* write checksum to aas */
	ext = exts;
	while ( *ext )
	{
		/* mangle name */
		strcpy( aas, source );
		StripExtension( aas );
		strcat( aas, *ext );
		Sys_Printf( "Trying %s\n", aas );
		ext++;

		/* fix it */
		file = fopen( aas, "r+b" );
		if ( !file ) {
			continue;
		}
		if ( fwrite( &checksum, 4, 1, file ) != 1 ) {
			Error( "Error writing checksum to %s", aas );
		}
		fclose( file );
	}

	/* return to sender */
	return 0;
}