/* cdpreader -- Trainz CDP file reader/analyser
 *
 * Dan Horák <dan@danny.cz>
 *
 * 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.
 *
 * (C) Copyright 2010 Daniel Horák
 */


#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>
#include <fcntl.h>

struct CDPHeader {
	char	header[4];
	int32_t	version;
	int32_t	val1;
	int32_t	length;
};

int readblock(int f)
{
	int32_t	block_length;
	int8_t	name_length, value_type;
	char	name[256];
	int32_t	int_value, kuid1, kuid2;
	float	float_value;
	char	char_value;
	off_t	filepos;
	int	value_length;

	filepos = lseek(f, 0, SEEK_CUR);
	if (read(f, &block_length, sizeof(block_length)) <= 0)
		return -1;
	if (read(f, &name_length, sizeof(name_length)) < 0)
		return -1;
	if (read(f, name, name_length) < 0)
		return -1;
	if (read(f, &value_type, sizeof(value_type)) < 0)
		return -1;

	value_length = block_length - 1 - name_length - 1;
	printf("block: start=0x%08x length=%ld name=%s value_type=0x%02x value_length=%d\n", filepos, block_length, name, value_type, value_length);

	switch (value_type) {
		case 0x00:
			return readblock(f);
			break;
		case 0x01:
			while (value_length > 0)
			{
				read(f, &int_value, sizeof(int32_t));
				printf("int=%d\n", int_value);
				value_length -= 4;
			}
			break;
		case 0x02:
			while (value_length > 0)
			{
				read(f, &float_value, sizeof(float));
				printf("float=%f\n", float_value);
				value_length -= 4;
			}
			break;
		case 0x03:
			printf("string=");
			while (value_length-- > 0)
			{
				read(f, &char_value, 1);
				if (char_value)
					printf("%c", char_value);
			}
			printf("\n");
			break;
		case 0x04:
			lseek(f, value_length, SEEK_CUR);
			printf("skipping content\n");
			break;
		case 0x0d:
			read(f, &kuid1, sizeof(int32_t));
			read(f, &kuid2, sizeof(int32_t));
			printf("kuid=%d:%d\n", kuid1, kuid2);
			break;
		default:
			lseek(f, value_length, SEEK_CUR);
			printf("unknown type 0x%02x, skipping content\n", value_type);
			break;
	}

	return 0;
}

int main(int argc, char **argv)
{
	int f;
	char *file;
	struct CDPHeader cdp;
	int res;

	if (argc != 2)
	{
		printf("Usage: %s <file.cdp>\n", argv[0]);
		return 1;
	}

	file = argv[1];

	if ((f = open(argv[1], O_RDONLY)) == -1)
	{
		printf("can't open %s\n", file);
		return 2;
	}

	printf("checking file: %s\n", file);

	if (read(f, &cdp, sizeof(cdp)) == -1)
	{
		printf("can't read %s\n", file);
		close(f);
		return 2;
	}

	if (strncmp(cdp.header, "ACS$", 4) != 0)
	{
		printf("file %s is not CDP\n", file);
	}
	printf("version=%d val1=%d lenght=%ld\n",
		cdp.version, cdp.val1, cdp.length);


	while (res == 0) {
		res = readblock(f);
	}

	close(f);

	return 0;
}