/*
 * This program reads a TCH/FS downlink capture produced with FreeCalypso tools
 * (fw version with TCH downlink sniffing feature and fc-shell tch record),
 * parses the frame bits according to our current understanding, and dumps
 * everything in human-readable form for further analysis.
 */

#include <ctype.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <gsm.h>
#include "../libgsmfrp/gsm_fr_preproc.h"

static void
process_record(lineno, fn_mod_104, status_words, tidsp_bytes, dummy_state)
	int lineno;
	unsigned fn_mod_104;
	uint16_t *status_words;
	uint8_t *tidsp_bytes;
	gsm dummy_state;
{
	uint8_t libgsm_bytes[33];
	int16_t params[76];
	int i, j, n;

	printf("#%d: fn=%u DSP %04X %04X %04X\n", lineno, fn_mod_104,
		status_words[0], status_words[1], status_words[2]);
	gsm0610_tidsp_to_libgsm(tidsp_bytes, libgsm_bytes);
	fputs("  bits ", stdout);
	for (i = 0; i < 33; i++)
		printf("%02X", tidsp_bytes[i]);
	printf(" SID=%d\n", gsmfr_preproc_sid_classify(libgsm_bytes));
	gsm_explode(dummy_state, libgsm_bytes, params);
	fputs("  FR", stdout);
	n = 0;
	for (i = 0; i < 8; i++)
		printf(" %d", params[n++]);
	putchar('\n');
	for (i = 0; i < 4; i++) {
		putchar(' ');
		for (j = 0; j < 17; j++)
			printf(" %d", params[n++]);
		putchar('\n');
	}
}

main(argc, argv)
	char **argv;
{
	FILE *inf;
	gsm dummy_state;
	char linebuf[128];
	int lineno, rc;
	uint16_t status_words[3];
	uint8_t tidsp_bytes[33];
	unsigned fn_mod_104;

	if (argc != 2) {
		fprintf(stderr, "usage: %s dlcap-file\n", argv[0]);
		exit(1);
	}
	inf = fopen(argv[1], "r");
	if (!inf) {
		perror(argv[1]);
		exit(1);
	}
	dummy_state = gsm_create();
	if (!dummy_state) {
		fprintf(stderr, "gsm_create() failed!\n");
		exit(1);
	}
	for (lineno = 1; fgets(linebuf, sizeof linebuf, inf); lineno++) {
		/* support both old and new formats */
		if (isxdigit(linebuf[0]) && isxdigit(linebuf[1]) &&
		    isxdigit(linebuf[2]) && isxdigit(linebuf[3])) {
			/* also support parsing output from fc-vm2hex */
			if (linebuf[4] == '\n') {
				printf("#%d: fn=0 DSP %.4s\n", lineno, linebuf);
				continue;
			}
			rc = parse_dlcap_common(linebuf, status_words,
						tidsp_bytes);
			if (rc < 0) {
invalid:			fprintf(stderr,
				"error: %s is not in the expected format\n",
					argv[1]);
				exit(1);
			}
			fn_mod_104 = 0;		/* won't have TAF */
		} else if (!strncmp(linebuf, "FR ", 3)) {
			rc = parse_dlcap_common(linebuf + 3, status_words,
						tidsp_bytes);
			if (rc < 0)
				goto invalid;
			if (linebuf[84] != ' ')
				goto invalid;
			if (!isdigit(linebuf[85]))
				goto invalid;
			fn_mod_104 = strtoul(linebuf + 85, 0, 10);
		} else
			goto invalid;
		process_record(lineno, fn_mod_104, status_words, tidsp_bytes,
				dummy_state);
	}
	exit(0);
}