/*
 * (c) <kuchn@buha.info> 2004-2006
 *
 * This small tool tunes through list of frequencys
 * while every round a given command will be executed.
 * The frequencys may be given as arguments or they can
 * be parsed from a channels.conf.
 *
 * Useful for example to find programs (another tool would
 * have to check if there's a multiplex) or to get a
 * full EPG (with tv_grab_dvb) - last one was my intention.
 *
 * Example:
 *
 *  $ ./freqtool -e "~/tv_grab_dvb-0.9/update.sh" -f 650000000 -f 834000000 -f 514000000 -f 698000000 -f 826000000
 *
 * My 'update.sh' looks like this:
 * -
 *  #!/bin/sh
 *  /home/myth/tv_grab_dvb-0.9/tv_grab_dvb -o 1 -t 3 > /tmp/tv.xml 2>/dev/null && /usr/local/bin/mythfilldatabase --file 1 0 /tmp/tv.xml > /dev/null 2>&1
 * -
 *
 * This would update the EPG of mythtv for every channel (one frequency is a multiplex of multiple channels).
 */

#define MAX_FREQS 30
#define VERSION "0.2"

#include <stdio.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <getopt.h>

#include "linux/dvb/frontend.h"

int open_frontend(int adapter, int frontend);
int set_frontend(int frequency);
int help(char *exe);
int parse_channelsconf(char *channelsconf);

int fd_frontend, freq[MAX_FREQS], frequencys_done=0;

int main(int argc, char *argv[]) {
	int i, adapter=0, frontend=0, execute_done=0, channelsconf_done=0, parsed;
	char option, *execute, *channelsconf;

	while((option=getopt(argc, argv, "a:c:e:f:l:hv")) != -1) {
		switch(option) {
			case 'a':
				adapter = atoi(optarg);
				break;
			case 'c':
				channelsconf = (char *)malloc(strlen(optarg)+1);
				channelsconf = optarg;
				channelsconf_done = 1;
				break;
			case 'e':
				execute = (char *)malloc(strlen(optarg)+1);
				execute = optarg;
				execute_done = 1;
				break;
			case 'l':
				frontend = atoi(optarg);
			case 'f':
				if(frequencys_done<MAX_FREQS) {
					freq[frequencys_done] = atoi(optarg);
					frequencys_done++;
				} else {
					fprintf(stderr, "Error: too many frequencys. The maximum is %d.\n", MAX_FREQS);
					exit(4);
				}
				break;
			case 'h':
				help(argv[0]);
				exit(0);
			case 'v':
				printf("freqtool "VERSION" - (c) 2004-2006 <kuchn@buha.info>\n");
				exit(0);
		}
	}
	if (execute_done<1) {
		fprintf(stderr, "Error: You must set a path to the program that should be executed.\n\n");
		help(argv[0]);
		exit(1);
	}
	if (frequencys_done<1) {
		if(channelsconf_done<1) {
			fprintf(stderr, "Error: You must set at least one frequency.\n\n");
			help(argv[0]);
			exit(1);
		} else {
			parsed = parse_channelsconf(channelsconf);
			if(parsed<1) {
				exit(5);
			}
			printf("%d frequencys parsed (with %d channels).\n", frequencys_done, parsed);
		}
	}

	if (open_frontend(adapter, frontend) < 0) {
		exit(2);
	}

	for (i=0; i<frequencys_done; i++) {
		printf("%d. Tuning to %d Hz..", i+1, freq[i]);

		if (set_frontend(freq[i]) < 0) {
			perror("ioctl FE_SET_FRONTEND failed");
			exit(3);
		}

		printf(" executing.. ", execute);
		fflush(stdout);
		if (system(execute) < 0) {
			fprintf(stderr, "failed.");
			exit(6);
		} else {
			printf("done.");
		}
		printf("\n");
	}

	exit(0);
}

int open_frontend(int adapter, int frontend) {
	struct dvb_frontend_info info;
	static char path[28];

	snprintf(path, 28, "/dev/dvb/adapter%d/frontend%d", adapter, frontend);
	if ((fd_frontend = open (path, O_RDWR)) < 0) {
		perror(path);
		return -1;
	}

	ioctl(fd_frontend, FE_GET_INFO, &info);

	switch (info.type) {
		case FE_QPSK:
			fprintf(stderr, "Error: Satellite frontend is not supported.\n");
			return -2;
			break;
		case FE_QAM:
			fprintf(stderr, "Error: Cable frontend is not supported.\n");
			return -2;
			break;
		case FE_OFDM:
			printf("Terrestrial");
			break;
		default:
			fprintf(stderr, "Error: Unknown frontend.\n");
			return -2;
	}

	printf (" frontend opened (%s).\n", info.name);
	printf ("  Minimum frequency: %d\n", info.frequency_min);
	printf ("  Maximum frequency: %d\n", info.frequency_max);
	printf ("  Stepsize: %d\n\n", info.frequency_stepsize);

	return 1;
}

int set_frontend(int frequency) {
	struct dvb_frontend_parameters parameters;

	parameters.frequency = frequency;
	// some other settings like BANDWIDTH_AUTO or HIERARCHY_AUTO cause problems here. maybe to change.
	parameters.inversion = INVERSION_OFF;
	parameters.u.ofdm.bandwidth = BANDWIDTH_8_MHZ;
	parameters.u.ofdm.code_rate_HP = FEC_AUTO;
	parameters.u.ofdm.code_rate_LP = FEC_AUTO;
	parameters.u.ofdm.constellation = QAM_AUTO;
	parameters.u.ofdm.transmission_mode = TRANSMISSION_MODE_AUTO;
	parameters.u.ofdm.guard_interval = GUARD_INTERVAL_AUTO;
	parameters.u.ofdm.hierarchy_information = HIERARCHY_NONE;
									
	if (ioctl(fd_frontend, FE_SET_FRONTEND, &parameters) < 0) {
		return -1;
	}

	return 1;
}

int help(char *exe) {
	printf("freqtool "VERSION" - <kuchn@buha.info>\n\n"
		" Usage: %s [ -a <n> ] [ -c <path> ] -e <path>\n"
		"           [ -f <freq> (-f <freq> ...) ] [ -l <n> ]\n\n"
		"Options:\n"
		" -a <n>          DVB-Adapter (default: 0)\n"
		" -c <path>       Path to channels.conf\n"
		" -e <path>       Program to execute\n"
		" -f <freq>       Frequency in Hz\n"
		" -l <n>          DVB-Frontend (default: 0)\n"
		" -h              Help (this one)\n"
		" -v              Version\n\n"
		"It's either -c or at least one -f. -e is needed.\n", exe);
}

int parse_channelsconf(char *channelsconf) {
	FILE *fd_channels;
	int i, fr, j, k, frequencys_done_save;

	fd_channels = fopen(channelsconf, "r");
	if(fd_channels == NULL) {
		perror(channelsconf);
		return -1;
	}

	while(fscanf(fd_channels, "%*[^:]:%d:%*s\n", &fr) != EOF) {
		if(frequencys_done<MAX_FREQS) {
			freq[frequencys_done] = fr*1000;
			frequencys_done++;
		} else {
			fprintf(stderr, "Error: Maximum amount of frequencys reached (%d).\n", MAX_FREQS);
			return -2;
		}
	}

	// gibts des nit ah in a schenen funktion?
	frequencys_done_save = frequencys_done;
	for(i=1;i<frequencys_done;i++) {
		j=i;
		while(freq[i]==freq[i-1]) {
			freq[i]=freq[++j];
			frequencys_done--;
		}
		for(k=i+1;k<frequencys_done_save-1;k++) {
			freq[k]=freq[j];
			j++;
		}
	}

	return frequencys_done_save;
}