/*-------------------------------------------------------------------------
 * main.c
 *
 * Copyright (c) 2016, Teodor Sigaev <teodor@sigaev.ru>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *	  notice, this list of conditions and the following disclaimer in the
 *	  documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *-------------------------------------------------------------------------
 */

#include <fcntl.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <hidapi/hidapi.h>
#include <sys/param.h>

#include <trinket.h>

static char*	dbdir = NULL;
static int		period = (300); /* in seconds */
static char*	pidfile = NULL;
static char*	logfile = NULL;
static bool		daemonize = false;
static bool		workaround = false;
static char		tfile[MAXPATHLEN],
				ofile[MAXPATHLEN];

static const double coefficient = (248e-6 / 2637.0);

static void
usage(const char *errmsg) {
	puts("trinketd - collecting info from AtomPro");
	puts("Copyright (c) 2016, Teodor Sigaev <teodor@sigaev.ru>");
	puts("trinketd [-d] [-l logfile] [-p pidfile] [-P period] [-D datadir] [-w]");

	if (errmsg) {
		puts("");
		puts(errmsg);
	}

	exit(1);
}

static void
main_loop() {
	double	prevDose,
			curDose;

restart:
	prevDose = -1;

	if (trinketOpen() != ERR_OK) {
		fprintf(stderr, "trinketOpen fails\n");
		sleep(1);
		goto restart;
	}

	while(42) {
		if (workaround)
			trinketPing();

		if (trinketGetCumDose(&curDose) != ERR_OK) {
			fprintf(stderr, "trinketGetCumDose fails\n");
			trinketClose();
			sleep(1);
			goto restart;
		}

		if (prevDose >= 0.0) {
			double	counts = curDose - prevDose;
			double	radlevel = 1e6 * coefficient * counts * 3600.0 / (double)period;
			FILE	*fh = stdout;
			bool	successOpen = true;

			if (daemonize) {
				if ((fh = fopen(tfile, "w")) == NULL) {
					fprintf(stderr, "fopen fails\n");
					successOpen = false;
				}
			}

			if (successOpen) {
				fprintf(fh, "total: %lld\n", (long long)curDose);
				fprintf(fh, "counts: %lld\n", (long long)counts);
				fprintf(fh, "radlevel: %.02f\n", radlevel);
			}

			if (fh && fh != stdout) {
				fflush(fh);
				fclose(fh);
				rename(tfile, ofile);
			}
		}

		prevDose = curDose;
		sleep(period);
	}

	trinketClose();
}


extern char *optarg;
extern int opterr, optind;

int
main(int argn, char* argv[]) {
	int i;
	int	pidfd,
		logfd;

	opterr = 0;
	while((i=getopt(argn,argv,"dD:l:p:P:wh")) != EOF) {
		switch(i) {
			case 'd':
				daemonize = true;
				break;
			case 'D':
				dbdir = strdup(optarg);
				break;
			case 'l':
				logfile = strdup(optarg);
				break;
			case 'p':
				pidfile = strdup(optarg);
				break;
			case 'P':
				period = atoi(optarg);
				break;
			case 'w':
				workaround = true;
				break;
			case 'h':
			default:
				usage(NULL);
		}
	}

	if (opterr || optind != argn)
		usage("argument err");

	if (period <= 0)
		usage("Collecting period could not be zero nor negative");

	if (daemonize && !dbdir)
		usage("trinketd: it is useless to use -d without -D");

	if (dbdir && strlen(dbdir) > MAXPATHLEN - 32)
		usage("datadir is too long");

	if (pidfile) {
		pidfd = open(pidfile, O_CREAT | O_WRONLY | O_TRUNC, 0666);
		if (pidfd < 0)
			usage("could not write pidfile");
	}

	if (logfile) {
		logfd = open(logfile, O_CREAT | O_WRONLY | O_APPEND, 0666);
		if (logfd < 0)
			usage("could not write logfile");
	}

	if (daemonize) {
		if (daemon(0, 0) == -1)
			usage("could not daemonize");
	}

	if (pidfile) {
		char pid[64];

		snprintf(pid, sizeof(pid), "%lld", (long long)getpid());
		if (write(pidfd, pid, strlen(pid)) != strlen(pid))
			usage("could not write pid");
		close(pidfd);
	}

	if (logfile) {
		dup2(logfd, fileno(stderr));
		close(logfd);
	}

	if (hid_init() < 0) {
		fprintf(stderr, "hid_init fails\n");
		exit(1);
	}

	if (dbdir) {
		snprintf(tfile, MAXPATHLEN, "%s/trinket.tmp", dbdir);
		snprintf(ofile, MAXPATHLEN, "%s/trinket.dat", dbdir);
	}

	main_loop();

	hid_exit();
	return 0;
}