/*
 * Copyright (C) 2018 AVM GmbH <fritzbox_info@avm.de>
 *
 * 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.
 */

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdbool.h>
#include <unistd.h>
#include <errno.h>
#include <getopt.h>
#include <string.h>
#include "wdt.h"
#include "wdt-private.h"

static void warn(const char *argv0, const char *fmt, ...)
{
    va_list ap;

    fprintf(stderr, "%s: ", argv0);
    va_start(ap, fmt);
    vfprintf(stderr, fmt, ap);
    va_end(ap);
}

static int detect_device(void)
{
    const char *devname;

    devname = watchdog_device_name();

    if (devname)
        printf("Found AVM watchdog device: %s\n", devname);
    else
        puts("No AVM watchdog device found");

    return !devname;
}

static int write_args_to_device(const char *argv0, char **argv)
{
    const char *action;
    int fd, i, ret;
    FILE *fp;

    ret = -1;

    action = "opening";
    fd = watchdog_open_device();
    if (fd < 0)
        goto bail;

    fp = fdopen(fd, "w");
    if (!fp)
        goto bail;

    action = "writing to";
    for (i = 0; argv[i]; ++i) {
        if (i > 0)
            fputc(' ', fp);

        ret = fputs(argv[i], fp);
        if (ret == EOF)
            goto bail;
    }

    ret = fclose(fp);

bail:
    if (ret)
        warn(argv0, "Error %s watchdog device: %s\n", action, strerror(errno));

    return ret;
}

int main(int argc, char *argv[])
{
    static struct option lopt[] = {{"detect", no_argument, 0, 0}};
    bool detectonly = false;
    int c, ret;

    c = getopt_long(argc, argv, "", lopt, NULL);
    switch (c) {
        case -1:
            break;
        case 0:
            detectonly = true;
            break;
        default:
            warn(argv[0], "Unknown options.\n");
            return EXIT_FAILURE;
    }

    if (detectonly)
        ret = detect_device();
    else
        ret = write_args_to_device(argv[0], &argv[optind]);

    return !!ret;
}