/*
 * idevicedate.c
 * Simple utility to get and set the clock on a device
 *
 * Copyright (c) 2011 Martin Szulecki All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#if HAVE_LANGINFO_CODESET
# include <langinfo.h>
#endif

#include <libimobiledevice/libimobiledevice.h>
#include <libimobiledevice/lockdown.h>

#ifdef _DATE_FMT
# define DATE_FMT_LANGINFO() nl_langinfo (_DATE_FMT)
#else
# define DATE_FMT_LANGINFO() ""
#endif

static void print_usage(int argc, char **argv)
{
	char *name = NULL;
	
	name = strrchr(argv[0], '/');
	printf("Usage: %s [OPTIONS]\n", (name ? name + 1: argv[0]));
	printf("Display the current date or set it on a device.\n\n");
	printf("NOTE: Setting the time on iOS 6 and later is only supported\n");
	printf("      in the setup wizard screens before device activation.\n\n");
	printf("  -d, --debug\t\tenable communication debugging\n");
	printf("  -u, --udid UDID\ttarget specific device by its 40-digit device UDID\n");
	printf("  -s, --set TIMESTAMP\tset UTC time described by TIMESTAMP\n");
	printf("  -c, --sync\t\tset time of device to current system time\n");
	printf("  -h, --help\t\tprints usage information\n");
	printf("\n");
}

int main(int argc, char *argv[])
{
	lockdownd_client_t client = NULL;
	idevice_t device = NULL;
	idevice_error_t ret = IDEVICE_E_UNKNOWN_ERROR;
	int i;
	const char* udid = NULL;
	time_t setdate = 0;
	plist_t node = NULL;
	int node_type = -1;
	uint64_t datetime = 0;
	time_t rawtime;
	struct tm * tmp;
	char const *format = NULL;
	char buffer[80];
	int result = 0;

	/* parse cmdline args */
	for (i = 1; i < argc; i++) {
		if (!strcmp(argv[i], "-d") || !strcmp(argv[i], "--debug")) {
			idevice_set_debug_level(1);
			continue;
		}
		else if (!strcmp(argv[i], "-u") || !strcmp(argv[i], "--udid")) {
			i++;
			if (!argv[i] || (strlen(argv[i]) != 40)) {
				print_usage(argc, argv);
				return 0;
			}
			udid = argv[i];
			continue;
		}
		else if (!strcmp(argv[i], "-s") || !strcmp(argv[i], "--set")) {
			i++;
			if (!argv[i] || (strlen(argv[i]) <= 1)) {
				print_usage(argc, argv);
				return 0;
			}
			setdate = atoi(argv[i]);
			if (setdate == 0) {
				printf("ERROR: Invalid timestamp value.\n");
				print_usage(argc, argv);
				return 0;
			}
			continue;
		}
		else if (!strcmp(argv[i], "-c") || !strcmp(argv[i], "--sync")) {
			i++;
			/* get current time */
			setdate = time(NULL);
			/* convert it to local time which sets timezone/daylight variables */
			tmp = localtime(&setdate);
			/* recalculate to make it UTC */
			setdate = mktime(tmp);
			continue;
		}
		else if (!strcmp(argv[i], "-h") || !strcmp(argv[i], "--help")) {
			print_usage(argc, argv);
			return 0;
		}
		else {
			print_usage(argc, argv);
			return 0;
		}
	}

	/* determine a date format */
	if (!format) {
		format = DATE_FMT_LANGINFO ();
		if (!*format) {
			format = "%a %b %e %H:%M:%S %Z %Y";
		}
	}

	ret = idevice_new(&device, udid);
	if (ret != IDEVICE_E_SUCCESS) {
		if (udid) {
			printf("No device found with udid %s, is it plugged in?\n", udid);
		} else {
			printf("No device found, is it plugged in?\n");
		}
		return -1;
	}

	if (LOCKDOWN_E_SUCCESS != lockdownd_client_new_with_handshake(device, &client, "idevicedate")) {
		result = -1;
		goto cleanup;
	}

	if(lockdownd_get_value(client, NULL, "TimeIntervalSince1970", &node) != LOCKDOWN_E_SUCCESS) {
		fprintf(stderr, "ERROR: Unable to retrieve 'TimeIntervalSince1970' node from device.\n");
		result = -1;
		goto cleanup;
	}

	if (node == NULL) {
		fprintf(stderr, "ERROR: Empty node for 'TimeIntervalSince1970' received.\n");
		result = -1;
		goto cleanup;
	}

	node_type = plist_get_node_type(node);

	/* get or set? */
	if (setdate == 0) {
		/* get time value from device */
		switch (node_type) {
			case PLIST_UINT:
				plist_get_uint_val(node, &datetime);
				break;
			case PLIST_REAL:
				{
					double rv = 0;
					plist_get_real_val(node, &rv);
					datetime = rv;
				}
				break;
			default:
				fprintf(stderr, "ERROR: Unexpected node type for 'TimeIntervalSince1970'\n");
				break;
		}
		plist_free(node);
		node = NULL;

		/* date/time calculations */
		rawtime = (time_t)datetime;
		tmp = localtime(&rawtime);

		/* finally we format and print the current date */
		strftime(buffer, 80, format, tmp);
		puts(buffer);
	} else {
		datetime = setdate;

		plist_free(node);
		node = NULL;

		switch (node_type) {
			case PLIST_UINT:
				node = plist_new_uint(datetime);
				break;
			case PLIST_REAL:
				node = plist_new_real((double)datetime);
				break;
			default:
				fprintf(stderr, "ERROR: Unexpected node type for 'TimeIntervalSince1970'\n");
				break;
		}

		if(lockdownd_set_value(client, NULL, "TimeIntervalSince1970", node) == LOCKDOWN_E_SUCCESS) {
			tmp = localtime(&setdate);
			strftime(buffer, 80, format, tmp);
			puts(buffer);
		} else {
			printf("ERROR: Failed to set date on device.\n");
		}
		node = NULL;
	}

cleanup:
	if (client)
		lockdownd_client_free(client);

	if (device)
		idevice_free(device);

	return result;
}