<?php
/*
 +-------------------------------------------------------------------------+
 | Copyright (C) 2004-2021 The Cacti Group                                 |
 |                                                                         |
 | 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.                  |
 |                                                                         |
 | This program 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 General Public License for more details.                            |
 +-------------------------------------------------------------------------+
 | Cacti: The Complete RRDtool-based Graphing Solution                     |
 +-------------------------------------------------------------------------+
 | This code is designed, written, and maintained by the Cacti Group. See  |
 | about.php and/or the AUTHORS file for specific developer information.   |
 +-------------------------------------------------------------------------+
 | http://www.cacti.net/                                                   |
 +-------------------------------------------------------------------------+
*/

/* ================= input validation ================= */
get_filter_request_var('predefined_timespan');
get_filter_request_var('predefined_timeshift');
get_filter_request_var('date1', FILTER_CALLBACK, array('options' => 'sanitize_search_string'));
get_filter_request_var('date2', FILTER_CALLBACK, array('options' => 'sanitize_search_string'));
/* ==================================================== */

include_once($config['base_path'] . '/lib/time.php');

/* initialize the timespan array */
$timespan = array();

/* set variables for first time use */
initialize_timespan($timespan);
$timeshift = set_timeshift();

/* if the user does not want to see timespan selectors */
process_html_variables();
process_user_input($timespan, $timeshift);

/* save session variables */
finalize_timespan($timespan);

/* initialize the timespan selector for first use */
function initialize_timespan(&$timespan) {
	/* initialize the default timespan if not set */
	if ((!isset($_SESSION['sess_current_timespan'])) || (isset_request_var('button_clear'))) {
		$_SESSION['sess_current_timespan'] = read_user_setting('default_timespan');
		set_request_var('predefined_timespan', read_user_setting('default_timespan'));
		$_SESSION['custom'] = 0;
	}

	/* initialize the date sessions if not set */
	if (!isset($_SESSION['sess_current_date1'])) {
		set_preset_timespan($timespan);
	}
}

/* preformat for timespan selector */
function process_html_variables() {
	if (isset_request_var('predefined_timespan')) {
		if (!is_numeric(get_filter_request_var('predefined_timespan'))) {
			if (isset($_SESSION['sess_current_timespan'])) {
				if ($_SESSION['custom']) {
					set_request_var('predefined_timespan', GT_CUSTOM);
					$_SESSION['sess_current_timespan'] = GT_CUSTOM;
				}else {
					set_request_var('predefined_timespan', $_SESSION['sess_current_timespan']);
				}
			}else {
				set_request_var('predefined_timespan', read_user_setting('default_timespan'));
				$_SESSION['sess_current_timespan'] = read_user_setting('default_timespan');
			}
		}
	} else {
		if (isset($_SESSION['sess_current_timespan'])) {
			set_request_var('predefined_timespan', $_SESSION['sess_current_timespan']);
		}else {
			set_request_var('predefined_timespan', read_user_setting('default_timespan'));
			$_SESSION['sess_current_timespan'] = read_user_setting('default_timespan');
		}
	}
	load_current_session_value('predefined_timespan', 'sess_current_timespan', read_user_setting('default_timespan'));

	# process timeshift
	if (isset_request_var('predefined_timeshift')) {
		if (!is_numeric(get_filter_request_var('predefined_timeshift'))) {
			if (isset($_SESSION['sess_current_timeshift'])) {
				set_request_var('predefined_timeshift', $_SESSION['sess_current_timeshift']);
			}else {
				set_request_var('predefined_timeshift', read_user_setting('default_timeshift'));
				$_SESSION['sess_current_timeshift'] = read_user_setting('default_timeshift');
			}
		}
	} else {
		if (isset($_SESSION['sess_current_timeshift'])) {
			set_request_var('predefined_timeshift', $_SESSION['sess_current_timeshift']);
		}else {
			set_request_var('predefined_timeshift', read_user_setting('default_timeshift'));
			$_SESSION['sess_current_timeshift'] = read_user_setting('default_timeshift');
		}
	}
	load_current_session_value('predefined_timeshift', 'sess_current_timeshift', read_user_setting('default_timeshift'));
}

/* when a span time preselection has been defined update the span time fields */
/* someone hit a button and not a dropdown */
function process_user_input(&$timespan, $timeshift) {
	if (isset_request_var('date1')) {
		/* the dates have changed, therefore, I am now custom */
		if (($_SESSION['sess_current_date1'] != get_nfilter_request_var('date1')) || ($_SESSION['sess_current_date2'] != get_nfilter_request_var('date2')) || (isset_request_var('custom'))) {
			$timespan['current_value_date1']   = sanitize_search_string(get_nfilter_request_var('date1'));
			$timespan['begin_now']             = strtotime($timespan['current_value_date1']);
			$timespan['current_value_date2']   = sanitize_search_string(get_nfilter_request_var('date2'));
			$timespan['end_now']               = strtotime($timespan['current_value_date2']);
			$_SESSION['sess_current_timespan'] = GT_CUSTOM;
			$_SESSION['custom'] = 1;
			set_request_var('predefined_timespan', GT_CUSTOM);
		}else {
			/* the default button wasn't pushed */
			if (!isset_request_var('button_clear')) {
				$timespan['current_value_date1'] = sanitize_search_string(get_nfilter_request_var('date1'));
				$timespan['current_value_date2'] = sanitize_search_string(get_nfilter_request_var('date2'));
				$timespan['begin_now']           = $_SESSION['sess_current_timespan_begin_now'];
				$timespan['end_now']             = $_SESSION['sess_current_timespan_end_now'];

				/* time shifter: shift left                                           */
				if (isset_request_var('move_left_x')) {
					shift_time($timespan, '-', $timeshift);
				}
				/* time shifter: shift right                                          */
				if (isset_request_var('move_right_x')) {
					shift_time($timespan, '+', $timeshift);
				}

				/* custom display refresh */
				if (isset($_SESSION['custom'])) {
					$_SESSION['sess_current_timespan'] = GT_CUSTOM;
				/* refresh the display */
				}else {
					$_SESSION['custom'] = 0;
				}
			} else {
				/* first time in */
				set_preset_timespan($timespan);
			}
		}
	}else {
		if ((isset_request_var('predefined_timespan') && (get_request_var('predefined_timespan') != GT_CUSTOM)) ||
			(!isset($_SESSION['custom'])) ||
			(!isset_request_var('predefined_timespan') && ($_SESSION['custom'] == 0)) ||
			(!isset($_SESSION['sess_current_date1']))) {
			set_preset_timespan($timespan);
		}else {
			$timespan['current_value_date1'] = $_SESSION['sess_current_date1'];
			$timespan['current_value_date2'] = $_SESSION['sess_current_date2'];

			$timespan['begin_now'] = $_SESSION['sess_current_timespan_begin_now'];
			$timespan['end_now']   = $_SESSION['sess_current_timespan_end_now'];
				/* custom display refresh */
			if ($_SESSION['custom']) {
				$_SESSION['sess_current_timespan'] = GT_CUSTOM;
			}
		}
	}
}

/* establish graph timespan from either a user select or the default */
function set_preset_timespan(&$timespan) {
	# no current timespan: get default timespan
	if (!isset($_SESSION['sess_current_timespan'])) {
		$_SESSION['sess_current_timespan'] = read_user_setting('default_timespan');
	}

	# get config option for first-day-of-the-week
	$first_weekdayid = read_user_setting('first_weekdayid');
	# get start/end time-since-epoch for actual time (now()) and given current-session-timespan
	get_timespan($timespan, time(),$_SESSION['sess_current_timespan'] , $first_weekdayid);

	$_SESSION['custom'] = 0;
}

function finalize_timespan(&$timespan) {
	if (!isset($timespan['current_value_date1'])) {
		/* Default end date is now default time span */
		$timespan['current_value_date1'] = date('Y-m-d H:i', $timespan['begin_now']);
	}

	if (!isset($timespan['current_value_date2'])) {
		/* Default end date is now */
		$timespan['current_value_date2'] = date('Y-m-d H:i', $timespan['end_now']);
	}

	/* correct bad dates on calendar */
	if ($timespan['end_now'] < $timespan['begin_now']) {
		set_preset_timespan($timespan);
		$_SESSION['sess_current_timespan'] = read_user_setting('default_timespan');

		$timespan['current_value_date1'] = date('Y-m-d H:i', $timespan['begin_now']);
		$timespan['current_value_date2'] = date('Y-m-d H:i', $timespan['end_now']);
	}

	/* if moved to future although not allow by settings, stop at current time */
	if (($timespan['end_now'] > time()) && (read_user_setting('allow_graph_dates_in_future') == '')) {
		$timespan['end_now'] = time();
		# convert end time to human readable format
		$timespan['current_value_date2'] = date('Y-m-d H:i', $timespan['end_now']);
	}

	$_SESSION['sess_current_timespan_end_now']   = $timespan['end_now'];
	$_SESSION['sess_current_timespan_begin_now'] = $timespan['begin_now'];
	$_SESSION['sess_current_date1']              = $timespan['current_value_date1'];
	$_SESSION['sess_current_date2']              = $timespan['current_value_date2'];

	$timespan_sel_pos = strpos(get_browser_query_string(),'&predefined_timespan');
	if ($timespan_sel_pos) {
		$_SESSION['urlval'] = substr(get_browser_query_string(),0,$timespan_sel_pos);
	} else {
		$_SESSION['urlval'] = get_browser_query_string();
	}
}

/* establish graph timeshift from either a user select or the default */
function set_timeshift() {
	global $config, $graph_timeshifts_vals;

	# no current timeshift: get default timeshift
	if (!isset($_SESSION['sess_current_timeshift']) || isset_request_var('button_clear')) {
		$_SESSION['sess_current_timeshift'] = read_user_setting('default_timeshift');
		set_request_var('predefined_timeshift', read_user_setting('default_timeshift'));
		$_SESSION['custom'] = 0;
	}

	if (isset($graph_timeshifts_vals[$_SESSION['sess_current_timeshift']])) {
		return $graph_timeshifts_vals[$_SESSION['sess_current_timeshift']];
	} else {
		return DEFAULT_TIMESHIFT;
	}
}