<?php

//Pandora FMS- http://pandorafms.com
// ==================================================
// Copyright (c) 20012 Artica Soluciones Tecnologicas
// Please see http://pandorafms.org for full contribution list

// This program 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; version 2

// 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.

global $config;

include_once($config['homedir'] . "/include/functions_db.php");

// Update the execution interval of the given module
function cron_update_module_interval ($module_id, $cron) {
	
	// Check for a valid cron
	if (!cron_check_syntax($cron)) {
		return;
	}
	
	if($cron == "* * * * *"){
		$module_interval = db_get_value_filter('module_interval','tagente_modulo',array("id_agente_modulo" => $module_id));
		return db_process_sql ('UPDATE tagente_estado SET current_interval = ' . $module_interval . ' WHERE id_agente_modulo = ' . (int) $module_id);
	} else {
		return db_process_sql (
			'UPDATE tagente_estado SET current_interval = ' .
			cron_next_execution ($cron, $module_interval, $module_id) .
			' WHERE id_agente_modulo = ' .
			(int) $module_id)
		;
	}
	
}


// Get the number of seconds left to the next execution of the given cron entry.
function cron_next_execution ($cron, $module_interval, $module_id) {

	// Get day of the week and month from cron config
	$cron_array = explode (" ", $cron);
	$minute = $cron_array[0];
	$hour = $cron_array[1];
	$mday = $cron_array[2];
	$month = $cron_array[3];
	$wday = $cron_array[4];

	// Get last execution time
	$last_execution = db_get_value('utimestamp', 'tagente_estado', 'id_agente_modulo', $module_id);
	$cur_time = ($last_execution !== false) ? $last_execution : time();

	// Any day of the way
	if ($wday == '*') {
		$nex_time = cron_next_execution_date ($cron,  $cur_time, $module_interval);
		return $nex_time - $cur_time;
	}

	// A specific day of the week
	$count = 0;
	$nex_time = $cur_time;
	do {
		$nex_time = cron_next_execution_date ($cron, $nex_time, $module_interval);
		$nex_time_wd = $nex_time;

		$array_nex = explode (" ", date ("m w", $nex_time_wd));
		$nex_mon   = $array_nex[0];
		$nex_wday  = $array_nex[1];

		do {
			// Check the day of the week
			if ($nex_wday == $wday) {
				return $nex_time_wd - $cur_time;
			}

			// Move to the next day of the month
			$nex_time_wd += SECONDS_1DAY;

			$array_nex_w = explode (" ", date ("m w", $nex_time_wd));
			$nex_mon_wd  = $array_nex_w[0];
			$nex_wday    = $array_nex_w[1];
		}
		while ($mday == '*' && $nex_mon_wd == $nex_mon);

		$count++;
	}
	while ($count < SECONDS_1MINUTE);

	// Something went wrong, default to 5 minutes
	return SECONDS_5MINUTES;
}

// Get the next execution date for the given cron entry in seconds since epoch.
function cron_next_execution_date ($cron, $cur_time = false, $module_interval = 300) {
	
	// Get cron configuration
	$cron_array = explode (" ", $cron);
	
	// REMARKS: Months start from 1 in php (different to server)
	
	// Get current time
	if ($cur_time === false) $cur_time = time();

	$nex_time = $cur_time + $module_interval;
	$nex_time_array = explode (" ", date ("i H d m Y", $nex_time));
	if (cron_is_in_cron($cron_array, $nex_time_array)) return $nex_time;

	// Update minutes
	$min_s = cron_get_interval ($cron_array[0]);
	$nex_time_array[0] = ($min_s['down'] == '*') ? 0 : $min_s['down'];
	
	$nex_time = cron_valid_date($nex_time_array);
	if ($nex_time >= $cur_time) {
		if (cron_is_in_cron($cron_array, $nex_time_array) && $nex_time) {
			return $nex_time;
		}
	}

	// Check if next hour is in cron
	$nex_time_array[1]++;
	$nex_time = cron_valid_date($nex_time_array);

	if ($nex_time === false) {
		// Update the month day if overflow
		$nex_time_array[1] = 0;
		$nex_time_array[2]++;
		$nex_time = cron_valid_date($nex_time_array);
		if ($nex_time === false) {
			// Update the month if overflow
			$nex_time_array[2] = 1;
			$nex_time_array[3]++;
			$nex_time = cron_valid_date($nex_time_array);
			if ($nex_time === false) {
				#Update the year if overflow
				$nex_time_array[3] = 1;
				$nex_time_array[4]++;
				$nex_time = cron_valid_date($nex_time_array);
			}
		}
	}
	// Check the hour
	if (cron_is_in_cron($cron_array, $nex_time_array) && $nex_time) {
		return $nex_time;
	}

	// Update the hour if fails
	$hour_s = cron_get_interval ($cron_array[1]);
	$nex_time_array[1] = ($hour_s['down'] == '*') ? 0 : $hour_s['down'];

	// When an overflow is passed check the hour update again
	$nex_time = cron_valid_date($nex_time_array);
	if ($nex_time >= $cur_time) {
		if (cron_is_in_cron($cron_array, $nex_time_array) && $nex_time) {
			return $nex_time;
		}
	}

	// Check if next day is in cron
	$nex_time_array[2]++;
	$nex_time = cron_valid_date($nex_time_array);
	if ($nex_time === false) {
		// Update the month if overflow
		$nex_time_array[2] = 1;
		$nex_time_array[3]++;
		$nex_time = cron_valid_date($nex_time_array);
		if ($nex_time === false) {
			// Update the year if overflow
			$nex_time_array[3] = 1;
			$nex_time_array[4]++;
			$nex_time = cron_valid_date($nex_time_array);
		}
	}
	// Check the day
	if (cron_is_in_cron($cron_array, $nex_time_array) && $nex_time) {
		return $nex_time;
	}

	// Update the day if fails
	$mday_s = cron_get_interval ($cron_array[2]);
	$nex_time_array[2] = ($mday_s['down'] == '*') ? 1 : $mday_s['down'];

	// When an overflow is passed check the hour update in the next execution
	$nex_time = cron_valid_date($nex_time_array);
	if ($nex_time >= $cur_time) {
		if (cron_is_in_cron($cron_array, $nex_time_array) && $nex_time) {
			return $nex_time;
		}
	}

	// Check if next month is in cron
	$nex_time_array[3]++;
	$nex_time = cron_valid_date($nex_time_array);
	if ($nex_time === false) {
		#Update the year if overflow
		$nex_time_array[3] = 1;
		$nex_time_array[4]++;
		$nex_time = cron_valid_date($nex_time_array);
	}

	// Check the month
	if (cron_is_in_cron($cron_array, $nex_time_array) && $nex_time) {
		return $nex_time;
	}

	// Update the month if fails
	$mon_s = cron_get_interval ($cron_array[3]);
	$nex_time_array[3] = ($mon_s['down'] == '*') ? 1 : $mon_s['down'];

	// When an overflow is passed check the hour update in the next execution
	$nex_time = cron_valid_date($nex_time_array);
	if ($nex_time >= $cur_time) {
		if (cron_is_in_cron($cron_array, $nex_time_array) && $nex_time) {
			return $nex_time;
		}
	}

	// Update the year
	$nex_time_array[4]++;
	$nex_time = cron_valid_date($nex_time_array);

	return ($nex_time !== false) ? $nex_time : $module_interval;
}

// Get an array with the cron interval
function cron_get_interval ($element) {
	# Not a range
	if (!preg_match('/(\d+)\-(\d+)/', $element, $capture)) {
		return array(
			'down' => $element,
			'up' => false
		);
	}
	return array(
		'down' => $capture[1],
		'up' => $capture[2]
	);
}

// Returns if a date is in a cron. Recursive.
function cron_is_in_cron($elems_cron, $elems_curr_time) {
	
	$elem_cron = array_shift($elems_cron);
	$elem_curr_time = array_shift($elems_curr_time);

	// If there is no elements means that is in cron
	if ($elem_cron === null || $elem_curr_time === null) return true;

	// Go to last element if current is a wild card
	if ($elem_cron != '*') {
		$elem_s = cron_get_interval($elem_cron);
		// Check if there is no a range
		if (($elem_s['up'] === false) && ($elem_s['down'] != $elem_curr_time)) {
			return false;
		}
		// Check if there is on the range
		if ($elem_s['up'] !== false) {
			if ($elem_s['down'] < $elem_s['up']) {
				if ($elem_curr_time < $elem_s['down'] || $elem_curr_time > $elem_s['up']){
					return false;
				}
			} else {
				if ($elem_curr_time > $elem_s['down'] || $elem_curr_time < $elem_s['up']){
					return false;
				}
			}
		}
	}
	return cron_is_in_cron($elems_cron, $elems_curr_time);
}

function cron_valid_date ($da) {
	$st = sprintf("%04d:%02d:%02d %02d:%02d:00", $da[4], $da[3], $da[2], $da[1], $da[0]);
	$time = strtotime($st);
	return $time;
}

// Check if cron is properly constructed
function cron_check_syntax($cron) {
	
	return preg_match("/^[\d|\*].* .*[\d|\*].* .*[\d|\*].* .*[\d|\*].* .*[\d|\*]$/", $cron);	
}

?>