<?php
  /**
   * Copyright (c) 2012 Georg Ehrke <ownclouddev@georgswebsite.de>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  /**
   * This class manages the caching of repeating events
   * Events will be cached for the current year ± 5 years
   */
  class OC_Calendar_Repeat{
  	/**
  	 * @brief returns the cache of an event
  	 * @param (int) $id - id of the event
  	 * @return (array)
  	 */
  	public static function get($id) {
  		$stmt = OCP\DB::prepare('SELECT * FROM `*PREFIX*clndr_repeat` WHERE `eventid` = ?');
  		$result = $stmt->execute(array($id));
  		$return = array();
  		while($row = $result->fetchRow()) {
  			$return[] = $row;
  		}
  		return $return;
  	}
  	/**
  	 * @brief returns the cache of an event in a specific peroid
  	 * @param (int) $id - id of the event
  	 * @param (DateTime) $from - start for period in UTC
  	 * @param (DateTime) $until - end for period in UTC
  	 * @return (array)
  	 */
  	public static function get_inperiod($id, $from, $until) {
  		$stmt = OCP\DB::prepare( 'SELECT * FROM `*PREFIX*clndr_repeat` WHERE `eventid` = ?'
  		.' AND ((`startdate` >= ? AND `startdate` <= ?)'
  		.' OR (`enddate` >= ? AND `enddate` <= ?))');
  		$result = $stmt->execute(array($id,
  					OC_Calendar_Object::getUTCforMDB($from), OC_Calendar_Object::getUTCforMDB($until),
  					OC_Calendar_Object::getUTCforMDB($from), OC_Calendar_Object::getUTCforMDB($until)));
  		$return = array();
  		while($row = $result->fetchRow()) {
  			$return[] = $row;
  		}
  		return $return;
  	}
  	/**
  	 * @brief returns the cache of all repeating events of a calendar
  	 * @param (int) $id - id of the calendar
  	 * @return (array)
  	 */
  	public static function getCalendar($id) {
  		$stmt = OCP\DB::prepare('SELECT * FROM `*PREFIX*clndr_repeat` WHERE `calid` = ?');
  		$result = $stmt->execute(array($id));
  		$return = array();
  		while($row = $result->fetchRow()) {
  			$return[] = $row;
  		}
  		return $return;
  	}
  	/**
  	 * @brief returns the cache of all repeating events of a calendar in a specific period
  	 * @param (int) $id - id of the event
  	 * @param (string) $from - start for period in UTC
  	 * @param (string) $until - end for period in UTC
  	 * @return (array)
  	 */
  	public static function getCalendar_inperiod($id, $from, $until) {
  		$stmt = OCP\DB::prepare( 'SELECT * FROM `*PREFIX*clndr_repeat` WHERE `calid` = ?'
  		.' AND ((`startdate` >= ? AND `startdate` <= ?)'
  		.' OR (`enddate` >= ? AND `enddate` <= ?))');
  		$result = $stmt->execute(array($id,
  					$from, $until,
  					$from, $until));
  		$return = array();
  		while($row = $result->fetchRow()) {
  			$return[] = $row;
  		}
  		return $return;
  	}
  	/**
  	 * @brief generates the cache the first time
  	 * @param (int) id - id of the event
  	 * @return (bool)
  	 */
  	public static function generate($id) {
  		$event = OC_Calendar_Object::find($id);
  		if($event['repeating'] == 0) {
  			return false;
  		}
  		$object = OC_VObject::parse($event['calendardata']);
  		$start = new DateTime('01-01-' . date('Y') . ' 00:00:00', new DateTimeZone('UTC'));
  		$start->modify('-5 years');
  		$end = new DateTime('31-12-' . date('Y') . ' 23:59:59', new DateTimeZone('UTC'));
  		$end->modify('+5 years');
  		$object->expand($start, $end);
  		foreach($object->getComponents() as $vevent) {
  			if(!($vevent instanceof Sabre\VObject\Component\VEvent)) {
  				continue;
  			}
  			$startenddate = OC_Calendar_Object::generateStartEndDate($vevent->DTSTART, OC_Calendar_Object::getDTEndFromVEvent($vevent), ($vevent->DTSTART->getDateType() == Sabre\VObject\Property\DateTime::DATE)?true:false, 'UTC');
  			$stmt = OCP\DB::prepare('INSERT INTO `*PREFIX*clndr_repeat` (`eventid`,`calid`,`startdate`,`enddate`) VALUES(?,?,?,?)');
  			$stmt->execute(array($id,OC_Calendar_Object::getCalendarid($id),$startenddate['start'],$startenddate['end']));
  		}
  		return true;
  	}
  	/**
  	 * @brief generates the cache the first time for all repeating event of an calendar
  	 * @param (int) id - id of the calendar
  	 * @return (bool)
  	 */
  	public static function generateCalendar($id) {
  		$allobjects = OC_Calendar_Object::all($id);
  		foreach($allobjects as $event) {
  			self::generate($event['id']);
  		}
  		return true;
  	}
  	/**
  	 * @brief updates an event that is already cached
  	 * @param (int) id - id of the event
  	 * @return (bool)
  	 */
  	public static function update($id) {
  		self::clean($id);
  		self::generate($id);
  		return true;
  	}
  	/**
  	 * @brief updates all repating events of a calendar that are already cached
  	 * @param (int) id - id of the calendar
  	 * @return (bool)
  	 */
  	public static function updateCalendar($id) {
  		self::cleanCalendar($id);
  		self::generateCalendar($id);
  		return true;
  	}
  	/**
  	 * @brief checks if an event is already cached
  	 * @param (int) id - id of the event
  	 * @return (bool)
  	 */
  	public static function is_cached($id) {
  		if(count(self::get($id)) != 0) {
  			return true;
  		}else{
  			return false;
  		}
  	}
  	/**
  	 * @brief checks if an event is already cached in a specific period
  	 * @param (int) id - id of the event
  	 * @param (DateTime) $from - start for period in UTC
  	 * @param (DateTime) $until - end for period in UTC
  	 * @return (bool)
  	 */
  	public static function is_cached_inperiod($id, $start, $end) {
  		if(count(self::get_inperiod($id, $start, $end)) != 0) {
  			return true;
  		}else{
  			return false;
  		}
  
  	}
  	/**
  	 * @brief checks if a whole calendar is already cached
  	 * @param (int) id - id of the calendar
  	 * @return (bool)
  	 */
  	public static function is_calendar_cached($id) {
  		$cachedevents = count(self::getCalendar($id));
  		$repeatingevents = 0;
  		$allevents = OC_Calendar_Object::all($id);
  		foreach($allevents as $event) {
  			if($event['repeating'] === 1) {
  				$repeatingevents++;
  			}
  		}
  		if($cachedevents < $repeatingevents) {
  			return false;
  		}else{
  			return true;
  		}
  	}
  	/**
  	 * @brief removes the cache of an event
  	 * @param (int) id - id of the event
  	 * @return (bool)
  	 */
  	public static function clean($id) {
  		$stmt = OCP\DB::prepare('DELETE FROM `*PREFIX*clndr_repeat` WHERE `eventid` = ?');
  		$stmt->execute(array($id));
  	}
  	/**
  	 * @brief removes the cache of all events of a calendar
  	 * @param (int) id - id of the calendar
  	 * @return (bool)
  	 */
  	public static function cleanCalendar($id) {
  		$stmt = OCP\DB::prepare('DELETE FROM `*PREFIX*clndr_repeat` WHERE `calid` = ?');
  		$stmt->execute(array($id));
  	}
  }