<?php
  
  /**
   * ownCloud - Activity App
   *
   * @author Joas Schilling
   * @copyright 2014 Joas Schilling nickvergessen@owncloud.com
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or 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 AFFERO 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, see <http://www.gnu.org/licenses/>.
   *
   */
  
  namespace OCA\Activity;
  
  /**
   * Class MailQueueHandler
   * Gets the users from the database and
   *
   * @package OCA\Activity
   */
  class MailQueueHandler {
  	/** @var array */
  	protected $languages;
  
  	/** @var string */
  	protected $senderAddress;
  
  	/** @var string */
  	protected $senderName;
  
  	/**
  	 * Get the users we want to send an email to
  	 *
  	 * @param int|null $limit
  	 * @return array
  	 */
  	public function getAffectedUsers($limit) {
  		$limit = (!$limit) ? null : (int) $limit;
  
  		$query = \OCP\DB::prepare(
  			'SELECT `amq_affecteduser`, MIN(`amq_latest_send`) AS `amq_trigger_time` '
  			. ' FROM `*PREFIX*activity_mq` '
  			. ' WHERE `amq_latest_send` < ? '
  			. ' GROUP BY `amq_affecteduser` '
  			. ' ORDER BY `amq_trigger_time` ASC',
  			$limit);
  		$result = $query->execute(array(time()));
  
  		$affectedUsers = array();
  		if (\OCP\DB::isError($result)) {
  			\OCP\Util::writeLog('OCA\Activity', \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
  		} else {
  			while ($row = $result->fetchRow()) {
  				$affectedUsers[] = $row['amq_affecteduser'];
  			}
  		}
  
  		return $affectedUsers;
  	}
  
  	/**
  	 * Get all items for the users we want to send an email to
  	 *
  	 * @param array $affectedUsers
  	 * @param int $maxTime
  	 * @return array Notification data (user => array of rows from the table)
  	 */
  	public function getItemsForUsers($affectedUsers, $maxTime) {
  		$placeholders = implode(',', array_fill(0, sizeof($affectedUsers), '?'));
  		$queryParams = $affectedUsers;
  		array_unshift($queryParams, (int) $maxTime);
  
  		$query = \OCP\DB::prepare(
  			'SELECT * '
  			. ' FROM `*PREFIX*activity_mq` '
  			. ' WHERE `amq_timestamp` <= ? '
  			. ' AND `amq_affecteduser` IN (' . $placeholders . ')'
  			. ' ORDER BY `amq_timestamp` ASC'
  		);
  		$result = $query->execute($queryParams);
  
  		$userActivityMap = array();
  		if (\OCP\DB::isError($result)) {
  			\OCP\Util::writeLog('Activity', \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
  		} else {
  			while ($row = $result->fetchRow()) {
  				$userActivityMap[$row['amq_affecteduser']][] = $row;
  			}
  		}
  
  		return $userActivityMap;
  	}
  
  	/**
  	 * Get a language object for a specific language
  	 *
  	 * @param string $lang Language identifier
  	 * @return \OC_L10N Language object of $lang
  	 */
  	protected function getLanguage($lang) {
  		if (!isset($this->languages[$lang])) {
  			$this->languages[$lang] = \OC_L10N::get('activity', $lang);
  		}
  
  		return $this->languages[$lang];
  	}
  
  	/**
  	 * Get the sender data
  	 * @param string $setting Either `email` or `name`
  	 * @return string
  	 */
  	protected function getSenderData($setting) {
  		if (empty($this->senderAddress)) {
  			$this->senderAddress = \OCP\Util::getDefaultEmailAddress('no-reply');
  		}
  		if (empty($this->senderName)) {
  			$defaults = new \OCP\Defaults();
  			$this->senderName = $defaults->getName();
  		}
  
  		if ($setting === 'email') {
  			return $this->senderAddress;
  		}
  		return $this->senderName;
  	}
  
  	/**
  	 * Get the selected setting for a time frame
  	 * However we are not very accurate here, so we match the setting of the user
  	 * a bit better.
  	 *
  	 * @param int $timestamp
  	 * @return int Email send option that is used.
  	 */
  	protected function getLangForApproximatedTimeFrame($timestamp) {
  		if (time() - $timestamp < 4000) {
  			return UserSettings::EMAIL_SEND_HOURLY;
  		} else if (time() - $timestamp < 90000) {
  			return UserSettings::EMAIL_SEND_DAILY;
  		} else {
  			return UserSettings::EMAIL_SEND_WEEKLY;
  		}
  	}
  
  	/**
  	 * Send a notification to one user
  	 *
  	 * @param string $user Username of the recipient
  	 * @param string $email Email address of the recipient
  	 * @param string $lang Selected language of the recipient
  	 * @param array $mailData Notification data we send to the user
  	 */
  	public function sendEmailToUser($user, $email, $lang, $mailData) {
  		$l = $this->getLanguage($lang);
  		$dataHelper = new DataHelper(\OC::$server->getActivityManager(), new ParameterHelper(new \OC\Files\View(''), $l), $l);
  
  		$activityList = array();
  		foreach ($mailData as $activity) {
  			$activityList[] = $dataHelper->translation(
  				$activity['amq_appid'], $activity['amq_subject'], unserialize($activity['amq_subjectparams'])
  			);
  		}
  
  		$alttext = new \OCP\Template('activity', 'email.notification', '');
  		$alttext->assign('username', \OCP\User::getDisplayName($user));
  		$alttext->assign('timeframe', $this->getLangForApproximatedTimeFrame($mailData[0]['amq_timestamp']));
  		$alttext->assign('activities', $activityList);
  		$alttext->assign('owncloud_installation', \OC_Helper::makeURLAbsolute('/'));
  		$emailText = $alttext->fetchPage();
  
  		try {
  			\OCP\Util::sendMail(
  				$email, $user,
  				$l->t('Activity notification'), $emailText,
  				$this->getSenderData('email'), $this->getSenderData('name')
  			);
  		} catch (\Exception $e) {
  			\OCP\Util::writeLog('Activity', 'A problem occurred while sending the e-mail. Please revisit your settings.', \OCP\Util::ERROR);
  		}
  	}
  
  	/**
  	 * Delete all entries we dealt with
  	 *
  	 * @param array $affectedUsers
  	 * @param int $maxTime
  	 */
  	public function deleteSentItems($affectedUsers, $maxTime) {
  		$placeholders = implode(',', array_fill(0, sizeof($affectedUsers), '?'));
  		$queryParams = $affectedUsers;
  		array_unshift($queryParams, (int) $maxTime);
  
  		$query = \OCP\DB::prepare(
  			'DELETE FROM `*PREFIX*activity_mq` '
  			. ' WHERE `amq_timestamp` <= ? '
  			. ' AND `amq_affecteduser` IN (' . $placeholders . ')');
  		$result = $query->execute($queryParams);
  
  		if (\OCP\DB::isError($result)) {
  			\OCP\Util::writeLog('Activity', \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
  		}
  	}
  }