<?php
/*
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2008 Bharat Mediratta
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
 */

GalleryCoreApi::requireOnce('modules/comment/module.inc');

/**
 * Utility functions useful in managing GalleryComments
 *
 * @package Comment
 * @subpackage Classes
 * @author Bharat Mediratta <bharat@menalto.com>
 * @version $Revision: 17990 $
 * @static
 */
class GalleryCommentHelper /* implements GalleryEventListener */ {

    /**
     * Return the comments associated with the given item
     *
     * @param int $itemId GalleryItem id
     * @param int $count (optional) max number to retrieve
     * @param string $orderDirection (optional) ORDER_DESCENDING to list newest first
     * @param int $publishStatus One of the COMMENT_PUBLISH_STATUS_XXX constants or null to
     *            get all comments
     * @return array GalleryStatus a status code,
     *               array (entityId => GalleryComment, ...)
     */
    function fetchComments($itemId, $count=null, $orderDirection=ORDER_ASCENDING,
			   $publishStatus=COMMENT_PUBLISH_STATUS_PUBLISHED) {
	global $gallery;

	switch($orderDirection) {
	case ORDER_ASCENDING:
	    $direction = 'ASC';
	    break;

	case ORDER_DESCENDING:
	    $direction = 'DESC';
	    break;

	default:
	    return array(GalleryCoreApi::error(ERROR_BAD_PARAMETER), null);
	}

	$data = array((int)$itemId);
	$query = '
	SELECT
	  [GalleryComment::id]
	FROM
	  [GalleryComment], [GalleryChildEntity]
	WHERE
	  [GalleryChildEntity::parentId] = ?
	  AND
	  [GalleryChildEntity::id] = [GalleryComment::id]
        ';
	if (isset($publishStatus)) {
	    $query .= '
          AND
          [GalleryComment::publishStatus] = ?
            ';
	    $data[] = $publishStatus;
	}
	$query .= '
	ORDER BY
	  [GalleryComment::date] ' . $direction . '
	';
	list ($ret, $searchResults) = $gallery->search(
	    $query, $data, array('limit' => array('count' => (int)$count)));

	if ($ret) {
	    return array($ret, null);
	}

	/* Get all of our ids */
	$allIds = array();
	while ($result = $searchResults->nextResult()) {
	    $allIds[] = (int)$result[0];
	}

	/* Load all the comments at once */
	$comments = array();
	if (!empty($allIds)) {
	    list ($ret, $comments) = GalleryCoreApi::loadEntitiesById($allIds, 'GalleryComment');
	    if ($ret) {
		return array($ret, null);
	    }
	}

	return array(null, $comments);
    }

    /**
     * Return all comments in subtree under given item, with comment.view permission
     *
     * @param array $itemId int GalleryItem id
     * @param int $count (optional) max number to retrieve
     * @param int $offset (optional) start of the range
     * @param string $orderDirection (optional) ORDER_DESCENDING to list newest first
     * @param mixed $publishStatus (optional) A single COMMENT_PUBLISH_STATUX_XXX constant, an array
     *               of constants or null to get all comments. Default is
     *               COMMENT_PUBLISH_STATUS_PUBLISHED.
     * @return array GalleryStatus a status code,
     *               array (entityId => GalleryComment, ...)
     *               int total number of comments available
     */
    function fetchAllComments($itemId, $count=null, $offset=null, $orderDirection=ORDER_ASCENDING,
			      $publishStatus=COMMENT_PUBLISH_STATUS_PUBLISHED) {
	global $gallery;

	switch($orderDirection) {
	case ORDER_ASCENDING:
	    $direction = 'ASC';
	    break;

	case ORDER_DESCENDING:
	    $direction = 'DESC';
	    break;

	default:
	    return array(GalleryCoreApi::error(ERROR_BAD_PARAMETER),
			 null, null);
	}
	list ($ret, $sequence) = GalleryCoreApi::fetchParentSequence($itemId);
	if ($ret) {
	    return array($ret, null, null);
	}
	$sequence = implode('/', $sequence);
	if (!empty($sequence)) {
	    $sequence .= '/';
	}
	$sequence .= $itemId . '/%';

	list ($ret, $aclIds) = GalleryCoreApi::fetchAccessListIds(
	    array('comment.view', 'core.view'), $gallery->getActiveUserId());
	if ($ret) {
	    return array($ret, null, null);
	}
	$aclMarkers = GalleryUtilities::makeMarkers(count($aclIds));

	if (empty($aclIds)) {
	    return array(null, array(), 0);
	}

	$queryBase = '
	FROM
	  [GalleryItemAttributesMap], [GalleryAccessSubscriberMap],
	  [GalleryChildEntity], [GalleryComment]
	WHERE
	  ([GalleryItemAttributesMap::itemId] = ?
	   OR
	   [GalleryItemAttributesMap::parentSequence] LIKE ?)
	 AND
	   [GalleryAccessSubscriberMap::itemId] = [GalleryItemAttributesMap::itemId]';
	if ($publishStatus !== null) {
	    $statusMarkers = GalleryUtilities::makeMarkers(count($publishStatus));
	    $queryBase .= '
	 AND
	   [GalleryComment::publishStatus] IN (' . $statusMarkers . ')';
	}
	$queryBase .= '
	 AND
	   [GalleryAccessSubscriberMap::accessListId] IN (' . $aclMarkers . ')
	 AND
	   [GalleryChildEntity::parentId] = [GalleryItemAttributesMap::itemId]
	 AND
	   [GalleryComment::id] = [GalleryChildEntity::id]
	';
	$query = '
	SELECT
	  [GalleryComment::id] ' . $queryBase . '
	ORDER BY
	  [GalleryComment::date] ' . $direction . '
	';
	$data = array((int)$itemId, $sequence);
	if ($publishStatus !== null) {
	    if (!is_array($publishStatus)) {
		$data[] = $publishStatus;
	    } else {
		$data = array_merge($data, $publishStatus);
	    }
	};
	$data = array_merge($data, $aclIds);

	list ($ret, $searchResults) =
	    $gallery->search($query, $data, array('limit' => array('count' => (int)$count,
								   'offset' => (int)$offset)));
	if ($ret) {
	    return array($ret, null, null);
	}

	/* Get all of our ids */
	$allIds = array();
	while ($result = $searchResults->nextResult()) {
	    $allIds[] = (int)$result[0];
	}

	/* Load all the comments at once */
	$comments = array();
	if (!empty($allIds)) {
	    list ($ret, $comments) = GalleryCoreApi::loadEntitiesById($allIds, 'GalleryComment');
	    if ($ret) {
		return array($ret, null, null);
	    }
	}

	/* Get total count of comments */
	if (!$count && !$offset) {
	    $totalCount = count($allIds);
	} else {
	    $query = '
	    SELECT
	      COUNT([GalleryComment::id]) ' . $queryBase;
	    list ($ret, $searchResults) = $gallery->search($query, $data);
	    if ($ret) {
		return array($ret, null, null);
	    }
	    if ($result = $searchResults->nextResult()) {
		$totalCount = (int)$result[0];
	    } else {
		$totalCount = count($allIds);
	    }
	}

	return array(null, $comments, $totalCount);
    }

    /**
     * Return the number of comments associated with the given item ids
     *
     * @param array $itemIds int GalleryItem ids
     * @return array GalleryStatus a status code
     *               int a count
     */
    function fetchCommentCounts($itemIds) {
	global $gallery;

	$markers = GalleryUtilities::makeMarkers(sizeof($itemIds));
	$query = '
	SELECT
	  [GalleryChildEntity::parentId],
	  COUNT([GalleryComment::id])
	FROM
	  [GalleryComment], [GalleryChildEntity]
	WHERE
	  [GalleryChildEntity::parentId] IN (' . $markers . ')
	  AND
	  [GalleryChildEntity::id] = [GalleryComment::id]
          AND
          [GalleryComment::publishStatus] = ?
	GROUP BY
	  [GalleryChildEntity::parentId]
	';

	$data = $itemIds;
	$data[] = COMMENT_PUBLISH_STATUS_PUBLISHED;
	list ($ret, $searchResults) = $gallery->search($query, $data);
	if ($ret) {
	    return array($ret, null);
	}

	$data = array();
	while ($result = $searchResults->nextResult()) {
	    $data[$result[0]] = (int)$result[1];
	}

	return array(null, $data);
    }

    /**
     * Return the timestamp of the most recent comment from this IP
     *
     * @param int $hostAddress IP address in question
     * @return array GalleryStatus a status code,
     *               int latest comment time
     */
    function getLatestCommentTime($hostAddress) {
	global $gallery;

	$data = array($hostAddress);
	$query = '
	SELECT
	  [GalleryComment::date]
	FROM
	  [GalleryComment]
	WHERE
	  [GalleryComment::host] = ?
	ORDER BY
	  [GalleryComment::date] DESC
        ';
	list ($ret, $searchResults) = $gallery->search(
	    $query, $data, array('limit' => array('count' => 1)));

	if ($ret) {
	    return array($ret, null);
	}

	$result = $searchResults->nextResult();
	if ($result) {
	    $result = (int)$result[0];
	} else {
	    $result = 0;
	}

	return array(null, $result);
    }
    
    /**
     * Get information needed for the AddComment page
     *
     * @param GalleryItem $item to work from
     * @param array $form form being modified
     * @return array GalleryStatus a status code
     *               array values used for the AddComment page (itemId, host, validation plugins)
     */
    function getAddComment(&$item, &$form) {
	/* Make sure we have permission to add a comment */
	list ($ret, $permissions) = GalleryCoreApi::getPermissions($item->getId());
	if ($ret) {
	    return array($ret, null);
	}
	if (empty($permissions['core.view'])) {
	    /* Avoid information disclosure, act as if the item didn't exist. */
	    return array(GalleryCoreApi::error(ERROR_MISSING_OBJECT), null);
	}
	if (empty($permissions['comment.add'])) {
	    return array(GalleryCoreApi::error(ERROR_PERMISSION_DENIED), null);
	}

	if ($form['formName'] != 'AddComment') {
	    $form['formName'] = 'AddComment';
	    $form['subject'] = $form['comment'] = $form['author'] = '';
	} else {
	    foreach (array('subject', 'comment', 'author') as $key) {
		if (empty($form[$key])) {
		    $form[$key] = '';
		}
	    }
	}

	/* Check if we should use validation plugins for new comments */
	$plugins = array();
	list ($ret, $useValidationPlugins) = GalleryCommentHelper::useValidationPlugins();
	if ($ret) {
	    return array($ret, null);
	} else if ($useValidationPlugins) {
	    list ($ret, $allPluginIds) =
		GalleryCoreApi::getAllFactoryImplementationIds('GalleryValidationPlugin');
	    if ( $ret) {
		return array($ret, null);
	    }

	    /* Let each plugin load its template data */
	    foreach (array_keys($allPluginIds) as $pluginId) {
		list ($ret, $plugin) =
		    GalleryCoreApi::newFactoryInstanceById('GalleryValidationPlugin', $pluginId);
		if ($ret) {
		    return array($ret, null);
		}
		list ($ret, $data['file'], $data['l10Domain']) = $plugin->loadTemplate($form);
		if ($ret) {
		    return array($ret, null);
		} else if (isset($data['file'])) {
		    $plugins[] = $data;
		}
	    }
	}

	$AddComment = array('itemId' => $item->getId(),
		'host' => GalleryUtilities::getRemoteHostAddress(),
		'plugins' => $plugins);

	return array(null, $AddComment);
    }

    /**
     * Determine if we should use validation plugins for new comments.
     *
     * @return array GalleryStatus a status code
     *               boolean true to use validation plugins
     */
    function useValidationPlugins() {
	list ($ret, $level) =
	    GalleryCoreApi::getPluginParameter('module', 'comment', 'validation.level');
	if ($ret) {
	    return array($ret, null);
	}
	if ($level == 'OFF') {
	    return array(null, false);
	}

	list ($ret, $isAnonymous) = GalleryCoreApi::isAnonymousUser();
	if ($ret) {
	    return array($ret, null);
	}

	return array(null, $isAnonymous);
    }

     /**
      * Event handler.
      *
      * GalleryEntity::delete
      *   Delete all comments by a user (Item deletion and their attached comments is already
      *   handled in GalleryItem::delete).
      * GalleryEntity::save
      *   Run newly created comments through Akismet and unpublish spam.
      *
      * @see GalleryEventListener::handleEvent
      */
    function handleEvent($event) {
	global $gallery;

	switch ($event->getEventName()) {
	case 'GalleryEntity::delete':
	    $entity = $event->getEntity();
	    if (!GalleryUtilities::isA($entity, 'GalleryUser')) {
		return array(null, null);
	    }

	    /* Delete all comments owned by this user */
	    $query = '
	    SELECT
	      [GalleryComment::id]
	    FROM
	      [GalleryComment]
	    WHERE
	      [GalleryComment::commenterId] = ?
	    ';

	    list ($ret, $searchResults) = $gallery->search($query, array((int)$entity->getId()));
	    if ($ret) {
		return array($ret, null);
	    }

	    while ($result = $searchResults->nextResult()) {
		$ret = GalleryCoreApi::deleteEntityById((int)$result[0], 'GalleryComment');
		if ($ret) {
		    return array($ret, null);
		}
	    }
	    break;

	case 'GalleryEntity::save':
	    if (!GalleryCommentHelper::getAkismetSaveListenerSwitch()) {
		break;
	    }
	    $comment =& $event->getEntity();
	    if (GalleryUtilities::isA($comment, 'GalleryComment')) {
		list ($ret, $akismetActive) =
		    GalleryCoreApi::getPluginParameter('module', 'comment', 'akismet.active');
		if ($ret) {
		    return array($ret, null);
		}
		if ($akismetActive) {
		    GalleryCoreApi::requireOnce('modules/comment/classes/AkismetApi.class');
		    $akismet = new AkismetApi();
		    $ret = $this->checkWithAkismet($comment, $akismet);
		    if ($ret) {
			return array($ret, null);
		    }
		}
	    }
	    break;
	}

	return array(null, null);
    }

    /**
     * Enable or disable the Akismet save listener for the rest of this request.  Set this value
     * to false to ignore changes to entities for the rest of this request.  You should disable
     * the save listener if you're changing a comment's publish status to match what you learned
     * with checkWithAkismet, so that we don't report a comment back to Akismet as spam, if it was
     * Akismet that told us this in the first place. The initial value for this switch is true.
     * @param $enabled bool true to enable the listener, false to disable it
     * @static
     */
    function setAkismetSaveListenerSwitch($enabled) {
	$switch =& GalleryCommentHelper::getAkismetSaveListenerSwitch();
	$switch = $enabled;
    }

    /**
     * Return a reference to a boolean that controls whether Akismet is used for this request.
     * @return bool the current status
     * @static
     */
    function &getAkismetSaveListenerSwitch() {
	static $enabled = true;
	return $enabled;
    }

    /**
     * Run a comment by Akismet.  If it's a new comment, check with Akismet to see if the comment
     * is spam.  If it's a modified comment, submit it as ham or spam as appropriate of the
     * publish status has changed.
     *
     * @param GalleryComment $comment an instance of GalleryComment
     * @param AkismetApi $akismet an instance of AkismetApi
     * @return GalleryStatus a status code
     */
    function checkWithAkismet(&$comment, $akismet) {
	$logError = false;
	if ($comment->testPersistentFlag(STORAGE_FLAG_NEWLY_CREATED)) {
	    list ($ret, $isSpam) = $akismet->checkComment($comment);
	    if ($ret && $ret->getErrorCode() & ERROR_UNKNOWN) {
		/* Akismet returned an error or akismet couldn't be contacted */
		$logError = true;
		if ($comment->getPublishStatus() == COMMENT_PUBLISH_STATUS_PUBLISHED) {
		    $comment->setPublishStatus(COMMENT_PUBLISH_STATUS_UNPUBLISHED);
		}
	    } else if ($ret) {
		return $ret;
	    } else if ($isSpam) {
		$comment->setPublishStatus(COMMENT_PUBLISH_STATUS_SPAM);
	    }
	} else {
	    $oldStatus = $comment->getOriginalValue('publishStatus');
	    if ($comment->isModified('publishStatus')) {
		if ($oldStatus == COMMENT_PUBLISH_STATUS_SPAM) {
		    $ret = $akismet->submitHam($comment);
		    if ($ret && $ret->getErrorCode() & ERROR_UNKNOWN) {
			/* Akismet returned an error or akismet couldn't be contacted */
			$logError = true;
		    } else if ($ret) {
			return $ret;
		    }
		} else if ($comment->getPublishStatus() == COMMENT_PUBLISH_STATUS_SPAM) {
		    $ret = $akismet->submitSpam($comment);
		    if ($ret && $ret->getErrorCode() & ERROR_UNKNOWN) {
			/* Akismet returned an error or akismet couldn't be contacted */
			$logError = true;
		    } else if ($ret) {
			return $ret;
		    }
		}
	    }
	}

	if ($logError) {
	    $ret = GalleryCoreApi::addEventLogEntry('Gallery Error', 'Error contacting Akismet',
		    'Failed to contact Akismet (an external spam filtering service) or Akismet '
		  . 'was unable to process the request.');
	    if ($ret) {
		return $ret;
	    }
	}
    }
}
?>