<?php

namespace WapplerSystems\Meilisearch\Domain\Index\Queue\GarbageRemover;

/***************************************************************
 *  Copyright notice
 *
 *  (c) 2018 - Timo Hund <timo.hund@dkd.de>
 *  All rights reserved
 *
 *  This script is part of the TYPO3 project. The TYPO3 project 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  The GNU General Public License can be found at
 *  http://www.gnu.org/copyleft/gpl.html.
 *
 *  This script 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.
 *
 *  This copyright notice MUST APPEAR in all copies of the script!
 ***************************************************************/

use WapplerSystems\Meilisearch\ConnectionManager;
use WapplerSystems\Meilisearch\GarbageCollectorPostProcessor;
use WapplerSystems\Meilisearch\IndexQueue\Queue;
use WapplerSystems\Meilisearch\System\Meilisearch\MeilisearchConnection;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * An implementation ob a garbage remover strategy is responsible to remove all garbage from the index queue and
 * the meilisearch server for a certain table and uid combination.
 */
abstract class AbstractStrategy
{

    /**
     * @var Queue
     */
    protected $queue;

    /**
     * @var ConnectionManager
     */
    protected $connectionManager;

    /**
     * AbstractStrategy constructor.
     * @param Queue|null $queue
     * @param ConnectionManager|null $connectionManager
     */
    public function __construct(Queue $queue = null, ConnectionManager $connectionManager = null)
    {
        $this->queue = $queue ?? GeneralUtility::makeInstance(Queue::class);
        $this->connectionManager = $connectionManager ?? GeneralUtility::makeInstance(ConnectionManager::class);
    }

    /**
     * Call's the removal of the strategy and afterwards the garbagecollector post processing hook.
     *
     * @param string $table
     * @param int $uid
     * @return mixed
     */
    public function removeGarbageOf($table, $uid)
    {
        $this->removeGarbageOfByStrategy($table, $uid);
        $this->callPostProcessGarbageCollectorHook($table, $uid);
    }

    /**
     * A implementation of the GarbageCollection strategy is responsible to remove the garbage from
     * the indexqueue and from the meilisearch server.
     *
     * @param string $table
     * @param int $uid
     * @return mixed
     */
    abstract protected function removeGarbageOfByStrategy($table, $uid);

    /**
     * Deletes a document from meilisearch and from the index queue.
     *
     * @param string $table
     * @param integer $uid
     */
    protected function deleteInMeilisearchAndRemoveFromIndexQueue($table, $uid)
    {
        $this->deleteIndexDocuments($table, $uid);
        $this->queue->deleteItem($table, $uid);
    }

    /**
     * Deletes a document from meilisearch and updates the item in the index queue (e.g. on page content updates).
     *
     * @param string $table
     * @param integer $uid
     */
    protected function deleteInMeilisearchAndUpdateIndexQueue($table, $uid)
    {
        $this->deleteIndexDocuments($table, $uid);
        $this->queue->updateItem($table, $uid);
    }

    /**
     * Deletes index documents for a given record identification.
     *
     * @param string $table The record's table name.
     * @param int $uid The record's uid.
     */
    protected function deleteIndexDocuments($table, $uid, $language = 0)
    {
        // record can be indexed for multiple sites
        $indexQueueItems = $this->queue->getItems($table, $uid);
        foreach ($indexQueueItems as $indexQueueItem) {
            $site = $indexQueueItem->getSite();
            $enableCommitsSetting = $site->getMeilisearchConfiguration()->getEnableCommits();
            $siteHash = $site->getSiteHash();
            // a site can have multiple connections (cores / languages)
            $meilisearchConnections = $this->connectionManager->getConnectionBySite($site);
            if ($language > 0) {
                $meilisearchConnections = [$language => $meilisearchConnections[$language]];
            }
            $this->deleteRecordInAllMeilisearchConnections($table, $uid, $meilisearchConnections, $siteHash, $enableCommitsSetting);
        }
    }

    /**
     * Deletes the record in all meilisearch connections from that site.
     *
     * @param string $table
     * @param int $uid
     * @param MeilisearchConnection[] $meilisearchConnections
     * @param string $siteHash
     * @param boolean $enableCommitsSetting
     */
    protected function deleteRecordInAllMeilisearchConnections($table, $uid, $meilisearchConnections, $siteHash, $enableCommitsSetting)
    {
        foreach ($meilisearchConnections as $meilisearch) {
            $meilisearch->getWriteService()->deleteByQuery('type:' . $table . ' AND uid:' . (int)$uid . ' AND siteHash:' . $siteHash);
            if ($enableCommitsSetting) {
                $meilisearch->getWriteService()->commit(false, false);
            }
        }
    }

    /**
     * Calls the registered post processing hooks after the garbageCollection.
     *
     * @param string $table
     * @param int $uid
     */
    protected function callPostProcessGarbageCollectorHook($table, $uid)
    {
        if (!is_array($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['meilisearch']['postProcessGarbageCollector'])) {
            return;
        }

        foreach ($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['meilisearch']['postProcessGarbageCollector'] as $classReference) {
            $garbageCollectorPostProcessor = GeneralUtility::makeInstance($classReference);

            if ($garbageCollectorPostProcessor instanceof GarbageCollectorPostProcessor) {
                $garbageCollectorPostProcessor->postProcessGarbageCollector($table, $uid);
            } else {
                $message = get_class($garbageCollectorPostProcessor) . ' must implement interface ' .
                    GarbageCollectorPostProcessor::class;
                throw new \UnexpectedValueException($message, 1345807460);
            }
        }
    }
}