<?php
/**
 * Nextcloud - News
 *
 * This file is licensed under the Affero General Public License version 3 or
 * later. See the COPYING file.
 *
 * @author    Alessandro Cosentino <cosenal@gmail.com>
 * @author    Bernhard Posselt <dev@bernhard-posselt.com>
 * @copyright 2012 Alessandro Cosentino
 * @copyright 2012-2014 Bernhard Posselt
 */

namespace OCA\News\Db;

use OCA\News\Utility\Time;
use OCP\AppFramework\Db\DoesNotExistException;
use OCP\AppFramework\Db\MultipleObjectsReturnedException;
use OCP\AppFramework\Db\QBMapper;
use OCP\IDBConnection;
use OCP\AppFramework\Db\Mapper;
use OCP\AppFramework\Db\Entity;

/**
 * Class NewsMapper
 *
 * @package OCA\News\Db
 */
abstract class NewsMapper extends Mapper
{
    const TABLE_NAME = '';

    /**
     * @var Time
     */
    private $time;

    /**
     * NewsMapper constructor.
     *
     * @param IDBConnection $db     Database connection
     * @param Time          $time   Time class
     * @param string        $entity Entity class
     */
    public function __construct(
        IDBConnection $db,
        Time $time,
        string $entity
    ) {
        parent::__construct($db, static::TABLE_NAME, $entity);
        $this->time = $time;
    }

    public function update(Entity $entity): Entity
    {
        $entity->setLastModified($this->time->getMicroTime());
        return parent::update($entity);
    }

    public function insert(Entity $entity): Entity
    {
        $entity->setLastModified($this->time->getMicroTime());
        return parent::insert($entity);
    }

    /**
     * Remove deleted items.
     *
     * @return void
     */
    public function purgeDeleted(): void
    {
        $builder = $this->db->getQueryBuilder();
        $builder->delete($this->tableName)
            ->where('deleted_at != 0')
            ->execute();
    }

    abstract public function find(string $userId, int $id);

    /**
     * Find all items.
     *
     * @return Entity[]
     */
    abstract public function findAll(): array;

    /**
     * Find all items for a user.
     *
     * @param string $userId ID of the user
     *
     * @return Entity[]
     */
    abstract public function findAllFromUser(string $userId): array;

    /**
     * Find item for a user.
     *
     * @param string $userId ID of the user
     * @param int    $id     ID of the item
     *
     * @return Feed
     *
     * @throws DoesNotExistException            The item is not found
     * @throws MultipleObjectsReturnedException Multiple items found
     */
    abstract public function findFromUser(string $userId, int $id): Entity;


    /**
     * Performs a SELECT query with all arguments appened to the WHERE clause
     * The SELECT will be performed on the current table and take the entity
     * that is related for transforming the properties into column names
     *
     * Important: This method does not filter marked as deleted rows!
     *
     * @param array $search an assoc array from property to filter value
     * @param int|null $limit  Output limit
     * @param int|null $offset Output offset
     *
     * @depreacted Legacy function
     *
     * @return array
     */
    public function where(array $search = [], ?int $limit = null, ?int $offset = null)
    {
        $entity = new $this->entityClass();

        // turn keys into sql query filter, e.g. feedId -> feed_id = :feedId
        $filter = array_map(
            function ($property) use ($entity) {
                // check if the property actually exists on the entity to prevent
                // accidental Sql injection
                if (!property_exists($entity, $property)) {
                    $msg = 'Property ' . $property . ' does not exist on '
                        . $this->entityClass;
                    throw new \BadFunctionCallException($msg);
                }

                $column = $entity->propertyToColumn($property);
                return $column . ' = :' . $property;
            },
            array_keys($search)
        );

        $andStatement = implode(' AND ', $filter);

        $sql = 'SELECT * FROM `' . $this->getTableName() . '`';

        if (count($search) > 0) {
            $sql .= 'WHERE ' . $andStatement;
        }

        return $this->findEntities($sql, $search, $limit, $offset);
    }
}