<?php

// SPDX-FileCopyrightText: 2004-2023 Ryan Parman, Sam Sneddon, Ryan McCue
// SPDX-License-Identifier: BSD-3-Clause

declare(strict_types=1);

namespace SimplePie\Cache;

/**
 * Caches data to a MySQL database
 *
 * Registered for URLs with the "mysql" protocol
 *
 * For example, `mysql://root:password@localhost:3306/mydb?prefix=sp_` will
 * connect to the `mydb` database on `localhost` on port 3306, with the user
 * `root` and the password `password`. All tables will be prefixed with `sp_`
 *
 * @deprecated since SimplePie 1.8.0, use implementation of "Psr\SimpleCache\CacheInterface" instead
 */
class MySQL extends DB
{
    /**
     * PDO instance
     *
     * @var \PDO|null
     */
    protected $mysql;

    /**
     * Options
     *
     * @var array<string, mixed>
     */
    protected $options;

    /**
     * Cache ID
     *
     * @var string
     */
    protected $id;

    /**
     * Create a new cache object
     *
     * @param string $location Location string (from SimplePie::$cache_location)
     * @param string $name Unique ID for the cache
     * @param Base::TYPE_FEED|Base::TYPE_IMAGE $type Either TYPE_FEED for SimplePie data, or TYPE_IMAGE for image data
     */
    public function __construct(string $location, string $name, $type)
    {
        $this->options = [
            'user' => null,
            'pass' => null,
            'host' => '127.0.0.1',
            'port' => '3306',
            'path' => '',
            'extras' => [
                'prefix' => '',
                'cache_purge_time' => 2592000
            ],
        ];

        $this->options = array_replace_recursive($this->options, \SimplePie\Cache::parse_URL($location));

        // Path is prefixed with a "/"
        $this->options['dbname'] = substr($this->options['path'], 1);

        try {
            $this->mysql = new \PDO("mysql:dbname={$this->options['dbname']};host={$this->options['host']};port={$this->options['port']}", $this->options['user'], $this->options['pass'], [\PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8']);
        } catch (\PDOException $e) {
            $this->mysql = null;
            return;
        }

        $this->id = $name . $type;

        if (!$query = $this->mysql->query('SHOW TABLES')) {
            $this->mysql = null;
            return;
        }

        $db = [];
        while ($row = $query->fetchColumn()) {
            $db[] = $row;
        }

        if (!in_array($this->options['extras']['prefix'] . 'cache_data', $db)) {
            $query = $this->mysql->exec('CREATE TABLE `' . $this->options['extras']['prefix'] . 'cache_data` (`id` TEXT CHARACTER SET utf8 NOT NULL, `items` SMALLINT NOT NULL DEFAULT 0, `data` BLOB NOT NULL, `mtime` INT UNSIGNED NOT NULL, UNIQUE (`id`(125)))');
            if ($query === false) {
                trigger_error("Can't create " . $this->options['extras']['prefix'] . "cache_data table, check permissions", \E_USER_WARNING);
                $this->mysql = null;
                return;
            }
        }

        if (!in_array($this->options['extras']['prefix'] . 'items', $db)) {
            $query = $this->mysql->exec('CREATE TABLE `' . $this->options['extras']['prefix'] . 'items` (`feed_id` TEXT CHARACTER SET utf8 NOT NULL, `id` TEXT CHARACTER SET utf8 NOT NULL, `data` MEDIUMBLOB NOT NULL, `posted` INT UNSIGNED NOT NULL, INDEX `feed_id` (`feed_id`(125)))');
            if ($query === false) {
                trigger_error("Can't create " . $this->options['extras']['prefix'] . "items table, check permissions", \E_USER_WARNING);
                $this->mysql = null;
                return;
            }
        }
    }

    /**
     * Save data to the cache
     *
     * @param array<string>|\SimplePie\SimplePie $data Data to store in the cache. If passed a SimplePie object, only cache the $data property
     * @return bool Successfulness
     */
    public function save($data)
    {
        if ($this->mysql === null) {
            return false;
        }

        $query = $this->mysql->prepare('DELETE i, cd FROM `' . $this->options['extras']['prefix'] . 'cache_data` cd, ' .
            '`' . $this->options['extras']['prefix'] . 'items` i ' .
            'WHERE cd.id = i.feed_id ' .
            'AND cd.mtime < (unix_timestamp() - :purge_time)');
        $query->bindValue(':purge_time', $this->options['extras']['cache_purge_time']);

        if (!$query->execute()) {
            return false;
        }

        if ($data instanceof \SimplePie\SimplePie) {
            $data = clone $data;

            $prepared = self::prepare_simplepie_object_for_cache($data);

            $query = $this->mysql->prepare('SELECT COUNT(*) FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :feed');
            $query->bindValue(':feed', $this->id);
            if ($query->execute()) {
                if ($query->fetchColumn() > 0) {
                    $items = count($prepared[1]);
                    if ($items) {
                        $sql = 'UPDATE `' . $this->options['extras']['prefix'] . 'cache_data` SET `items` = :items, `data` = :data, `mtime` = :time WHERE `id` = :feed';
                        $query = $this->mysql->prepare($sql);
                        $query->bindValue(':items', $items);
                    } else {
                        $sql = 'UPDATE `' . $this->options['extras']['prefix'] . 'cache_data` SET `data` = :data, `mtime` = :time WHERE `id` = :feed';
                        $query = $this->mysql->prepare($sql);
                    }

                    $query->bindValue(':data', $prepared[0]);
                    $query->bindValue(':time', time());
                    $query->bindValue(':feed', $this->id);
                    if (!$query->execute()) {
                        return false;
                    }
                } else {
                    $query = $this->mysql->prepare('INSERT INTO `' . $this->options['extras']['prefix'] . 'cache_data` (`id`, `items`, `data`, `mtime`) VALUES(:feed, :count, :data, :time)');
                    $query->bindValue(':feed', $this->id);
                    $query->bindValue(':count', count($prepared[1]));
                    $query->bindValue(':data', $prepared[0]);
                    $query->bindValue(':time', time());
                    if (!$query->execute()) {
                        return false;
                    }
                }

                $ids = array_keys($prepared[1]);
                if (!empty($ids)) {
                    foreach ($ids as $id) {
                        $database_ids[] = $this->mysql->quote($id);
                    }

                    $query = $this->mysql->prepare('SELECT `id` FROM `' . $this->options['extras']['prefix'] . 'items` WHERE `id` = ' . implode(' OR `id` = ', $database_ids) . ' AND `feed_id` = :feed');
                    $query->bindValue(':feed', $this->id);

                    if ($query->execute()) {
                        $existing_ids = [];
                        while ($row = $query->fetchColumn()) {
                            $existing_ids[] = $row;
                        }

                        $new_ids = array_diff($ids, $existing_ids);

                        foreach ($new_ids as $new_id) {
                            if (!($date = $prepared[1][$new_id]->get_date('U'))) {
                                $date = time();
                            }

                            $query = $this->mysql->prepare('INSERT INTO `' . $this->options['extras']['prefix'] . 'items` (`feed_id`, `id`, `data`, `posted`) VALUES(:feed, :id, :data, :date)');
                            $query->bindValue(':feed', $this->id);
                            $query->bindValue(':id', $new_id);
                            $query->bindValue(':data', serialize($prepared[1][$new_id]->data));
                            $query->bindValue(':date', $date);
                            if (!$query->execute()) {
                                return false;
                            }
                        }
                        return true;
                    }
                } else {
                    return true;
                }
            }
        } else {
            $query = $this->mysql->prepare('SELECT `id` FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :feed');
            $query->bindValue(':feed', $this->id);
            if ($query->execute()) {
                if ($query->rowCount() > 0) {
                    $query = $this->mysql->prepare('UPDATE `' . $this->options['extras']['prefix'] . 'cache_data` SET `items` = 0, `data` = :data, `mtime` = :time WHERE `id` = :feed');
                    $query->bindValue(':data', serialize($data));
                    $query->bindValue(':time', time());
                    $query->bindValue(':feed', $this->id);
                    if ($query->execute()) {
                        return true;
                    }
                } else {
                    $query = $this->mysql->prepare('INSERT INTO `' . $this->options['extras']['prefix'] . 'cache_data` (`id`, `items`, `data`, `mtime`) VALUES(:id, 0, :data, :time)');
                    $query->bindValue(':id', $this->id);
                    $query->bindValue(':data', serialize($data));
                    $query->bindValue(':time', time());
                    if ($query->execute()) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    /**
     * Retrieve the data saved to the cache
     *
     * @return array<string>|false Data for SimplePie::$data
     */
    public function load()
    {
        if ($this->mysql === null) {
            return false;
        }

        $query = $this->mysql->prepare('SELECT `items`, `data` FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :id');
        $query->bindValue(':id', $this->id);
        if ($query->execute() && ($row = $query->fetch())) {
            $data = unserialize($row[1]);

            if (isset($this->options['items'][0])) {
                $items = (int) $this->options['items'][0];
            } else {
                $items = (int) $row[0];
            }

            if ($items !== 0) {
                if (isset($data['child'][\SimplePie\SimplePie::NAMESPACE_ATOM_10]['feed'][0])) {
                    $feed = &$data['child'][\SimplePie\SimplePie::NAMESPACE_ATOM_10]['feed'][0];
                } elseif (isset($data['child'][\SimplePie\SimplePie::NAMESPACE_ATOM_03]['feed'][0])) {
                    $feed = &$data['child'][\SimplePie\SimplePie::NAMESPACE_ATOM_03]['feed'][0];
                } elseif (isset($data['child'][\SimplePie\SimplePie::NAMESPACE_RDF]['RDF'][0])) {
                    $feed = &$data['child'][\SimplePie\SimplePie::NAMESPACE_RDF]['RDF'][0];
                } elseif (isset($data['child'][\SimplePie\SimplePie::NAMESPACE_RSS_20]['rss'][0])) {
                    $feed = &$data['child'][\SimplePie\SimplePie::NAMESPACE_RSS_20]['rss'][0];
                } else {
                    $feed = null;
                }

                if ($feed !== null) {
                    $sql = 'SELECT `data` FROM `' . $this->options['extras']['prefix'] . 'items` WHERE `feed_id` = :feed ORDER BY `posted` DESC';
                    if ($items > 0) {
                        $sql .= ' LIMIT ' . $items;
                    }

                    $query = $this->mysql->prepare($sql);
                    $query->bindValue(':feed', $this->id);
                    if ($query->execute()) {
                        while ($row = $query->fetchColumn()) {
                            $feed['child'][\SimplePie\SimplePie::NAMESPACE_ATOM_10]['entry'][] = unserialize((string) $row);
                        }
                    } else {
                        return false;
                    }
                }
            }
            return $data;
        }
        return false;
    }

    /**
     * Retrieve the last modified time for the cache
     *
     * @return int|false Timestamp
     */
    public function mtime()
    {
        if ($this->mysql === null) {
            return false;
        }

        $query = $this->mysql->prepare('SELECT `mtime` FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :id');
        $query->bindValue(':id', $this->id);
        if ($query->execute() && ($time = $query->fetchColumn())) {
            return (int) $time;
        }

        return false;
    }

    /**
     * Set the last modified time to the current time
     *
     * @return bool Success status
     */
    public function touch()
    {
        if ($this->mysql === null) {
            return false;
        }

        $query = $this->mysql->prepare('UPDATE `' . $this->options['extras']['prefix'] . 'cache_data` SET `mtime` = :time WHERE `id` = :id');
        $query->bindValue(':time', time());
        $query->bindValue(':id', $this->id);

        return $query->execute() && $query->rowCount() > 0;
    }

    /**
     * Remove the cache
     *
     * @return bool Success status
     */
    public function unlink()
    {
        if ($this->mysql === null) {
            return false;
        }

        $query = $this->mysql->prepare('DELETE FROM `' . $this->options['extras']['prefix'] . 'cache_data` WHERE `id` = :id');
        $query->bindValue(':id', $this->id);
        $query2 = $this->mysql->prepare('DELETE FROM `' . $this->options['extras']['prefix'] . 'items` WHERE `feed_id` = :id');
        $query2->bindValue(':id', $this->id);

        return $query->execute() && $query2->execute();
    }
}

class_alias('SimplePie\Cache\MySQL', 'SimplePie_Cache_MySQL');