<?php
/**
 * SimplePie
 *
 * A PHP-Based RSS and Atom Feed Framework.
 * Takes the hard work out of managing a complete RSS/Atom solution.
 *
 * Copyright (c) 2004-2016, Ryan Parman, Sam Sneddon, Ryan McCue, and contributors
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 * 	* Redistributions of source code must retain the above copyright notice, this list of
 * 	  conditions and the following disclaimer.
 *
 * 	* Redistributions in binary form must reproduce the above copyright notice, this list
 * 	  of conditions and the following disclaimer in the documentation and/or other materials
 * 	  provided with the distribution.
 *
 * 	* Neither the name of the SimplePie Team nor the names of its contributors may be used
 * 	  to endorse or promote products derived from this software without specific prior
 * 	  written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
 * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * @package SimplePie
 * @copyright 2004-2016 Ryan Parman, Sam Sneddon, Ryan McCue
 * @author Ryan Parman
 * @author Sam Sneddon
 * @author Ryan McCue
 * @link https://simplepie.org/ SimplePie
 * @license https://www.opensource.org/licenses/bsd-license.php BSD License
 */

/**
 * 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_`
 *
 * @package SimplePie
 * @subpackage Caching
 */
class SimplePie_Cache_MySQL extends SimplePie_Cache_DB
{
	/**
	 * PDO instance
	 *
	 * @var PDO
	 */
	protected $mysql;

	/**
	 * Options
	 *
	 * @var array
	 */
	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 string $type Either TYPE_FEED for SimplePie data, or TYPE_IMAGE for image data
	 */
	public function __construct($location, $name, $type)
	{
		$this->options = array(
			'user' => null,
			'pass' => null,
			'host' => '127.0.0.1',
			'port' => '3306',
			'path' => '',
			'extras' => array(
				'prefix' => '',
				'cache_purge_time' => 2592000
			),
		);

		$this->options = SimplePie_Misc::array_merge_recursive($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'], array(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;
		}

		$db = array();
		while ($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|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)
		{
			$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())
					{
						$existing_ids = array();
						while ($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', $this->id);
					if ($this->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 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_NAMESPACE_ATOM_10]['feed'][0]))
				{
					$feed =& $data['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['feed'][0];
				}
				elseif (isset($data['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['feed'][0]))
				{
					$feed =& $data['child'][SIMPLEPIE_NAMESPACE_ATOM_03]['feed'][0];
				}
				elseif (isset($data['child'][SIMPLEPIE_NAMESPACE_RDF]['RDF'][0]))
				{
					$feed =& $data['child'][SIMPLEPIE_NAMESPACE_RDF]['RDF'][0];
				}
				elseif (isset($data['child'][SIMPLEPIE_NAMESPACE_RSS_20]['rss'][0]))
				{
					$feed =& $data['child'][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())
						{
							$feed['child'][SIMPLEPIE_NAMESPACE_ATOM_10]['entry'][] = unserialize($row);
						}
					}
					else
					{
						return false;
					}
				}
			}
			return $data;
		}
		return false;
	}

	/**
	 * Retrieve the last modified time for the cache
	 *
	 * @return int 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 $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();
	}
}
