<?php
/**
 * li₃: the most RAD framework for PHP (http://li3.me)
 *
 * Copyright 2009, Union of RAD. All rights reserved. This source
 * code is distributed under the terms of the BSD 3-Clause License.
 * The full license text can be found in the LICENSE.txt file.
 */

namespace lithium\analysis\logger\adapter;

use lithium\util\Text;

/**
 * The `Cache` logger allows log messages to be written to cache configurations set up in
 * `lithium\storage\Cache`. In order to use this adapter, you must first configure a cache adapter
 * for it to write to, as follows:
 * ```
 * lithium\storage\Cache::config([
 * 	'storage' => ['adapter' => 'Redis', 'host' => '127.0.0.1:6379']
 * ]);```
 *
 * Then, you can configure the `Cache` logger with the `'storage'` config:
 * ```
 * lithium\analysis\Logger::config([
 * 	'debug' => ['adapter' => 'Cache', 'config' => 'storage']
 * ]);
 * ```
 *
 * You can then send messages to the logger which will be written to the cache store:
 * ```
 * lithium\analysis\Logger::write('debug', 'This message will be written to a Redis data store.');
 * ```
 *
 * @see lithium\storage\Cache
 */
class Cache extends \lithium\core\ObjectDeprecated {

	/**
	 * Classes used by `Cache`.
	 *
	 * @var array
	 */
	protected $_classes = [
		'cache' => 'lithium\storage\Cache'
	];

	/**
	 * Constructor.
	 *
	 * @see lithium\util\Text
	 * @param array $config Possible configuration options are:
	 *        - `'config'`: The name of the cache configuration to use; defaults to none.
	 *        - `'expiry'`: Defines when the logged item should expire, by default will
	 *          try to expire as late as possible.
	 *        - `'key'`: Either a pattern where priority and timestamp will be inserted
	 *          or a closure wich must return a key to store the message under and
	 *          which gets passed a params array as first and only argument; defaults
	 *          to `'log_{:priority}_{:timestamp}'`.
	 * @return void
	 */
	public function __construct(array $config = []) {
		$cache = $this->_classes['cache'];

		$defaults = [
			'config' => null,
			'expiry' => $cache::PERSIST,
			'key' => 'log_{:priority}_{:timestamp}'
		];
		parent::__construct($config + $defaults);
	}

	/**
	 * Writes the message to the configured cache adapter.
	 *
	 * @param string $priority
	 * @param string $message
	 * @return \Closure Function returning boolean `true` on successful write, `false` otherwise.
	 */
	public function write($priority, $message) {
		return function($params) {
			$cache = $this->_classes['cache'];
			$params += ['timestamp' => strtotime('now')];

			if (!is_callable($key = $this->_config['key'])) {
				$key = function($data) use ($key) { return Text::insert($key, $data); };
			}
			return $cache::write(
				$this->_config['config'],
				$cache::key($this->_config['config'], $key, $params),
				$params['message'],
				$this->_config['expiry']
			);
		};
	}
}

?>