<?php
  /**
   * ownCloud
   *
   * @author Frank Karlitschek
   * @author Jakob Sack
   * @copyright 2012 Frank Karlitschek frank@owncloud.org
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or any later version.
   *
   * This library 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 AFFERO GENERAL PUBLIC LICENSE for more details.
   *
   * You should have received a copy of the GNU Affero General Public
   * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  /*
   *
   * An example of config.php
   *
   * <?php
   * $CONFIG = array(
   *     "database" => "mysql",
   *     "firstrun" => false,
   *     "pi" => 3.14
   * );
   * ?>
   *
   */
  
  namespace OC;
  
  /**
   * This class is responsible for reading and writing config.php, the very basic
   * configuration file of ownCloud.
   */
  class Config {
  	// associative array key => value
  	protected $cache = array();
  
  	protected $configDir;
  	protected $configFilename;
  
  	protected $debugMode;
  
  	/**
  	 * @param $configDir path to the config dir, needs to end with '/'
  	 */
  	public function __construct($configDir) {
  		$this->configDir = $configDir;
  		$this->configFilename = $this->configDir.'config.php';
  		$this->readData();
  		$this->setDebugMode(defined('DEBUG') && DEBUG);
  	}
  
  	public function setDebugMode($enable) {
  		$this->debugMode = $enable;
  	}
  
  	/**
  	 * @brief Lists all available config keys
  	 * @return array with key names
  	 *
  	 * This function returns all keys saved in config.php. Please note that it
  	 * does not return the values.
  	 */
  	public function getKeys() {
  		return array_keys($this->cache);
  	}
  
  	/**
  	 * @brief Gets a value from config.php
  	 * @param string $key key
  	 * @param string $default = null default value
  	 * @return string the value or $default
  	 *
  	 * This function gets the value from config.php. If it does not exist,
  	 * $default will be returned.
  	 */
  	public function getValue($key, $default = null) {
  		if (isset($this->cache[$key])) {
  			return $this->cache[$key];
  		}
  
  		return $default;
  	}
  
  	/**
  	 * @brief Sets a value
  	 * @param string $key key
  	 * @param string $value value
  	 *
  	 * This function sets the value and writes the config.php.
  	 *
  	 */
  	public function setValue($key, $value) {
  		// Add change
  		$this->cache[$key] = $value;
  
  		// Write changes
  		$this->writeData();
  	}
  
  	/**
  	 * @brief Removes a key from the config
  	 * @param string $key key
  	 *
  	 * This function removes a key from the config.php.
  	 *
  	 */
  	public function deleteKey($key) {
  		if (isset($this->cache[$key])) {
  			// Delete key from cache
  			unset($this->cache[$key]);
  
  			// Write changes
  			$this->writeData();
  		}
  	}
  
  	/**
  	 * @brief Loads the config file
  	 *
  	 * Reads the config file and saves it to the cache
  	 */
  	private function readData() {
  		// Default config
  		$configFiles = array($this->configFilename);
  		// Add all files in the config dir ending with config.php
  		$extra = glob($this->configDir.'*.config.php');
  		if (is_array($extra)) {
  			natsort($extra);
  			$configFiles = array_merge($configFiles, $extra);
  		}
  		// Include file and merge config
  		foreach ($configFiles as $file) {
  			if (!file_exists($file)) {
  				continue;
  			}
  			unset($CONFIG);
  			// ignore errors on include, this can happen when doing a fresh install
  			@include $file;
  			if (isset($CONFIG) && is_array($CONFIG)) {
  				$this->cache = array_merge($this->cache, $CONFIG);
  			}
  		}
  	}
  
  	/**
  	 * @brief Writes the config file
  	 *
  	 * Saves the config to the config file.
  	 *
  	 */
  	private function writeData() {
  		// Create a php file ...
  		$content = "<?php
  ";
  		if ($this->debugMode) {
  			$content .= "define('DEBUG',true);
  ";
  		}
  		$content .= '$CONFIG = ';
  		$content .= var_export($this->cache, true);
  		$content .= ";
  ";
  
  		// Write the file
  		$result = @file_put_contents($this->configFilename, $content);
  		if (!$result) {
  			$defaults = new \OC_Defaults;

  			$url = \OC_Helper::linkToDocs('admin-dir_permissions');

  			throw new HintException(
  				"Can't write into config directory!",
  				'This can usually be fixed by '
  					.'<a href="' . $url . '" target="_blank">giving the webserver write access to the config directory</a>.');
  		}
  		// Prevent others not to read the config
  		@chmod($this->configFilename, 0640);
  		\OC_Util::clearOpcodeCache();
  	}
  }