<?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
   * );
   * ?>
   *
   */
  
  /**
   * This class is responsible for reading and writing config.php, the very basic
   * configuration file of owncloud.
   */
  class OC_Config{
  	// associative array key => value
  	private static $cache = array();
  
  	// Is the cache filled?
  	private static $init = false;
  
  	/**
  	 * @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 static function getKeys() {
  		self::readData();
  
  		return array_keys( self::$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 static function getValue( $key, $default = null ) {
  		self::readData();
  
  		if( array_key_exists( $key, self::$cache )) {
  			return self::$cache[$key];
  		}
  
  		return $default;
  	}
  
  	/**
  	 * @brief Sets a value
  	 * @param string $key key
  	 * @param string $value value
  	 * @return bool
  	 *
  	 * This function sets the value and writes the config.php. If the file can
  	 * not be written, false will be returned.
  	 */
  	public static function setValue( $key, $value ) {
  		self::readData();
  
  		// Add change
  		self::$cache[$key] = $value;
  
  		// Write changes
  		self::writeData();
  		return true;
  	}
  
  	/**
  	 * @brief Removes a key from the config
  	 * @param string $key key
  	 * @return bool
  	 *
  	 * This function removes a key from the config.php. If owncloud has no
  	 * write access to config.php, the function will return false.
  	 */
  	public static function deleteKey( $key ) {
  		self::readData();
  
  		if( array_key_exists( $key, self::$cache )) {
  			// Delete key from cache
  			unset( self::$cache[$key] );
  
  			// Write changes
  			self::writeData();
  		}
  
  		return true;
  	}
  
  	/**
  	 * @brief Loads the config file
  	 * @return bool
  	 *
  	 * Reads the config file and saves it to the cache
  	 */
  	private static function readData() {
  		if( self::$init ) {
  			return true;
  		}
  
  		if( !file_exists( OC::$SERVERROOT."/config/config.php" )) {
  			return false;
  		}
  
  		// Include the file, save the data from $CONFIG
  		include OC::$SERVERROOT."/config/config.php";
  		if( isset( $CONFIG ) && is_array( $CONFIG )) {
  			self::$cache = $CONFIG;
  		}
  
  		// We cached everything
  		self::$init = true;
  
  		return true;
  	}
  
  	/**
  	 * @brief Writes the config file
  	 * @return bool
  	 *
  	 * Saves the config to the config file.
  	 *
  	 */
  	public static function writeData() {
  		// Create a php file ...
  		$defaults = new OC_Defaults;
  		
  		$content = "<?php
  \$CONFIG = ";
  		$content .= var_export(self::$cache, true);
  		$content .= ";
  ";
  
  		$filename = OC::$SERVERROOT."/config/config.php";
  		// Write the file
  		$result=@file_put_contents( $filename, $content );
  		if(!$result) {
  			$tmpl = new OC_Template( '', 'error', 'guest' );
  			$tmpl->assign('errors', array(1=>array(
  				'error'=>"Can't write into config directory 'config'",
  				'hint'=>'This can usually be fixed by '
  					.'<a href="' . $defaults->getDocBaseUrl() . '/server/5.0/admin_manual/installation/installation_source.html#set-the-directory-permissions" target="_blank">giving the webserver write access to the config directory</a>.')));
  			$tmpl->printPage();
  			exit;
  		}
  		// Prevent others not to read the config
  		@chmod($filename, 0640);
  		OC_Util::clearOpcodeCache();
  		return true;
  	}
  }