<?php defined('SYSPATH') or die('No direct access allowed.');

/**
 * This class takes care of communicating with LDAP
 *
 * @package    Kohana/LDAP
 * @category   Database/LDAP
 * @author     Deon George
 * @copyright  (c) phpLDAPadmin Development Team
 * @license    http://dev.phpldapadmin.org/license.html
 */
abstract class Kohana_Database_LDAP extends Database {
	// Our required abstract functions
	public function set_charset($charset) {}
	public function query($type, $sql, $as_object = FALSE, array $params = NULL) {}
	public function begin($mode = NULL) {}
	public function commit() {}
	public function rollback() {}
	public function list_tables($like = NULL) {}
	public function list_columns($table, $like = NULL, $add_prefix = TRUE) {}
	public function escape($value) { return $value;}

	/** OVERRIDES **/

	/**
	 * We override this parent function, since LDAP doesnt quote columns
	 * @note Override
	 */
	public function quote_column($column) {
		return $column;
	}

	/** Database_LDAP **/

	/**
	 * @var boolean Whether we are full connected connection & bind
	 */
	protected $_connected = FALSE;

	/**
	 * @var string Our default usage when connection
	 */
	public static $usage = 'default';

	private function _bind($u,$p) {
		/*
		// @todo To implement
		// If SASL has been configured for binding, then start it now.
		if ($this->isSASLEnabled())
			$br = $this->startSASL($this->_r,$method);

		// Normal bind...
		else
		*/

		if (Kohana::$profiling)
			$benchmark = Profiler::start("Database Bind ({$this->_instance})", $this->_instance);

		try {
			$br = ldap_bind($this->_connection,$u,$p);

		} catch (Exception $e) {
			// This benchmark is worthless
			if (isset($benchmark))
				Profiler::delete($benchmark);

			return FALSE;
		}

		if (! $br)
			return FALSE;

		$this->_connected = TRUE;

		/*
		// @todo To implement
		# If this is a proxy session, we need to switch to the proxy user
		if ($this->isProxyEnabled() && $bind['id'] && $method != 'anon')
			if (! $this->startProxy($this->_r,$method)) {
				$CACHE[$this->index][$method] = null;
			}
		*/

		/*
		// @todo To implement
		if (function_exists('run_hook'))
			run_hook('post_connect',array('server_id'=>$this->index,'method'=>$method,'id'=>$bind['id']));
		*/

		if (isset($benchmark))
			Profiler::stop($benchmark);

		return $br;
	}

	/**
	 * Bind to the LDAP server
	 *
	 * @param string User DN to connect with, or blank for anonymous
	 * @param string Password for DN, or blank for anonymous
	 */
	public function bind($user,$pass) {
		// If we are already connected, no need to re-bind.
		if ($this->_connected)
			return $this;

		// Make sure we are connected.
		$this->_connection OR $this->connect();

		// Do we need to do an search to find the DN
		if (! empty($this->_config['login_attr']) AND strtoupper($this->_config['login_attr']) != 'DN') {
			// Do we need to authenticate for this search?
			// Extract the connection parameters, adding required variabels
			extract($this->_config['connection'] + array(
				'username'   => '',
				'password'   => '',
				'hostname'   => '',
				'port'      => '',
			));

			// Prevent this information from showing up in traces
			unset($this->_config['connection']['username'], $this->_config['connection']['password']);

			// Sanity check
			if ($this->_instance == 'auth')
				throw new Kohana_Exception('We shouldnt be authing an auth');

			$config = array(
				'login_attr'=>'DN',
				'type'=>$this->_config['type'],
				'connection'=>array(
					'hostname'=>$hostname,
					'port'=>$port,
				),
			);

			try {
				$x = Database_LDAP::factory('auth',NULL,$config);

				// Our Auth Bind credentials are wrong
				if (! $x->bind($username,$password))
					return FALSE;

				$u = $x->search(NULL)
					->scope('sub')
					->where($this->_config['login_attr'],'=',$user)
					->run();

				if (! $u)
					return FALSE;

			} catch (Exception $e) {
				// If we are a command line, we can just print the error
				echo _('Unable to bind to LDAP server with CONFIG settings, please check them.');
				echo _('The error message is').': '.$e->getMessage();
				die();
			}

			foreach ($u as $base => $entries)
				foreach ($entries as $dn => $details)
					if ($this->_bind($details['dn'],$pass)) {
						// \xFF is a better delimiter, but the PHP driver uses underscore
						$this->_connection_id = sha1($this->_instance.'_'.$details['dn']);
						return $this;
					}

			// We didnt find an AUTH DN to bind with
			return FALSE;
		}

		// Bind
		if ($this->_bind($user,$pass))
			return $this;
		else
			return FALSE;
	}

	/**
	 * Create a connection to an LDAP server
	 */
	public function connect() {
		if ($this->_connection)
			return;

		// Extract the connection parameters, adding required variabels
		extract($this->_config['connection'] + array(
			'hostname'   => '',
			'port'       => '',
		));

		/*
		// @todo To implement
		if (function_exists('run_hook'))
			run_hook('pre_connect',array('server_id'=>$this->index,'method'=>$method));
		*/

		// Benchmark this connection for the current instance
		if (Kohana::$profiling)
			$benchmark = Profiler::start("Database Connect ({$this->_instance})", $this->_instance);

		$r = (! empty($this->_config['port'])) ? ldap_connect($hostname,$port) : ldap_connect($hostname);

		if (! is_resource($r)) {
			// This benchmark is worthless
			if (isset($benchmark))
				Profiler::delete($benchmark);

			throw HTTP_Exception::factory(501,'UNHANDLED, $r is not a resource');
		}

		// Go with LDAP version 3 if possible (needed for renaming and Novell schema fetching)
		ldap_set_option($r,LDAP_OPT_PROTOCOL_VERSION,3);

		/* Disabling this makes it possible to browse the tree for Active Directory, and seems
		 * to not affect other LDAP servers (tested with OpenLDAP) as phpLDAPadmin explicitly
		 * specifies deref behavior for each ldap_search operation. */
		ldap_set_option($r,LDAP_OPT_REFERRALS,0);

		/*
		// @todo To implement
		# Try to fire up TLS is specified in the config
		if ($this->isTLSEnabled())
			$this->startTLS($this->_connection);
		*/

		if (isset($benchmark))
			Profiler::stop($benchmark);

		$this->_connection = $r;
	}

	public function connected() {
		return ($this->_connection AND $this->_connected);
	}

	/**
	 * A wrapper for parent::instance(), so that we can create multiple connections
	 * to the same LDAP server with different credentials/purposes.
	 *
	 * @param string A free form usage name, for this connection
	 * @param string A database configuration name, as per parent::instance()
	 * @param array An alternative database configuration to use for $name.
	 * @see Database::instance();
	 */
	public static function factory($usage=NULL,$name=NULL,array $config=NULL) {
		// Use the default instance name
		if ($usage === NULL)
			$usage = Database_LDAP::$usage;

		if (! isset(Database::$instances[$usage])) {
			// Use the default instance name
			if ($name === NULL)
				$name = Database::$default;

			// Load the configuration for this database
			if ($config === NULL)
				$config = Kohana::$config->load('database')->$name;
		}

		return parent::instance($usage,$config);
	}

	public function search($base=array()) {
		return new Database_LDAP_Search($this->_connection,$base);
	}
}
?>