<?php

/*

 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between

 * pageprocess.php - intelligent retrieval of pages

 * Copyright (C) 2006-2009 Dan Fuhry

 *

 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for details.

 */

/**

 * Class to handle fetching page text (possibly from a cache) and formatting it.

 * As of 1.0.4, this also handles the fetching and editing of certain data for pages.

 * @package Enano

 * @subpackage UI

 * @copyright 2007 Dan Fuhry

 * @license GNU General Public License <http://www.gnu.org/licenses/gpl-2.0.html>

 */

class PageProcessor

{

	/**

 	* Page ID and namespace of the page handled by this instance

 	* @var string

 	*/

	var $page_id;

	var $namespace;

	/**

 	* The instance of the namespace processor for the namespace we're doing.

 	* @var object

 	*/

	var $ns;

	/**

 	* The title of the page sent to the template parser

 	* @var string

 	*/

	var $title = '';

	/**

 	* The information about the page(s) we were redirected from

 	* @var array

 	*/

	var $redirect_stack = array();

	/**

 	* The revision ID (history entry) to send. If set to 0 (the default) then the most recent revision will be sent.

 	* @var int

 	*/

	var $revision_id = 0;

	/**

 	* The time this revision was saved, as a UNIX timestamp

 	* @var int

 	*/

	var $revision_time = 0;

	/**

 	* Unsanitized page ID.

 	* @var string

 	*/

	var $page_id_unclean;

	/**

 	* Tracks if the page we're loading exists in the database or not.

 	* @var bool

 	*/

	var $page_exists = false;

	/**

 	* Permissions!

 	* @var object

 	*/

	var $perms = null;

	/**

 	* The SHA1 hash of the user-inputted password for the page

 	* @var string

 	*/

	var $password = '';

	/**

 	* Switch to track if redirects are allowed. Defaults to true.

 	* @var bool

 	*/

	var $allow_redir = true;

	/**

 	* Holds any error message from redirection code. Defaults to false (no error).

 	* @var mixed

 	*/

	var $redir_error = false;

	/**

 	* If this is set to true, this will call the header and footer funcs on $template when render() is called.

 	* @var bool

 	*/

	var $send_headers = false;

	/**

 	* Cache the fetched text so we don't fetch it from the DB twice.

 	* @var string

 	*/

	var $text_cache = '';

	/**

 	* Debugging information to track errors. You can set enable to false to disable sending debug information.

 	* @var array

 	*/

	var $debug = array(

			'enable' => false,

			'works'  => false

		);

	/**

 	* The list of errors raised in the class.

 	* @var array

 	*/

	var $_errors = array();

	/**

 	* Constructor.

 	* @param string The page ID (urlname) of the page

 	* @param string The namespace of the page

 	* @param int Optional. The revision ID to send.

 	*/

	function __construct( $page_id, $namespace, $revision_id = 0 )

	{

		global $db, $session, $paths, $template, $plugins; // Common objects

		profiler_log("PageProcessor [{$namespace}:{$page_id}]: Started constructor");

		// See if we can get some debug info

		if ( function_exists('debug_backtrace') && $this->debug['enable'] )

		{

			$this->debug['works'] = true;

			$this->debug['backtrace'] = enano_debug_print_backtrace(true);

		}

		// First things first - check page existence and permissions

		if ( !isset($paths->nslist[$namespace]) )

		{

			$this->send_error('The namespace "' . htmlspecialchars($namespace) . '" does not exist.');

		}

		if ( !is_int($revision_id) )

			$revision_id = 0;

		$this->_setup( $page_id, $namespace, $revision_id );

	}

	/**

 	* The main method to send the page content. Also responsible for checking permissions and calling the statistics counter.

 	* @param bool If true, the stat counter is called. Defaults to false.

 	*/

	function send( $do_stats = false )

	{

		global $db, $session, $paths, $template, $plugins; // Common objects

		global $lang, $output;

		profiler_log('PageProcessor: send() called');

		if ( !$this->perms->get_permissions('read') )

		{

			// Permission denied to read page. Is this one of our core pages that must always be allowed?

			// NOTE: Not even the administration panel will work if ACLs deny access to it.

			if ( $this->namespace == 'Special' && in_array($this->page_id, array('Login', 'Logout', 'LangExportJSON', 'CSS')) )

			{

				// Do nothing; allow execution to continue

			}

			else

			{

				// Page isn't whitelisted, behave as normal

				$this->err_access_denied();

				return false;

			}

		}

		if ( $this->revision_id > 0 && !$this->perms->get_permissions('history_view') )

		{

			$this->err_access_denied();

			return false;

		}

		// Is there a custom function registered for handling this namespace?

		// DEPRECATED (even though it only saw its way into one alpha release.)

		if ( $proc = $paths->get_namespace_processor($this->namespace) )

		{

			// yes, just call that

			// this is protected aggressively by the PathManager against overriding critical namespaces

			return call_user_func($proc, $this);

		}

		$pathskey = $paths->nslist[ $this->namespace ] . $this->page_id;

		$strict_no_headers = false;

		$admin_fail = false;

		if ( $this->namespace == 'Admin' && strstr($this->page_id, '/') )

		{

			$this->page_id = substr($this->page_id, 0, strpos($this->page_id, '/'));

			$funcname = "page_{$this->namespace}_{$this->page_id}";

			if ( function_exists($funcname) )

			{

				$this->page_exists = true;

			}

		}

		if ( isPage($pathskey) )

		{

			$cdata = $this->ns->get_cdata();

			if ( $cdata['special'] == 1 )

			{

				$this->send_headers = false;

				$strict_no_headers = true;

				$GLOBALS['output'] = new Output_Naked();

			}

			if ( isset($cdata['password']) )

			{

				if ( $cdata['password'] != '' && $cdata['password'] != sha1('') )

				{

					$password =& $cdata['password'];

					if ( $this->password != $password )

					{

						$this->err_wrong_password();

						return false;

					}

				}

			}

			if ( isset($cdata['require_admin']) && $cdata['require_admin'] )

			{

				if ( $session->auth_level < USER_LEVEL_ADMIN )

				{

					$admin_fail = true;

				}

			}

		}

		else if ( $this->namespace === $paths->namespace && $this->page_id == $paths->page_id )

		{

			if ( isset($paths->cpage['require_admin']) && $paths->cpage['require_admin'] )

			{

				if ( $session->auth_level < USER_LEVEL_ADMIN )

				{

					$admin_fail = true;

				}

			}

		}

		if ( $admin_fail )

		{

			header('Content-type: text/javascript');

			echo enano_json_encode(array(

					'mode' => 'error',

					'error' => 'need_auth_to_admin'

				));

			return true;

		}

		if ( $this->page_exists && $this->namespace != 'Special' && $this->namespace != 'Admin' && $do_stats )

		{

			require_once(ENANO_ROOT.'/includes/stats.php');

			doStats($this->page_id, $this->namespace);

		}

		// We are all done. Ship off the page.

		if ( !$this->allow_redir )

		{

			if ( method_exists($this->ns, 'get_redirect') )

			{

				if ( $result = $this->ns->get_redirect() )

					display_redirect_notice($result['page_id'], $result['namespace']);

			}

		}

		else

		{

			$this->process_redirects();

			if ( count($this->redirect_stack) > 0 )

			{

				$stack = array_reverse($this->redirect_stack);

				foreach ( $stack as $stackel )

				{

					$url = makeUrlNS($stackel['old_namespace'], $stackel['old_page_id'], 'redirect=no', true);

					$page_data = $this->ns->get_cdata();

					$title = $stackel['old_title'];

					$a = '<a href="' . $url . '">' . htmlspecialchars($title) . '</a>';

					$output->add_after_header('<small>' . $lang->get('page_msg_redirected_from', array('from' => $a)) . '<br /></small>');

				}

				$template->set_page($this);

			}

			if ( $this->redir_error )

			{

				$output->add_after_header('<div class="usermessage"><b>' . $this->redir_error . '</b></div>');

				$result = $this->ns->get_redirect();

				display_redirect_notice($result['page_id'], $result['namespace']);

			}

		}

		$this->ns->send();

	}

	/**

 	* Sends the page through by fetching it from the database.

 	*/

	function send_from_db($strict_no_headers = false)

	{

		global $db, $session, $paths, $template, $plugins; // Common objects

		global $lang;

		$this->ns->send_from_db();

	}

	/**

 	* Fetches the wikitext or HTML source for the page.

 	* @return string

 	*/

	function fetch_source()

	{

		global $db, $session, $paths, $template, $plugins; // Common objects

		if ( !$this->perms->get_permissions('view_source') )

		{

			return false;

		}

		if ( !$this->page_exists )

		{

			return '';

		}

		$cdata = $this->ns->get_cdata();

		if ( isset($cdata['password']) )

		{

			if ( $cdata['password'] != sha1('') && $cdata['password'] !== $this->password && !empty($cdata['password']) )

			{

				return false;

			}

		}

		return $this->fetch_text();

	}

	/**

 	* Updates (saves/changes/edits) the content of the page.

 	* @param string The new text for the page

 	* @param string A summary of edits made to the page.

 	* @param bool If true, the edit is marked as a minor revision

 	* @param string Page format - wikitext or xhtml. REQUIRED, and new in 1.1.6.

 	* @param array Optional - the entire incoming request. Plugins can add their own data to it.

 	* @return bool True on success, false on failure. When returning false, it will push errors to the PageProcessor error stack; read with $page->pop_error()

 	*/

	function update_page($text, $edit_summary = false, $minor_edit = false, $page_format, $raw_request = array())

	{

		global $db, $session, $paths, $template, $plugins; // Common objects

		global $lang;

		// Create the page if it doesn't exist

		$page_just_created = false;

		if ( !$this->page_exists )

		{

			if ( !$this->create_page() )

			{

				return false;

			}

			// This is just to tell plugins if a page was just created, or is being edited.

			$page_just_created = true;

		}

		//

		// Validation

		//

		$page_id = $db->escape($this->page_id);

		$namespace = $db->escape($this->namespace);

		$q = $db->sql_query('SELECT protected FROM ' . table_prefix . "pages WHERE urlname='$page_id' AND namespace='$namespace';");

		if ( !$q )

			$db->_die('PageProcess updating page content');

		if ( $db->numrows() < 1 )

		{

			$this->raise_error($lang->get('editor_err_no_rows'));

			return false;

		}

		// Do we have permission to edit the page?

		if ( !$this->perms->get_permissions('edit_page') )

		{

			$this->raise_error($lang->get('editor_err_no_permission'));

			return false;

		}

		list($protection) = $db->fetchrow_num();

		$db->free_result();

		if ( $protection == 1 )

		{

			// The page is protected - do we have permission to edit protected pages?

			if ( !$this->perms->get_permissions('even_when_protected') )

			{

				$this->raise_error($lang->get('editor_err_page_protected'));

				return false;

			}

		}

		else if ( $protection == 2 )

		{

			// The page is semi-protected.

			if (

 					( !$session->user_logged_in || // Is the user logged in?

 						( $session->user_logged_in && $session->reg_time + ( 4 * 86400 ) >= time() ) ) // If so, have they been registered for 4 days?

 					&& !$this->perms->get_permissions('even_when_protected') ) // And of course, is there an ACL that overrides semi-protection?

			{

				$this->raise_error($lang->get('editor_err_page_protected'));

				return false;

			}

		}

		// Spam check

		if ( !spamalyze($text) )

		{

			$this->raise_error($lang->get('editor_err_spamcheck_failed'));

			return false;

		}

		// Page format check

		if ( !in_array($page_format, array('xhtml', 'wikitext')) )

		{

			$this->raise_error("format \"$page_format\" not one of [xhtml, wikitext]");

			return false;

		}

		//

		// Protection validated; update page content

		//

		$text_undb = RenderMan::preprocess_text($text, false, false);

		$text = $db->escape($text_undb);

		$author = $db->escape($session->username);

		$time = time();

		$edit_summary = ( strval($edit_summary) === $edit_summary ) ? $db->escape($edit_summary) : '';

		$minor_edit = ( $minor_edit ) ? '1' : '0';

		$date_string = enano_date(ED_DATE | ED_TIME);

		// Allow stuff to be run when the page is saved

		$code = $plugins->setHook('update_page');

		foreach ( $code as $cmd )

		{

			eval($cmd);

		}

		// If a plugin raised an error, honor it.

		if ( $this->_errors )

		{

			return false;

		}

		// Insert log entry

		$sql = 'INSERT INTO ' . table_prefix . "logs ( time_id, date_string, log_type, action, page_id, namespace, author, author_uid, page_text, edit_summary, minor_edit, page_format )\n"

 				. "  VALUES ( $time, '$date_string', 'page', 'edit', '{$this->page_id}', '{$this->namespace}', '$author', $session->user_id, '$text', '$edit_summary', $minor_edit, '$page_format' );";

		if ( !$db->sql_query($sql) )

		{

			$this->raise_error($db->get_error());

			return false;

		}

		// Update the master text entry

		$sql = 'UPDATE ' . table_prefix . "page_text SET page_text = '$text' WHERE page_id = '{$this->page_id}' AND namespace = '{$this->namespace}';";

		if ( !$db->sql_query($sql) )

		{

			$this->raise_error($db->get_error());

			return false;

		}

		// If there's an identical draft copy, delete it

		$sql = 'DELETE FROM ' . table_prefix . "logs WHERE is_draft = 1 AND page_id = '{$this->page_id}' AND namespace = '{$this->namespace}' AND page_text = '{$text}';";