<?php

/**
 * This file handles the administration of languages tasks.
 *
 * Simple Machines Forum (SMF)
 *
 * @package SMF
 * @author Simple Machines
 * @copyright 2014 Simple Machines and individual contributors
 * @license http://www.simplemachines.org/about/smf/license.php BSD
 *
 * @version 2.1 Alpha 1
 */

if (!defined('SMF'))
	die('No direct access...');

/**
 * This is the main function for the languages area.
 * It dispatches the requests.
 * Loads the ManageLanguages template. (sub-actions will use it)
 * @todo lazy loading.
 *
 * @uses ManageSettings language file
 */
function ManageLanguages()
{
	global $context, $txt, $scripturl, $modSettings;

	loadTemplate('ManageLanguages');
	loadLanguage('ManageSettings');

	$context['page_title'] = $txt['edit_languages'];
	$context['sub_template'] = 'show_settings';

	$subActions = array(
		'edit' => 'ModifyLanguages',
		'add' => 'AddLanguage',
		'settings' => 'ModifyLanguageSettings',
		'downloadlang' => 'DownloadLanguage',
		'editlang' => 'ModifyLanguage',
	);

	call_integration_hook('integrate_manage_languages', array(&$subActions));

	// By default we're managing languages.
	$_REQUEST['sa'] = isset($_REQUEST['sa']) && isset($subActions[$_REQUEST['sa']]) ? $_REQUEST['sa'] : 'edit';
	$context['sub_action'] = $_REQUEST['sa'];

	// Load up all the tabs...
	$context[$context['admin_menu_name']]['tab_data'] = array(
		'title' => $txt['language_configuration'],
		'description' => $txt['language_description'],
	);

	// Call the right function for this sub-action.
	$subActions[$_REQUEST['sa']]();
}

/**
 * Interface for adding a new language
 *
 * @uses ManageLanguages template, add_language sub-template.
 */
function AddLanguage()
{
	global $context, $sourcedir, $boarddir, $txt, $smcFunc, $scripturl;

	// Are we searching for new languages courtesy of Simple Machines?
	if (!empty($_POST['smf_add_sub']))
	{
		// Need fetch_web_data.
		require_once($sourcedir . '/Subs-Package.php');

		$context['smf_search_term'] = $smcFunc['htmlspecialchars'](trim($_POST['smf_add']));

		$listOptions = array(
			'id' => 'smf_languages',
			'get_items' => array(
				'function' => 'list_getLanguagesList',
			),
			'columns' => array(
				'name' => array(
					'header' => array(
						'value' => $txt['name'],
					),
					'data' => array(
						'db' => 'name',
					),
				),
				'description' => array(
					'header' => array(
						'value' => $txt['add_language_smf_desc'],
					),
					'data' => array(
						'db' => 'description',
					),
				),
				'version' => array(
					'header' => array(
						'value' => $txt['add_language_smf_version'],
					),
					'data' => array(
						'db' => 'version',
					),
				),
				'utf8' => array(
					'header' => array(
						'value' => $txt['add_language_smf_utf8'],
					),
					'data' => array(
						'db' => 'utf8',
					),
				),
				'install_link' => array(
					'header' => array(
						'value' => $txt['add_language_smf_install'],
						'class' => 'centercol',
					),
					'data' => array(
						'db' => 'install_link',
						'class' => 'centercol',
					),
				),
			),
		);

		require_once($sourcedir . '/Subs-List.php');
		createList($listOptions);

		$context['default_list'] = 'smf_languages';
	}

	$context['sub_template'] = 'add_language';
}

/**
 * Gets a list of available languages from the mother ship
 * Will return a subset if searching, otherwise all avaialble
 *
 * @return string
 */
function list_getLanguagesList()
{
	global $forum_version, $context, $sourcedir, $smcFunc, $txt, $scripturl;

	// We're going to use this URL.
	$url = 'http://download.simplemachines.org/fetch_language.php?version=' . urlencode(strtr($forum_version, array('SMF ' => '')));

	// Load the class file and stick it into an array.
	require_once($sourcedir . '/Class-Package.php');
	$language_list = new xmlArray(fetch_web_data($url), true);

	// Check that the site responded and that the language exists.
	if (!$language_list->exists('languages'))
		$context['smf_error'] = 'no_response';
	elseif (!$language_list->exists('languages/language'))
		$context['smf_error'] = 'no_files';
	else
	{
		$language_list = $language_list->path('languages[0]');
		$lang_files = $language_list->set('language');
		$smf_languages = array();
		foreach ($lang_files as $file)
		{
			// Were we searching?
			if (!empty($context['smf_search_term']) && strpos($file->fetch('name'), $smcFunc['strtolower']($context['smf_search_term'])) === false)
				continue;

			$smf_languages[] = array(
				'id' => $file->fetch('id'),
				'name' => $smcFunc['ucwords']($file->fetch('name')),
				'version' => $file->fetch('version'),
				'utf8' => $file->fetch('utf8') ? $txt['yes'] : $txt['no'],
				'description' => $file->fetch('description'),
				'install_link' => '<a href="' . $scripturl . '?action=admin;area=languages;sa=downloadlang;did=' . $file->fetch('id') . ';' . $context['session_var'] . '=' . $context['session_id'] . '">' . $txt['add_language_smf_install'] . '</a>',
			);
		}
		if (empty($smf_languages))
			$context['smf_error'] = 'no_files';
		else
			return $smf_languages;
	}
}

/**
 * Download a language file from the Simple Machines website.
 * Requires a valid download ID ("did") in the URL.
 * Also handles installing language files.
 * Attempts to chmod things as needed.
 * Uses a standard list to display information about all the files and where they'll be put.
 *
 * @uses ManageLanguages template, download_language sub-template.
 * @uses Admin template, show_list sub-template.
 */
function DownloadLanguage()
{
	global $context, $sourcedir, $forum_version, $boarddir, $txt, $smcFunc, $scripturl, $modSettings;

	loadLanguage('ManageSettings');
	require_once($sourcedir . '/Subs-Package.php');

	// Clearly we need to know what to request.
	if (!isset($_GET['did']))
		fatal_lang_error('no_access', false);

	// Some lovely context.
	$context['download_id'] = $_GET['did'];
	$context['sub_template'] = 'download_language';
	$context['menu_data_' . $context['admin_menu_id']]['current_subsection'] = 'add';

	// Can we actually do the installation - and do they want to?
	if (!empty($_POST['do_install']) && !empty($_POST['copy_file']))
	{
		checkSession('get');
		validateToken('admin-dlang');

		$chmod_files = array();
		$install_files = array();

		// Check writable status.
		foreach ($_POST['copy_file'] as $file)
		{
			// Check it's not very bad.
			if (strpos($file, '..') !== false || (strpos($file, 'Themes') !== 0 && !preg_match('~agreement\.[A-Za-z-_0-9]+\.txt$~', $file)))
				fatal_error($txt['languages_download_illegal_paths']);

			$chmod_files[] = $boarddir . '/' . $file;
			$install_files[] = $file;
		}

		// Call this in case we have work to do.
		$file_status = create_chmod_control($chmod_files);
		$files_left = $file_status['files']['notwritable'];

		// Something not writable?
		if (!empty($files_left))
			$context['error_message'] = $txt['languages_download_not_chmod'];
		// Otherwise, go go go!
		elseif (!empty($install_files))
		{
			$archive_content = read_tgz_file('http://download.simplemachines.org/fetch_language.php?version=' . urlencode(strtr($forum_version, array('SMF ' => ''))) . ';fetch=' . urlencode($_GET['did']), $boarddir, false, true, $install_files);
			// Make sure the files aren't stuck in the cache.
			package_flush_cache();
			$context['install_complete'] = sprintf($txt['languages_download_complete_desc'], $scripturl . '?action=admin;area=languages');

			return;
		}
	}

	// Open up the old china.
	if (!isset($archive_content))
		$archive_content = read_tgz_file('http://download.simplemachines.org/fetch_language.php?version=' . urlencode(strtr($forum_version, array('SMF ' => ''))) . ';fetch=' . urlencode($_GET['did']), null);

	if (empty($archive_content))
		fatal_error($txt['add_language_error_no_response']);

	// Now for each of the files, let's do some *stuff*
	$context['files'] = array(
		'lang' => array(),
		'other' => array(),
	);
	$context['make_writable'] = array();
	foreach ($archive_content as $file)
	{
		$dirname = dirname($file['filename']);
		$filename = basename($file['filename']);
		$extension = substr($filename, strrpos($filename, '.') + 1);

		// Don't do anything with files we don't understand.
		if (!in_array($extension, array('php', 'jpg', 'gif', 'jpeg', 'png', 'txt')))
			continue;

		// Basic data.
		$context_data = array(
			'name' => $filename,
			'destination' => $boarddir . '/' . $file['filename'],
			'generaldest' => $file['filename'],
			'size' => $file['size'],
			// Does chmod status allow the copy?
			'writable' => false,
			// Should we suggest they copy this file?
			'default_copy' => true,
			// Does the file already exist, if so is it same or different?
			'exists' => false,
		);

		// Does the file exist, is it different and can we overwrite?
		if (file_exists($boarddir . '/' . $file['filename']))
		{
			if (is_writable($boarddir . '/' . $file['filename']))
				$context_data['writable'] = true;

			// Finally, do we actually think the content has changed?
			if ($file['size'] == filesize($boarddir . '/' . $file['filename']) && $file['md5'] == md5_file($boarddir . '/' . $file['filename']))
			{
				$context_data['exists'] = 'same';
				$context_data['default_copy'] = false;
			}
			// Attempt to discover newline character differences.
			elseif ($file['md5'] == md5(preg_replace("~[\r]?\n~", "\r\n", file_get_contents($boarddir . '/' . $file['filename']))))
			{
				$context_data['exists'] = 'same';
				$context_data['default_copy'] = false;
			}
			else
				$context_data['exists'] = 'different';
		}
		// No overwrite?
		else
		{
			// Can we at least stick it in the directory...
			if (is_writable($boarddir . '/' . $dirname))
				$context_data['writable'] = true;
		}

		// I love PHP files, that's why I'm a developer and not an artistic type spending my time drinking absinth and living a life of sin...
		if ($extension == 'php' && preg_match('~\w+\.\w+(?:-utf8)?\.php~', $filename))
		{
			$context_data += array(
				'version' => '??',
				'cur_version' => false,
				'version_compare' => 'newer',
			);

			list ($name, $language) = explode('.', $filename);

			// Let's get the new version, I like versions, they tell me that I'm up to date.
			if (preg_match('~\s*Version:\s+(.+?);\s*' . preg_quote($name, '~') . '~i', $file['preview'], $match) == 1)
				$context_data['version'] = $match[1];

			// Now does the old file exist - if so what is it's version?
			if (file_exists($boarddir . '/' . $file['filename']))
			{
				// OK - what is the current version?
				$fp = fopen($boarddir . '/' . $file['filename'], 'rb');
				$header = fread($fp, 768);
				fclose($fp);

				// Find the version.
				if (preg_match('~(?://|/\*)\s*Version:\s+(.+?);\s*' . preg_quote($name, '~') . '(?:[\s]{2}|\*/)~i', $header, $match) == 1)
				{
					$context_data['cur_version'] = $match[1];

					// How does this compare?
					if ($context_data['cur_version'] == $context_data['version'])
						$context_data['version_compare'] = 'same';
					elseif ($context_data['cur_version'] > $context_data['version'])
						$context_data['version_compare'] = 'older';

					// Don't recommend copying if the version is the same.
					if ($context_data['version_compare'] != 'newer')
						$context_data['default_copy'] = false;
				}
			}

			// Add the context data to the main set.
			$context['files']['lang'][] = $context_data;
		}
		else
		{
			// If we think it's a theme thing, work out what the theme is.
			if (strpos($dirname, 'Themes') === 0 && preg_match('~Themes[\\/]([^\\/]+)[\\/]~', $dirname, $match))
				$theme_name = $match[1];
			else
				$theme_name = 'misc';

			// Assume it's an image, could be an acceptance note etc but rare.
			$context['files']['images'][$theme_name][] = $context_data;
		}

		// Collect together all non-writable areas.
		if (!$context_data['writable'])
			$context['make_writable'][] = $context_data['destination'];
	}

	// So, I'm a perfectionist - let's get the theme names.
	$theme_indexes = array();
	foreach ($context['files']['images'] as $k => $dummy)
		$indexes[] = $k;

	$context['theme_names'] = array();
	if (!empty($indexes))
	{
		$value_data = array(
			'query' => array(),
			'params' => array(),
		);

		foreach ($indexes as $k => $index)
		{
			$value_data['query'][] = 'value LIKE {string:value_' . $k . '}';
			$value_data['params']['value_' . $k] = '%' . $index;
		}

		$request = $smcFunc['db_query']('', '
			SELECT id_theme, value
			FROM {db_prefix}themes
			WHERE id_member = {int:no_member}
				AND variable = {string:theme_dir}
				AND (' . implode(' OR ', $value_data['query']) . ')',
			array_merge($value_data['params'], array(
				'no_member' => 0,
				'theme_dir' => 'theme_dir',
				'index_compare_explode' => 'value LIKE \'%' . implode('\' OR value LIKE \'%', $indexes) . '\'',
			))
		);
		$themes = array();
		while ($row = $smcFunc['db_fetch_assoc']($request))
		{
			// Find the right one.
			foreach ($indexes as $index)
				if (strpos($row['value'], $index) !== false)
					$themes[$row['id_theme']] = $index;
		}
		$smcFunc['db_free_result']($request);

		if (!empty($themes))
		{
			// Now we have the id_theme we can get the pretty description.
			$request = $smcFunc['db_query']('', '
				SELECT id_theme, value
				FROM {db_prefix}themes
				WHERE id_member = {int:no_member}
					AND variable = {string:name}
					AND id_theme IN ({array_int:theme_list})',
				array(
					'theme_list' => array_keys($themes),
					'no_member' => 0,
					'name' => 'name',
				)
			);
			while ($row = $smcFunc['db_fetch_assoc']($request))
			{
				// Now we have it...
				$context['theme_names'][$themes[$row['id_theme']]] = $row['value'];
			}
			$smcFunc['db_free_result']($request);
		}
	}

	// Before we go to far can we make anything writable, eh, eh?
	if (!empty($context['make_writable']))
	{
		// What is left to be made writable?
		$file_status = create_chmod_control($context['make_writable']);
		$context['still_not_writable'] = $file_status['files']['notwritable'];

		// Mark those which are now writable as such.
		foreach ($context['files'] as $type => $data)
		{
			if ($type == 'lang')
			{
				foreach ($data as $k => $file)
					if (!$file['writable'] && !in_array($file['destination'], $context['still_not_writable']))
						$context['files'][$type][$k]['writable'] = true;
			}
			else
			{
				foreach ($data as $theme => $files)
					foreach ($files as $k => $file)
						if (!$file['writable'] && !in_array($file['destination'], $context['still_not_writable']))
							$context['files'][$type][$theme][$k]['writable'] = true;
			}
		}

		// Are we going to need more language stuff?
		if (!empty($context['still_not_writable']))
			loadLanguage('Packages');
	}

	// This is the list for the main files.
	$listOptions = array(
		'id' => 'lang_main_files_list',
		'title' => $txt['languages_download_main_files'],
		'get_items' => array(
			'function' => create_function('', '
				global $context;
				return $context[\'files\'][\'lang\'];
			'),
		),
		'columns' => array(
			'name' => array(
				'header' => array(
					'value' => $txt['languages_download_filename'],
				),
				'data' => array(
					'function' => create_function('$rowData', '
						global $context, $txt;

						return \'<strong>\' . $rowData[\'name\'] . \'</strong><br /><span class="smalltext">\' . $txt[\'languages_download_dest\'] . \': \' . $rowData[\'destination\'] . \'</span>\' . ($rowData[\'version_compare\'] == \'older\' ? \'<br />\' . $txt[\'languages_download_older\'] : \'\');
					'),
				),
			),
			'writable' => array(
				'header' => array(
					'value' => $txt['languages_download_writable'],
				),
				'data' => array(
					'function' => create_function('$rowData', '
						global $txt;

						return \'<span style="color: \' . ($rowData[\'writable\'] ? \'green\' : \'red\') . \';">\' . ($rowData[\'writable\'] ? $txt[\'yes\'] : $txt[\'no\']) . \'</span>\';
					'),
				),
			),
			'version' => array(
				'header' => array(
					'value' => $txt['languages_download_version'],
				),
				'data' => array(
					'function' => create_function('$rowData', '
						global $txt;

						return \'<span style="color: \' . ($rowData[\'version_compare\'] == \'older\' ? \'red\' : ($rowData[\'version_compare\'] == \'same\' ? \'orange\' : \'green\')) . \';">\' . $rowData[\'version\'] . \'</span>\';
					'),
				),
			),
			'exists' => array(
				'header' => array(
					'value' => $txt['languages_download_exists'],
				),
				'data' => array(
					'function' => create_function('$rowData', '
						global $txt;

						return $rowData[\'exists\'] ? ($rowData[\'exists\'] == \'same\' ? $txt[\'languages_download_exists_same\'] : $txt[\'languages_download_exists_different\']) : $txt[\'no\'];
					'),
				),
			),
			'copy' => array(
				'header' => array(
					'value' => $txt['languages_download_copy'],
					'class' => 'centercol',
				),
				'data' => array(
					'function' => create_function('$rowData', '
						return \'<input type="checkbox" name="copy_file[]" value="\' . $rowData[\'generaldest\'] . \'" \' . ($rowData[\'default_copy\'] ? \'checked="checked"\' : \'\') . \' class="input_check" />\';
					'),
					'style' => 'width: 4%;',
					'class' => 'centercol',
				),
			),
		),
	);

	// Kill the cache, as it is now invalid..
	if (!empty($modSettings['cache_enable']))
	{
		cache_put_data('known_languages', null, !empty($modSettings['cache_enable']) && $modSettings['cache_enable'] < 1 ? 86400 : 3600);
		cache_put_data('known_languages_all', null, !empty($modSettings['cache_enable']) && $modSettings['cache_enable'] < 1 ? 86400 : 3600);
	}

	require_once($sourcedir . '/Subs-List.php');
	createList($listOptions);

	$context['default_list'] = 'lang_main_files_list';
	createToken('admin-dlang');
}

/**
 * This lists all the current languages and allows editing of them.
 */
function ModifyLanguages()
{
	global $txt, $context, $scripturl;
	global $user_info, $smcFunc, $sourcedir, $language, $boarddir, $forum_version;

	// Setting a new default?
	if (!empty($_POST['set_default']) && !empty($_POST['def_language']))
	{
		checkSession();
		validateToken('admin-lang');

		getLanguages(true, false);
		$lang_exists = false;
		foreach ($context['languages'] as $lang)
		{
			if ($_POST['def_language'] == $lang['filename'])
			{
				$lang_exists = true;
				break;
			}
		}

		if ($_POST['def_language'] != $language && $lang_exists)
		{
			require_once($sourcedir . '/Subs-Admin.php');
			updateSettingsFile(array('language' => '\'' . $_POST['def_language'] . '\''));
			$language = $_POST['def_language'];
		}
	}

	// Create another one time token here.
	createToken('admin-lang');

	$listOptions = array(
		'id' => 'language_list',
		'items_per_page' => 20,
		'base_href' => $scripturl . '?action=admin;area=languages',
		'title' => $txt['edit_languages'],
		'get_items' => array(
			'function' => 'list_getLanguages',
		),
		'get_count' => array(
			'function' => 'list_getNumLanguages',
		),
		'columns' => array(
			'default' => array(
				'header' => array(
					'value' => $txt['languages_default'],
					'class' => 'centercol',
				),
				'data' => array(
					'function' => create_function('$rowData', '
						return \'<input type="radio" name="def_language" value="\' . $rowData[\'id\'] . \'" \' . ($rowData[\'default\'] ? \'checked="checked"\' : \'\') . \' onclick="highlightSelected(\\\'list_language_list_\' . $rowData[\'id\'] . \'\\\');" class="input_radio" />\';
					'),
					'style' => 'width: 8%;',
					'class' => 'centercol',
				),
			),
			'name' => array(
				'header' => array(
					'value' => $txt['languages_lang_name'],
				),
				'data' => array(
					'function' => create_function('$rowData', '
						global $scripturl, $context;

						return sprintf(\'<a href="%1$s?action=admin;area=languages;sa=editlang;lid=%2$s">%3$s</a>\', $scripturl, $rowData[\'id\'], $rowData[\'name\']);
					'),
				),
			),
			'character_set' => array(
				'header' => array(
					'value' => $txt['languages_character_set'],
				),
				'data' => array(
					'db_htmlsafe' => 'char_set',
				),
			),
			'count' => array(
				'header' => array(
					'value' => $txt['languages_users'],
				),
				'data' => array(
					'db_htmlsafe' => 'count',
				),
			),
			'locale' => array(
				'header' => array(
					'value' => $txt['languages_locale'],
				),
				'data' => array(
					'db_htmlsafe' => 'locale',
				),
			),
		),
		'form' => array(
			'href' => $scripturl . '?action=admin;area=languages',
			'token' => 'admin-lang',
		),
		'additional_rows' => array(
			array(
				'position' => 'bottom_of_list',
				'value' => '<input type="hidden" name="' . $context['session_var'] . '" value="' . $context['session_id'] . '" /><input type="submit" name="set_default" value="' . $txt['save'] . '"' . (is_writable($boarddir . '/Settings.php') ? '' : ' disabled="disabled"') . ' class="button_submit" />',
			),
		),
	);

	// We want to highlight the selected language. Need some Javascript for this.
	addInlineJavascript('
	function highlightSelected(box)
	{
		$("tr.highlight2").removeClass("highlight2");
		$("#" + box).addClass("highlight2");
	}
	highlightSelected("list_language_list_' . ($language == '' ? 'english' : $language). '");', true);

	// Display a warning if we cannot edit the default setting.
	if (!is_writable($boarddir . '/Settings.php'))
		$listOptions['additional_rows'][] = array(
				'position' => 'after_title',
				'value' => $txt['language_settings_writable'],
				'class' => 'smalltext alert',
			);

	require_once($sourcedir . '/Subs-List.php');
	createList($listOptions);

	$context['sub_template'] = 'show_list';
	$context['default_list'] = 'language_list';
}

/**
 * How many languages?
 * Callback for the list in ManageLanguageSettings().
 */
function list_getNumLanguages()
{
	return count(getLanguages(true, false));
}

/**
 * Fetch the actual language information.
 * Callback for $listOptions['get_items']['function'] in ManageLanguageSettings.
 * Determines which languages are available by looking for the "index.{language}.php" file.
 * Also figures out how many users are using a particular language.
 */
function list_getLanguages()
{
	global $settings, $smcFunc, $language, $context, $txt;

	$languages = array();
	// Keep our old entries.
	$old_txt = $txt;
	$backup_actual_theme_dir = $settings['actual_theme_dir'];
	$backup_base_theme_dir = !empty($settings['base_theme_dir']) ? $settings['base_theme_dir'] : '';

	// Override these for now.
	$settings['actual_theme_dir'] = $settings['base_theme_dir'] = $settings['default_theme_dir'];
	getLanguages(true, false);

	// Put them back.
	$settings['actual_theme_dir'] = $backup_actual_theme_dir;
	if (!empty($backup_base_theme_dir))
		$settings['base_theme_dir'] = $backup_base_theme_dir;
	else
		unset($settings['base_theme_dir']);

	// Get the language files and data...
	foreach ($context['languages'] as $lang)
	{
		// Load the file to get the character set.
		require($settings['default_theme_dir'] . '/languages/index.' . $lang['filename'] . '.php');

		$languages[$lang['filename']] = array(
			'id' => $lang['filename'],
			'count' => 0,
			'char_set' => $txt['lang_character_set'],
			'default' => $language == $lang['filename'] || ($language == '' && $lang['filename'] == 'english'),
			'locale' => $txt['lang_locale'],
			'name' => $smcFunc['ucwords'](strtr($lang['filename'], array('_' => ' ', '-utf8' => ''))),
		);
	}

	// Work out how many people are using each language.
	$request = $smcFunc['db_query']('', '
		SELECT lngfile, COUNT(*) AS num_users
		FROM {db_prefix}members
		GROUP BY lngfile',
		array(
		)
	);
	while ($row = $smcFunc['db_fetch_assoc']($request))
	{
		// Default?
		if (empty($row['lngfile']) || !isset($languages[$row['lngfile']]))
			$row['lngfile'] = $language;

		if (!isset($languages[$row['lngfile']]) && isset($languages['english']))
			$languages['english']['count'] += $row['num_users'];
		elseif (isset($languages[$row['lngfile']]))
			$languages[$row['lngfile']]['count'] += $row['num_users'];
	}
	$smcFunc['db_free_result']($request);

	// Restore the current users language.
	$txt = $old_txt;

	// Return how many we have.
	return $languages;
}

/**
 * Edit language related settings.
 *
 * @param bool $return_config = false
 */
function ModifyLanguageSettings($return_config = false)
{
	global $scripturl, $context, $txt, $boarddir, $settings, $smcFunc, $sourcedir;

	// We'll want to save them someday.
	require_once $sourcedir . '/ManageServer.php';

	// Warn the user if the backup of Settings.php failed.
	$settings_not_writable = !is_writable($boarddir . '/Settings.php');
	$settings_backup_fail = !@is_writable($boarddir . '/Settings_bak.php') || !@copy($boarddir . '/Settings.php', $boarddir . '/Settings_bak.php');

	/* If you're writing a mod, it's a bad idea to add things here....
	For each option:
		variable name, description, type (constant), size/possible values, helptext.
	OR	an empty string for a horizontal rule.
	OR	a string for a titled section. */
	$config_vars = array(
		'language' => array('language', $txt['default_language'], 'file', 'select', array(), null, 'disabled' => $settings_not_writable),
		array('userLanguage', $txt['userLanguage'], 'db', 'check', null, 'userLanguage'),
	);

	call_integration_hook('integrate_language_settings', array(&$config_vars));

	if ($return_config)
		return $config_vars;

	// Get our languages. No cache and use utf8.
	getLanguages(false, false);
	foreach ($context['languages'] as $lang)
		$config_vars['language'][4][$lang['filename']] = array($lang['filename'], strtr($lang['name'], array('-utf8' => ' (UTF-8)')));

	// Saving settings?
	if (isset($_REQUEST['save']))
	{
		checkSession();

		call_integration_hook('integrate_save_language_settings', array(&$config_vars));

		saveSettings($config_vars);
		if (!$settings_not_writable && !$settings_backup_fail)
			$_SESSION['adm-save'] = true;
		redirectexit('action=admin;area=languages;sa=settings');
	}

	// Setup the template stuff.
	$context['post_url'] = $scripturl . '?action=admin;area=languages;sa=settings;save';
	$context['settings_title'] = $txt['language_settings'];
	$context['save_disabled'] = $settings_not_writable;

	if ($settings_not_writable)
		$context['settings_message'] = '<div class="centertext"><strong>' . $txt['settings_not_writable'] . '</strong></div><br />';
	elseif ($settings_backup_fail)
		$context['settings_message'] = '<div class="centertext"><strong>' . $txt['admin_backup_fail'] . '</strong></div><br />';

	// Fill the config array.
	prepareServerSettingsContext($config_vars);
}

/**
 * Edit a particular set of language entries.
 */
function ModifyLanguage()
{
	global $settings, $context, $smcFunc, $txt, $modSettings, $boarddir, $sourcedir, $language;

	loadLanguage('ManageSettings');

	// Select the languages tab.
	$context['menu_data_' . $context['admin_menu_id']]['current_subsection'] = 'edit';
	$context['page_title'] = $txt['edit_languages'];
	$context['sub_template'] = 'modify_language_entries';

	$context['lang_id'] = $_GET['lid'];
	list($theme_id, $file_id) = empty($_REQUEST['tfid']) || strpos($_REQUEST['tfid'], '+') === false ? array(1, '') : explode('+', $_REQUEST['tfid']);

	// Clean the ID - just in case.
	preg_match('~([A-Za-z0-9_-]+)~', $context['lang_id'], $matches);
	$context['lang_id'] = $matches[1];

	// Get all the theme data.
	$request = $smcFunc['db_query']('', '
		SELECT id_theme, variable, value
		FROM {db_prefix}themes
		WHERE id_theme != {int:default_theme}
			AND id_member = {int:no_member}
			AND variable IN ({string:name}, {string:theme_dir})',
		array(
			'default_theme' => 1,
			'no_member' => 0,
			'name' => 'name',
			'theme_dir' => 'theme_dir',
		)
	);
	$themes = array(
		1 => array(
			'name' => $txt['dvc_default'],
			'theme_dir' => $settings['default_theme_dir'],
		),
	);
	while ($row = $smcFunc['db_fetch_assoc']($request))
		$themes[$row['id_theme']][$row['variable']] = $row['value'];
	$smcFunc['db_free_result']($request);

	// This will be where we look
	$lang_dirs = array();
	// Check we have themes with a path and a name - just in case - and add the path.
	foreach ($themes as $id => $data)
	{
		if (count($data) != 2)
			unset($themes[$id]);
		elseif (is_dir($data['theme_dir'] . '/languages'))
			$lang_dirs[$id] = $data['theme_dir'] . '/languages';

		// How about image directories?
		if (is_dir($data['theme_dir'] . '/images/' . $context['lang_id']))
			$images_dirs[$id] = $data['theme_dir'] . '/images/' . $context['lang_id'];
	}

	$current_file = $file_id ? $lang_dirs[$theme_id] . '/' . $file_id . '.' . $context['lang_id'] . '.php' : '';

	// Now for every theme get all the files and stick them in context!
	$context['possible_files'] = array();
	foreach ($lang_dirs as $theme => $theme_dir)
	{
		// Open it up.
		$dir = dir($theme_dir);
		while ($entry = $dir->read())
		{
			// We're only after the files for this language.
			if (preg_match('~^([A-Za-z]+)\.' . $context['lang_id'] . '\.php$~', $entry, $matches) == 0)
				continue;

			if (!isset($context['possible_files'][$theme]))
				$context['possible_files'][$theme] = array(
					'id' => $theme,
					'name' => $themes[$theme]['name'],
					'files' => array(),
				);

			$context['possible_files'][$theme]['files'][] = array(
				'id' => $matches[1],
				'name' => isset($txt['lang_file_desc_' . $matches[1]]) ? $txt['lang_file_desc_' . $matches[1]] : $matches[1],
				'selected' => $theme_id == $theme && $file_id == $matches[1],
			);
		}
		$dir->close();
		usort($context['possible_files'][$theme]['files'], create_function('$val1, $val2', 'return strcmp($val1[\'name\'], $val2[\'name\']);'));
	}

	// We no longer wish to speak this language.
	if (!empty($_POST['delete_main']) && $context['lang_id'] != 'english')
	{
		checkSession();
		validateToken('admin-mlang');

		// @todo Todo: FTP Controls?
		require_once($sourcedir . '/Subs-Package.php');

		// First, Make a backup?
		if (!empty($modSettings['package_make_backups']) && (!isset($_SESSION['last_backup_for']) || $_SESSION['last_backup_for'] != $context['lang_id'] . '$$$'))
		{
			$_SESSION['last_backup_for'] = $context['lang_id'] . '$$$';
			package_create_backup('backup_lang_' . $context['lang_id']);
		}

		// Second, loop through the array to remove the files.
		foreach ($lang_dirs as $curPath)
		{
			foreach ($context['possible_files'][1]['files'] as $lang)
				if (file_exists($curPath . '/' . $lang['id'] . '.' . $context['lang_id'] . '.php'))
					unlink($curPath . '/' . $lang['id'] . '.' . $context['lang_id'] . '.php');

			// Check for the email template.
			if (file_exists($curPath . '/EmailTemplates.' . $context['lang_id'] . '.php'))
				unlink($curPath . '/EmailTemplates.' . $context['lang_id'] . '.php');
		}

		// Third, the agreement file.
		if (file_exists($boarddir . '/agreement.' . $context['lang_id'] . '.txt'))
			unlink($boarddir . '/agreement.' . $context['lang_id'] . '.txt');

		// Fourth, a related images folder?
		foreach ($images_dirs as $curPath)
			if (is_dir($curPath))
				deltree($curPath);

		// Members can no longer use this language.
		$smcFunc['db_query']('', '
			UPDATE {db_prefix}members
			SET lngfile = {empty}
			WHERE lngfile = {string:current_language}',
			array(
				'empty_string' => '',
				'current_language' => $context['lang_id'],
			)
		);

		// Fifth, update getLanguages() cache.
		if (!empty($modSettings['cache_enable']))
		{
			cache_put_data('known_languages', null, !empty($modSettings['cache_enable']) && $modSettings['cache_enable'] < 1 ? 86400 : 3600);
			cache_put_data('known_languages_all', null, !empty($modSettings['cache_enable']) && $modSettings['cache_enable'] < 1 ? 86400 : 3600);
		}

		// Sixth, if we deleted the default language, set us back to english?
		if ($context['lang_id'] == $language)
		{
			require_once($sourcedir . '/Subs-Admin.php');
			$language = 'english';
			updateSettingsFile(array('language' => '\'' . $language . '\''));
		}

		// Seventh, get out of here.
		redirectexit('action=admin;area=languages;sa=edit;' . $context['session_var'] . '=' . $context['session_id']);
	}

	// Saving primary settings?
	$madeSave = false;
	if (!empty($_POST['save_main']) && !$current_file)
	{
		checkSession();
		validateToken('admin-mlang');

		// Read in the current file.
		$current_data = implode('', file($settings['default_theme_dir'] . '/languages/index.' . $context['lang_id'] . '.php'));
		// These are the replacements. old => new
		$replace_array = array(
			'~\$txt\[\'lang_character_set\'\]\s=\s(\'|")[^\r\n]+~' => '$txt[\'lang_character_set\'] = \'' . preg_replace('~[^\w-]~i', '', $_POST['character_set']) . '\';',
			'~\$txt\[\'lang_locale\'\]\s=\s(\'|")[^\r\n]+~' => '$txt[\'lang_locale\'] = \'' . preg_replace('~[^\w-]~i', '', $_POST['locale']) . '\';',
			'~\$txt\[\'lang_dictionary\'\]\s=\s(\'|")[^\r\n]+~' => '$txt[\'lang_dictionary\'] = \'' . preg_replace('~[^\w-]~i', '', $_POST['dictionary']) . '\';',
			'~\$txt\[\'lang_spelling\'\]\s=\s(\'|")[^\r\n]+~' => '$txt[\'lang_spelling\'] = \'' . preg_replace('~[^\w-]~i', '', $_POST['spelling']) . '\';',
			'~\$txt\[\'lang_rtl\'\]\s=\s[A-Za-z0-9]+;~' => '$txt[\'lang_rtl\'] = ' . (!empty($_POST['rtl']) ? 'true' : 'false') . ';',
		);
		$current_data = preg_replace(array_keys($replace_array), array_values($replace_array), $current_data);
		$fp = fopen($settings['default_theme_dir'] . '/languages/index.' . $context['lang_id'] . '.php', 'w+');
		fwrite($fp, $current_data);
		fclose($fp);

		$madeSave = true;
	}

	// Quickly load index language entries.
	$old_txt = $txt;
	require($settings['default_theme_dir'] . '/languages/index.' . $context['lang_id'] . '.php');
	$context['lang_file_not_writable_message'] = is_writable($settings['default_theme_dir'] . '/languages/index.' . $context['lang_id'] . '.php') ? '' : sprintf($txt['lang_file_not_writable'], $settings['default_theme_dir'] . '/languages/index.' . $context['lang_id'] . '.php');
	// Setup the primary settings context.
	$context['primary_settings'] = array(
		'name' => $smcFunc['ucwords'](strtr($context['lang_id'], array('_' => ' ', '-utf8' => ''))),
		'character_set' => $txt['lang_character_set'],
		'locale' => $txt['lang_locale'],
		'dictionary' => $txt['lang_dictionary'],
		'spelling' => $txt['lang_spelling'],
		'rtl' => $txt['lang_rtl'],
	);

	// Restore normal service.
	$txt = $old_txt;

	// Are we saving?
	$save_strings = array();
	if (isset($_POST['save_entries']) && !empty($_POST['entry']))
	{
		checkSession();
		validateToken('admin-mlang');

		// Clean each entry!
		foreach ($_POST['entry'] as $k => $v)
		{
			// Only try to save if it's changed!
			if ($_POST['entry'][$k] != $_POST['comp'][$k])
				$save_strings[$k] = cleanLangString($v, false);
		}
	}

	// If we are editing a file work away at that.
	if ($current_file)
	{
		$context['entries_not_writable_message'] = is_writable($current_file) ? '' : sprintf($txt['lang_entries_not_writable'], $current_file);

		$entries = array();
		// We can't just require it I'm afraid - otherwise we pass in all kinds of variables!
		$multiline_cache = '';
		foreach (file($current_file) as $line)
		{
			// Got a new entry?
			if ($line[0] == '$' && !empty($multiline_cache))
			{
				preg_match('~\$(helptxt|txt|editortxt)\[\'(.+)\'\]\s?=\s?(.+);~ms', strtr($multiline_cache, array("\r" => '')), $matches);
				if (!empty($matches[3]))
				{
					$entries[$matches[2]] = array(
						'type' => $matches[1],
						'full' => $matches[0],
						'entry' => $matches[3],
					);
					$multiline_cache = '';
				}
			}
			$multiline_cache .= $line;
		}
		// Last entry to add?
		if ($multiline_cache)
		{
			preg_match('~\$(helptxt|txt|editortxt)\[\'(.+)\'\]\s?=\s?(.+);~ms', strtr($multiline_cache, array("\r" => '')), $matches);
			if (!empty($matches[3]))
				$entries[$matches[2]] = array(
					'type' => $matches[1],
					'full' => $matches[0],
					'entry' => $matches[3],
				);
		}

		// These are the entries we can definitely save.
		$final_saves = array();

		$context['file_entries'] = array();
		foreach ($entries as $entryKey => $entryValue)
		{
			// Ignore some things we set separately.
			$ignore_files = array('lang_character_set', 'lang_locale', 'lang_dictionary', 'lang_spelling', 'lang_rtl');
			if (in_array($entryKey, $ignore_files))
				continue;

			// These are arrays that need breaking out.
			$arrays = array('days', 'days_short', 'months', 'months_titles', 'months_short', 'happy_birthday_author', 'karlbenson1_author', 'nite0859_author', 'zwaldowski_author', 'geezmo_author', 'karlbenson2_author');
			if (in_array($entryKey, $arrays))
			{
				// Get off the first bits.
				$entryValue['entry'] = substr($entryValue['entry'], strpos($entryValue['entry'], '(') + 1, strrpos($entryValue['entry'], ')') - strpos($entryValue['entry'], '('));
				$entryValue['entry'] = explode(',', strtr($entryValue['entry'], array(' ' => '')));

				// Now create an entry for each item.
				$cur_index = 0;
				$save_cache = array(
					'enabled' => false,
					'entries' => array(),
				);
				foreach ($entryValue['entry'] as $id => $subValue)
				{
					// Is this a new index?
					if (preg_match('~^(\d+)~', $subValue, $matches))
					{
						$cur_index = $matches[1];
						$subValue = substr($subValue, strpos($subValue, '\''));
					}

					// Clean up some bits.
					$subValue = strtr($subValue, array('"' => '', '\'' => '', ')' => ''));

					// Can we save?
					if (isset($save_strings[$entryKey . '-+- ' . $cur_index]))
					{
						$save_cache['entries'][$cur_index] = strtr($save_strings[$entryKey . '-+- ' . $cur_index], array('\'' => ''));
						$save_cache['enabled'] = true;
					}
					else
						$save_cache['entries'][$cur_index] = $subValue;

					$context['file_entries'][] = array(
						'key' => $entryKey . '-+- ' . $cur_index,
						'value' => $subValue,
						'rows' => 1,
					);
					$cur_index++;
				}

				// Do we need to save?
				if ($save_cache['enabled'])
				{
					// Format the string, checking the indexes first.
					$items = array();
					$cur_index = 0;
					foreach ($save_cache['entries'] as $k2 => $v2)
					{
						// Manually show the custom index.
						if ($k2 != $cur_index)
						{
							$items[] = $k2 . ' => \'' . $v2 . '\'';
							$cur_index = $k2;
						}
						else
							$items[] = '\'' . $v2 . '\'';

						$cur_index++;
					}
					// Now create the string!
					$final_saves[$entryKey] = array(
						'find' => $entryValue['full'],
						'replace' => '$' . $entryValue['type'] . '[\'' . $entryKey . '\'] = array(' . implode(', ', $items) . ');',
					);
				}
			}
			else
			{
				// Saving?
				if (isset($save_strings[$entryKey]) && $save_strings[$entryKey] != $entryValue['entry'])
				{
					// @todo Fix this properly.
					if ($save_strings[$entryKey] == '')
						$save_strings[$entryKey] = '\'\'';

					// Set the new value.
					$entryValue['entry'] = $save_strings[$entryKey];
					// And we know what to save now!
					$final_saves[$entryKey] = array(
						'find' => $entryValue['full'],
						'replace' => '$' . $entryValue['type'] . '[\'' . $entryKey . '\'] = ' . $save_strings[$entryKey] . ';',
					);
				}

				$editing_string = cleanLangString($entryValue['entry'], true);
				$context['file_entries'][] = array(
					'key' => $entryKey,
					'value' => $editing_string,
					'rows' => (int) (strlen($editing_string) / 38) + substr_count($editing_string, "\n") + 1,
				);
			}
		}

		// Any saves to make?
		if (!empty($final_saves))
		{
			checkSession();

			$file_contents = implode('', file($current_file));
			foreach ($final_saves as $save)
				$file_contents = strtr($file_contents, array($save['find'] => $save['replace']));

			// Save the actual changes.
			$fp = fopen($current_file, 'w+');
			fwrite($fp, strtr($file_contents, array("\r" => '')));
			fclose($fp);

			$madeSave = true;
		}

		// Another restore.
		$txt = $old_txt;
	}

	// If we saved, redirect.
	if ($madeSave)
		redirectexit('action=admin;area=languages;sa=editlang;lid=' . $context['lang_id']);

	createToken('admin-mlang');
}

/**
 * This function cleans language entries to/from display.
 * @todo This function could be two functions?
 *
 * @param $string
 * @param $to_display
 */
function cleanLangString($string, $to_display = true)
{
	global $smcFunc;

	// If going to display we make sure it doesn't have any HTML in it - etc.
	$new_string = '';
	if ($to_display)
	{
		// Are we in a string (0 = no, 1 = single quote, 2 = parsed)
		$in_string = 0;
		$is_escape = false;
		for ($i = 0; $i < strlen($string); $i++)
		{
			// Handle ecapes first.
			if ($string{$i} == '\\')
			{
				// Toggle the escape.
				$is_escape = !$is_escape;
				// If we're now escaped don't add this string.
				if ($is_escape)
					continue;
			}
			// Special case - parsed string with line break etc?
			elseif (($string{$i} == 'n' || $string{$i} == 't') && $in_string == 2 && $is_escape)
			{
				// Put the escape back...
				$new_string .= $string{$i} == 'n' ? "\n" : "\t";
				$is_escape = false;
				continue;
			}
			// Have we got a single quote?
			elseif ($string{$i} == '\'')
			{
				// Already in a parsed string, or escaped in a linear string, means we print it - otherwise something special.
				if ($in_string != 2 && ($in_string != 1 || !$is_escape))
				{
					// Is it the end of a single quote string?
					if ($in_string == 1)
						$in_string = 0;
					// Otherwise it's the start!
					else
						$in_string = 1;

					// Don't actually include this character!
					continue;
				}
			}
			// Otherwise a double quote?
			elseif ($string{$i} == '"')
			{
				// Already in a single quote string, or escaped in a parsed string, means we print it - otherwise something special.
				if ($in_string != 1 && ($in_string != 2 || !$is_escape))
				{
					// Is it the end of a double quote string?
					if ($in_string == 2)
						$in_string = 0;
					// Otherwise it's the start!
					else
						$in_string = 2;

					// Don't actually include this character!
					continue;
				}
			}
			// A join/space outside of a string is simply removed.
			elseif ($in_string == 0 && (empty($string{$i}) || $string{$i} == '.'))
				continue;
			// Start of a variable?
			elseif ($in_string == 0 && $string{$i} == '$')
			{
				// Find the whole of it!
				preg_match('~([\$A-Za-z0-9\'\[\]_-]+)~', substr($string, $i), $matches);
				if (!empty($matches[1]))
				{
					// Come up with some pseudo thing to indicate this is a var.
					/**
					 * @todo Do better than this, please!
					 */
					$new_string .= '{%' . $matches[1] . '%}';

					// We're not going to reparse this.
					$i += strlen($matches[1]) - 1;
				}

				continue;
			}
			// Right, if we're outside of a string we have DANGER, DANGER!
			elseif ($in_string == 0)
			{
				continue;
			}

			// Actually add the character to the string!
			$new_string .= $string{$i};
			// If anything was escaped it ain't any longer!
			$is_escape = false;
		}

		// Unhtml then rehtml the whole thing!
		$new_string = $smcFunc['htmlspecialchars'](un_htmlspecialchars($new_string));
	}
	else
	{
		// Keep track of what we're doing...
		$in_string = 0;
		// This is for deciding whether to HTML a quote.
		$in_html = false;
		for ($i = 0; $i < strlen($string); $i++)
		{
			// We don't do parsed strings apart from for breaks.
			if ($in_string == 2)
			{
				$in_string = 0;
				$new_string .= '"';
			}

			// Not in a string yet?
			if ($in_string != 1)
			{
				$in_string = 1;
				$new_string .= ($new_string ? ' . ' : '') . '\'';
			}

			// Is this a variable?
			if ($string{$i} == '{' && $string{$i + 1} == '%' && $string{$i + 2} == '$')
			{
				// Grab the variable.
				preg_match('~\{%([\$A-Za-z0-9\'\[\]_-]+)%\}~', substr($string, $i), $matches);
				if (!empty($matches[1]))
				{
					if ($in_string == 1)
						$new_string .= '\' . ';
					elseif ($new_string)
						$new_string .= ' . ';

					$new_string .= $matches[1];
					$i += strlen($matches[1]) + 3;
					$in_string = 0;
				}

				continue;
			}
			// Is this a lt sign?
			elseif ($string{$i} == '<')
			{
				// Probably HTML?
				if ($string{$i + 1} != ' ')
					$in_html = true;
				// Assume we need an entity...
				else
				{
					$new_string .= '&lt;';
					continue;
				}
			}
			// What about gt?
			elseif ($string{$i} == '>')
			{
				// Will it be HTML?
				if ($in_html)
					$in_html = false;
				// Otherwise we need an entity...
				else
				{
					$new_string .= '&gt;';
					continue;
				}
			}
			// Is it a slash? If so escape it...
			if ($string{$i} == '\\')
				$new_string .= '\\';
			// The infamous double quote?
			elseif ($string{$i} == '"')
			{
				// If we're in HTML we leave it as a quote - otherwise we entity it.
				if (!$in_html)
				{
					$new_string .= '&quot;';
					continue;
				}
			}
			// A single quote?
			elseif ($string{$i} == '\'')
			{
				// Must be in a string so escape it.
				$new_string .= '\\';
			}

			// Finally add the character to the string!
			$new_string .= $string{$i};
		}

		// If we ended as a string then close it off.
		if ($in_string == 1)
			$new_string .= '\'';
		elseif ($in_string == 2)
			$new_string .= '"';
	}

	return $new_string;
}

?>