<?php namespace ProcessWire;

/**
 * Multi-language support page names module
 *
 * ProcessWire 3.x, Copyright 2017 by Ryan Cramer
 * https://processwire.com
 * 
 * @property int $moduleVersion
 * @property int $inheritInactive
 * @property int $useHomeSegment
 *
 */

class LanguageSupportPageNames extends WireData implements Module, ConfigurableModule {

	/**
	 * Return information about the module
	 *
	 */
	static public function getModuleInfo() {
			return array(
				'title' => 'Languages Support - Page Names',
				'version' => 10,
				'summary' => 'Required to use multi-language page names.',
				'author' => 'Ryan Cramer',
				'autoload' => true,
				'singular' => true,
				'requires' => array(
					'LanguageSupport',
					'LanguageSupportFields'
					)
				);
	}

	/**
	 * The path that was requested, before processing
	 *
	 */
	protected $requestPath = '';

	/**
	 * Language that should be set for this request
	 *
	 */
	protected $setLanguage = null;

	/**
	 * Whether to force a 404 when ProcessPageView runs
	 *
	 */
	protected $force404 = null;

	/**
	 * Whether to bypass the functions provided by this module (like for a secure pagefile request)
	 * 
	 */
	protected $bypass = false;

	/**
	 * Default configuration data
	 *
	 */
	static protected $defaultConfigData = array(
		/**
		 * module version, for schema changes when necessary
	 	 *
		 */
		'moduleVersion' => 0,

		/**
		 * Whether an 'inactive' state (status123=0) should inherit to children
	 	 *
		 * Note: we don't have a reasonable way to make this work with PageFinder queries, 
		 * so it is not anything more than a placeholder at present. 
	 	 *
		 */
		'inheritInactive' => 0,

		/**
		 * Whether or not the default language homepage should be served by a language segment.
	 	 *
		 */
		'useHomeSegment' => 0,

		);

	/**
	 * Populate default config data
	 *
	 */
	public function __construct() {
		foreach(self::$defaultConfigData as $key => $value) $this->set($key, $value);
	}

	/**
	 * Initialize the module, save the requested path
	 *
	 */
	public function init() { 
		$this->addHookBefore('ProcessPageView::execute', $this, 'hookProcessPageViewExecute'); 
		$this->addHookAfter('PageFinder::getQuery', $this, 'hookPageFinderGetQuery'); 

		// tell ProcessPageView which segments are allowed for pagination
		$config = $this->wire('config');
		$pageNumUrlPrefixes = array();
		$fields = $this->wire('fields');
		foreach($this->wire('languages') as $language) {
			$pageNumUrlPrefix = $this->get("pageNumUrlPrefix$language"); 
			if($pageNumUrlPrefix) $pageNumUrlPrefixes[] = $pageNumUrlPrefix;
			$fields->setNative("name$language"); 
			$fields->setNative("status$language"); 
		}
		if(count($pageNumUrlPrefixes)) {
			$pageNumUrlPrefixes[] = $config->pageNumUrlPrefix; // original/fallback prefix
			$config->set('pageNumUrlPrefixes', $pageNumUrlPrefixes);
		}
	}

	/**
	 * Attach hooks
	 *
	 */
	public function ready() {

		$this->checkModuleVersion();
		$this->addHookAfter('Page::path', $this, 'hookPagePath'); 
		$this->addHookAfter('Page::viewable', $this, 'hookPageViewable'); 
		$this->addHookBefore('Page::render', $this, 'hookPageRender'); 
		$this->addHook('Page::localName', $this, 'hookPageLocalName'); 
		$this->addHook('Page::localUrl', $this, 'hookPageLocalUrl');
		$this->addHook('Page::localHttpUrl', $this, 'hookPageLocalHttpUrl'); 
		$this->addHook('Page::localPath', $this, 'hookPageLocalPath');

		// bypass means the request was to something in /site/*/ that has no possibilty of language support
		// note that the hooks above are added before this so that 404s can still be handled properly
		if($this->bypass) return;

		// verify that page path doesn't have mixed languages where it shouldn't
		$redirectURL = $this->verifyPath($this->requestPath);
		if($redirectURL) {
			$this->wire('session')->redirect($redirectURL);
			return;
		}

		$page = $this->wire('page'); 

		if($page->template == 'admin' && $page->process && in_array('WirePageEditor', wireClassImplements($page->process))) { 
			// when in admin, add inputs for each language's page name
			if(!in_array('ProcessPageType', wireClassParents($page->process))) {
				$page->addHookBefore('WirePageEditor::execute', $this, 'hookWirePageEditorExecute');
				$this->addHookAfter('InputfieldPageName::render', $this, 'hookInputfieldPageNameRenderAfter');
				$this->addHookAfter('InputfieldPageName::processInput', $this, 'hookInputfieldPageNameProcess');
			}
		}

		$this->addHookBefore('LanguageSupportFields::languageDeleted', $this, 'hookLanguageDeleted'); 
		$this->addHookBefore('LanguageSupportFields::languageAdded', $this, 'hookLanguageAdded'); 

		$this->wire('pages')->addHookAfter('saveReady', $this, 'hookPageSaveReady');
		$this->wire('pages')->addHookAfter('saved', $this, 'hookPageSaved');
		$this->wire('pages')->addHookAfter('setupNew', $this, 'hookPageSetupNew'); 
		
		$language = $this->wire('user')->language; 
		$prefix = $this->get("pageNumUrlPrefix$language"); 
		if(strlen($prefix)) {
			$config = $this->wire('config');
			$config->set('_pageNumUrlPrefix', $config->pageNumUrlPrefix); // origial/backup url prefix
			$config->pageNumUrlPrefix = $prefix;
		}
	}

	/**
	 * Is the given path a site assets path? (i.e. /site/)
	 * 
	 * Determines whether this is a path we should attempt to perform any language processing on.
	 * 
	 * @param string $path
	 * @return bool
	 *
	 */
	protected function isAssetPath($path) {
		$config = $this->wire('config');
		// determine if this is a asset request, for compatibility with pagefileSecure
		$segments = explode('/', trim($config->urls->assets, '/')); // start with [subdir]/site/assets
		array_pop($segments); // pop off /assets, reduce to [subdir]/site
		$sitePath = '/' . implode('/', $segments) . '/'; // combine to [/subdir]/site/
		$sitePath = str_replace($config->urls->root, '', $sitePath); // remove possible subdir, reduce to: site/
		// if it is a request to assets, then don't attempt to modify it
		$sitePath = rtrim($sitePath, '/') . '/';
		$path = rtrim($path, '/') . '/';
		return strpos($path, $sitePath) === 0;
	}

	/**
	 * Given a page path, return an updated version that lacks the language segment
	 *
	 * It extracts the language segment and uses that to later set the language
	 * 
	 * @param string $path
	 * @return string
	 *
	 */
	public function updatePath($path) {
		if($path === '/' || !strlen($path)) return $path;
		$trailingSlash = substr($path, -1) == '/';
		$testPath = trim($path, '/') . '/';
		$home = $this->wire('pages')->get(1);
		foreach($this->wire('languages') as $language) {
			$name = $language->isDefault() ? $home->get("name") : $home->get("name$language"); 
			if($name == Pages::defaultRootName) continue;
			if(!strlen($name)) continue; 
			$name = "$name/"; 
			if(strpos($testPath, $name) === 0) {
				$this->setLanguage = $language; 
				$path = substr($testPath, strlen($name)); 
			}
		}	
		if(!$trailingSlash && $path != '/') $path = rtrim($path, '/'); 
		return $path; 
	}

	/**
	 * Determine language from requested path, and if a redirect needs to be performed
	 *
	 * Sets the user's language to that determined from the URL.
	 *
	 * @param string $requestPath
	 * @return string $redirectURL Returns URL to be redirected to, when applicable. Blank when not.
	 *
	 */
	protected function verifyPath($requestPath) {

		$languages = $this->wire('languages'); 
		if(!count($languages)) return '';
		
		$page = $this->wire('page');
		if($page->template == 'admin') return ''; 
		
		$user = $this->wire('user');
		$config = $this->wire('config');
	
		$requestedParts = explode('/', $requestPath); 
		$parentsAndPage = $page->parents()->getArray();
		$parentsAndPage[] = $page; 
		array_shift($parentsAndPage); // shift off the homepage
		$redirectURL = '';
		$setLanguage = $this->setLanguage;

		// determine if we should set the current language based on requested URL
		if(!$setLanguage) foreach($parentsAndPage as $p) {
			/** @var Page $p */

			$requestedPart = strtolower(array_shift($requestedParts)); 
			if($requestedPart === $p->name) continue; 

			foreach($languages as $language) {
				if($language->isDefault()) {
					$name = $p->get("name"); 
				} else {
					$name = $p->get("name$language"); 
				}
				if($name === $requestedPart) {
					$setLanguage = $language; 
				}
			}
		}

		// check to see if the $page or any of its parents has an inactive status for the $setLanguage
		if($setLanguage && !$setLanguage->isDefault()) {
			$active = true;
			if($this->inheritInactive) {
				// inactive status on a parent inherits through to children
				foreach($parentsAndPage as $p) {
					$status = $p->get("status$setLanguage"); 
					if(!$status) $active = false;
				}
			} else {	
				// inactive status only applies to the page itself
				$active = $page->get("status$setLanguage") > 0; 
			
				// https://github.com/processwire/processwire-issues/issues/463
				// $active = $page->get("status$setLanguage") > 0 || $page->template->noLang;
			}
			// if page is inactive for a language, and it's not editable, send a 404
			if(!$active && !$page->editable() && $page->id != $config->http404PageID) {
				// 404 or redirect to default language version
				$this->force404 = true; 
				return '';
			}
		}


		// set the language	
		if(!$setLanguage) $setLanguage = $languages->get('default'); 
		$user->language = $setLanguage; 
		$this->setLanguage = $setLanguage;
		$languages->setLocale();
	
		// if $page is the 404 page, exit out now
		if($page->id == $config->http404PageID) return '';

		// determine if requested URL was correct or if we need to redirect
		$hasSlashURL = substr($requestPath, -1) == '/';
		$useSlashURL = (bool) $page->template->slashUrls;
		$expectedPath = trim($this->getPagePath($page, $user->language), '/');
		$requestPath = trim($requestPath, '/');
		$pageNum = $this->wire('input')->pageNum;
		$urlSegmentStr = $this->wire('input')->urlSegmentStr;
	
		// URL segments
		if(strlen($urlSegmentStr)) {
			$expectedPath .= '/' . $urlSegmentStr; 
			$useSlashURL = $hasSlashURL;
		}
	
		// page numbers
		if($pageNum > 1) {
			$prefix = $this->get("pageNumUrlPrefix$user->language");
			if(empty($prefix)) $prefix = $this->wire('config')->pageNumUrlPrefix;
			$expectedPath .= (strlen($expectedPath) ? "/" : "") . "$prefix$pageNum";
			$useSlashURL = false;
		}
		
		$expectedPathLength = strlen($expectedPath);
	
		if($expectedPathLength) {
			$requestPath = substr($requestPath, 0, $expectedPathLength); 
		}
		
		if(trim($expectedPath, '/') != trim($requestPath, '/')) {
			if($expectedPathLength && $useSlashURL) $expectedPath .= '/';
			$redirectURL = $this->wire('config')->urls->root . ltrim($expectedPath, '/');
			
		} else if($useSlashURL && !$hasSlashURL && strlen($expectedPath)) {
			$redirectURL = $this->wire('config')->urls->root . $expectedPath . '/';
			
		} else if(!$useSlashURL && $hasSlashURL && $pageNum == 1) {
			$redirectURL = $this->wire('config')->urls->root . $expectedPath; 
		}

		return $redirectURL; 	
	}

	/**
	 * Given a page and language, return the path to the page in that language
	 * 
	 * @param Page $page
	 * @param Language $language
	 * @return string
	 *
	 */
	public function getPagePath(Page $page, Language $language) {

		$isDefault = $language->isDefault();
		
		if(!$isDefault && $page->template && $page->template->noLang) {
			$language = $this->wire()->languages->getDefault();
			$isDefault = true;
		}

		if($page->id == 1) {
			// special case: homepage
			$name = $isDefault ? '' : $page->get("name$language"); 
			if($isDefault && $this->useHomeSegment) $name = $page->name;
			if($name == Pages::defaultRootName || !strlen($name)) return '/';
			return $page->template->slashUrls ? "/$name/" : "/$name";
		}

		$path = '';

		foreach($page->parents() as $parent) {
			$name = $isDefault ? $parent->get("name") : $parent->get("name$language|name"); 
			if($parent->id == 1) { 
				// bypass ProcessWire's default homepage name of 'home', as we don't want it in URLs
				if($name == Pages::defaultRootName) continue; 
				// avoid having default language name inherited at homepage level
				// if($isDefault && $name === $parent->get("name")) continue; 
			}
			if(strlen($name)) $path .= "/" . $name;
		}

		$name = $page->get("name$language|name"); 
		$path = strlen($name) ? "$path/$name/" : "$path/";
		
		if(!$page->template->slashUrls && $path != '/') $path = rtrim($path, '/'); 
		
		return $path;
	}


	/**
	 * Hook in before ProcesssPageView::execute to capture and modify $_GET[it] as needed
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookProcessPageViewExecute(HookEvent $event) {
		/** @var ProcessPageView $process */
		$process = $event->object;
		$process->setDelayRedirects(true); 
		// save now, since ProcessPageView removes $_GET['it'] when it executes
		$it = isset($_GET['it']) ? $_GET['it'] : '';
		$this->requestPath = $it; 
		if($this->isAssetPath($it)) {
			$this->bypass = true; 
		} else {
			$it = $this->updatePath($it); 
			if($it != $this->requestPath) $_GET['it'] = $it;
		}
	}

	/**
	 * Hook in before ProcesssPageView::render to throw 404 when appropriate
	 * 
	 * @param HookEvent $event
	 * @throws WireException
	 *
	 */
	public function hookPageRender(HookEvent $event) {
		if($event) {}
		if($this->force404) {
			$this->force404 = false; // prevent another 404 on the 404 page
			throw new Wire404Exception('Not available in requested language', Wire404Exception::codeLanguage);
			// $page = $event->wire('page');		
			// if(!$page || ($page->id != $event->wire('config')->http404PageID)) {
			//	throw new Wire404Exception();
			// }
		}
	}

	/**
	 * Hook in after ProcesssPageView::viewable account for specific language versions
	 *
	 * May be passed a Language name or page to check viewable for that language
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPageViewable(HookEvent $event) {
		if(!$event->return) return;
		/** @var Page $page */
		$page = $event->object;
		// if(wire('user')->isSuperuser() || $page->editable()) return;
		/** @var Language $language */
		$language = $event->arguments(0);
		if(!$language) return;
		if(is_string($language)) $language = $this->wire('languages')->get($this->wire('sanitizer')->pageNameUTF8($language));
		if(!$language instanceof Language) return; // some other non-language argument
		if($language->isDefault()) return; // we accept the result of the original viewable() call
		$status = $page->get("status$language");
		$event->return = $status > 0 && $status < Page::statusUnpublished;
	}

	/**
	 * Hook into WirePageEditor (i.e. ProcessPageEdit) to remove the non-applicable default home name of 'home'
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookWirePageEditorExecute(HookEvent $event) {
		/** @var WirePageEditor $editor */
		$editor = $event->object; 
		$page = $editor->getPage();
		if($page && $page->id == 1) {
			if($page->name == Pages::defaultRootName) $page->name = '';
		}
	}

	/**
	 * Hook into the page name render for when in ProcessPageEdit
	 *
	 * Adds additional inputs for each language
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookInputfieldPageNameRenderAfter(HookEvent $event) {

		/** @var InputfieldPageName $inputfield */
		$inputfield = $event->object; 
		if($inputfield->languageSupportLabel) return; // prevent recursion

		$page = $this->process instanceof WirePageEditor ? $this->process->getPage() : $this->wire('pages')->newNullPage();
		if(!$page->id && $inputfield->editPage) $page = $inputfield->editPage;
		$template = $page->template ? $page->template : null;
		if($template && $template->noLang) return;
		
		/** @var Languages $languages */
		$user = $this->wire('user');
		$languages = $this->wire('languages');
		$savedLanguage = $user->language; 
		$savedValue = $inputfield->attr('value');
		$savedName = $inputfield->attr('name'); 
		$savedID = $inputfield->attr('id');
		$trackChanges = $inputfield->trackChanges();
		$inputfield->setTrackChanges(false);
		$checkboxLabel = $this->_('Active?');
		$out = ''; 

		$language = $languages->getDefault();
		$user->language = $language; 
		$inputfield->languageSupportLabel = $language->get('title|name');
		$out .= $inputfield->render();
		$editable = true; 
		if($page->id && !$page->editable('name', false)) $editable = false;

		// add labels and inputs for other languages
		foreach($languages as $language) {
			if($language->isDefault()) continue; 
			$user->language = $language; 
			$value = $page->get("name$language"); 
			if(is_null($value)) $value = $savedValue; 
			$id = "$savedID$language"; 
			$name  = "$savedName$language";
			$label = $language->get('title|name'); 
			$inputfield->languageSupportLabel = $label;
			$inputfield->attr('id', $id); 
			$inputfield->attr('name', $name); 
			$inputfield->attr('value', $value); 
			$inputfield->checkboxName = "status" . $language->id; 
			$inputfield->checkboxValue = 1; 
			$inputfield->checkboxLabel = $checkboxLabel;
			if($page->id > 0) {
				$inputfield->checkboxChecked = $page->get($inputfield->checkboxName) > 0;
			} else if($inputfield->parentPage) {
				$inputfield->checkboxChecked = $inputfield->parentPage->get($inputfield->checkboxName) > 0;
			}
			if(!$editable) $inputfield->attr('disabled', 'disabled');
			$out .= $inputfield->render();
		}

		// restore language that was saved in the 'before' hook
		$user->language = $savedLanguage; 

		// restore Inputfield values back to what they were
		$inputfield->attr('name', $savedName); 
		$inputfield->attr('savedID', $savedID); 
		$inputfield->attr('value', $savedValue); 
		$inputfield->setTrackChanges($trackChanges); 

		$event->return = $out; 
	}

	/**
	 * Process the input data from hookInputfieldPageNameRender
	 *
	 * @todo Just move this to the InputfieldPageName module rather than using hooks
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookInputfieldPageNameProcess(HookEvent $event) {

		/** @var InputfieldPageName $inputfield */
		$inputfield = $event->object; 
		//$page = $this->process == 'ProcessPageEdit' ? $this->process->getPage() : new NullPage();
		/** @var WirePageEditor $process */
		$process = $this->process; 
		/** @var Page $page */
		$page = $process instanceof WirePageEditor ? $process->getPage() : new NullPage();
		if($page->id && !$page->editable('name', false)) return; // name is not editable
		$input = $event->arguments[0];
		/** @var Languages $languages */
		$languages = $this->wire('languages');
		$sanitizer = $this->wire('sanitizer');

		foreach($languages as $language) {

			if($language->isDefault()) continue; 
			if(!$languages->editable($language)) continue;

			// set language status 
			$key = "status" . (int) $language->id; 
			$value = (int) $input->{"$key$inputfield->checkboxSuffix"};
			if($page->get($key) != $value) {
				$inputfield->trackChange($key);
				$inputfield->trackChange('value');
				if($page->id) $page->set($key, $value); 
					else $page->setQuietly($key, $value); 
			}

			// set language page name
			$name = $inputfield->attr('name') . $language;
			$value = $sanitizer->pageNameUTF8($input->$name);
			
			// if it matches the value for the default language, avoid double storing it
			if($value === $page->name) $value = '';
			
			// if it matches the value already on the page, then no need to go further
			$key = "name$language";
			if($value == $page->get($key)) continue; 
			
			$parentID = $page->parent_id;
			if(!$parentID) $parentID = (int) $this->wire('input')->post('parent_id');
			if(!$this->checkLanguagePageName($language, $page, $parentID, $value, $inputfield)) continue;

			if($page->id) {
				$page->set($key, $value);
			} else {
				$page->setQuietly($key, $value); // avoid non-template exception when new page
			}
		}
	}

	/**
	 * Check changed page name for given language
	 * 
	 * @param Language $language
	 * @param Page $page
	 * @param int $parentID
	 * @param string $value New page name
	 * @param Wire|null $errorTarget Object to send error to (Inputfield likely)
	 * @return bool True if all good, false if not
	 * 
	 */
	public function checkLanguagePageName(Language $language, Page $page, $parentID, $value, Wire $errorTarget = null) {
		// verify that it does not conflict with another page inheriting name from default language
		$isValid = true;
		$nameKey = "name$language->id";
		
		if(!strlen($value)) return true; 
		
		if($this->wire('config')->pageNameCharset == 'UTF8') {
			$value = $this->wire('sanitizer')->pageName($value, Sanitizer::toAscii); 
		}
		
		$sql =
			"SELECT id, name, $nameKey FROM pages " .
			"WHERE parent_id=:parent_id " .
			"AND id!=:id " .
			"AND (" .
				"(name=:newName AND $nameKey IS NULL) " . // default name matches and lang name inherits it (is null)
				"OR ($nameKey=:newName2)" . // or lang name is same as requested one
			")";
		
		$query = $this->wire('database')->prepare($sql);
		$query->bindValue(':parent_id', $parentID, \PDO::PARAM_INT);
		$query->bindValue(':newName', $value);
		$query->bindValue(':newName2', $value);
		$query->bindValue(':id', $page->id, \PDO::PARAM_INT);
		
		try {
			$query->execute();
			$row = $query->fetch(\PDO::FETCH_ASSOC); 
			if($row) {
				$isValid = false;
				if($errorTarget) $errorTarget->error(sprintf(
					$this->_('A sibling page (id=%1$d) is already using name "%2$s" for language: %3$s'), 
					$row['id'], $value, $language->get('title|name')
				));
			}
		} catch(\Exception $e) {
			$this->error($e->getMessage());
			$isValid = false;
		}
		
		$query->closeCursor();
		
		return $isValid;
	}

	/**
	 * Hook into PageFinder::getQuery to add language status check
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPageFinderGetQuery(HookEvent $event) {
		$query = $event->return;
		/** @var PageFinder $pageFinder */
		$pageFinder = $event->object; 
		$options = $pageFinder->getOptions();
		
		// don't enforce language status check with findAll is active
		if(!empty($options['findAll'])) return; 
		
		// don't apply exclusions when output formatting is off
		if(!$this->wire('pages')->outputFormatting) return;

		$language = $this->wire('user')->language; 
		if(!$language || $language->isDefault()) return;

		$status = "status" . (int) $language->id;	
		$query->where("pages.$status>0"); 
	}

	/**
	 * Hook into Page::path to localize path for current language
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPagePath(HookEvent $event) {
		/** @var Page $page */
		$page = $event->object; 
		if($page->template->name == 'admin') return;
		$language = $this->wire()->user->language;
		if(!$language) $language = $this->wire()->languages->getDefault();
		$event->return = $this->getPagePath($page, $language); 
	}

	/**
	 * Add a Page::localName function with optional $language as argument
	 *
	 * event param Language|string|int|bool Optional language, or boolean true for behavior of 2nd argument. 
	 * event param bool Substitute default language page name when page name is not defined for requested language.
	 * event return string Localized language name or blank if not set
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPageLocalName(HookEvent $event) {
		/** @var Page $page */
		$page = $event->object; 
		$language = $this->getLanguage($event->arguments(0)); 
		$nameField = $language->isDefault() ? "name" : "name$language";
		$value = $page->get($nameField);
		if(is_null($value)) $value = '';
		if(empty($value) && $nameField !== 'name' && ($event->arguments(0) === true || $event->arguments(1) === true)) {
			$value = $page->name;
		}
		$event->return = $value; 
	}

	/**
	 * Add a Page::localPath function with optional $language as argument
	 *
	 * event param Language|string|int Optional language 
	 * event return string Localized language path
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPageLocalPath(HookEvent $event) {
		/** @var Page $page */
		$page = $event->object; 
		$language = $this->getLanguage($event->arguments(0)); 
		$event->return = $this->getPagePath($page, $language); 	
	}

	/**
	 * Add a Page::localUrl function with optional $language as argument
	 *
	 * event param Language|string|int Optional language 
	 * event return string Localized language URL
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPageLocalUrl(HookEvent $event) {
		/** @var Page $page */
		$page = $event->object; 
		$language = $this->getLanguage($event->arguments(0)); 
		$event->return = $this->wire('config')->urls->root . ltrim($this->getPagePath($page, $language), '/'); 	
	}
	
	/**
	 * Add a Page::localHttpUrl function with optional $language as argument
	 *
	 * event param Language|string|int Optional language
	 * event return string Localized language name or blank if not set
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPageLocalHttpUrl(HookEvent $event) {
		$this->hookPageLocalUrl($event); 
		$url = $event->return;
		$event->return = $this->wire('input')->scheme() . "://" . $this->wire('config')->httpHost . $url;
	}

	/**
	 * Given an object, integer or string, return the Language object instance
	 *
	 * @param int|string|Language
	 * @return Language
	 *
	 */
	protected function getLanguage($language) {

		if(is_object($language)) {
			if($language instanceof Language) return $language; 
			$language = '';
		}

		if($language && (is_string($language) || is_int($language))) {
			if(ctype_digit("$language")) $language = (int) $language; 
				else $language = $this->wire('sanitizer')->pageNameUTF8($language); 
			$language = $this->wire("languages")->get($language); 
		}

		if(!$language || !$language->id || !$language instanceof Language) {
			$language = $this->wire('languages')->get('default'); 
		}

		return $language; 
	}

	/**
	 * Update pages table for new column when a language is added
	 * 
	 * @param Language|Page $language
	 *
	 */
	public function languageAdded(Page $language) {
		
		static $languagesAdded = array();
		
		if(!$language->id || $language->name == 'default') return;
		if($language instanceof Language && $language->isDefault()) return;
		if(isset($languagesAdded[$language->id])) return;
		
		$name = "name" . (int) $language->id;
		$status = "status" . (int) $language->id;
		$database = $this->wire('database');
		$errors = 0;
		$sqls = array(
			"Add column $name" => "ALTER TABLE pages ADD $name VARCHAR(" . Pages::nameMaxLength . ") CHARACTER SET ascii",
			"Add index for $name" => "ALTER TABLE pages ADD UNIQUE {$name}_parent_id ($name, parent_id)",
			"Add column $status" => "ALTER TABLE pages ADD $status INT UNSIGNED NOT NULL DEFAULT " . Page::statusOn,
		);
		
		foreach($sqls as $label => $sql) {
			try {
				$database->exec($sql);
			} catch(\Exception $e) {
				$this->error("$label: " . $e->getMessage(), Notice::log);
				$errors++;
			}
		}
		
		if(!$errors) $languagesAdded[$language->id] = $language->id;
	}

	/**
	 * Hook called when language is added
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookLanguageAdded(HookEvent $event) {
		$language = $event->arguments[0]; 
		$this->languageAdded($language); 
	}

	/**
	 * Update pages table to remove column when a language is deleted
	 * 
	 * @param Language|Page $language
	 *
	 */
	protected function languageDeleted(Page $language) {
		if(!$language->id || $language->name == 'default') return;
		$name = "name" . (int) $language->id; 
		$status = "status" . (int) $language->id;
		$database = $this->wire('database');
		try {
			$database->exec("ALTER TABLE pages DROP INDEX {$name}_parent_id"); 
			$database->exec("ALTER TABLE pages DROP $name"); 
			$database->exec("ALTER TABLE pages DROP $status"); 
		} catch(\Exception $e) {
			// $this->error($e->getMessage(), Notice::log); // error message can be ignored here
		}
	}

	/**
	 * Hook called when language is deleted
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookLanguageDeleted(HookEvent $event) {
		$language = $event->arguments[0]; 
		$this->languageDeleted($language); 
	}

	/**
	 * Hook called immediately before a page is saved
	 *
	 * Here we make use of the 'extraData' return property of the saveReady hook
	 * to bundle in the language name fields into the query.
	 * 
	 * @param HookEvent $event
	 *
	 */
	public function hookPageSaveReady(HookEvent $event) {

		/** @var Page $page */
		$page = $event->arguments[0];
		
		/** @var Pages $pages */
		$pages = $event->object; 
	
		/** @var Sanitizer $sanitizer */
		$sanitizer = $this->wire('sanitizer');
	
		/** @var array $extraData */
		$extraData = $event->return; 
		
		$alwaysActiveTypes = array(
			'User', 'UserPage', 
			'Role', 'RolePage', 
			'Permission', 'PermissionPage', 
			'Language', 'LanguagePage',
		); 
		$pageNameCharset = $this->wire('config')->pageNameCharset;
		$isCloning = $pages->editor()->isCloning();
		
		if(!is_array($extraData)) $extraData = array();
		
		foreach($this->wire()->languages as $language) {
			
			if($language->isDefault()) continue; 
			$language_id = (int) $language->id; 

			// populate a name123 field for each language
			$name = "name$language_id";
			$value = $sanitizer->pageNameUTF8($page->get($name)); 
			if(!strlen($value)) {
				$value = 'NULL';
			} else if($isCloning) {
				// this save is the result of a clone() operation
				// make sure that the name is unique for other languages
				$value = $pages->names()->uniquePageName(array(
					'name' => $value, 
					'page' => $page, 
					'language' => $language, 
				));
			}
			if($pageNameCharset == 'UTF8') {
				$extraData[$name] = $sanitizer->pageName($value, Sanitizer::toAscii);
			} else {
				$extraData[$name] = $value;
			}

			// populate a status123 field for each language
			$name = "status$language_id";
			if(method_exists($page, 'getForPage')) {
				// repeater page, pull status from 'for' page
				$value = (int) $page->getForPage()->get($name); 
				
			} else if(in_array($page->className(), $alwaysActiveTypes)) {
				// User, Role, Permission or Language: assume active status
				$value = Page::statusOn;
				
			} else {
				// regular page
				$value = (int) $page->get($name);
			}
			$extraData[$name] = $value; 
		}

		$event->return = $extraData; 
	}

	/**
	 * Hook into Pages::setupNew
	 * 
	 * Used to assign a $page->name when none has been assigned, like if a user has added
	 * a page in another language but not configured anything for default language
	 * 
	 * @param HookEvent $event
	 * 
	 */
	public function hookPageSetupNew(HookEvent $event) {
	
		/** @var Page $page */
		$page = $event->arguments[0];
		
		// if page already has a name, then no need to continue
		if($page->name) return;
		
		// account for possibility that a new page with non-default language name/title exists
		// this prevents an exception from being thrown by Pages::save
		$user = $this->wire('user');
		$userTrackChanges = $user->trackChanges();
		$userLanguage = $user->language;
		if($userTrackChanges) $user->setTrackChanges(false); 
		
		foreach($this->wire('languages') as $language) {
			if($language->isDefault()) continue; 
			$user->language = $language; 
			$name = $page->get("name$language"); 
			if(strlen($name)) $page->name = $name; 
			$title = $page->title;
			if(strlen($title)) {
				$page->title = $title;
				if(!$page->name) {
					if($this->wire('config')->pageNameCharset === 'UTF8') {
						$page->name = $this->wire('sanitizer')->pageNameUTF8($title);
					} else {
						$page->name = $this->wire('sanitizer')->pageName($title, Sanitizer::translate);
					}
				}
			}
			if($page->name) break;
		}
	
		// restore user to previous state
		$user->language = $userLanguage; 
		if($userTrackChanges) $user->setTrackChanges(true); 
	}

	/**
	 * Hook called immediately after a page is saved
	 * 
	 * @param HookEvent $event
	 * 
	 */
	public function hookPageSaved(HookEvent $event) {
		// The setLanguage may get lost upon some page save events, so this restores that
		// $this->user->language = $this->setLanguage;
		$page = $event->arguments(0);
		$sanitizer = $this->wire('sanitizer');
		if(!$page->namePrevious) {
			// go into this only if we know the renamed hook hasn't already been called
			$renamed = false;
			foreach($this->wire('languages') as $language) {
				if($language->isDefault()) continue;
				$namePrevious = $page->get("-name$language");
				if(!$namePrevious) continue;
				$name = $sanitizer->pageNameUTF8($page->get("name$language"));
				if($sanitizer->pageNameUTF8($namePrevious) != $name) {
					$renamed = true;
					break;
				}
			}
			// trigger renamed hook if one of the language names changed
			if($renamed) $this->wire('pages')->renamed($page);
		}
	}

	/**
	 * Return the unsanitized/original requested path
	 * 
	 * @return string
	 * 
	 */	
	public function getRequestPath() {
		return $this->requestPath;	
	}
	
	/**
	 * Return the Language that the given path is in or null if can't determine
	 *
	 * @param string $path Page path without without installation subdir or URL segments or page numbers
	 * @param Page $page If you already know the $page that resulted from the path, provide it here for faster performance
	 * @return Language|null
	 *
	 */
	public function getPagePathLanguage($path, Page $page = null) {

		$languages = $this->wire('languages');

		if(!$page || !$page->id) $page = $this->wire('pages')->getByPath($path, array(
			'useLanguages' => true,
			'useHistory' => true
		));

		$foundLanguage = null;
		$path = trim($path, '/');
	
		// a blank path can only be homepage in default language
		if(!strlen($path)) return $languages->getDefault();

		// first check entire path for a match
		if($page->id) foreach($languages as $language) {
			$languages->setLanguage($language);
			if($path === trim($page->path(), '/')) $foundLanguage = $language;
			$languages->unsetLanguage();
			if($foundLanguage) break;
		}

		if($foundLanguage) return $foundLanguage;

		// if we get to this point, then we'll be checking the first segment and last segment
		$parts = explode('/', $path);
		$homepageID = $this->wire('config')->rootPageID;
		$homepage = $this->wire('pages')->get($homepageID);
		$firstPart = reset($parts);
		$lastPart = end($parts);
		
		$tests = array($firstPart => $homepage);
		if($homepage->id != $page->id && $firstPart != $lastPart) $tests[$lastPart] = $page; 

		foreach($tests as $part => $p) {
			if(!$p->id) continue;
			$duplicates = 0; // count duplicate names, which would invalidate any $foundLanguage
			foreach($languages as $language) {
				$key = 'name' . ($language->isDefault() ? '' : $language->id);
				$name = $p->get($key);
				if($name === $part) {
					$foundLanguage = $language;
					$duplicates++;
				}
			}
			if($foundLanguage && $duplicates > 1) $foundLanguage = null;
			if($foundLanguage) break;
		}
		
		if(!$foundLanguage && $page->parent_id > $homepageID && count($parts) > 1) {
			// if language not yet found, go recursive on the parent path before we throw in the towel
			array_pop($parts);
			$foundLanguage = $this->getPagePathLanguage(implode('/', $parts), $page->parent());
		}

		return $foundLanguage;
	}


	/**
	 * Check to make sure that the status table exists and creates it if not
	 * 
	 * @param bool $force
	 *
	 */
	public function checkModuleVersion($force = false) {

		$info = self::getModuleInfo();

		if(!$force) {
			if($info['version'] == $this->moduleVersion) return;
		}

		$database = $this->wire('database');	
		
		// version 3 to 4 check: addition of language-specific status columns
		$query = $database->prepare("SHOW COLUMNS FROM pages WHERE Field LIKE 'status%'");
		$query->execute();
		
		if($query->rowCount() < 2) {
			foreach($this->wire('languages') as $language) {
				if($language->isDefault()) continue;
				$status = "status" . (int) $language->id;
				$database->exec("ALTER TABLE pages ADD $status INT UNSIGNED NOT NULL DEFAULT " . Page::statusOn);
				$this->message("Added status column for language: $language->name", Notice::log);
			}
		}

		// save module version in config data
		if($info['version'] != $this->moduleVersion) {
			$data = $this->wire('modules')->getModuleConfigData($this); 
			$data['moduleVersion'] = $info['version'];
			$this->wire('modules')->saveModuleConfigData($this, $data);
		}

	}

	/**
	 * Module interactive configuration fields
	 * 
	 * @param array $data
	 * @return InputfieldWrapper
	 *
	 */
	public function getModuleConfigInputfields(array $data) {

		$module = $this->wire('modules')->get('LanguageSupportPageNames'); 
		$module->checkModuleVersion(true); 
		$inputfields = $this->wire(new InputfieldWrapper());
		$config = $this->wire('config');
		$defaultUrlPrefix = $config->get('_pageNumUrlPrefix|pageNumUrlPrefix');
		
		foreach($this->wire('languages') as $language) {
			$f = $this->wire('modules')->get('InputfieldName'); 
			$name = "pageNumUrlPrefix$language";
			if($language->isDefault() && empty($data[$name])) $data[$name] = $defaultUrlPrefix;
			$f->attr('name', $name); 
			$f->attr('value', isset($data[$name]) ? $data[$name] : ''); 
			$f->label = "$language->title ($language->name) - " . $this->_('Page number prefix for pagination'); 
			$f->description = sprintf(
				$this->_('The page number is appended to this word in paginated URLs for this language. If omitted, "%s" will be used.'), 
				$defaultUrlPrefix
			); 
			$f->required = false;
			$inputfields->add($f); 
		}

		$input = $this->wire('modules')->get('InputfieldRadios'); 
		$input->attr('name', 'useHomeSegment'); 
		$input->label = $this->_('Default language homepage URL is same as root URL?'); // label for the home segment option
		$input->description = $this->_('Choose **Yes** if you want the homepage of your default language to be served by the root URL **/** (recommended). Choose **No** if you want your root URL to perform a redirect to **/name/** (where /name/ is the default language name of your homepage).');  // description for the home segment option
		$input->notes = $this->_('This setting only affects the homepage behavior. If you select No, you must also make sure your homepage has a name defined for the default language.'); // notes for the home segment option
		$input->addOption(0, $this->_('Yes - Root URL serves default language homepage (recommended)')); 	
		$input->addOption(1, $this->_('No - Root URL performs a redirect to: /name/')); 
		$input->attr('value', empty($data['useHomeSegment']) ? 0 : 1); 
		$input->collapsed = Inputfield::collapsedYes; 
		$inputfields->add($input); 

		return $inputfields;
	}

	/**
	 * Install the module
	 *
	 */
	public function ___install() {

		foreach($this->wire('languages') as $language) {
			$this->languageAdded($language); 
		}

	}

	/**
	 * Uninstall the module
	 *
	 */
	public function ___uninstall() {
		foreach($this->wire('languages') as $language) {
			$this->languageDeleted($language); 
		}
	}

}