<?php namespace ProcessWire;

/**
 * ProcessWire Login Process
 *
 * Provides Login capability for ProcessWire Admin 
 * 
 * For more details about how Process modules work, please see: 
 * /wire/core/Process.php 
 * 
 * ProcessWire 3.x, Copyright 2016 by Ryan Cramer
 * https://processwire.com
 * 
 * @property bool $allowForgot Whether the ProcessForgotPassword module is installed. 
 * 
 * @method void beforeLogin() #pw-hooker
 * @method void afterLogin() #pw-hooker
 * @method void executeLogout() #pw-hooker
 * @method void afterLoginRedirect() #pw-hooker
 * @method string afterLoginURL($url) #pw-hooker
 * @method string renderLoginForm() #pw-hooker
 * @method InputfieldForm buildLoginForm() #pw-hooker
 *
 */

class ProcessLogin extends Process {
	
	public static function getModuleInfo() {
		return array(
			'title' => 'Login',
			'summary' => 'Login to ProcessWire',
			'version' => 103,
			'permanent' => true,
			'permission' => 'page-view',
		);
	}

	/**
	 * @var Inputfield
	 * 
	 */
	protected $nameField;
	
	/**
	 * @var Inputfield
	 *
	 */
	protected $passField;

	/**
	 * @var InputfieldSubmit
	 * 
	 */
	protected $submitField;

	/**
	 * @var InputfieldForm
	 * 
	 */
	protected $form;

	/**
	 * @var int
	 * 
	 */
	protected $id; 

	/**
	 * Is this login form being used for admin login?
	 * 
	 * @var bool
	 * 
	 */
	protected $isAdmin = false;

	/**
	 * URL to redirect to after login
	 * 
	 * @var string
	 * 
	 */
	protected $loginURL = '';

	/**
	 * URL to redirect to after logout
	 * 
	 * @var string
	 * 
	 */
	protected $logoutURL = '';

	/**
	 * Build the login form 
	 *
	 */
	public function init() {

		$this->id = isset($_GET['id']) ? (int) $_GET['id'] : ''; 
		$this->allowForgot = $this->modules->isInstalled('ProcessForgotPassword'); 
		$this->isAdmin = $this->wire('page')->template == 'admin';

		return parent::init();
	}

	/**
	 * Set URL to redirect to after login success
	 * 
	 * If not set, redirect will be back to the current page with a "login=1" GET variable. 
	 * However, you should only check if the user is logged in with if($user->isLoggedin()).
	 * 
	 * @param $url
	 * @return $this
	 * @throws WireException if given invalid URL
	 * 
	 */
	public function setLoginURL($url) {
		$url = $this->wire('sanitizer')->url($url, array('throw' => true)); 
		$this->loginURL = $url;
		return $this; 
	}
	
	/**
	 * Set URL to redirect to after logout success
	 *
	 * If not set, redirect will be back to the current page with a "logout=2" GET variable. 
	 *
	 * @param $url
	 * @return $this
	 * @throws WireException if given invalid URL
	 *
	 */
	public function setLogoutURL($url) {
		$url = $this->wire('sanitizer')->url($url, array('throw' => true));
		$this->logoutURL = $url;
		return $this;
	}
	
	/**
	 * Check if login posted and attempt login, otherwise render the login form
	 * 
	 * @return string
	 *
	 */
	public function ___execute() {
		
		if($this->user->isLoggedin()) {
			if($this->loginURL) $this->wire('session')->redirect($this->afterLoginURL($this->loginURL));
			if($this->input->get('layout')) return ''; // blank placeholder page option for admin themes
			$this->message($this->_("You are logged in.")); 
			if($this->isAdmin && $this->user->hasPermission('page-edit')) $this->afterLoginRedirect();
			// fallback if nothing set
			$url = $this->config->urls->root;
			return "<p><a href='$url'>" . $this->_('Continue') . "</a></p>";
		}

		if($this->input->get('forgot') && $this->allowForgot) {
			/** @var ProcessForgotPassword $process */
			$process = $this->modules->get("ProcessForgotPassword"); 
			return $process->execute();
		}

		$this->buildLoginForm();

		if($this->wire('input')->post('login_submit')) {
			$this->form->processInput($this->wire('input')->post);
		} else if($this->isAdmin) {
			$this->beforeLogin();
		}

		if(!$this->nameField->attr('value') || !$this->passField->attr('value')) {
			return $this->renderLoginForm();
		}

		$name = $this->wire('sanitizer')->pageName($this->nameField->attr('value')); 
		$pass = substr($this->passField->attr('value'), 0, 128); 
	
		if($this->wire('session')->login($name, $pass)) {
			$this->session->message($name . ' - ' . $this->_("Successful login")); 
			if($this->isAdmin) {
				$this->session->set('hidpi', $this->wire('input')->post->login_hidpi ? true : false);
				$this->session->set('touch', $this->wire('input')->post->login_touch ? true : false);
				$this->session->set('clientWidth', (int) $this->wire('input')->post('login_width'));
				$this->session->remove('error');
				$this->afterLogin();
			}
			$url = $this->afterLoginURL("./?login=1" . ($this->id ? "&id=$this->id" : ''));
			$this->session->redirect($url);  
		} else {
			$this->error($name . " - " . $this->_("Login failed")); 
		}

		return $this->renderLoginForm();
	}
	
	/**
	 * Log the user out
	 *
	 */
	public function ___executeLogout() {
		if($this->logoutURL) {
			$url = $this->logoutURL;
		} else if($this->isAdmin) {
			$url = $this->config->urls->admin;
			$this->message($this->_("You have logged out"));
		} else {
			$url = "./?logout=2";
		}
		$this->session->logout();
		$this->session->redirect($url);
	}


	/**
	 * Check that sessions can be initiated and attempt to rectify situation if not
	 * 
	 * Happens only on the admin login form. 
	 *
	 */
	protected function ___beforeLogin() {
		
		// if checks already completed don't run them again
		if($this->wire('session')->get($this, 'beforeLoginChecks')) return;
		
		if(	ini_get('session.save_handler') == 'files' 
			&& !$this->wire('modules')->isInstalled('SessionHandlerDB')
			&& !$this->wire('input')->get('db')
			) {
			
			$installSessionDB = false;
			$path = $this->config->paths->sessions;
			$error = '';
			
			if(!file_exists($path)) {
				$this->wire('files')->mkdir($path);
				clearstatcache();
				if(file_exists($path)) {
					$this->wire('log')->message("Created session path $path"); 
				} else {
					$installSessionDB = true;
					$error = "Session path $path does not exist and we are unable to create it.";
				}
				
			} 
			
			if(!is_writable($path)) {
				$this->wire('files')->chmod($path);
				clearstatcache();
				if(is_writable($path)) {
					$this->wire('log')->message("Updated session path to be writable $path"); 
				} else {
					$installSessionDB = true;
					$error = "Unable to write to session path $path, and unable to fix the permissions.";
				}
			}
			
			// if we can't get file-based sessions going, switch to database sessions to ensure admin can login
			if($installSessionDB) {
				if($error) $this->wire('log')->error($error); 
				if($this->wire('modules')->get('SessionHandlerDB')) {
					$this->wire('log')->error("Installed SessionHandlerDB as an alternate session handler. If you wish to uninstall this, do so after correcting the session path error."); 
					$this->wire('session')->redirect("./?db=1"); // db param to prevent potential infinite redirect
				} else {
					$this->wire('log')->error("Unable to install alternate session handler module SessionHandlerDB"); 	
					$this->error("Session write error. Login may not be possible."); 
				}
			}
		}
		
		$this->wire('session')->set($this, 'beforeLoginChecks', 1); 
	}

	/**
	 * Hook called after login
	 *
	 * Notify admin if there are any issues that need their attention.
	 * Happens only on the admin login form after superuser login. 
	 *
	 */
	protected function ___afterLogin() {
		if(!$this->user->isSuperuser()) return;

		$indexVersion = ProcessWire::indexVersion; 
		$htaccessVersion = ProcessWire::htaccessVersion;
		
		if(PROCESSWIRE < $indexVersion) {
			$this->warning(
				"Not urgent, but note that your root index.php file is not up-to-date with this ProcessWire version - please update it when possible. " . 
				"<br /><small>Required version: $indexVersion, Found version: " . PROCESSWIRE . "</small>", Notice::log | Notice::allowMarkup
				); 
		}

		$htaccessFile = $this->wire('config')->paths->root . '.htaccess';
		if(is_readable($htaccessFile)) {
			$htaccessData = file_get_contents($htaccessFile); 
			if(!preg_match('/@(?:index|htaccess)Version\s+(\d+)\b/', $htaccessData, $matches) || ((int) $matches[1]) < $htaccessVersion) {	
				$this->warning(
					"Not urgent, but note that your root .htaccess file is not up-to-date with this ProcessWire version - please update it when possible.<br />" .  
					"<small>To ignore this warning, replace or add the following in the top of your existing .htaccess file:</small> " . 
					"<span style='font-family: monospace;'># @indexVersion $htaccessVersion</span>", Notice::log | Notice::allowMarkup
					); 
			}
		}

		// if($this->config->showSecurityWarnings === false) return;
		// if(is_writable($this->config->paths->root . "site/config.php")) $this->error("Security Warning: /site/config.php is writable and ideally should not be."); 
		// if(is_writable($this->config->paths->root . "index.php")) $this->error("Security Warning: /index.php is writable and ideally should not be."); 
		$warningText = $this->_("Security Warning: %s exists and should be deleted as soon as possible."); 
		if(is_file($this->config->paths->root . "install.php")) $this->error(sprintf($warningText, '/install.php'), Notice::log); 

		$file = $this->config->paths->assets . "active.php";
		if(!is_file($file)) {
			$data = "<?php // Do not delete this file. " . 
				"The existence of this file indicates the site is confirmed active " . 
				"and first-time use errors may be suppressed. Installed at: " . 
				"[{$this->config->paths->root}]";
			file_put_contents($file, $data); 
		}
	
		// warnings about 0666/0777 file permissions
		if($this->config->chmodWarn && ($this->config->chmodDir == '0777' || $this->config->chmodFile == '0666')) {
			$warning = 
				$this->_('Warning, your /site/config.php specifies file permissions that are too loose for many environments:') . '<br />' . 
				"<span style='font-family:monospace'>" . 
				"\$config->chmodFile = '{$this->config->chmodFile}';<br />" . 
				"\$config->chmodDir = '{$this->config->chmodDir}';" . 
				"</span><br /><i class='fa fa-angle-right'></i> " . 
				"<a href='https://processwire.com/docs/security/file-permissions/' target='_blank'>" . 
				$this->_('Read "Securing file permissions" for more details') . "</a><br />" . 
				"<small class='ui-priority-secondary'>" . 
				$this->_('To suppress this warning, set $config->chmodWarn = false; in your /site/config.php file.') . 
				"</small>";
			$warning = str_replace(array('0666', '0777'), array('<u>0666</u>', '<u>0777</u>'), $warning);
			$this->warning($warning, Notice::allowMarkup | Notice::log);
		}
		
		if($this->wire('fields')->get('published')) {
			$this->error("Warning: you have a field named 'published' that conflicts with the page 'published' property. Please rename your field field to something else and update any templates referencing it.");
		}

		// warning about servers with locales that break UTF-8 strings called by basename
		// and other file functions, due to a long running PHP bug 
		if(basename("§") === "") {
			$example = stripos(PHP_OS, 'WIN') === 0 ? 'en-US' : 'en_US.UTF-8';
			$msg = $this->_('Warning: your server locale is undefined and may cause issues.') . ' ';
			if($this->wire('modules')->isInstalled('LanguageSupport')) {
				$msg .= sprintf($this->_('Please translate the “C” locale setting for each language to the proper locale in %s'),
					'<u>/wire/modules/LanguageSupport/LanguageSupport.module</u> (shortcuts provided below):');
				foreach($this->wire('languages') as $language) {
					$url = $this->wire('config')->urls->admin . "setup/language-translator/edit/?language_id=$language->id&" . 
						"textdomain=wire--modules--languagesupport--languagesupport-module&" . 
						"filename=wire/modules/LanguageSupport/LanguageSupport.module";
					$msg .= "<br />• <a target='_blank' href='$url'>" . $language->get('title|name') . "</a>";
				}
				$msg .= "<br /><small>" . 
					sprintf($this->_('For example, the locale setting for US English might be: %s'), "<strong>$example</strong>") . 
					"</small>";
				$this->warning($msg, Notice::allowMarkup);
			} else {
				$msg .= sprintf($this->_('Please add this to /site/config.php file (adjust “%s” as needed):'), $example) . ' ' .
					"setlocale(LC_ALL,'$example');";
				$this->warning($msg);
			}
		}

	}

	/**
	 * Build the login form
	 * 
	 * @return InputfieldForm
	 * 
	 */
	protected function ___buildLoginForm() {

		$this->nameField = $this->modules->get('InputfieldText');
		$this->nameField->set('label', $this->_('Username')); // Login form: username field label
		$this->nameField->attr('id+name', 'login_name'); 
		$this->nameField->attr('class', $this->className() . 'Name');
		$this->nameField->collapsed = Inputfield::collapsedNever;

		$this->passField = $this->modules->get('InputfieldText');
		$this->passField->set('label', $this->_('Password')); // Login form: password field label
		$this->passField->attr('id+name', 'login_pass'); 
		$this->passField->attr('type', 'password'); 
		$this->passField->attr('class', $this->className() . 'Pass');
		$this->passField->collapsed = Inputfield::collapsedNever;

		$this->submitField = $this->modules->get('InputfieldSubmit');
		$this->submitField->attr('name', 'login_submit'); 
		$this->submitField->attr('value', $this->_('Login')); // Login form: submit login button 
		
		$this->form = $this->modules->get('InputfieldForm');

		// we'll retain an ID field in the GET url, if it was there
		$this->form->attr('action', "./" . ($this->id ? "?id={$this->id}" : '')); 
		$this->form->addClass('InputfieldFormFocusFirst');

		$this->form->attr('id', $this->className() . 'Form'); 
		$this->form->add($this->nameField); 
		$this->form->add($this->passField); 
		$this->form->add($this->submitField);

		if($this->isAdmin) {
			// detect hidpi at login (populated from js)
			/** @var InputfieldHidden $f */
			$f = $this->modules->get('InputfieldHidden');
			$f->attr('id+name', 'login_hidpi');
			$f->attr('value', 0);
			$this->form->add($f);

			// detect touch device login (populated from js)
			$f = $this->modules->get('InputfieldHidden');
			$f->attr('id+name', 'login_touch');
			$f->attr('value', 0);
			$this->form->add($f);
			
			// detect touch device login (populated from js)
			$f = $this->modules->get('InputfieldHidden');
			$f->attr('id+name', 'login_width');
			$f->attr('value', 0);
			$this->form->add($f);
		}

		return $this->form; 
	}

	/**
	 * Render the login form
	 * 
	 * @return string
	 *
	 */
	protected function ___renderLoginForm() {
		$loggedIn = $this->wire('user')->isLoggedin();
		$out = '';
		
		if($this->wire('input')->get('login') && $loggedIn) {
			// redirect to page after login
			$this->afterLoginRedirect();
		} else if($loggedIn) {
			// user is already logged in, do nothing
		} else {
			// note the space after 'Login ' is intentional to separate it from the Login button for translation purposes
			$this->headline($this->_('Login ')); // Headline for login form page
			$this->passField->attr('value', '');
			$out = $this->form->render();
			$links = '';
			if($this->allowForgot) {
				$links .= "<div><a href='./?forgot=1'><i class='fa fa-question-circle'></i> " . $this->_("Forgot your password?") . "</a></div>"; // Forgot password link text
			}
			$home = $this->pages->get("/"); 
			$links .= "<div><a href='{$home->url}'><i class='fa fa-home'></i> {$home->title}</a></div>";
			if($links) $out .= "<p>$links</p>";
		}
		
		return $out;
	}

	/**
	 * Redirect to admin root after login
	 *
	 * Called only if the login request originated on the actual login page. 
	 *
	 */
	protected function ___afterLoginRedirect() {
		$url = $this->wire('config')->urls->admin . 'page/?login=1';
		$url = $this->afterLoginURL($url);
		$this->wire('session')->redirect($url);
	}

	/**
	 * #pw-hooker
	 * #pw-internal
	 * 
	 * @param string $url
	 * @return string
	 * 
	 */
	public function ___afterLoginURL($url) {
		return $url;
	}


}

