<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\base;

use Yii;

/**
 * Controller is the base class for classes containing controller logic.
 *
 * @property Module[] $modules All ancestor modules that this controller is located within. This property is
 * read-only.
 * @property string $route The route (module ID, controller ID and action ID) of the current request. This
 * property is read-only.
 * @property string $uniqueId The controller ID that is prefixed with the module ID (if any). This property is
 * read-only.
 * @property View|\yii\web\View $view The view object that can be used to render views or view files.
 * @property string $viewPath The directory containing the view files for this controller. This property is
 * read-only.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class Controller extends Component implements ViewContextInterface
{
 /**
 * @event ActionEvent an event raised right before executing a controller action.
 * You may set [[ActionEvent::isValid]] to be false to cancel the action execution.
 */
 const EVENT_BEFORE_ACTION = 'beforeAction';
 /**
 * @event ActionEvent an event raised right after executing a controller action.
 */
 const EVENT_AFTER_ACTION = 'afterAction';

 /**
 * @var string the ID of this controller.
 */
 public $id;
 /**
 * @var Module $module the module that this controller belongs to.
 */
 public $module;
 /**
 * @var string the ID of the action that is used when the action ID is not specified
 * in the request. Defaults to 'index'.
 */
 public $defaultAction = 'index';
 /**
 * @var string|boolean the name of the layout to be applied to this controller's views.
 * This property mainly affects the behavior of [[render()]].
 * Defaults to null, meaning the actual layout value should inherit that from [[module]]'s layout value.
 * If false, no layout will be applied.
 */
 public $layout;
 /**
 * @var Action the action that is currently being executed. This property will be set
 * by [[run()]] when it is called by [[Application]] to run an action.
 */
 public $action;

 /**
 * @var View the view object that can be used to render views or view files.
 */
 private $_view;


 /**
 * @param string $id the ID of this controller.
 * @param Module $module the module that this controller belongs to.
 * @param array $config name-value pairs that will be used to initialize the object properties.
 */
 public function __construct($id, $module, $config = [])
 {
 $this->id = $id;
 $this->module = $module;
 parent::__construct($config);
 }

 /**
 * Declares external actions for the controller.
 * This method is meant to be overwritten to declare external actions for the controller.
 * It should return an array, with array keys being action IDs, and array values the corresponding
 * action class names or action configuration arrays. For example,
 *
 * ~~~
 * return [
 * 'action1' => 'app\components\Action1',
 * 'action2' => [
 * 'class' => 'app\components\Action2',
 * 'property1' => 'value1',
 * 'property2' => 'value2',
 * ],
 * ];
 * ~~~
 *
 * [[\Yii::createObject()]] will be used later to create the requested action
 * using the configuration provided here.
 */
 public function actions()
 {
 return [];
 }

 /**
 * Runs an action within this controller with the specified action ID and parameters.
 * If the action ID is empty, the method will use [[defaultAction]].
 * @param string $id the ID of the action to be executed.
 * @param array $params the parameters (name-value pairs) to be passed to the action.
 * @return mixed the result of the action.
 * @throws InvalidRouteException if the requested action ID cannot be resolved into an action successfully.
 * @see createAction()
 */
 public function runAction($id, $params = [])
 {
 $action = $this->createAction($id);
 if ($action === null) {
 throw new InvalidRouteException('Unable to resolve the request: ' . $this->getUniqueId() . '/' . $id);
 }

 Yii::trace("Route to run: " . $action->getUniqueId(), __METHOD__);

 if (Yii::$app->requestedAction === null) {
 Yii::$app->requestedAction = $action;
 }

 $oldAction = $this->action;
 $this->action = $action;

 $modules = [];
 $runAction = true;

 // call beforeAction on modules
 foreach ($this->getModules() as $module) {
 if ($module->beforeAction($action)) {
 array_unshift($modules, $module);
 } else {
 $runAction = false;
 break;
 }
 }

 $result = null;

 if ($runAction && $this->beforeAction($action)) {
 // run the action
 $result = $action->runWithParams($params);

 $result = $this->afterAction($action, $result);

 // call afterAction on modules
 foreach ($modules as $module) {
 /* @var $module Module */
 $result = $module->afterAction($action, $result);
 }
 }

 $this->action = $oldAction;

 return $result;
 }

 /**
 * Runs a request specified in terms of a route.
 * The route can be either an ID of an action within this controller or a complete route consisting
 * of module IDs, controller ID and action ID. If the route starts with a slash '/', the parsing of
 * the route will start from the application; otherwise, it will start from the parent module of this controller.
 * @param string $route the route to be handled, e.g., 'view', 'comment/view', '/admin/comment/view'.
 * @param array $params the parameters to be passed to the action.
 * @return mixed the result of the action.
 * @see runAction()
 */
 public function run($route, $params = [])
 {
 $pos = strpos($route, '/');
 if ($pos === false) {
 return $this->runAction($route, $params);
 } elseif ($pos > 0) {
 return $this->module->runAction($route, $params);
 } else {
 return Yii::$app->runAction(ltrim($route, '/'), $params);
 }
 }

 /**
 * Binds the parameters to the action.
 * This method is invoked by [[Action]] when it begins to run with the given parameters.
 * @param Action $action the action to be bound with parameters.
 * @param array $params the parameters to be bound to the action.
 * @return array the valid parameters that the action can run with.
 */
 public function bindActionParams($action, $params)
 {
 return [];
 }

 /**
 * Creates an action based on the given action ID.
 * The method first checks if the action ID has been declared in [[actions()]]. If so,
 * it will use the configuration declared there to create the action object.
 * If not, it will look for a controller method whose name is in the format of `actionXyz`
 * where `Xyz` stands for the action ID. If found, an [[InlineAction]] representing that
 * method will be created and returned.
 * @param string $id the action ID.
 * @return Action the newly created action instance. Null if the ID doesn't resolve into any action.
 */
 public function createAction($id)
 {
 if ($id === '') {
 $id = $this->defaultAction;
 }

 $actionMap = $this->actions();
 if (isset($actionMap[$id])) {
 return Yii::createObject($actionMap[$id], [$id, $this]);
 } elseif (preg_match('/^[a-z0-9\\-_]+$/', $id) && strpos($id, '--') === false && trim($id, '-') === $id) {
 $methodName = 'action' . str_replace(' ', '', ucwords(implode(' ', explode('-', $id))));
 if (method_exists($this, $methodName)) {
 $method = new \ReflectionMethod($this, $methodName);
 if ($method->isPublic() && $method->getName() === $methodName) {
 return new InlineAction($id, $this, $methodName);
 }
 }
 }

 return null;
 }

 /**
 * This method is invoked right before an action is executed.
 *
 * The method will trigger the [[EVENT_BEFORE_ACTION]] event. The return value of the method
 * will determine whether the action should continue to run.
 *
 * In case the action should not run, the request should be handled inside of the `beforeAction` code
 * by either providing the necessary output or redirecting the request. Otherwise the response will be empty.
 *
 * If you override this method, your code should look like the following:
 *
 * ```php
 * public function beforeAction($action)
 * {
 * if (!parent::beforeAction($action)) {
 * return false;
 * }
 *
 * // your custom code here
 *
 * return true; // or false to not run the action
 * }
 * ```
 *
 * @param Action $action the action to be executed.
 * @return boolean whether the action should continue to run.
 */
 public function beforeAction($action)
 {
 $event = new ActionEvent($action);
 $this->trigger(self::EVENT_BEFORE_ACTION, $event);
 return $event->isValid;
 }

 /**
 * This method is invoked right after an action is executed.
 *
 * The method will trigger the [[EVENT_AFTER_ACTION]] event. The return value of the method
 * will be used as the action return value.
 *
 * If you override this method, your code should look like the following:
 *
 * ```php
 * public function afterAction($action, $result)
 * {
 * $result = parent::afterAction($action, $result);
 * // your custom code here
 * return $result;
 * }
 * ```
 *
 * @param Action $action the action just executed.
 * @param mixed $result the action return result.
 * @return mixed the processed action result.
 */
 public function afterAction($action, $result)
 {
 $event = new ActionEvent($action);
 $event->result = $result;
 $this->trigger(self::EVENT_AFTER_ACTION, $event);
 return $event->result;
 }

 /**
 * Returns all ancestor modules of this controller.
 * The first module in the array is the outermost one (i.e., the application instance),
 * while the last is the innermost one.
 * @return Module[] all ancestor modules that this controller is located within.
 */
 public function getModules()
 {
 $modules = [$this->module];
 $module = $this->module;
 while ($module->module !== null) {
 array_unshift($modules, $module->module);
 $module = $module->module;
 }
 return $modules;
 }

 /**
 * @return string the controller ID that is prefixed with the module ID (if any).
 */
 public function getUniqueId()
 {
 return $this->module instanceof Application ? $this->id : $this->module->getUniqueId() . '/' . $this->id;
 }

 /**
 * Returns the route of the current request.
 * @return string the route (module ID, controller ID and action ID) of the current request.
 */
 public function getRoute()
 {
 return $this->action !== null ? $this->action->getUniqueId() : $this->getUniqueId();
 }

 /**
 * Renders a view and applies layout if available.
 *
 * The view to be rendered can be specified in one of the following formats:
 *
 * - path alias (e.g. "@app/views/site/index");
 * - absolute path within application (e.g. "//site/index"): the view name starts with double slashes.
 * The actual view file will be looked for under the [[Application::viewPath|view path]] of the application.
 * - absolute path within module (e.g. "/site/index"): the view name starts with a single slash.
 * The actual view file will be looked for under the [[Module::viewPath|view path]] of [[module]].
 * - relative path (e.g. "index"): the actual view file will be looked for under [[viewPath]].
 *
 * To determine which layout should be applied, the following two steps are conducted:
 *
 * 1. In the first step, it determines the layout name and the context module:
 *
 * - If [[layout]] is specified as a string, use it as the layout name and [[module]] as the context module;
 * - If [[layout]] is null, search through all ancestor modules of this controller and find the first
 * module whose [[Module::layout|layout]] is not null. The layout and the corresponding module
 * are used as the layout name and the context module, respectively. If such a module is not found
 * or the corresponding layout is not a string, it will return false, meaning no applicable layout.
 *
 * 2. In the second step, it determines the actual layout file according to the previously found layout name
 * and context module. The layout name can be:
 *
 * - a path alias (e.g. "@app/views/layouts/main");
 * - an absolute path (e.g. "/main"): the layout name starts with a slash. The actual layout file will be
 * looked for under the [[Application::layoutPath|layout path]] of the application;
 * - a relative path (e.g. "main"): the actual layout file will be looked for under the
 * [[Module::layoutPath|layout path]] of the context module.
 *
 * If the layout name does not contain a file extension, it will use the default one `.php`.
 *
 * @param string $view the view name.
 * @param array $params the parameters (name-value pairs) that should be made available in the view.
 * These parameters will not be available in the layout.
 * @return string the rendering result.
 * @throws InvalidParamException if the view file or the layout file does not exist.
 */
 public function render($view, $params = [])
 {
 $content = $this->getView()->render($view, $params, $this);
 return $this->renderContent($content);
 }

 /**
 * Renders a static string by applying a layout.
 * @param string $content the static string being rendered
 * @return string the rendering result of the layout with the given static string as the `$content` variable.
 * If the layout is disabled, the string will be returned back.
 * @since 2.0.1
 */
 public function renderContent($content)
 {
 $layoutFile = $this->findLayoutFile($this->getView());
 if ($layoutFile !== false) {
 return $this->getView()->renderFile($layoutFile, ['content' => $content], $this);
 } else {
 return $content;
 }
 }

 /**
 * Renders a view without applying layout.
 * This method differs from [[render()]] in that it does not apply any layout.
 * @param string $view the view name. Please refer to [[render()]] on how to specify a view name.
 * @param array $params the parameters (name-value pairs) that should be made available in the view.
 * @return string the rendering result.
 * @throws InvalidParamException if the view file does not exist.
 */
 public function renderPartial($view, $params = [])
 {
 return $this->getView()->render($view, $params, $this);
 }

 /**
 * Renders a view file.
 * @param string $file the view file to be rendered. This can be either a file path or a path alias.
 * @param array $params the parameters (name-value pairs) that should be made available in the view.
 * @return string the rendering result.
 * @throws InvalidParamException if the view file does not exist.
 */
 public function renderFile($file, $params = [])
 {
 return $this->getView()->renderFile($file, $params, $this);
 }

 /**
 * Returns the view object that can be used to render views or view files.
 * The [[render()]], [[renderPartial()]] and [[renderFile()]] methods will use
 * this view object to implement the actual view rendering.
 * If not set, it will default to the "view" application component.
 * @return View|\yii\web\View the view object that can be used to render views or view files.
 */
 public function getView()
 {
 if ($this->_view === null) {
 $this->_view = Yii::$app->getView();
 }
 return $this->_view;
 }

 /**
 * Sets the view object to be used by this controller.
 * @param View|\yii\web\View $view the view object that can be used to render views or view files.
 */
 public function setView($view)
 {
 $this->_view = $view;
 }

 /**
 * Returns the directory containing view files for this controller.
 * The default implementation returns the directory named as controller [[id]] under the [[module]]'s
 * [[viewPath]] directory.
 * @return string the directory containing the view files for this controller.
 */
 public function getViewPath()
 {
 return $this->module->getViewPath() . DIRECTORY_SEPARATOR . $this->id;
 }

 /**
 * Finds the applicable layout file.
 * @param View $view the view object to render the layout file.
 * @return string|boolean the layout file path, or false if layout is not needed.
 * Please refer to [[render()]] on how to specify this parameter.
 * @throws InvalidParamException if an invalid path alias is used to specify the layout.
 */
 public function findLayoutFile($view)
 {
 $module = $this->module;
 if (is_string($this->layout)) {
 $layout = $this->layout;
 } elseif ($this->layout === null) {
 while ($module !== null && $module->layout === null) {
 $module = $module->module;
 }
 if ($module !== null && is_string($module->layout)) {
 $layout = $module->layout;
 }
 }

 if (!isset($layout)) {
 return false;
 }

 if (strncmp($layout, '@', 1) === 0) {
 $file = Yii::getAlias($layout);
 } elseif (strncmp($layout, '/', 1) === 0) {
 $file = Yii::$app->getLayoutPath() . DIRECTORY_SEPARATOR . substr($layout, 1);
 } else {
 $file = $module->getLayoutPath() . DIRECTORY_SEPARATOR . $layout;
 }

 if (pathinfo($file, PATHINFO_EXTENSION) !== '') {
 return $file;
 }
 $path = $file . '.' . $view->defaultExtension;
 if ($view->defaultExtension !== 'php' && !is_file($path)) {
 $path = $file . '.php';
 }

 return $path;
 }
}