<?php
/**
 * Twig view renderer class file.
 *
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\twig;

use Yii;
use yii\base\View;
use yii\base\ViewRenderer as BaseViewRenderer;
use yii\helpers\Html;

/**
 * TwigViewRenderer allows you to use Twig templates in views.
 *
 * @author Alexander Makarov <sam@rmcreative.ru>
 * @since 2.0
 */
class ViewRenderer extends BaseViewRenderer
{
	/**
	 * @var string the directory or path alias pointing to where Twig cache will be stored.
	 */
	public $cachePath = '@runtime/Twig/cache';

	/**
	 * @var array Twig options
	 * @see http://twig.sensiolabs.org/doc/api.html#environment-options
	 */
	public $options = [];

    /**
     * @var array Objects or static classes
     * Keys of array are names to call in template, values - objects or names of static class as string
     * Example: ['html' => '\yii\helpers\Html']
     * Than in template: {{ html.link('Login', 'site/login') }}
     */
    public $globals = [];

    /**
     * @var array Custom functions
     * Keys of array are names to call in template, values - names of functions or static methods of some class
     * Example: ['rot13' => 'str_rot13', 'link' => '\yii\helpers\Html::link']
     * Than in template: {{ rot13('test') }} or {{ link('Login', 'site/login') }}
     */
    public $functions = [];

    /**
     * @var array Custom filters
     * Keys of array are names to call in template, values - names of functions or static methods of some class
     * Example: ['rot13' => 'str_rot13', 'jsonEncode' => '\yii\helpers\Json::encode']
     * Then in template: {{ 'test'|rot13 }} or {{ model|jsonEncode }}
     */
    public $filters = [];

    /**
     * @var array Custom extensions
     * Example: ['Twig_Extension_Sandbox', 'Twig_Extension_Text']
     */
    public $extensions = [];

    /**
     * @var array Twig lexer options
     * @see http://twig.sensiolabs.org/doc/recipes.html#customizing-the-syntax
     * Example: Smarty-like syntax
     * array(
     *     'tag_comment'  => ['{*', '*}'],
     *     'tag_block'    => ['{', '}'],
     *     'tag_variable' => ['{$', '}']
     * )
     */
    public $lexerOptions = [];

    /**
	 * @var \Twig_Environment twig environment object that do all rendering twig templates
	 */
	public $twig;

	public function init()
	{

		$this->twig = new \Twig_Environment(null, array_merge([
			'cache' => Yii::getAlias($this->cachePath),
			'charset' => Yii::$app->charset,
		], $this->options));

		// Adding custom extensions
		if (!empty($this->extensions)) {
			foreach ($this->extensions as $extension) {
				$this->twig->addExtension(new $extension());
			}
		}

		// Adding custom globals (objects or static classes)
		if (!empty($this->globals)) {
			$this->addGlobals($this->globals);
		}

		// Adding custom functions
		if (!empty($this->functions)) {
			$this->addFunctions($this->functions);
		}

		// Adding custom filters
		if (!empty($this->filters)) {
			$this->addFilters($this->filters);
		}

		// Adding custom extensions
		if (!empty($this->extensions)) {
			$this->addExtensions($this->extensions);
		}

		// Change lexer syntax
		if (!empty($this->lexerOptions)) {
			$this->setLexerOptions($this->lexerOptions);
		}

		// Adding global 'void' function (usage: {{void(App.clientScript.registerScriptFile(...))}})
		$this->twig->addFunction('void', new \Twig_Function_Function(function($argument){
		}));

		$this->twig->addFunction('path', new \Twig_Function_Function(function ($path, $args = []) {
			return Html::url(array_merge([$path], $args));
		}));

		$this->twig->addGlobal('app', \Yii::$app);
	}

	/**
	 * Renders a view file.
	 *
	 * This method is invoked by [[View]] whenever it tries to render a view.
	 * Child classes must implement this method to render the given view file.
	 *
	 * @param View $view the view object used for rendering the file.
	 * @param string $file the view file.
	 * @param array $params the parameters to be passed to the view file.
	 *
	 * @return string the rendering result
	 */
	public function render($view, $file, $params)
	{
		$this->twig->addGlobal('this', $view);
		$this->twig->setLoader(new TwigSimpleFileLoader(dirname($file)));
		return $this->twig->render(pathinfo($file, PATHINFO_BASENAME), $params);
	}

	/**
	 * Adds global objects or static classes
	 * @param array $globals @see self::$globals
	 */
	public function addGlobals($globals)
	{
		foreach ($globals as $name => $value) {
			if (!is_object($value)) {
				$value = new ViewRendererStaticClassProxy($value);
			}
			$this->twig->addGlobal($name, $value);
		}
	}

	/**
 	 * Adds custom functions
	 * @param array $functions @see self::$functions
	 */
	public function addFunctions($functions)
	{
		$this->_addCustom('Function', $functions);
	}

	/**
	 * Adds custom filters
	 * @param array $filters @see self::$filters
	 */
	public function addFilters($filters)
	{
		$this->_addCustom('Filter', $filters);
	}

	/**
	 * Adds custom extensions
	 * @param array $extensions @see self::$extensions
	 */
	public function addExtensions($extensions)
	{
		foreach ($extensions as $extName) {
			$this->twig->addExtension(new $extName());
		}
	}

	/**
	 * Sets Twig lexer options to change templates syntax
	 * @param array $options @see self::$lexerOptions
	 */
	public function setLexerOptions($options)
	{
		$lexer = new \Twig_Lexer($this->twig, $options);
		$this->twig->setLexer($lexer);
	}

	/**
	 * Adds custom function or filter
	 * @param string $classType 'Function' or 'Filter'
	 * @param array $elements Parameters of elements to add
	 * @throws \Exception
	 */
	private function _addCustom($classType, $elements)
	{
		$classFunction = 'Twig_' . $classType . '_Function';

		foreach ($elements as $name => $func) {
			$twigElement = null;

			switch ($func) {
				// Just a name of function
				case is_string($func):
					$twigElement = new $classFunction($func);
					break;
				// Name of function + options array
				case is_array($func) && is_string($func[0]) && isset($func[1]) && is_array($func[1]):
					$twigElement = new $classFunction($func[0], $func[1]);
					break;
			}

			if ($twigElement !== null) {
				$this->twig->{'add'.$classType}($name, $twigElement);
			} else {
				throw new \Exception("Incorrect options for \"$classType\" $name.");
			}
		}
	}
}
