<?php
/**
 * Javascript Generator class file.
 *
 * PHP 5
 *
 * CakePHP :  Rapid Development Framework (http://cakephp.org)
 * Copyright 2005-2011, Cake Software Foundation, Inc.
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright 2005-2011, Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.View.Helper
 * @since         CakePHP(tm) v 1.2
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

App::uses('AppHelper', 'View/Helper');
App::uses('JsBaseEngineHelper', 'View/Helper');
App::uses('Multibyte', 'I18n');

/**
 * Javascript Generator helper class for easy use of JavaScript.
 *
 * JsHelper provides an abstract interface for authoring JavaScript with a
 * given client-side library.
 *
 * @package       Cake.View.Helper
 * @property      HtmlHelper $Html
 * @property      FormHelper $Form
 */
class JsHelper extends AppHelper {
/**
 * Whether or not you want scripts to be buffered or output.
 *
 * @var boolean
 */
	public $bufferScripts = true;

/**
 * helpers
 *
 * @var array
 */
	public $helpers = array('Html', 'Form');

/**
 * Variables to pass to Javascript.
 *
 * @var array
 * @see JsHelper::set()
 */
	protected $_jsVars = array();

/**
 * Scripts that are queued for output
 *
 * @var array
 * @see JsHelper::buffer()
 */
	protected $_bufferedScripts = array();

/**
 * Current Javascript Engine that is being used
 *
 * @var string
 */
	protected $_engineName;

/**
 * The javascript variable created by set() variables.
 *
 * @var string
 */
	public $setVariable = 'app';

/**
 * Constructor - determines engine helper
 *
 * @param View $View the view object the helper is attached to.
 * @param array $settings Settings array contains name of engine helper.
 */
	public function __construct(View $View, $settings = array()) {
		$className = 'Jquery';
		if (is_array($settings) && isset($settings[0])) {
			$className = $settings[0];
		} elseif (is_string($settings)) {
			$className = $settings;
		}
		$engineName = $className;
		list($plugin, $className) = pluginSplit($className);

		$this->_engineName = $className . 'Engine';
		$engineClass = $engineName . 'Engine';
		$this->helpers[] = $engineClass;
		parent::__construct($View, $settings);
	}

/**
 * call__ Allows for dispatching of methods to the Engine Helper.
 * methods in the Engines bufferedMethods list will be automatically buffered.
 * You can control buffering with the buffer param as well. By setting the last parameter to
 * any engine method to a boolean you can force or disable buffering.
 *
 * e.g. `$js->get('#foo')->effect('fadeIn', array('speed' => 'slow'), true);`
 *
 * Will force buffering for the effect method. If the method takes an options array you may also add
 * a 'buffer' param to the options array and control buffering there as well.
 *
 * e.g. `$js->get('#foo')->event('click', $functionContents, array('buffer' => true));`
 *
 * The buffer parameter will not be passed onto the EngineHelper.
 *
 * @param string $method Method to be called
 * @param array $params Parameters for the method being called.
 * @return mixed Depends on the return of the dispatched method, or it could be an instance of the EngineHelper
 */
	public function __call($method, $params) {
		if ($this->{$this->_engineName} && method_exists($this->{$this->_engineName}, $method)) {
			$buffer = false;
			$engineHelper = $this->{$this->_engineName};
			if (in_array(strtolower($method), $engineHelper->bufferedMethods)) {
				$buffer = true;
			}
			if (count($params) > 0) {
				$lastParam = $params[count($params) - 1];
				$hasBufferParam = (is_bool($lastParam) || is_array($lastParam) && isset($lastParam['buffer']));
				if ($hasBufferParam && is_bool($lastParam)) {
					$buffer = $lastParam;
					unset($params[count($params) - 1]);
				} elseif ($hasBufferParam && is_array($lastParam)) {
					$buffer = $lastParam['buffer'];
					unset($params['buffer']);
				}
			}

			$out = call_user_func_array(array(&$engineHelper, $method), $params);
			if ($this->bufferScripts && $buffer && is_string($out)) {
				$this->buffer($out);
				return null;
			}
			if (is_object($out) && is_a($out, 'JsBaseEngineHelper')) {
				return $this;
			}
			return $out;
		}
		if (method_exists($this, $method . '_')) {
			return call_user_func(array(&$this, $method . '_'), $params);
		}
		trigger_error(__d('cake_dev', 'JsHelper:: Missing Method %s is undefined', $method), E_USER_WARNING);
	}

/**
 * Overwrite inherited Helper::value()
 * See JsBaseEngineHelper::value() for more information on this method.
 *
 * @param mixed $val A PHP variable to be converted to JSON
 * @param boolean $quoteString If false, leaves string values unquoted
 * @return string a JavaScript-safe/JSON representation of $val
 **/
	public function value($val, $quoteString = true) {
		return $this->{$this->_engineName}->value($val, $quoteString);
	}

/**
 * Writes all Javascript generated so far to a code block or
 * caches them to a file and returns a linked script.  If no scripts have been
 * buffered this method will return null.  If the request is an XHR(ajax) request
 * onDomReady will be set to false. As the dom is already 'ready'.
 *
 * ### Options
 *
 * - `inline` - Set to true to have scripts output as a script block inline
 *   if `cache` is also true, a script link tag will be generated. (default true)
 * - `cache` - Set to true to have scripts cached to a file and linked in (default false)
 * - `clear` - Set to false to prevent script cache from being cleared (default true)
 * - `onDomReady` - wrap cached scripts in domready event (default true)
 * - `safe` - if an inline block is generated should it be wrapped in <![CDATA[ ... ]]> (default true)
 *
 * @param array $options options for the code block
 * @return mixed Completed javascript tag if there are scripts, if there are no buffered
 *   scripts null will be returned.
 */
	public function writeBuffer($options = array()) {
		$domReady = $this->request->is('ajax');
		$defaults = array(
			'onDomReady' => $domReady, 'inline' => true,
			'cache' => false, 'clear' => true, 'safe' => true
		);
		$options = array_merge($defaults, $options);
		$script = implode("\n", $this->getBuffer($options['clear']));

		if (empty($script)) {
			return null;
		}

		if ($options['onDomReady']) {
			$script = $this->{$this->_engineName}->domReady($script);
		}
		$opts = $options;
		unset($opts['onDomReady'], $opts['cache'], $opts['clear']);

		if (!$options['cache'] && $options['inline']) {
			return $this->Html->scriptBlock($script, $opts);
		}

		if ($options['cache'] && $options['inline']) {
			$filename = md5($script);
			if (!file_exists(JS . $filename . '.js')) {
				cache(str_replace(WWW_ROOT, '', JS) . $filename . '.js', $script, '+999 days', 'public');
			}
			return $this->Html->script($filename);
		}
		$this->Html->scriptBlock($script, $opts);
		return null;
	}

/**
 * Write a script to the buffered scripts.
 *
 * @param string $script Script string to add to the buffer.
 * @param boolean $top If true the script will be added to the top of the
 *   buffered scripts array.  If false the bottom.
 * @return void
 */
	public function buffer($script, $top = false) {
		if ($top) {
			array_unshift($this->_bufferedScripts, $script);
		} else {
			$this->_bufferedScripts[] = $script;
		}
	}

/**
 * Get all the buffered scripts
 *
 * @param boolean $clear Whether or not to clear the script caches (default true)
 * @return array Array of scripts added to the request.
 */
	public function getBuffer($clear = true) {
		$this->_createVars();
		$scripts = $this->_bufferedScripts;
		if ($clear) {
			$this->_bufferedScripts = array();
			$this->_jsVars = array();
		}
		return $scripts;
	}

/**
 * Generates the object string for variables passed to javascript.
 *
 * @return string Generated JSON object of all set vars
 */
	protected function _createVars() {
		if (!empty($this->_jsVars)) {
			$setVar = (strpos($this->setVariable, '.')) ? $this->setVariable : 'window.' . $this->setVariable;
			$this->buffer($setVar . ' = ' . $this->object($this->_jsVars) . ';', true);
		}
	}

/**
 * Generate an 'Ajax' link.  Uses the selected JS engine to create a link
 * element that is enhanced with Javascript.  Options can include
 * both those for HtmlHelper::link() and JsBaseEngine::request(), JsBaseEngine::event();
 *
 * ### Options
 *
 * - `confirm` - Generate a confirm() dialog before sending the event.
 * - `id` - use a custom id.
 * - `htmlAttributes` - additional non-standard htmlAttributes.  Standard attributes are class, id,
 *    rel, title, escape, onblur and onfocus.
 * - `buffer` - Disable the buffering and return a script tag in addition to the link.
 *
 * @param string $title Title for the link.
 * @param mixed $url Mixed either a string URL or an cake url array.
 * @param array $options Options for both the HTML element and Js::request()
 * @return string Completed link. If buffering is disabled a script tag will be returned as well.
 */
	public function link($title, $url = null, $options = array()) {
		if (!isset($options['id'])) {
			$options['id'] = 'link-' . intval(mt_rand());
		}
		list($options, $htmlOptions) = $this->_getHtmlOptions($options);
		$out = $this->Html->link($title, $url, $htmlOptions);
		$this->get('#' . $htmlOptions['id']);
		$requestString = $event = '';
		if (isset($options['confirm'])) {
			$requestString = $this->confirmReturn($options['confirm']);
			unset($options['confirm']);
		}
		$buffer = isset($options['buffer']) ? $options['buffer'] : null;
		$safe = isset($options['safe']) ? $options['safe'] : true;
		unset($options['buffer'], $options['safe']);

		$requestString .= $this->request($url, $options);

		if (!empty($requestString)) {
			$event = $this->event('click', $requestString, $options + array('buffer' => $buffer));
		}
		if (isset($buffer) && !$buffer) {
			$opts = array('safe' => $safe);
			$out .= $this->Html->scriptBlock($event, $opts);
		}
		return $out;
	}

/**
 * Pass variables into Javascript.  Allows you to set variables that will be
 * output when the buffer is fetched with `JsHelper::getBuffer()` or `JsHelper::writeBuffer()`
 * The Javascript variable used to output set variables can be controlled with `JsHelper::$setVariable`
 *
 * @param mixed $one Either an array of variables to set, or the name of the variable to set.
 * @param mixed $two If $one is a string, $two is the value for that key.
 * @return void
 */
	public function set($one, $two = null) {
		$data = null;
		if (is_array($one)) {
			if (is_array($two)) {
				$data = array_combine($one, $two);
			} else {
				$data = $one;
			}
		} else {
			$data = array($one => $two);
		}
		if ($data == null) {
			return false;
		}
		$this->_jsVars = array_merge($this->_jsVars, $data);
	}

/**
 * Uses the selected JS engine to create a submit input
 * element that is enhanced with Javascript.  Options can include
 * both those for FormHelper::submit() and JsBaseEngine::request(), JsBaseEngine::event();
 *
 * Forms submitting with this method, cannot send files. Files do not transfer over XmlHttpRequest
 * and require an iframe or flash.
 *
 * ### Options
 *
 * - `url` The url you wish the XHR request to submit to.
 * - `confirm` A string to use for a confirm() message prior to submitting the request.
 * - `method` The method you wish the form to send by, defaults to POST
 * - `buffer` Whether or not you wish the script code to be buffered, defaults to true.
 * - Also see options for JsHelper::request() and JsHelper::event()
 *
 * @param string $caption The display text of the submit button.
 * @param array $options Array of options to use. See the options for the above mentioned methods.
 * @return string Completed submit button.
 */
	public function submit($caption = null, $options = array()) {
		if (!isset($options['id'])) {
			$options['id'] = 'submit-' . intval(mt_rand());
		}
		$formOptions = array('div');
		list($options, $htmlOptions) = $this->_getHtmlOptions($options, $formOptions);
		$out = $this->Form->submit($caption, $htmlOptions);

		$this->get('#' . $htmlOptions['id']);

		$options['data'] = $this->serializeForm(array('isForm' => false, 'inline' => true));
		$requestString = $url = '';
		if (isset($options['confirm'])) {
			$requestString = $this->confirmReturn($options['confirm']);
			unset($options['confirm']);
		}
		if (isset($options['url'])) {
			$url = $options['url'];
			unset($options['url']);
		}
		if (!isset($options['method'])) {
			$options['method'] = 'post';
		}
		$options['dataExpression'] = true;

		$buffer = isset($options['buffer']) ? $options['buffer'] : null;
		$safe = isset($options['safe']) ? $options['safe'] : true;
		unset($options['buffer'], $options['safe']);

		$requestString .= $this->request($url, $options);
		if (!empty($requestString)) {
			$event = $this->event('click', $requestString, $options + array('buffer' => $buffer));
		}
		if (isset($buffer) && !$buffer) {
			$opts = array('safe' => $safe);
			$out .= $this->Html->scriptBlock($event, $opts);
		}
		return $out;
	}

/**
 * Parse a set of Options and extract the Html options.
 * Extracted Html Options are removed from the $options param.
 *
 * @param array $options Options to filter.
 * @param array $additional Array of additional keys to extract and include in the return options array.
 * @return array Array of js options and Htmloptions
 */
	protected function _getHtmlOptions($options, $additional = array()) {
		$htmlKeys = array_merge(
			array('class', 'id', 'escape', 'onblur', 'onfocus', 'rel', 'title', 'style'),
			$additional
		);
		$htmlOptions = array();
		foreach ($htmlKeys as $key) {
			if (isset($options[$key])) {
				$htmlOptions[$key] = $options[$key];
			}
			unset($options[$key]);
		}
		if (isset($options['htmlAttributes'])) {
			$htmlOptions = array_merge($htmlOptions, $options['htmlAttributes']);
			unset($options['htmlAttributes']);
		}
		return array($options, $htmlOptions);
	}
}