<?php
/**
 * Harmony
 * Copyright (c) 2008 Maxime Bouroumeau-Fuseau
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @category Harmony
 * @package Harmony_Parser 
 * @author Maxime Bouroumeau-Fuseau
 * @copyright 2008 (c) Maxime Bouroumeau-Fuseau
 * @license http://www.opensource.org/licenses/mit-license.php
 * @link http://www.harmony-framework.com
 */

/** Harmony_Parser_Abstract */
require_once 'Harmony/Parser/Abstract.php';

/**
 * @category Harmony
 * @package Harmony_Parser 
 * @copyright 2008 (c) Maxime Bouroumeau-Fuseau
 * @license http://www.opensource.org/licenses/mit-license.php
 */
abstract class Harmony_Parser_Context
{
	/**
	 * Current parser
	 *
	 * @var Harmony_Parser_Abstract
	 */
	protected $_parser;
	
	/**
	 * Tokens for the current context
	 *
	 * @var array
	 */
	protected $_tokens = array();
	
	/**
	 * Params for the context
	 *
	 * @var array
	 */
	protected $_params;
	
	/**
	 * Data returned to the parent context
	 *
	 * @var array
	 */
	protected $_exitData;
	
	/**
	 * Whether to exit context after a token method
	 *
	 * @var bool
	 */
	protected $_exitContext;
	
	/**
	 * Create a new context
	 *
	 * @param Harmony_Parser_Abstract $parser
	 */
	public function __construct(Harmony_Parser_Abstract $parser, $params = array())
	{
		$this->_parser = $parser;
		$this->_params = $params;
		$this->_exitData = '';
		$this->_exitContext = false;
		$this->init();
	}
	
	/**
	 * Context logic when initialized
	 */
	protected function init()
	{
	}
	
	/**
	 * Current parser
	 *
	 * @return Harmony_Parser_Abstract
	 */
	public function getParser()
	{
		return $this->_parser;
	}
	
	/**
	 * Checks if a parameter exists
	 *
	 * @param string $name
	 * @return bool
	 */
	public function hasParam($name)
	{
		return array_key_exists($name, $this->_params);
	}
	
	/**
	 * Gets a parameter's value
	 *
	 * @param string $name
	 * @return mixed
	 */
	public function getParam($name)
	{
		if (!$this->hasParam($name)) {
			require_once 'Harmony/Parser/Exception.php';
			throw new Harmony_Parser_Exception('Missing parameter ' . $name . 
				' in context ' . get_class($this));
		}
		return $this->_params[$name];
	}
	
	/**
	 * Gets all params
	 *
	 * @return array
	 */
	public function getParams()
	{
		return $this->_params;
	}
	
	/**
	 * Exit the context at the end of the current action
	 *
	 * @param mixed $data OPTIONAL
	 */
	public function exitContext($data = array())
	{
		$this->_exitData = $data;
		$this->_exitContext = true;
	}
	
	/**
	 * Get tokens for the current context
	 *
	 * @return array
	 */
	public function _getTokens()
	{
		return $this->_tokens;
	}
	
	/**
	 * Execute the action associated to a token
	 * 
	 * @param string $token
	 * @param string $data
	 * @return mixed
	 */
	public function _doActionForToken($token, $data)
	{
		$method = 'token' . ucfirst($token);
		if (!method_exists($this, $method) && !method_exists($this, '__call')) {
			return null;
		}
		
		$this->beforeToken();
		$this->{$method}($data);
		$this->afterToken();
		
		return $this->_exitContext;
	}
	
	/**
	 * Gets data returned by context
	 *
	 * @var mixed
	 */
	public function _getExitData()
	{
		return $this->_exitData;
	}
	
	/**
	 * Method called before a specific token method
	 */
	protected function beforeToken()
	{
	}
	
	/**
	 * Method called after a specific token method
	 */
	protected function afterToken()
	{
	}
	
	/**
	 * End of file reached by parser
	 */
	public function tokenEof($data)
	{
		$this->exitContext();
	}
}