<?php 
/**
 * Jaxl (Jabber XMPP Library)
 *
 * Copyright (c) 2009-2012, Abhinav Singh <me@abhinavsingh.com>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * distribution.
 *
 * * Neither the name of Abhinav Singh nor the names of his
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRIC
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

abstract class JAXLFsm {
	
	protected $state = null;
	
	// abstract method
	abstract public function handle_invalid_state($r);
	
	public function __construct($state) {
		$this->state = $state;
	}
	
	// returned value from state callbacks can be:
	// 1) array() <-- is_callable method
	// 2) array([0]=>'new_state', [1]=>'return value for current callback') <-- is_not_callable method
	// 3) array([0]=>'new_state')
	// 4) 'new_state'
	//
	// for case 1) new state will be an array
	// for other cases new state will be a string
	public function __call($event, $args) {
		if($this->state) {
			// call state method
			_debug("calling state handler '".(is_array($this->state) ? $this->state[1] : $this->state)."' for incoming event '".$event."'");
			$call = is_callable($this->state) ? $this->state : (method_exists($this, $this->state) ? array(&$this, $this->state): $this->state);
			$r = call_user_func($call, $event, $args);
			
			// 4 cases of possible return value
			if(is_callable($r)) $this->state = $r;
			else if(is_array($r) && sizeof($r) == 2) list($this->state, $ret) = $r;
			else if(is_array($r) && sizeof($r) == 1) $this->state = $r[0];
			else if(is_string($r)) $this->state = $r;
			else $this->handle_invalid_state($r);
			_debug("current state '".(is_array($this->state) ? $this->state[1] : $this->state)."'");
			
			// return case
			if(!is_callable($r) && is_array($r) && sizeof($r) == 2) 
				return $ret;
		}
		else {
			_debug("invalid state found, nothing called for event ".$event."");
		}
	}
	
}

?>
