<?php
/**
 * A generic state resolver class
 *
 * @author		Roland Haeder <webmaster@shipsimu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 Hub Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.shipsimu.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
class BaseStateResolver extends BaseResolver {
	/**
	 * Prefix for local, remote or other resolver
	 */
	private $statePrefix = '';

	/**
	 * Validated state name
	 */
	private $stateName = '';

	/**
	 * Protected constructor
	 *
	 * @param	$className	Name of the real class
	 * @return	void
	 */
	protected function __construct ($className) {
		// Call parent constructor
		parent::__construct($className);
	}

	/**
	 * Setter for state prefix
	 *
	 * @param	$statePrefix	Last validated statePrefix
	 * @return	void
	 */
	protected final function setStatePrefix ($statePrefix) {
		$this->statePrefix = $statePrefix;
	}

	/**
	 * Getter for state prefix
	 *
	 * @param	$statePrefix	Last validated statePrefix
	 * @return	void
	 */
	protected final function getStatePrefix () {
		return $this->statePrefix;
	}

	/**
	 * Setter for state name
	 *
	 * @param	$stateName		Last validated state name
	 * @return	void
	 */
	protected final function setStateName ($stateName) {
		$this->stateName = $stateName;
	}

	/**
	 * Getter for state name
	 *
	 * @return	$stateName	Last validated state name
	 */
	public final function getStateName () {
		return $this->stateName;
	}

	/**
	 * "Loads" a given state and instances it if not yet cached. If the
	 * state was not found an UnresolveableStateException is thrown
	 *
	 * @param	$stateName			A state name we shall look for
	 * @return	$stateInstance		A loaded state instance
	 * @throws	UnresolveableStateException		Thrown if even the requested
	 *											state class is missing (bad!)
	 */
	protected function loadState ($stateName) {
		// Init state instance
		$stateInstance = NULL;

		// Create state class name
		$className = $this->getStatePrefix() . '' . self::convertToClassName($stateName) . 'State';

		// ... and set it
		$this->setClassName($className);

		// Is this class loaded?
		if (!class_exists($this->getClassName())) {
			// Throw an exception here
			throw new UnresolveableStateException(array($this, $stateName), self::EXCEPTION_INVALID_STATE);
		} // END - if

		// Initialize the state
		$stateInstance = ObjectFactory::createObjectByName(
			$this->getClassName(),
			array($this)
		);

		// Return the result
		return $stateInstance;
	}

	/**
	 * Checks whether the given state is valid
	 *
	 * @param	$stateName				The default state we shall execute
	 * @return	$isValid				Whether the given state is valid
	 * @throws	EmptyVariableException	Thrown if given state is not set
	 * @throws	DefaultStateException	Thrown if default state was not found
	 */
	public function isStateValid ($stateName) {
		// By default nothing shall be valid
		$isValid = FALSE;

		// Is a state set?
		if (empty($stateName)) {
			// Then thrown an exception here
			throw new EmptyVariableException(array($this, 'stateName'), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
		} // END - if

		// Create class name
		$className = $this->statePrefix . self::convertToClassName($stateName) . 'State';

		// Now, let us create the full name of the state class
		$this->setClassName($className);

		// Try it hard to get an state
		while ($isValid === FALSE) {
			// Is this class already loaded?
			if (class_exists($this->getClassName())) {
				// This class does exist. :-)
				$isValid = TRUE;
			} elseif ($this->getClassName() != $this->statePrefix . 'DefaultState') {
				// Set default state
				$this->setClassName($this->statePrefix . 'DefaultState');
			} else {
				// All is tried, give it up here
				throw new DefaultStateException($this, self::EXCEPTION_DEFAULT_STATE_GONE);
			}
		} // END - while

		// Return the result
		return $isValid;
	}
}

// [EOF]
?>