<?php
/**
 * The language sub-system for handling language strings being used in the
 * application and whole framework
 *
 * @author		Roland Haeder <webmaster@shipsimu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 Core 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 LanguageSystem extends BaseFrameworkSystem implements ManageableLanguage, Registerable {
	/**
	 * The full-qualified base path for the language include files
	 */
	private $languageBasePath = '';

	/**
	 * The 2-char language code
	 */
	private $langCode = 'xx'; // This will later be overwritten!

	/**
	 * The array-object for all language strings
	 */
	private $langStrings = NULL;

	/**
	 * An instance of this class
	 */
	private static $selfInstance = NULL;

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);
	}

	/**
	 * Creates an instance of the class LanguageSystem and prepares it for usage
	 *
	 * @param	$languageBasePath	The local base path for all language strings or emty for auto-detection
	 * @return	$langInstance	An instance of LanguageSystem
	 * @throws	LanguagePathIsEmptyException	If the provided $languageBasePath is empty
	 * @throws	InvalidLanguagePathStringException	If $languageBasePath is no string
	 * @throws	LanguagePathIsNoDirectoryException	If $languageBasePath is no
	 *										directory or not found
	 * @throws	LanguagePathReadProtectedException	If $languageBasePath is
	 *										read-protected
	 */
	public static final function createLanguageSystem ($languageBasePath = '') {
		// Get a new instance
		$langInstance = new LanguageSystem();

		// Is the base path set?
		if (empty($languageBasePath)) {
			// No, then attempt "auto-dection":
			// 1) Get application
			$applicationInstance = Registry::getRegistry()->getInstance('app');

			// 2) Try to build it
			$languageBasePath = sprintf('%sapplication/%s/language/',
				$langInstance->getConfigInstance()->getConfigEntry('base_path'),
				// Don't allow any underscores/dashes in application names
				str_replace(array('_', '-'), array('', ''), $applicationInstance->getAppShortName())
			);
		} // END - if

		// Is the base path valid?
		if (empty($languageBasePath)) {
			// Language path is empty
			throw new LanguagePathIsEmptyException($langInstance, self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
		} elseif (!is_string($languageBasePath)) {
			// Is not a string
			throw new InvalidLanguagePathStringException(array($langInstance, $languageBasePath), self::EXCEPTION_INVALID_STRING);
		} elseif (!is_dir($languageBasePath)) {
			// Is not a path
			throw new LanguagePathIsNoDirectoryException(array($langInstance, $languageBasePath), self::EXCEPTION_INVALID_PATH_NAME);
		} elseif (!is_readable($languageBasePath)) {
			// Is not readable
			throw new LanguagePathReadProtectedException(array($langInstance, $languageBasePath), self::EXCEPTION_READ_PROTECED_PATH);
		}

		// Set the base path
		$langInstance->setLanguageBasePath($languageBasePath);

		// Initialize the variable stack
		$langInstance->initLanguageStrings();

		// Set language code from default config
		$langInstance->setLanguageCode(FrameworkConfiguration::getSelfInstance()->getConfigEntry('default_lang'));

		// Remember this instance
		self::$selfInstance = $langInstance;

		// Return the prepared instance
		return $langInstance;
	}

	/**
	 * Singleton getter for this instance
	 *
	 * @return	$selfInstance	An instance of this class
	 */
	public static final function getSelfInstance () {
		return self::$selfInstance;
	}

	/**
	 * Setter for base path
	 *
	 * @param	$languageBasePath	The relative base path for all language files
	 * @return	void
	 */
	protected final function setLanguageBasePath ($languageBasePath) {
		// And set it
		$this->languageBasePath = (string) $languageBasePath;
	}

	/**
	 * Setter for language code
	 *
	 * @param	$langCode	The language code for the current application
	 * @return	void
	 */
	protected final function setLanguageCode ($langCode) {
		// Cast it
		$langCode = (string) $langCode;

		// And set it (only 2 chars)
		$this->langCode = substr($langCode, 0, 2);
	}

	/**
	 * Initialize the array-object for all later language strings
	 *
	 * @return	void
	 */
	public function initLanguageStrings () {
		$this->langStrings = new FrameworkArrayObject('FakedLanguageStrings');
	}

	/**
	 * Getter for language code
	 *
	 * @return	$langCode	The language code for the current application
	 */
	public final function getLanguageCode () {
		return $this->langCode;
	}

	/**
	 * Get the plain message from the cache variable for the given message id
	 *
	 * @param	$messageId		The message id we shall find in the cache variable
	 * @return	$messageText	The plain message text
	 */
	public function getMessage ($messageId) {
		// Default is missing message text
		$messageText = sprintf('!%s!',
			$messageId
		);

		// Try to look it up in the cache variable
		if ($this->langStrings->offsetExists($messageId)) {
			// Return the message string
			$messageText = $this->langStrings->offsetGet($messageId);
		} // END - if

		// Return the text
		return $messageText;
	}
}

// [EOF]
?>