<?php
/**
 * A class for the configuration stuff implemented in a singleton design paddern
 *
 * NOTE: We cannot put this in inc/classes/ because it would be loaded (again) in
 * class loader. See inc/loader/class_ClassLoader.php for instance
 *
 * @see			ClassLoader
 * @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 FrameworkConfiguration implements Registerable {
	/**
	 * The framework's main configuration array which will be initialized with
	 * hard-coded configuration data and might be overwritten/extended by
	 * config data from the database.
	 */
	private $config = array();

	/**
	 * The configuration instance itself
	 */
	private static $configInstance = NULL;

	// Some constants for the configuration system
	const EXCEPTION_CONFIG_KEY_IS_EMPTY           = 0x130;
	const EXCEPTION_CONFIG_KEY_WAS_NOT_FOUND      = 0x131;
	const EXCEPTION_CONFIG_VALUE_TYPE_UNSUPPORTED = 0x132;

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Empty for now
	}

	/**
	 * Compatiblity method to return this class' name
	 *
	 * @return	__CLASS__	This class' name
	 */
	public function __toString () {
		return get_class($this);
	}

	/**
	 * Getter for a singleton instance of this class
	 *
	 * @return	$configInstance		A singleton instance of this class
	 */
	public static final function getSelfInstance () {
		// is the instance there?
		if (is_null(self::$configInstance))  {
			// Create a config instance
			self::$configInstance = new FrameworkConfiguration();
		} // END - if

		// Return singleton instance
		return self::$configInstance;
	}

	/**
	 * Converts dashes to underscores, e.g. useable for configuration entries
	 *
	 * @param	$str	The string with maybe dashes inside
	 * @return	$str	The converted string with no dashed, but underscores
	 */
	private final function convertDashesToUnderscores ($str) {
		// Convert them all
		$str = str_replace('-', '_', $str);

		// Return converted string
		return $str;
	}

	/**
	 * Setter for default time zone (must be correct!)
	 *
	 * @param	$zone	The time-zone string (e.g. Europe/Berlin)
	 * @return	void
	 */
	public final function setDefaultTimezone ($zone) {
		// Is PHP version 5.1.0 or higher? Older versions are being ignored
		if (version_compare(phpversion(), '5.1.0', '>=')) {
			/*
			 * Set desired time zone to prevent date() and related functions to
			 * issue a E_WARNING.
			 */
			date_default_timezone_set($zone);
		} // END - if
	}

	/**
	 * Setter for runtime magic quotes
	 *
	 * @param	$enableQuotes	Whether enable magic runtime quotes (should be disabled for security reasons)
	 * @return	void
	 * @todo	This method encapsulates a deprecated PHP function and should be deprecated, too.
	 */
	public final function setMagicQuotesRuntime ($enableQuotes) {
		// Is the PHP version < 5.4?
		if (version_compare(phpversion(), '5.4', '>=')) {
			// Then silently skip this part as set_magic_quotes_runtime() is deprecated
			return;
		} // END - if

		// Cast it to boolean
		$enableQuotes = (boolean) $enableQuotes;

		// Set it
		set_magic_quotes_runtime($enableQuotes);
	}

	/**
	 * Checks whether the given configuration key is set
	 *
	 * @param	$configKey	The configuration key we shall check
	 * @return	$isset		Whether the given configuration key is set
	 */
	public function isConfigurationEntrySet ($configKey) {
		// Is it set?
		$isset = isset($this->config[$configKey]);

		// Return the result
		return $isset;
	}

	/**
	 * Read a configuration element.
	 *
	 * @param	$configKey		The configuration element
	 * @return	$configValue	The fetched configuration value
	 * @throws	ConfigEntryIsEmptyException		If $configKey is empty
	 * @throws	NoConfigEntryException			If a configuration element was not found
	 */
	public function getConfigEntry ($configKey) {
		// Convert dashes to underscore
		$configKey = $this->convertDashesToUnderscores($configKey);

		// Is a valid configuration key provided?
		if (empty($configKey)) {
			// Entry is empty
			throw new ConfigEntryIsEmptyException($this, self::EXCEPTION_CONFIG_KEY_IS_EMPTY);
		} elseif (!$this->isConfigurationEntrySet($configKey)) {
			// Entry was not found!
			throw new NoConfigEntryException(array(__CLASS__, $configKey), self::EXCEPTION_CONFIG_KEY_WAS_NOT_FOUND);
		}

		// Return the requested value
		return $this->config[$configKey];
	}

	/**
	 * Set a configuration key
	 *
	 * @param	$configKey	The configuration key we want to add/change
	 * @param	$configValue	The configuration value we want to set
	 * @return	void
	 * @throws	ConfigEntryIsEmptyException			If $configKey is empty
	 * @throws	ConfigValueTypeUnsupportedException	If $configValue has an unsupported variable type
	 */
	public final function setConfigEntry ($configKey, $configValue) {
		// Cast to string
		$configKey = $this->convertDashesToUnderscores($configKey);

		// Is a valid configuration key key provided?
		if ((empty($configKey)) || (!is_string($configKey))) {
			// Entry is empty
			throw new ConfigEntryIsEmptyException($this, self::EXCEPTION_CONFIG_KEY_IS_EMPTY);
		} elseif ((is_null($configValue)) || (is_array($configValue)) || (is_object($configValue)) || (is_resource($configValue))) {
			// These cannot be set as this is not intended for configuration values, please use FrameworkArrayObject instead.
			throw new ConfigValueTypeUnsupportedException(array($this, $configKey, $configValue), self::EXCEPTION_CONFIG_VALUE_TYPE_UNSUPPORTED);
		}

		// Set the configuration value
		//* NOISY-DEBUG: */ print(__METHOD__ . ':configEntry=' . $configKey . ',configValue[' . gettype($configValue) . ']=' . $configValue . PHP_EOL);
		$this->config[$configKey] = $configValue;

		// Resort the array
		ksort($this->config);
	}

	/**
	 * Unset a configuration key, the entry must be there or else an
	 * exception is thrown.
	 *
	 * @param	$configKey	Configuration key to unset
	 * @return	void
	 * @throws	NoConfigEntryException	If a configuration element was not found
	 */
	public final function unsetConfigEntry ($configKey) {
		// Convert dashes to underscore
		$configKey = $this->convertDashesToUnderscores($configKey);

		// Is the configuration key there?
		if (!$this->isConfigurationEntrySet($configKey)) {
			// Entry was not found!
			throw new NoConfigEntryException(array(__CLASS__, $configKey), self::EXCEPTION_CONFIG_KEY_WAS_NOT_FOUND);
		} // END - if

		// Unset it
		unset($this->config[$configKey]);
	}

	/**
	 * Detects the server address (SERVER_ADDR) and set it in configuration
	 *
	 * @return	$serverAddress	The detected server address
	 * @todo	We have to add some more entries from $_SERVER here
	 */
	public function detectServerAddress () {
		// Is the entry set?
		if (!$this->isConfigurationEntrySet('server_addr')) {
			// Is it set in $_SERVER?
			if (isset($_SERVER['SERVER_ADDR'])) {
				// Set it from $_SERVER
				$this->setServerAddress($_SERVER['SERVER_ADDR']);
			} elseif (class_exists('ConsoleTools')) {
				// Run auto-detecting through console tools lib
				ConsoleTools::acquireSelfIPAddress();
			}
		} // END - if

		// Now get it from configuration
		$serverAddress = $this->getServerAddress();

		// Return it
		return $serverAddress;
	}

	/**
	 * Setter for SERVER_ADDR
	 *
	 * @param	$serverAddress	New SERVER_ADDR value to set
	 * @return	void
	 */
	public function setServerAddress ($serverAddress) {
		$this->setConfigEntry('server_addr', (string) $serverAddress);
	}

	/**
	 * Getter for SERVER_ADDR
	 *
	 * @return	$serverAddress	New SERVER_ADDR value to set
	 */
	public function getServerAddress () {
		return $this->getConfigEntry('server_addr');
	}

	/**
	 * Detects the HTTPS flag
	 *
	 * @return	$https	The detected HTTPS flag or null if failed
	 */
	public function detectHttpSecured () {
		// Default is null
		$https = NULL;

		// Is HTTPS set?
		if ($this->isHttpSecured()) {
			// Then use it
			$https = $_SERVER['HTTPS'];
		} // END - if

		// Return it
		return $https;
	}

	/**
	 * Checks whether HTTPS is set in $_SERVER
	 *
	 * @return $isset	Whether HTTPS is set
	 */
	public function isHttpSecured () {
		return (isset($_SERVER['HTTPS']));
	}

	/**
	 * Dectect and return the base URL for all URLs and forms
	 *
	 * @return	$baseUrl	Detected base URL
	 */
	public function detectBaseUrl () {
		// Initialize the URL
		$baseUrl = 'http';

		// Do we have HTTPS?
		if ($this->isHttpSecured()) {
			// Add the >s< for HTTPS
			$baseUrl .= 's';
		} // END - if

		// Construct the full URL and secure it against CSRF attacks
		$baseUrl = $baseUrl . '://' . $this->detectDomain() . $this->detectScriptPath();

		// Return the URL
		return $baseUrl;
	}

	/**
	 * Detect safely and return the full domain where this script is installed
	 *
	 * @return	$fullDomain		The detected full domain
	 */
	public function detectDomain () {
		// Full domain is localnet.invalid by default
		$fullDomain = 'localnet.invalid';

		// Is the server name there?
		if (isset($_SERVER['SERVER_NAME'])) {
			// Detect the full domain
			$fullDomain = htmlentities(strip_tags($_SERVER['SERVER_NAME']), ENT_QUOTES);
		} // END - if

		// Return it
		return $fullDomain;
	}

	/**
	 * Detect safely the script path without trailing slash which is the glue
	 * between "http://your-domain.invalid/" and "script-name.php"
	 *
	 * @return	$scriptPath		The script path extracted from $_SERVER['SCRIPT_NAME']
	 */
	public function detectScriptPath () {
		// Default is empty
		$scriptPath = '';

		// Is the scriptname set?
		if (isset($_SERVER['SCRIPT_NAME'])) {
			// Get dirname from it and replace back-slashes with slashes for lame OSes...
			$scriptPath = str_replace("\\", '/', dirname($_SERVER['SCRIPT_NAME']));
		} // END - if

		// Return it
		return $scriptPath;
	}

	/**
	 * Getter for field name
	 *
	 * @param	$fieldName		Field name which we shall get
	 * @return	$fieldValue		Field value from the user
	 * @throws	NullPointerException	If the result instance is null
	 */
	public final function getField ($fieldName) {
		// Our super interface "FrameworkInterface" requires this
	}

	/**
	 * Checks if given field is set
	 *
	 * @param	$fieldName	Field name to check
	 * @return	$isSet		Whether the given field name is set
	 * @throws	NullPointerException	If the result instance is null
	 */
	public function isFieldSet ($fieldName) {
		// Our super interface "FrameworkInterface" requires this
	}

	/**
	 * Generates a code for hashes from this class
	 *
	 * @return	$hashCode	The hash code respresenting this class
	 */
	public function hashCode () {
		return crc32($this->__toString());
	}

	/**
	 * Checks whether an object equals this object. You should overwrite this
	 * method to implement own equality checks
	 *
	 * @param	$objectInstance		An instance of a FrameworkInterface object
	 * @return	$equals				Whether both objects equals
	 */
	public function equals (FrameworkInterface $objectInstance) {
		// Now test it
		$equals = ((
			$this->__toString() == $objectInstance->__toString()
		) && (
			$this->hashCode() == $objectInstance->hashCode()
		));

		// Return the result
		return $equals;
	}
}

// [EOF]
?>