<?php

namespace Vn\Lib;

require_once ('vn/lib/method.php');
require_once ('vn/lib/locale.php');
require_once ('vn/db/db.php');

use Vn\Db\Conn;
use Vn\Lib\Locale;

if (!defined ('_DEBUG_MODE'))
	define ('_DEBUG_MODE', FALSE);
if (!defined ('_CONFIG_DIR'))
	define ('_CONFIG_DIR', '/etc');
if (!defined ('_LOG_DIR'))
	define ('_LOG_DIR', '/var/log');

/**
 * Exception thrown when user credentials could not be fetched.
 **/
class SessionExpiredException extends \Exception {}

/**
 * Exception thrown when user credentials are invalid.
 **/
class BadLoginException extends \Exception {}

/**
 * Base class for applications.
 **/
class App
{
	protected $conn = NULL;
	protected $name;
	private $conf = NULL;
	private $sysConn = NULL;
	
	/**
	 * Creates e new application object.
	 *
	 * @param name string The application name
	 **/
	function __construct ($name)
	{
		$this->name = $name;
	}

	/**
	 * Initializes Application. Should be the first called function in any 
	 * application that uses this class.
	 **/
	function init ()
	{
		ini_set ('log_errors', TRUE);
//		ini_set ('error_log', _LOG_DIR .'/'. $this->name .'.log');

		$configFile = $this->getConfigFile ();
		$this->conf = include ($configFile);

		register_shutdown_function ([$this, 'deinit']);
	}

	/**
	 * Deinitializes the Application. When init method is called, this 
	 * function is called automatically at the end of the script .
	 **/
	function deinit ()
	{
		if ($this->sysConn)
		{
			$this->sysConn->close ();
			$this->sysConn = NULL;
		}
	}
	
	/**
	 * Obtains the application version number. It is based on de last
	 * modification date of the main script.
	 **/
	function getVersion ()
	{
		return (int) filectime (__FILE__);
	}

	/**
	 * Gets the configuration file name.
	 **/
	function getConfigFile ()
	{
		$configDir = _CONFIG_DIR .'/'. $this->name;
		$customFile =  "$configDir/config.my.php";

		if (file_exists ($customFile))
			return $customFile;
		else
			return "$configDir/config.php";
	}

	/**
	 * Creates a new connection object using the configuration parameters and
	 * the passed user and password.
	 **/
	function createConnection ($user, $password, $persistent = FALSE)
	{
		$dbConf = $this->conf['db'];
		$host = $dbConf['host'];
		
		if ($persistent)
			$host = 'p:'.$host;
		
		$conn = new Conn ();
		$conn->open (
			 $host
			,$user
			,$password
			,$dbConf['schema']
			,$dbConf['port']
		);
		$conn->query ('SET @lang = #', [Locale::get ()]);
		return $conn;
	}
	
	/**
	 * Opens the system database connection.
	 *
	 * @return Vn\Db\Conn The connection
	 **/
	function getSysConn ()
	{
		if (!$this->sysConn)
		{
			$dbConf = $this->conf['db'];
			$this->sysConn = $this->createConnection (
				$dbConf['user'], base64_decode ($dbConf['pass']), TRUE);
		}

		return $this->sysConn;
	}

	/**
	 * Starts the application. Should be implemented by child classes.
	 **/
	function run () {}
	
	/**
	 * Authenticates the user. Should be reimplemented by child classes.
	 **/
	function login () {}
	
	/**
	 * Deauthenticates the user. Should be reimplemented by child classes.
	 **/
	function logout () {}

	/**
	 * Runs a method.
	 **/
	function runMethod ($baseDir, $methodName)
	{
		if (empty ($methodName))
			throw new \Exception ('Method not defined');
		if (!isHyphen ($methodName))
			throw new \Exception ('Method contains invalid characters');

		$className = hyphenToCamelCase ($methodName, TRUE);
		$methodFile = "$baseDir/$methodName.php";		
		include_once ($methodFile);

		if (!class_exists ($className))
			throw new \Exception ('Method class not exists');
		if (!is_subclass_of ($className, __NAMESPACE__ .'\Method'))
			throw new \Exception ('Class is not a Method class child');

		Locale::addPath ("$baseDir/$methodName");
		return new $className ($this);
	}
	
}

?>