<?php

class Database
{

    protected static $instance = null;

    final private function __construct()
    {

    }

    final private function __clone()
    {

    }

    /**
     * @return PDO
     */
    public static function instance()
    {
        if (self::$instance === null) {
            try {
                self::$instance = new PDO(DB_DSN, DB_USER, DB_PASS, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'"));
                self::$instance->setAttribute(PDO::ATTR_PERSISTENT, true);
                /*                 * ************************** Persient tilkoblinger * */
                #self::$instance->setAttribute(PDO::MYSQL_ATTR_INIT_COMMAND, "SET NAMES 'utf8'"); /****** UTF-8                 **/
                self::$instance->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
                /*                 * *********** Feilmeldingsmodus     * */
                self::$instance->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);
                /*                 * ************ Mysql buffered query  * */
                self::$instance->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
                /*                 * ****** Default fetch metode  * */
            } catch (PDOException $e) {
                die('Kunne ikke opprette tilkobling til databasen!');
            }
        }
        return self::$instance;
    }

    /**
     * Update
     *
     * @access public
     */
    public static function update($table, $values, $where)
    {
        try {
            if (gettype($values) !== 'array') {
                exit('Upt: Param må være aray!');
            }
            $sql = 'UPDATE ' . $table . ' SET ';
            $fields = array();
            foreach ($values as $key => $value) {
                if (gettype($value) === 'string')
                    $y = '\'' . $value . '\'';
                array_push($fields, ($key . '=' . $value));
            }
            $update = implode(', ', $fields);
            $sql = $sql . $update . ' WHERE ' . $where;
            return self::$instance->query($sql);
        } catch (Exception $e) {
            return $e->getMessage() . ':' . $e->getLine();
        }
    }

    /**
     * @return PDOStatement
     */
    public static function q($query)
    {
        if (func_num_args() == 1) {
            return self::instance()->query($query);
        }
        $args = func_get_args();
        return self::instance()->query(self::autoQuote(array_shift($args), $args));
    }

    public static function x($query)
    {
        if (func_num_args() == 1) {
            return self::instance()->exec($query);
        }
        $args = func_get_args();
        return self::instance()->exec(self::autoQuote(array_shift($args), $args));
    }

    public static function autoQuote($query, array $args)
    {
        $i = strlen($query) - 1;
        $c = count($args);
        while ($i--) {
            if ('?' === $query[$i] && false !== $type = strpos('sia', $query[$i + 1])) {
                if (--$c < 0) {
                    throw new InvalidArgumentException('For få parametere!');
                }
                if (0 === $type) {
                    $replace = self::instance()->quote($args[$c]);
                }
                elseif (1 === $type) {
                    $replace = intval($args[$c]);
                }
                elseif (2 === $type) {
                    foreach ($args[$c] as &$value) {
                        $value = self::instance()->quote($value);
                    }
                    $replace = '(' . implode(',', $args[$c]) . ')';
                }
                $query = substr_replace($query, $replace, $i, 2);
            }
        }
        if ($c > 0) {
            throw new InvalidArgumentException('For mange parametere!');
        }
        return $query;
    }

    public static function beginTransaction()
    {
        return self::instance()->beginTransaction();
    }

    public static function commit()
    {
        return self::instance()->commit();
    }

    public static function errorCode()
    {
        return self::instance()->errorCode();
    }

    public static function errorInfo()
    {
        return self::instance()->errorInfo();
    }

    public static function exec($statement)
    {
        return self::instance()->exec($statement);
    }

    public static function getAttribute($attribute)
    {
        return self::instance()->getAttribute($attribute);
    }

    public static function getAvailableDrivers()
    {
        return self::instance()->getAvailableDrivers();
    }

    public static function inTransaction()
    {
        return self::instance()->inTransaction();
    }

    public static function lastInsertId($name = NULL)
    {
        return self::instance()->lastInsertId($name);
    }

    public static function prepare($statement, $driver_options = array())
    {
        return self::instance()->prepare($statement, $driver_options);
    }

    public static function query()
    {
        $arguments = func_get_args();
        return call_user_func_array(array(self::instance(), 'query'), $arguments);
    }

    public static function quote($string, $parameter_type = PDO::PARAM_STR)
    {
        return self::instance()->quote($string, $parameter_type);
    }

    public static function rollBack()
    {
        return self::instance()->rollBack();
    }

    public static function setAttribute($attribute, $value)
    {
        return self::instance()->setAttribute($attribute, $value);
    }

    public static function Rows()
    {
        $row = self::instance()->query('SELECT found_rows() AS rows');
        foreach ($row->fetchAll(PDO::FETCH_OBJ) as $obj)
            $rowsAntall = $obj->rows;
        $row->closeCursor();
        return $rowsAntall;
    }

}