<?php
class MySession
{
    // Creates a session
    function Create($id = NULL, $username = NULL, $password = NULL, $cookie = FALSE) {
        $_SESSION['id']     = $id;
        $_SESSION['username']   = $username;
        $_SESSION['password']   = md5($password);
        $_SESSION['sid']    = md5(rand(1,1000) . rand(1,100) . rand(1,10));
        $insert_session = "UPDATE `users`
                   SET `session_id` = '".mysql_real_escape_string($_SESSION['sid'])."'
                   WHERE `id` = '".mysql_real_escape_string($id)."';";
        mysql_query($insert_session) or die('Error: ' . mysql_error());
        // We create the cookie here
        if($cookie!=FALSE){
        $expire=time()+60*60*24*30;
        setcookie("id",     $_SESSION['id'],    $expire);
        setcookie("username",   $_SESSION['username'],  $expire);
        setcookie("password",   $_SESSION['password'],  $expire);
        setcookie("sid",    $_SESSION['sid'],   $expire);
        }
        // Done Creating a happy cookie
    }
    // Validates a session with the db
    function Validate($id = NULL, $username = NULL, $password = NULL, $sid = NULL) {
        $fail=FALSE;
        if(isset($_SESSION['username'])) {
            $id     = $_SESSION['id'];
            $username   = $_SESSION['username'];
            $password   = $_SESSION['password'];
            $sid        = $_SESSION['sid'];
        }
        elseif(isset($_COOKIE['username'])) {
            $id     = $_COOKIE['id'];
            $username   = $_COOKIE['username'];
            $password   = $_COOKIE['password'];
            $sid        = $_COOKIE['sid'];
        }
        elseif(isset($id)==TRUE && isset($username)==TRUE && isset($password)==TRUE && isset($sid)==TRUE) {
            // do nothing, the values have been passed to this function, validate the values.
        }
        else {
            $fail=TRUE;
        }
        $sql = "SELECT *
                FROM `users`
                WHERE
                `username`  = '".mysql_real_escape_string($username)."' AND
                `password`  = '".mysql_real_escape_string($password)."' AND
                `session_id`    = '".mysql_real_escape_string($sid)."' AND
                `ID`        = '".mysql_real_escape_string($id)."' LIMIT 0,1;";
        $result = mysql_query($sql) or die('Error: ' . mysql_error());
        $count = mysql_num_rows($result);

        if($count==1 && $fail==FALSE) {
            return TRUE;
        }
        else {
            return FALSE;
        }

    }
    // Login the user
    function Login($username = NULL, $password = NULL) {
        $sql =  "SELECT *
                FROM users
                WHERE `username` = '".mysql_real_escape_string($username)."'
                AND `password` = '".md5($password)."'
                LIMIT 0,1;";
        $sqlresult  = mysql_query($sql) or die('Error: ' . mysql_error());
        $count      = mysql_num_rows($sqlresult);
        $user_row   = mysql_fetch_assoc($sqlresult);
        if($count==1) {
            return $user_row['ID'];
        }
        else {
            return FALSE;
        }
    }
    // Logout the user
    function Logout($id = NULL, $username = NULL, $password = NULL, $sid = NULL) {
        if(isset($id)==FALSE && isset($username)==FALSE && isset($password)==FALSE && isset($sid)==FALSE) {
            $id     = $_SESSION['id'];
            $username   = $_SESSION['username'];
            $password   = $_SESSION['password'];
            $sid        = $_SESSION['sid'];
        }
        if(Validate()==TRUE) {
            $sql = "UPDATE `users`
                    SET `session_id` = 'NULL'
                    WHERE `ID` = 'ID';";
            mysql_query($sql);
            session_destroy();
            setcookie("id",     "",     time()-3600);
            setcookie("username",   "",     time()-3600);
            setcookie("password",   "",     time()-3600);
            setcookie("sid",    "",     time()-3600);
            return TRUE;
        } else {
            return FALSE;
        }
    }
}
?>