<?php
//DB.class.php

class DB {

protected $db_name = 'login';
protected $db_user = 'testuser';
protected $db_pass = 'password';
protected $db_host = 'localhost';

//open a connection to the database. Make sure this is called
//on every page that needs to use the database.
public function connect() {
$connection = mysql_connect($this->db_host, $this->db_user, $this->db_pass);
mysql_select_db($this->db_name);

return true;
}

//takes a mysql row set and returns an associative array, where the keys
//in the array are the column names in the row set. If singleRow is set to
//true, then it will return a single row instead of an array of rows.
public function processRowSet($rowSet, $singleRow=false)
{
$resultArray = array();
while($row = mysql_fetch_assoc($rowSet))
{
array_push($resultArray, $row);
}

if($singleRow === true)
return $resultArray[0];

return $resultArray;
}

//Select rows from the database.
//returns a full row or rows from $table using $where as the where clause.
//return value is an associative array with column names as keys.
public function select($table) {
$sql = "SELECT * FROM $table";
$result = mysql_query($sql);
if(mysql_num_rows($result) == 1)
return $this->processRowSet($result, true);

return $this->processRowSet($result);
}

//Updates a current row in the database.
//takes an array of data, where the keys in the array are the column names
//and the values are the data that will be inserted into those columns.
//$table is the name of the table and $where is the sql where clause.
public function update($data, $table, $where) {
foreach ($data as $column => $value) {
$sql = "UPDATE $table SET $column = $value WHERE $where";
mysql_query($sql) or die(mysql_error());
}
return true;
}

//Inserts a new row into the database.
//takes an array of data, where the keys in the array are the column names
//and the values are the data that will be inserted into those columns.
//$table is the name of the table.
public function insert($data, $table) {

$columns = "";
$values = "";

foreach ($data as $column => $value) {
$columns .= ($columns == "") ? "" : ", ";
$columns .= $column;
$values .= ($values == "") ? "" : ", ";
$values .= $value;
}

$sql = "insert into $table ($columns) values ($values)";

mysql_query($sql) or die(mysql_error());

//return the ID of the user in the database.
return mysql_insert_id();

}
}
?>

<?php
//User.class.php

//import
require_once ('DB.class.php');

class User {

public $id;
public $username;
public $hashedPassword;
public $email;
public $joinDate;

//Constructor is called whenever a new object is created.
//Takes an associative array with the DB row as an argument.
function __construct($data) {
$this->id = (isset($data['id'])) ? $data['id'] : "";
$this->username = (isset($data['username'])) ? $data['username'] : "";
$this->hashedPassword = (isset($data['password'])) ? $data['password'] : "";
$this->email = (isset($data['email'])) ? $data['email'] : "";
$this->joinDate = (isset($data['join_date'])) ? $data['join_date'] : "";
}

public function save($isNewUser = false) {
//create a new database object.
$db = new DB();

//if the user is already registered and we're
//just updating their info.
if(!$isNewUser) {
//set the data array
$data = array(
"username" => "'$this->username'",
"password" => "'$this->hashedPassword'",
"email" => "'$this->email'"
);

//update the row in the database
$db->update($data, 'users', 'id = '.$this->id);
}else {
//if the user is being registered for the first time.
$data = array(
"username" => "'$this->username'",
"password" => "'$this->hashedPassword'",
"email" => "'$this->email'",
"join_date" => "'".date("Y-m-d H:i:s",time())."'"
);

$this->id = $db->insert($data, 'users');
$this->joinDate = time();
}
return true;
}

}

?>

<?php
//UserTools.class.php

//import
require_once ('User.class.php');
require_once ('DB.class.php');

class UserTools {

//Log the user in. First checks to see if the
//username and password match a row in the database.
//If it is successful, set the session variables
//and store the user object within.
public function login($username, $password)
{

$hashedPassword = md5($password);
$result = mysql_query("SELECT * FROM users WHERE username = '$username' AND password = '$hashedPassword'");

if(mysql_num_rows($result) == 1)
{
$_SESSION["user"] = serialize(new User(mysql_fetch_assoc($result)));
$_SESSION["login_time"] = time();
$_SESSION["logged_in"] = 1;
return true;
}else{
return false;
}
}

//Log the user out. Destroy the session variables.
public function logout() {
unset($_SESSION['user']);
unset($_SESSION['login_time']);
unset($_SESSION['logged_in']);
session_destroy();
}

//Check to see if a username exists.
//This is called during registration to make sure all user names are unique.
public function checkUsernameExists($username) {
$result = mysql_query("select id from users where username='$username'");
if(mysql_num_rows($result) == 0)
{
return false;
}else{
return true;
}
}

//get a user
//returns a User object. Takes the users id as an input
public function get($id)
{
$db = new DB();
$result = $db->select('users', "id = $id");

return new User($result);
}

}

?>

<?php
//global.inc.php

//import
require_once ('classes/User.class.php');
require_once ('classes/UserTools.class.php');
require_once ('classes/DB.class.php');

//connect to the database
$db = new DB();
$db->connect();

//initialize UserTools object
$userTools = new UserTools();

//start the session
session_start();

//refresh session variables if logged in
if(isset($_SESSION['logged_in'])) {
$user = unserialize($_SESSION['user']);
$_SESSION['user'] = serialize($userTools->get($user->id));
}
?>

<?php
//register.php

require_once ('includes/global.inc.php');

//initialize php variables used in the form
$username = "";
$password = "";
$password_confirm = "";
$email = "";
$error = "";

//check to see that the form has been submitted
if(isset($_POST['submit-form'])) {

//retrieve the $_POST variables
$username = $_POST['username'];
$password = $_POST['password'];
$password_confirm = $_POST['password-confirm'];
$email = $_POST['email'];

//initialize variables for form validation
$success = true;
$userTools = new UserTools();

//validate that the form was filled out correctly
//check to see if user name already exists
if($userTools->checkUsernameExists($username))
{
$error .= "That username is already taken.</br> \n\r";
$success = false;
}

//check to see if passwords match
if($password != $password_confirm) {
$error .= "Passwords do not match.</br> \n\r";
$success = false;
}

if($success)
{
//prep the data for saving in a new user object
$data['username'] = $username;
$data['password'] = md5($password); //encrypt the password for storage
$data['email'] = $email;

//create the new user object
$newUser = new User($data);

//save the new user to the database
$newUser->save(true);

//log them in
$userTools->login($username, $password);

//redirect them to a welcome page
header("Location: welcome.php");

}

}

//If the form wasn't submitted, or didn't validate
//then we show the registration form again
?>

<html>
<head>
<title>Registration</title>
</head>
<body>
<?php echo ($error != "") ? $error : ""; ?>
<form action="register.php" method="post">

Username: <input type="text" value="<?php echo $username; ?>" name="username" /></br>
Password: <input type="password" value="<?php echo $password; ?>" name="password" /></br>
Password (confirm): <input type="password" value="<?php echo $password_confirm; ?>" name="password-confirm" /></br>
E-Mail: <input type="text" value="<?php echo $email; ?>" name="email" /></br>
<input type="submit" value="Register" name="submit-form" />

</form>
</body>
</html>

<?php
//login.php

require_once ('includes/global.inc.php');

$error = "";
$username = "";
$password = "";

//check to see if they've submitted the login form
if(isset($_POST['submit-login'])) {

$username = $_POST['username'];
$password = $_POST['password'];

$userTools = new UserTools();
if($userTools->login($username, $password)){
//successful login, redirect them to a page
header("Location: index.php");
}else{
$error = "Incorrect username or password. Please try again.";
}
}
?>

<html>
<head>
<title>Login</title>
</head>
<body>
<?php
if($error != "")
{
echo $error."</br>";
}
?>
<form action="login.php" method="post">
Username: <input type="text" name="username" value="<?php echo $username; ?>" /></br>
Password: <input type="password" name="password" value="<?php echo $password; ?>" /></br>
<input type="submit" value="Login" name="submit-login" />
</form>
</body>
</html>

<?php
//logout.php
require_once 'includes/global.inc.php';

$userTools = new UserTools();
$userTools->logout();

header("Location: index.php");

?>

<?php
//settings.php

require_once ('includes/global.inc.php');

//check to see if they're logged in
if(!isset($_SESSION['logged_in'])) {
header("Location: login.php");
}

//get the user object from the session
$user = unserialize($_SESSION['user']);

//initialize php variables used in the form
$email = $user->email;
$message = "";

//check to see that the form has been submitted
if(isset($_POST['submit-settings'])) {

//retrieve the $_POST variables
$email = $_POST['email'];

$user->email = $email;
$user->save();

$message = "Settings Saved</br>";
}

//If the form wasn't submitted, or didn't validate
//then we show the registration form again
?>

<html>
<head>
<title>Change Settings</title>
</head>
<body>
<?php echo $message; ?>

<form action="settings.php" method="post">

E-Mail: <input type="text" value="<?php echo $email; ?>" name="email" /></br>
<input type="submit" value="Update" name="submit-settings" />

</form>
</body>
</html>

<?php
//welcome.php

require_once ('includes/global.inc.php');

//check to see if they're logged in
if(!isset($_SESSION['logged_in'])) {
header("Location: login.php");
}

//get the user object from the session
$user = unserialize($_SESSION['user']);

?>

<html>
<head>
<title>Welcome <?php echo $user->username; ?></title>
</head>
<body>
Hey there, <?php echo $user->username; ?>. You've been registered and logged in. Welcome! <a href="logout.php">Log Out</a> | <a href="index.php">Return to Homepage</a>
</body>
</html>

<?php
//index.php

require_once ('includes/global.inc.php');
?>

<html>
<head>
<title>Homepage</title>
</head>
<body>

<?php if(isset($_SESSION['logged_in'])) : ?>
<?php $user = unserialize($_SESSION['user']); ?>
Hello, <?php echo $user->username; ?>. You are logged in. <a href="logout.php">Logout</a> | <a href="settings.php">Change Email</a>
<?php else : ?>
You are not logged in. <a href="login.php">Log In</a> | <a href="register.php">Register</a>
<?php endif; ?>
</body>
</html>