<?php

session_start();

//Initializing variables

$username ="";
$emaill = "";

$errors = array();

//Connect to the Database

$db = mysqli_connect('localhost', 'USERNAME', 'PASSWORD', 'DATABASE') or die("Could not connect to database");

//Register Users

$username = mysqli_real_escape_string($db, $_POST['username']);
$email = mysqli_real_escape_string($db, $_POST['email']);
$password_1 = mysqli_real_escape_string($db, $_POST['password_1']);
$password_2 = mysqli_real_escape_string($db, $_POST['password_2']);

//Form Validation

if(empty($username)) {array_push($errors, "Username is required")};
if(empty($email)) {array_push($errors, "Email is required")};
if(empty($password_1)) {array_push($errors, "Password is required")};
if($password_1 != $password_2){array_push($errors, "Passwords do not match")};

// Check Database for existing users with similar usernames

$user_check_query = "SELECT * FROM user WHERE username = '$username' or email = '$email' LIMIT 1";

$results = mysqli_query($db, $user_check_query);
$user = mysqli_fetch_assoc($result);

if($user) {

    if($user['username'] === $username){array_push($errors, "Username already exists");}
    if($user['email'] === $email){array_push($errors, "This email is already registered to a username");}

}

//register the userif no error

if(count($errors) == 0){

    $password = md5($password_1); //this will encrpyt the password
    $query = "INSERT INTO user (username, email, password) VALUES ('$username', '$email', '$password')";

    mysqli_query($db,$query);
    $_SESSION['username'] = $username;
    $_SESSION['success'] = "You are now logged in";

    header('location: index.php');

}