<?php
/*Connect to a the database, or it should be in a connect.php file that is included here*/
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "chris";

// Create connection
$mysqli = new mysqli($servername, $username, $password, $dbname);
/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

/*The main register function*/
function register ($mysqli)
{

	/*Check if the request is POST method*/
	if($_POST)
	{
		// Required field names
		$required = array('first_name', 'last_name', 'email', 'password', 'password_verify');

		// Loop over field names, make sure each one exists and is not empty
		foreach($required as $field)
		{
		  if (empty($_POST[$field]))
		  {
			return errorMsg($field." Can't be empty!");
		  }
		}

    /*Escape string to avoid sql injection*/
    $first_name 	  = $mysqli->real_escape_string($_POST['first_name']);
    $last_name      = $mysqli->real_escape_string($_POST['last_name']);
    $email 			    = $mysqli->real_escape_string($_POST['email']);
    $password  		  = $mysqli->real_escape_string($_POST['password']);
    $password_verify= $mysqli->real_escape_string($_POST['password_verify']);

		/*Check if e-mail address syntax is valid or not*/
		$email = filter_var($email, FILTER_SANITIZE_EMAIL); // Sanitizing email(Remove unexpected symbol like <,>,?,#,!, etc.)
		if (!filter_var($email, FILTER_VALIDATE_EMAIL))
		{
			return errorMsg('Invalid Email!');
		}

		/*validate password is confirmed*/
		if($password != $password_verify)
		{
			return errorMsg('Passwords don\'t match!');
		}

    /*Hash password, never ever try to store passwords as plain text in database*/
    $password   = password_hash( $password, PASSWORD_BCRYPT, array('cost' => 11));

    /*Get all records associated with that email*/
    $result = $mysqli->query("SELECT * FROM users WHERE email='$email'");
    $exists = $result->num_rows;

		/*Check if the email is already registered*/
		if($exists!=0)
		{
			return errorMsg('The email is already registered, Please try another one!');
		}

    /*Insert query*/
    $query = $mysqli->query("INSERT INTO users(first_name, last_name, email, password) values ('$first_name', '$last_name', '$email', '$password')");

		/*Success*/
		if($query)
		{
			return successMsg("You have been Successfully Registered");
		}
		else
		{
			/*Failure*/
			errorMsg(mysqli_error($conn));
		}
	}
}

/*Function that returns the error message in JSON format*/
function errorMsg($msg)
{
	print(json_encode(["status" => "error",'message'=> $msg]));
}

/*Function that returns the success message in JSON format*/
function successMsg($msg)
{
	print(json_encode(["status" => "success",'message'=> $msg]));
}

/*Main register function call*/
register($mysqli);

$mysqli->close();

?>