<?php

    /*
        This register.php script was inspired by https://www.w3schools.com/php/php_mysql_insert.asp
    */

    //Define and initialize variables to connect to database server
    $servername = "localhost";
    $username = "id1148117_xirokx";
    $password = "project";
    $dbName = "id1148117_login";

    //Create new database connection
    $con = mysqli_connect($servername, $username, $password, $dbName);

    //check connection - If database connection unsuccessful display error = connection failed
    if ($con->connect_error) {
        die("Connection failed: " . $con->connect_error);
    }


    //use Php ISSET() function to check that form variables contain values and are not empty
    //when passing data from my login form to this Php script to avoid empty values being stored in database tables
    if(isset($_POST["username"]) && isset($_POST["password"]) && isset($_POST["name"]) && isset($_POST["age"])) {

        //define and intialize variables that are to be used with this Php script
        //send ("POST") the data obtained from user form in my application, to my web server
        $name = $_POST["name"];
        $age = $_POST["age"];
        $username = $_POST["username"];
        $password = $_POST["password"];

        //Create a "prepare" SQL statement to be used as a template for INSERTing data into database table
        //the database will only accept the values for variables defined above so will protect against SQL Injection
        $statement = mysqli_prepare($con, "INSERT INTO user (name, username, age, password) VALUES (?, ?, ?, ?)");

        //attaches ("bind's") my form variables to my SQL query
        mysqli_stmt_bind_param($statement, "ssis", $name, $username, $age, $password);

        //executes the SQL query
        //At this point the user form values contained in these variables is INSERTED into my database table
        //under the correct table fields.
        mysqli_stmt_execute($statement);

        //declare and initialize a list to store SQL prepared statement result
        $response = array();

        //return true and store the word "success" in above list if my SQL statement successfully INSERTED data into my table.
        $response["success"] = true;

        //encode the Php String response as a JSON object which is returned to my mobile application
        //a JSON object is returned so my mobile application can easily read and work with it as a "String"
        echo json_encode($response);

    }
    //if form variables are empty then respond with an error
    else {
        echo json_encode ("please ensure all form values are complete to proceed");
    }

    //Close database connection to service further db requests and
    //avoid application from slowing down
    $conn->close();
?>