<?php
    $con =  mysqli_connect("localhost", "mpampis", "abcd1234", "quiz");
    mysqli_set_charset($con, 'utf8');

    $username = $_POST["username"];
    $password = $_POST["password"];
    function get_salt(){
        global $username,$con;
        $query = mysqli_prepare($con, "select salt FROM users WHERE username = ?");
        mysqli_stmt_bind_param($query, "s", $username);
        mysqli_stmt_execute($query);
        mysqli_stmt_store_result($query);
        mysqli_stmt_bind_result($query, $salt);
        mysqli_stmt_fetch($query);
        return $salt;
    }



    $salt = get_salt();
    $combine = $salt . $password;
    $password_hash = md5($combine);
    $statement = mysqli_prepare($con, "select firstname,lastname,username,age FROM users WHERE username = ? AND password = ?");
    mysqli_stmt_bind_param($statement, "ss", $username, $password_hash);
    mysqli_stmt_execute($statement);
    mysqli_stmt_store_result($statement);
    mysqli_stmt_bind_result($statement, $firstname, $lastname, $username, $age);

    $response = array();
    $response["success"] = false;
    while(mysqli_stmt_fetch($statement)){
        $response["success"] = true;
        $response["firstname"] = $firstname;
        $response["lastname"] = $lastname;
        $response["username"] = $username;
        $response["age"] = $age;
    }

    echo json_encode($response);


?>