Variety of Functions

//Variety of functions for signup and login system

# Checking if any of the fields have been left blank
    function emptyInputSignup($fname, $lname, $uname, $email, $pwd, $rpwd){
        $result;
        if(empty($fname) || empty($lname) || empty($uname) || empty($email) || empty($pwd) || empty($rpwd)){
            $result = true;
        }else{
            $result = false;
        }
        return $result;
    }

/************************************************************************************************************************************************************************************/

# Checking if any of the fields have been left blank
    function invalidUid($uname){
        $result;
        if(!preg_match("/^[a-zA-Z0-9]*$/", $uname)){
            // True = error
            $result = true;
        }else{
            $result = false;
        }
        return $result;
    }

/************************************************************************************************************************************************************************************/

# Checking if valid email string
    function invalidEmail($email){
        $result;
        if(!filter_var($email, FILTER_VALIDATE_EMAIL)){
            //true = error
            $result = true;
        }else{
            $result = false;
        }
        return $result;
    }

/************************************************************************************************************************************************************************************/

# Checking if passwords match
    function pwdMatch($pwd, $cpwd){
        $result;
        if($pwd != $cpwd){
            // true = error
            $result = true;
        }else{
            $result = false;
        }
        return $result;
    }

/************************************************************************************************************************************************************************************/

    # Password not long enough
        function pwdTooShort($pwd){
            $result;
            if($pwd >= 8){
                // true = error
                $result = true;
            }else{
                $result = false;
            }
            return $result;
        }

/************************************************************************************************************************************************************************************/

# Checking if username already exists
    function uidExists($dbc, $uname, $email){
        $sql = "SELECT * FROM adminusers WHERE username = ? OR email = ?;";



        $stmt = mysqli_stmt_init($dbc);

        if(!mysqli_stmt_prepare($stmt, $sql)){
            header('Location: register.php?error=stmtfailed');
            exit();
        }

        mysqli_stmt_bind_param($stmt, "ss", $uname, $email);
        mysqli_stmt_execute($stmt);

        $resultData = mysqli_stmt_get_result($stmt);

        if($row = mysqli_fetch_assoc($resultData)){
            return $row;
        }else{
            $result = false;
            return $result;
        }

        mysqli_stmt_close($stmt);

    }

/************************************************************************************************************************************************************************************/

 # Checking if username already exists
    function createUser($dbc, $fname, $lname, $uname, $email, $pwd){
        $sql = "INSERT INTO adminusers (first, last, email, username, password) VALUES (?,?,?,?,?);";

        $stmt = mysqli_stmt_init($dbc);

        if(!mysqli_stmt_prepare($stmt, $sql)){
            header('Location: register.php?error=databaseerror');
            exit();
        }

        //Hashing pwd
        $hashedPwd = password_hash($pwd, PASSWORD_DEFAULT);


        mysqli_stmt_bind_param($stmt, "sssss", $fname, $lname, $email, $uname, $hashedPwd);
        mysqli_stmt_execute($stmt);

        mysqli_stmt_close($stmt);
        header("Location: register.php?none");
        exit();
    }

/************************************************************************************************************************************************************************************/

function emptyInputLogin($uname, $pwd){
        $result;
        if(empty($uname) || empty($pwd)){
            $result = true;
        }else{
            $result = false;
        }
        return $result;
    }

/************************************************************************************************************************************************************************************/

function loginUser($dbc, $uname, $pwd){

        $uidExists = uidExists($dbc, $uname, $uname);

        //If false username/email doesn't exist in dbase
        if($uidExists === false){
            header('Location: login.php?error=incorrectlogindetails');
            exit();
        }

        $pwd_hashed = $uidExists['password'];
        $checkpwd = password_verify($pwd, $pwd_hashed);

        if($checkpwd === false){
            header('Location: login.php?error=incorrectlogindetails');
            exit();
        }elseif($checkpwd === true){
            $_SESSION['userid'] = $uidExists['id'];
            $_SESSION['useruid'] = $uidExists['username'];
            $_SESSION['useremail'] = $uidExists['email'];
            $_SESSION['userfirst'] = $uidExists['first'];
            $_SESSION['userlast'] = $uidExists['last'];
            $_SESSION['userstatus'] = $uidExists['status'];



            header('Location: index.php');
            exit();
        }
    }