<?php
    include("conn.php");//add connection to the php page

    //to check for member session
    session_start();
    // if don't have session user..then
    if(! isset($_SESSION['memname']))
    {
    session_write_close();
    die("<script>alert('Please login first before booking courts!');window.location.href='login.html';</script>");
    }

    //To check whether the duration selected is compatible with the start time and end time
    $duration= $_POST['duration'];

    $date1 = $_POST['starttime'];
    $date2 = $_POST['endtime'];

    $diff = round((strtotime($date2) - strtotime($date1))/(60*60));

    if ($diff != $duration)
    {
        echo "<script>alert('Please make sure that the duration selected is correct with the start time and end time!');</script>";
        die("<script>window.history.go(-1);</script>");
    }

    //To check that the booking is on future not the past
    $date = $_POST['starttime'];
    $datenow = date('Y-m-d H:i a');
    if ($date < $datenow) {
        echo "<script>alert('Please make sure that your booking date time is valid!'); </script>";
        die("<script>window.history.go(-1);</script>");
    }

    //To prevent double booking of the court at same time
    $courtnumber = $_POST['cid'];
    $bookingstarttime = $_POST['starttime'];
    $bookingendtime = $_POST['endtime'];

    $checkBookingQuery = "SELECT * FROM `squash_court_booking` WHERE `Court_ID` = {$courtnumber} AND (Start_Time >= '{$bookingstarttime}' AND End_Time <= '{$bookingendtime}')";
    $checkBooking = mysqli_query($conn, $checkBookingQuery);

    if(mysqli_num_rows($checkBooking)>0) {
        echo "<script>alert('Sorry the court is booked by other during that period of time! Please try with other date time/courts!'); </script>";
        die("<script>window.history.go(-1);</script>");	
    }


        $bid = $_POST['bid'];
        $cid = $_POST['cid'];
        $starttime = $_POST['starttime'];
        $endtime = $_POST['endtime'];
        $duration = $_POST['duration'];


        $sql = "UPDATE squash_court_booking SET Court_ID = '$cid', Start_Time = '$starttime', End_Time = '$endtime', Duration = '$duration' WHERE Booking_ID = '$bid'";
        $result = mysqli_query($conn, $sql);

        if($result)
        {
            echo '<script> alert("Successfully change for booking time!");</script>';
            echo "<script>window.location.href='booking_history.php';</script>";
        }
        else
        {
            echo '<script> alert("Data Not Updated!");window.history.go(-1);</script>';
        }

?>