<?php 
    header('Content-Type: application/json');
    require_once '../DB/db_credentials.php';
    require_once '../DB/db_connection.php';
    // global $dbc; // needs to be set globally so $dbc is accessible in this file too

    if ($_SERVER["REQUEST_METHOD"] === "POST") {
        $scheduleID = $_POST["scheduleID"];
        $filmID = $_POST["filmID"];
        $start = $_POST["start"];    
        $end = $_POST["end"];   
    
        if (empty($scheduleID) || empty($start) || empty($end)) {
            echo json_encode(["status" => "error", "message" => "Missing data"]);
            exit;
        }
    
        // get title from the film table using the film ID
        $query = "SELECT title FROM citeLeParis_film WHERE pk_filmID = ?";
        $stmt = mysqli_prepare($dbc, $query);
        mysqli_stmt_bind_param($stmt, "i", $filmID);
        mysqli_stmt_execute($stmt);
        mysqli_stmt_bind_result($stmt, $filmTitle);
        mysqli_stmt_fetch($stmt);
        mysqli_stmt_close($stmt);
    
        if (!$filmTitle) {
            echo json_encode(["status" => "error", "message" => "Film not found"]);
            exit;
        }
    
        // update event in schedule table
        $query = "UPDATE citeLeParis_schedule SET fk_filmID = ?, startTime = ?, endTime = ? WHERE pk_scheduleID = ?";
        $stmt = mysqli_prepare($dbc, $query);
        mysqli_stmt_bind_param($stmt, "issi", $filmID, $start, $end, $scheduleID);
        $result = mysqli_stmt_execute($stmt);

        // check if update was successful
        if ($result) {
            $affectedRows = mysqli_affected_rows($dbc);

            if ($affectedRows > 0) {
                echo json_encode([
                    "status" => "success", 
                    "filmTitle" => $filmTitle, 
                    "start" => $start, 
                    "end" => $end,
                    "scheduleID" => $scheduleID 
                ]);
            } else {
                // no rows were updated, schedule ID was not found
                echo json_encode([
                    "status" => "error", 
                    "message" => "No rows updated, scheduleID doesn't exist", 
                    "scheduleID" => $scheduleID
                ]);
            }
        } else {
            echo json_encode([
                "status" => "error", 
                "message" => "Failed to execute update",
                "scheduleID" => $scheduleID
            ]);
        }

        mysqli_stmt_close($stmt);
    }
?>