function resetInsertAppointmentForm() {
    $.get(getResetSelectedAppointmentUrl());

    $("#scheduler-start-time, #scheduler-end-time, #subject, #location, #notice").val("");

    $("#scheduler-start-date, #scheduler-end-date").val(moment().format("DD.MM.YYYY"));
}

function submitInsertAppointmentForm() {
    showSpinner();
    validateAppointmentForm();
}

function submitSchedulerDateForm() {
    showSpinner();
    $("#scheduler-date-form").submit();
}

function validateAppointmentForm() {
    var startTimePicker = $("#scheduler-start-time-picker");
    var startDatePicker = $("#scheduler-start-date-picker");
    var endTimePicker = $("#scheduler-end-time-picker");
    var endDatePicker = $("#scheduler-end-date-picker");

    var isStartTimeInputEmpty = isEmptyOrSpaces($("#scheduler-start-time").val());
    var isEndTimeInputEmpty = isEmptyOrSpaces($("#scheduler-end-time").val());
    var isStartDateInputEmpty = isEmptyOrSpaces($("#scheduler-start-date").val());
    var isEndDateInputEmpty = isEmptyOrSpaces($("#scheduler-end-date").val());
    
    startTimePicker.datetimepicker("show");
    startTimePicker.datetimepicker("hide");

    startDatePicker.datetimepicker("show");
    startDatePicker.datetimepicker("hide");

    endTimePicker.datetimepicker("show");
    endTimePicker.datetimepicker("hide");

    endDatePicker.datetimepicker("show");
    endDatePicker.datetimepicker("hide");

    var startTime = startTimePicker.datetimepicker("date");
    var endTime = endTimePicker.datetimepicker("date");
    var startDate = startDatePicker.datetimepicker("date");
    var endDate = endDatePicker.datetimepicker("date");

    var a = startDate === undefined || startDate === null || !startDate.isValid();
    var b = endDate === undefined || endDate === null || !endDate.isValid();
    var c = startTime === undefined || startTime === null || !startTime.isValid();
    var d = endTime === undefined || endTime === null || !endTime.isValid();

    if(a || b || c || d || isStartDateInputEmpty || isStartTimeInputEmpty || isEndTimeInputEmpty || isEndDateInputEmpty) {
        
        hideSpinner();
        $("#messagePopup .modal-body").html('<div class="alert alert-danger" role="alert">Die Zeit- und/oder Datumsangaben sind nicht korrekt.</div>');
        showMessagePopup("Fehler");
        $("#scheduler-start-time, #scheduler-end-time").val("");
        return;
    }

    if(endDate.isValid() === false) {
        endDate = startDate.clone();
    }

    startDate = startDate.hours(startTime.hours());
    startDate = startDate.minutes(startTime.minutes());

    endDate = endDate.hours(endTime.hours());
    endDate = endDate.minutes(endTime.minutes());

    if(endDate.isBefore(startDate)) {
        hideSpinner();
        $("#messagePopup .modal-body").html('<div class="alert alert-danger" role="alert">Das Startdatum muss vor dem Enddatum liegen.</div>');
        showMessagePopup("Fehler");
        return;
    }

    $.get(
        getCheckForOverlappingAppointmentsUrl(),
        {
            startDateRaw: startDate.format("DD.MM.YYYY"),
            endDateRaw: endDate.format("DD.MM.YYYY"),
            startTimeRaw: startDate.format("HH:mm"),
            endTimeRaw: endDate.format("HH:mm")
        }
    ).done(function(result) {
        var isOverlapping = $.parseJSON(result);

        if(isOverlapping === true) {
            hideSpinner();
            $("#messagePopup .modal-body").html('<div class="alert alert-warning" role="alert">Dieser Termin überschneidet sich mit einem anderen bereits existierenden Termin.<br/> Möchten Sie ihn wirklich speichern?</div>');
            showMessagePopupWithCallback("Überschneidung",
                null,
                function() {
                    $("#messagePopup .modal-body").html();
                    showSpinner();
                    $("#insert-appointment-form").submit();
                });
        } else {
            $("#insert-appointment-form").submit();
        }
    });
}

function toggleFormVisibility() {
    if($("#form-toggle-button").css("display") === "none") {
        showAppointmentForm();
    } else {
        hideAppointmentForm();
    }
}

function hideAppointmentForm() {
    $("#form-container").collapse("hide");
}

function showAppointmentForm() {
    $("#form-container").collapse("show");
}

function toggleAppointmentForm() {
    var isVisible = $("#form-container").css("display") === "block";

    if (isVisible) {
        hideAppointmentForm();
    } else {
        showAppointmentForm();
    }
}