window.calendarSwipe = {
    register: function (element, dotnetHelper) {
        let startX = 0;
        let endX = 0;

        element.addEventListener('touchstart', (e) => {
            if (e.touches.length === 1) {
                startX = e.touches[0].clientX;
            }
        });

        element.addEventListener('touchend', (e) => {
            if (e.changedTouches.length === 1) {
                endX = e.changedTouches[0].clientX;
                handle();
            }
        });

        // Per desktop: mouse drag
        let mouseDown = false;
        element.addEventListener('mousedown', (e) => {
            if (e.button !== 0) return; // solo left mouse
            mouseDown = true;
            startX = e.clientX;
        });
        element.addEventListener('mouseup', (e) => {
            if (!mouseDown) return;
            mouseDown = false;
            endX = e.clientX;
            handle();
        });

        function handle() {
            let diff = endX - startX;
            if (Math.abs(diff) > 40) {
                if (diff < 0) dotnetHelper.invokeMethodAsync('OnSwipeLeft');
                else dotnetHelper.invokeMethodAsync('OnSwipeRight');
            }
        }
    }
};