/**
 * 썸네일 미리보기 확대 (길게 누르는 동안만 표시)
 */
(function initDeckPreviewHold() {
    /** @type {HTMLElement|null} */
    let overlay = null;

    /** @type {number|null} */
    let holdTimer = null;

    /** @type {number} */
    const HOLD_THRESHOLD_MS = 280;

    /**
     * @returns {HTMLElement}
     */
    function ensureOverlay() {
        if (!overlay) {
            overlay = document.createElement('div');
            overlay.className = 'deck-preview-hold-overlay hidden';
            overlay.setAttribute('role', 'dialog');
            overlay.setAttribute('aria-modal', 'true');
            overlay.innerHTML =
                '<div class="deck-preview-hold-box"><img alt="" draggable="false" /></div>';
            document.body.appendChild(overlay);
        }
        return overlay;
    }

    /**
     * @param {string} src
     */
    function show(src) {
        if (!src) return;
        const el = ensureOverlay();
        const img = el.querySelector('img');
        if (img) img.src = src;
        el.classList.remove('hidden');
    }

    function clearHoldTimer() {
        if (holdTimer !== null) {
            window.clearTimeout(holdTimer);
            holdTimer = null;
        }
    }

    function hide() {
        clearHoldTimer();
        if (overlay) overlay.classList.add('hidden');
    }

    /**
     * @param {Event} e
     * @returns {HTMLElement|null}
     */
    function findHoldTarget(e) {
        const target = e.target;
        if (!(target instanceof Element)) return null;
        return target.closest('[data-hold-preview]');
    }

    /**
     * @param {HTMLElement} hold
     * @returns {string}
     */
    function getPreviewSrc(hold) {
        return hold.dataset.previewSrc || '';
    }

    /**
     * @param {PointerEvent} e
     * @param {HTMLElement|null} hold
     */
    function releaseCapture(e, hold) {
        if (hold?.releasePointerCapture && e.pointerId !== undefined) {
            try {
                hold.releasePointerCapture(e.pointerId);
            } catch {
                /* ignore */
            }
        }
    }

    function initGlobal() {
        if (document.documentElement.dataset.deckHoldInit === '1') return;
        document.documentElement.dataset.deckHoldInit = '1';

        document.addEventListener(
            'pointerdown',
            (e) => {
                const hold = findHoldTarget(e);
                if (!hold) return;
                const src = getPreviewSrc(hold);
                if (!src) return;

                clearHoldTimer();
                holdTimer = window.setTimeout(() => {
                    holdTimer = null;
                    show(src);
                }, HOLD_THRESHOLD_MS);

                if (hold.setPointerCapture && e.pointerId !== undefined) {
                    try {
                        hold.setPointerCapture(e.pointerId);
                    } catch {
                        /* ignore */
                    }
                }
            },
            true,
        );

        document.addEventListener(
            'pointerup',
            (e) => {
                const hold = findHoldTarget(e);
                releaseCapture(e, hold);
                hide();
            },
            true,
        );

        document.addEventListener(
            'pointercancel',
            () => {
                hide();
            },
            true,
        );

        document.addEventListener('keydown', (e) => {
            if (e.key === 'Escape') hide();
        });
    }

    /**
     * @param {HTMLElement} _container
     */
    function bindHoldPreview(_container) {
        initGlobal();
    }

    initGlobal();

    window.UaDeckPreviewHold = { bindHoldPreview, hide };
})();