$(() => {
    var fullPageMediaDisplayed = false;
    var selectedThumbnails = [];
    var lastSelection = null;

    function onItemSelected(mediaItem) {
        document.getElementById("pch-mediaList").classList.add("selection");
    }

    function onItemDeselected(mediaItem) {
        if (!selectedThumbnails.length)
            document.getElementById("pch-mediaList").classList.remove("selection");
    }

    function buildThumbnail(mediaItem) {
        if (mediaItem.ui)
            return mediaItem.ui;
        let checkbox = document.createElement("input");
        let editButton = document.createElement("button");
        let img = document.createElement("img");
        let container = document.createElement("li");
        let loadingImg = document.createElement("div");
        checkbox.type = "checkbox";
        editButton.type = "button";
        if (!mediaItem.writeAccess)
            editButton.classList.add("hidden");
        let editButtonSpan = document.createElement("span");
        editButtonSpan.className = "bi bi-pen";
        editButton.appendChild(editButtonSpan);
        container.className = "pch-image loading col-12 col-md-6 col-xl-4";
        loadingImg.classList.add("spinner");
        loadingImg.innerHTML = "<span class='spinner-grow'></span>";
        container.dataset.md5sum = mediaItem.md5sum;
        img.loading = "lazy";
        let requestSize = mediaItem.resize(450, 450);
        requestSize = requestSize ? `w=${requestSize.width}&h=${requestSize.height}&` : "";
        img.src = `${mediaItem.thumbnail}?${requestSize}q=4`;
        img.classList.add("img-fluid");
        img.classList.add("img-thumbnail");
        img.addEventListener("load", () => {
            container.classList.remove("loading");
            container.classList.remove("spinner-grow");
        });
        container.style.width = `${requestSize.width}px`;
        container.appendChild(loadingImg);
        container.appendChild(img);
        container.appendChild(checkbox);
        container.appendChild(editButton);
        let setSelectionCheckboxValue = function(media, value) {
            media.ui.checkbox.checked = value;
            let indexInSelection = selectedThumbnails.indexOf(media.md5sum);
            if (value && indexInSelection < 0) {
                selectedThumbnails.push(media.md5sum);
                onItemSelected(media);
                return true;
            } else if (!value && indexInSelection >= 0) {
                selectedThumbnails.splice(indexInSelection, 1);
                onItemDeselected(media);
                return true;
            }
            return false;
        }
        mediaItem.setSelectionCheckboxValue = value => setSelectionCheckboxValue(mediaItem, value);
        let cascadeSetSelectionCheckboxValue = function(value) {
            if (!setSelectionCheckboxValue(mediaItem, value))
                return;
            if (window.lastKeyboardEvent?.shiftKey && lastSelection) {
                let _lastKeyboardEvent = window.lastKeyboardEvent;
                window.lastKeyboardEvent = null;
                for (let i of MediaStorage.Instance.getMediaBetween(lastSelection, mediaItem)) {
                    if (i === mediaItem)
                        continue;
                    i.ui.checkbox.setAttribute("checked", value);
                    i.ui.checkbox.checked = value;
                    setSelectionCheckboxValue(i, value);
                }
                window.lastKeyboardEvent = _lastKeyboardEvent;
            }
            lastSelection = mediaItem;
        }
        editButton.addEventListener("click", e => {
            e.stopPropagation();
            if (!checkbox.checked) {
                checkbox.checked = true;
                setSelectionCheckboxValue(mediaItem, true);
            }
            let sel = selectedThumbnails.map(x => MediaStorage.Instance.getMediaLocal(x)).filter(x => x.writeAccess);
            if (sel.length === 1 && sel[0].md5sum === mediaItem.md5sum) {
                checkbox.checked = false;
                setSelectionCheckboxValue(mediaItem, false);
                document.location.hash = mediaItem.md5sum;
                return;
            }
            console.log(sel);
        });
        container.addEventListener("click", () => {
            if (selectedThumbnails.length || window.lastKeyboardEvent?.ctrlKey) {
                let value = !checkbox.checked;
                checkbox.setAttribute("checked", value);
                checkbox.checked = value;
                cascadeSetSelectionCheckboxValue(value);
                return;
            }
            document.location.hash = mediaItem.md5sum;
        });
        checkbox.addEventListener("click", evt => {
            evt.stopPropagation();
        });
        checkbox.addEventListener("change", evt => {
            cascadeSetSelectionCheckboxValue(checkbox.checked);
        });
        return mediaItem.ui = {
            root: container,
            img: img,
            checkbox: checkbox
        };
    }

    function buildYear(date) {
        let result = document.createElement('h3');
        result.className = "col-12";
        result.textContent = date.getUTCFullYear();
        return result;
    }

    function buildMonth(date) {
        let result = document.createElement('h4');
        result.className = "col-12";
        result.textContent = date.toLocaleString('default', { month: 'long' });
        return result;
    }

    let lastItemDisplayed = null;
    let displayedItemCount = 0;
    const displayItemBatchCount = 15;
    let targetDisplayedItems = displayItemBatchCount;

    function redraw(container, media) {
        buildThumbnail(media);
        if (!media.ui)
            return;
        let yearUpdated = !container.dataset.lastItemYear || container.dataset.lastItemYear != media.date.getUTCFullYear();
        if (yearUpdated) {
            container.appendChild(buildYear(media.date));
            container.dataset.lastItemYear = media.date.getUTCFullYear();
        }
        if (yearUpdated || container.dataset.lastItemMonth === undefined || container.dataset.lastItemMonth != media.date.getUTCMonth()) {
            container.appendChild(buildMonth(media.date));
            container.dataset.lastItemMonth = media.date.getUTCMonth();
        }
        container.appendChild(media.ui.root);

        lastItemDisplayed = media;
        displayedItemCount++;
    }

    MediaStorage.Instance.addEventListener("rebuildMedia", (evt) => {
        let newContainer = document.getElementById('pch-mediaList');
        newContainer.textContent = '';
        newContainer.dataset.lastItemYear = null;
        newContainer.dataset.lastItemMonth = null;
        lastItemDisplayed = null;
        displayedItemCount = 0;
        targetDisplayedItems = displayItemBatchCount;
        for (let i of selectedThumbnails) {
            let media = MediaStorage.Instance.getMediaLocal(i);
            media?.setSelectionCheckboxValue(false);
        }
        lastSelection = null;
        for (let i of MediaStorage.Instance.medias)
            if (window.FilterManager.match(i)) {
                redraw(newContainer, i);
                if (displayedItemCount >= targetDisplayedItems)
                    break;
            }
    });

    MediaStorage.Instance.addEventListener("newMedia", (evt) => {
        if (displayedItemCount < targetDisplayedItems && window.FilterManager.match(evt.detail)) {
            let container = document.getElementById('pch-mediaList');
            redraw(container, evt.detail);
        }
    });

    window.displayMoreMedia = () => {
        targetDisplayedItems += displayItemBatchCount;
        let container = document.getElementById('pch-mediaList');
        for (let index = lastItemDisplayed ? (MediaStorage.Instance.getMediaIndex(lastItemDisplayed) +1) : 0;
            displayedItemCount < targetDisplayedItems; ++index) {
            let media = MediaStorage.Instance.medias[index];
            if (!media)
                return;
            if (window.FilterManager.match(media))
                redraw(container, media);
        }
    }
});