import { parseHost } from "./add_an_instance.mjs";
import { initializeAddInstanceFlow } from "./add_instance_flow.mjs";
import { initializeInstanceDetailsDialog } from "./confirm_instance_details.mjs";
import { findButtonOrFail, findDialogOrFail, findOlOrFail } from "./dom.mjs";
import storageManager from "./storage_manager.mjs";

let reordering = false;
// Dragging code is a heavily modified version of https://stackoverflow.com/a/28962290
let elementBeingDragged: HTMLLIElement | undefined;

const mainDialog = findDialogOrFail(document.body, "#mainDialog");
const showAddInstanceDialogButton = findButtonOrFail(document.body, "#showAddInstanceDialog");
const detailsDialog = findDialogOrFail(document.body, "#instanceDetails");
const addDialog = findDialogOrFail(document.body, "#addInstance");
const instanceList = findOlOrFail(document.body, "#instanceList");
const saveButton = findButtonOrFail(document.body, "#save");
const reorderButton = findButtonOrFail(document.body, "#reorder");

showAddInstanceDialogButton.addEventListener("click", e => showAddInstanceDialog());

saveButton.addEventListener("click", e => {
    storageManager.save();
});

reorderButton.addEventListener("click", () => {
    reordering = !reordering;
    if (!reordering) applyReordering();
    updateInstanceList();
    reorderButton.innerText = reordering ? "Finish reordering" : "Reorder";
});

const {
    showInstanceDetailsDialog,
    hideInstanceDetailsDialog,
    populateInstanceDetailsDialog,
} = initializeInstanceDetailsDialog(detailsDialog, () => { });

const {
    showAddInstanceDialog,
    hideAddInstanceDialog
} = initializeAddInstanceFlow(detailsDialog, addDialog);

updateInstanceList();
storageManager.addSaveCallback(updateInstanceList);

mainDialog.show();

function updateInstanceList() {
    instanceList.replaceChildren(); // Erase all child nodes
    instanceList.style.listStyleType = reordering ? "\"≡ \"" : "disc";
    for (let n = 0; n < storageManager.storage.instances.length; n++) {
        const instance = storageManager.storage.instances[n];
        const li = document.createElement("li");
        li.setAttribute("x-option", n.toString());
        const label = document.createElement("label");
        label.htmlFor = instance.origin;
        label.innerText = instance.name + " ";
        label.style.cursor = "inherit";
        if (instance.iconURL) {
            const img = new Image();
            img.src = instance.iconURL;
            img.alt = `${instance.name} icon`;
            img.className = "inlineIcon medium-height";
            label.append(img, " ");
        }
        if (reordering) {
            li.draggable = true;
            li.addEventListener("dragstart", e => {
                if (e.dataTransfer === null) return;
                if (!(e.target instanceof HTMLLIElement)) return;
                e.dataTransfer.effectAllowed = "move";
                e.dataTransfer.setData("text/plain", "");
                elementBeingDragged = e.target;
            });
            li.addEventListener("dragover", e => {
                if (elementBeingDragged === undefined) return;
                if (!(e.target instanceof HTMLElement)) return;
                const listElement = e.target.closest("li");
                if (listElement === null) return;
                if (listElement.parentNode === null) return;
                if (isBefore(elementBeingDragged, listElement))
                    listElement.parentNode.insertBefore(elementBeingDragged, listElement);
                else
                    listElement.parentNode.insertBefore(elementBeingDragged, listElement.nextSibling);
                e.preventDefault();
            });
            li.addEventListener("dragenter", e => e.preventDefault());
            li.style.cursor = "grab";
        } else {
            const editLink = document.createElement("a");
            editLink.innerText = `Edit`;
            editLink.href = "#";
            editLink.addEventListener("click", e => {
                const host = parseHost(instance.origin)!;
                populateInstanceDetailsDialog(
                    instance.name,
                    host.host,
                    host.secure,
                    instance.software,
                    instance.iconURL ?? null
                );
                showInstanceDetailsDialog();
            });
            const deleteLink = document.createElement("a");
            deleteLink.innerText = `Delete`;
            deleteLink.href = "#";
            deleteLink.addEventListener("click", e => {
                storageManager.storage.instances.splice(
                    storageManager.storage.instances.indexOf(instance)
                );
                updateInstanceList();
            });
            label.append(editLink, " ", deleteLink);
        }
        li.appendChild(label);
        instanceList.appendChild(li);
    }
}

function isBefore(el1: HTMLLIElement, el2: HTMLLIElement) {
    if (el2.parentNode === el1.parentNode)
        for (let cur = el1.previousSibling; cur && cur.nodeType !== 9; cur = cur.previousSibling)
            if (cur === el2)
                return true;
    return false;
}

function applyReordering() {
    const indices: number[] = [];
    for (const el of instanceList.children) {
        if (!(el instanceof HTMLLIElement)) continue;
        const option = el.getAttribute("x-option");
        if (option === null) continue;
        indices.push(parseInt(option));
    }
    storageManager.storage.instances = indices.map(i => storageManager.storage.instances[i]);
}