import "@polymer/paper-spinner/paper-spinner.js";
import "./ncg-dashboard-panel";

import * as Polymer from "@polymer/polymer";
import { timeOut } from "@polymer/polymer/lib/utils/async.js";
import { Debouncer } from "@polymer/polymer/lib/utils/debounce.js";
import { afterNextRender } from "@polymer/polymer/lib/utils/render-status.js";
import Draggabilly from "draggabilly";
import Packery from "packery";

import type { NodeCG } from "../../../types/nodecg";
import type { NcgDashboardPanel } from "./ncg-dashboard-panel";

class NcgWorkspace extends Polymer.PolymerElement {
	static get template() {
		return Polymer.html`
		<style include="nodecg-theme">
			:host {
				display: block;
				width: 100%;
				height: 100%;
				pointer-events: none;
				box-sizing: border-box;
			}

			#panels {
				transform: translateY(40px);
				opacity: 0;
				transition: opacity 500ms ease, transform 600ms ease-out;
			}

			:host(:not([fullbleed])) {
				padding: 32px;
			}

			:host(:not([fullbleed])) #panels {
				padding-bottom: 32px;
			}

			#panels {
				width: 100%;
				height: 100%;
			}

			#loadingSpinner {
				position: fixed;
				top: 50%;
				left: 50%;
				transform: translate(-50%);
				width: 68px;
				height: 68px;
				--paper-spinner-stroke-width: 5px;
				--paper-spinner-layer-1-color: #645BA6;
				--paper-spinner-layer-2-color: #A50074;
				--paper-spinner-layer-3-color: #5BA664;
				--paper-spinner-layer-4-color: #C9513E;
			}

			iframe {
				display: block;
				width: 100%;
				height: 100%;
			}
		</style>

		<div id="panels">
			<template is="dom-repeat" items="[[panels]]" as="panel">
				<ncg-dashboard-panel id="[[panel.bundleName]]_[[panel.name]]" display-title="[[panel.title]]" bundle="[[panel.bundleName]]" panel="[[panel.name]]" header-color="[[panel.headerColor]]" width="[[panel.width]]" on-transitioning-changed="_handlePanelCollapseTransition" fullbleed="[[panel.fullbleed]]">
					<iframe src="/bundles/[[panel.bundleName]]/dashboard/[[panel.file]]" frameborder="0" scrolling\$="[[_calcIframeScrolling(panel.fullbleed)]]" id="[[panel.bundleName]]_[[panel.name]]_iframe" on-iframe-resized="shiftPackery" fullbleed\$="[[panel.fullbleed]]" loading="lazy">
					</iframe>
				</ncg-dashboard-panel>
			</template>
		</div>

		<paper-spinner id="loadingSpinner" active=""></paper-spinner>
`;
	}

	static get is() {
		return "ncg-workspace";
	}

	static get properties() {
		return {
			workspace: Object,
			panels: {
				type: Array,
				computed: "_computePanels(workspace)",
			},
			fullbleed: {
				type: Boolean,
				computed: "_computeFullbleed(workspace)",
				reflectToAttribute: true,
				value: false,
			},
			usePackery: {
				type: Boolean,
				computed: "_computeUsePackery(fullbleed)",
			},
			route: {
				type: Object,
				observer: "_routeChanged",
			},
			PANEL_SORT_ORDER_STORAGE_KEY: {
				type: String,
				computed: "_computePanelSortOrderStorageKey(workspace)",
			},
		};
	}

	override ready(): void {
		super.ready();

		// 2018-08-26: This is a quick fix for workspaces never initializing on Firefox.
		// For some reason FF never fires the `load` event, or it's firing it before we start listening.
		// This is less than ideal for us, because this quick fix doesn't _actually_ hide the loads,
		// so it looks quite ugly.
		// This might need to move to listening for the load events of each individual iframe instead?
		if (document.readyState === "complete") {
			this._init();
		} else {
			window.addEventListener("load", () => {
				this._init();
			});
		}
	}

	_init() {
		if (this._initialized) {
			throw new Error("attempted multiple init");
		}

		this._initialized = true;

		this.$.loadingSpinner.active = false;
		this.applyPackery();
		setTimeout(() => {
			this.addEventListener("tap", this.shiftPackery);
			this.$.panels.style.opacity = 1;
			this.$.panels.style.transform = "translateY(0)";
			this.$.panels.style.pointerEvents = "auto";
		}, 750);
	}

	override connectedCallback(): void {
		super.connectedCallback();

		afterNextRender(this, () => {
			if (this.usePackery) {
				// Init Packery
				this.initPackery();
				this.startObservingPanelMutations();
			}
		});
	}

	startObservingPanelMutations() {
		// Packery causes attributes changes, so before applying it
		// we disconnect then reconnect our observer to avoid infinite loops
		try {
			if (this._panelMutationObserver) {
				return;
			}

			// Create a MutationObserver which will watch for changes to the DOM and re-apply masonry
			this._panelMutationObserver = new MutationObserver(() => {
				this._handleMutationDebounce = Debouncer.debounce(
					this._handleMutationDebounce,
					timeOut.after(150),
					this._debouncedMutationHandler.bind(this),
				);
			});

			// Define what element should be observed by the observer
			// and what types of mutations trigger the callback
			this._panelMutationObserver.observe(this.$.panels, {
				subtree: true,
				attributes: true,
				childList: true,
				characterData: true,
				attributeOldValue: false,
				characterDataOldValue: false,
			});
		} catch (_: unknown) {
			console.warn(
				"MutationObserver not supported, dashboard panels may be less responsive to DOM changes",
			);
		}
	}

	initPackery() {
		const packery = new Packery(this.$.panels, {
			itemSelector: "ncg-dashboard-panel",
			columnWidth: 128,
			gutter: 16,
			isInitLayout: false,
			containerStyle: { position: "relative" },
		});

		this._packery = packery;

		// Initial sort
		const sortOrder: string[] = []; // global variable for saving order, used later
		const rawStoredSortOrder = localStorage.getItem(
			this.PANEL_SORT_ORDER_STORAGE_KEY,
		);
		if (rawStoredSortOrder) {
			const storedSortOrder: string[] = JSON.parse(rawStoredSortOrder);

			// Create a hash of items
			const itemsByFullName: Record<string, HTMLElement> = {};
			const allPanels: string[] = [];
			let panelName;
			let bundleName;
			let i;
			let len;
			for (i = 0, len = packery.items.length; i < len; i++) {
				const item = packery.items[i];
				panelName = item.element.getAttribute("panel");
				bundleName = item.element.getAttribute("bundle");
				const fullName = `${bundleName}.${panelName}`;
				allPanels[i] = fullName;
				itemsByFullName[fullName] = item;
			}

			// Merge the saved panel array with our currently loaded panels, remove dupes
			const allPanelsOrdered = arrayUnique(storedSortOrder.concat(allPanels));

			// Remove panels that no longer exist
			const removededOld = allPanelsOrdered.filter((val) =>
				allPanels.includes(val),
			);

			// Overwrite packery item order
			len = removededOld.length;
			for (i = 0; i < len; i++) {
				panelName = removededOld[i]!;
				packery.items[i] = itemsByFullName[panelName];
			}
		}

		// Manually trigger initial layout
		packery.layout();
		this._packeryInitialized = true;

		const panelsList: NcgDashboardPanel[] = this.$.panels.querySelectorAll(
			"ncg-dashboard-panel",
		);
		panelsList.forEach((itemElem) => {
			// Make element draggable with Draggabilly
			const draggie = new Draggabilly(itemElem);

			// Manually set the handle because we can't just use a CSS selector due to ShadowDOM
			draggie.handles = [itemElem.$.dragHandle];

			// Bind Draggabilly events to Packery
			packery.bindDraggabillyEvents(draggie);
		});

		// Currently, there is no built-in option to force dragged elements to gravitate to their
		// nearest neighbour in a specific direction. This will reset their locations 100ms after a drag
		// causing them to gravitate.
		packery.on("dragItemPositioned", () => {
			setTimeout(() => {
				packery.layout();
			}, 100);
		});

		const orderItems = () => {
			const itemElems = packery.getItemElements();

			// Reset / empty order array
			sortOrder.length = 0;

			for (let i = 0; i < itemElems.length; i++) {
				sortOrder[i] =
					`${itemElems[i].getAttribute("bundle")}.${itemElems[i].getAttribute("panel")}`;
			}

			// Save ordering
			localStorage.setItem(
				this.PANEL_SORT_ORDER_STORAGE_KEY,
				JSON.stringify(sortOrder),
			);
		};

		packery.on("layoutComplete", orderItems);
		packery.on("dragItemPositioned", orderItems);
	}

	applyPackery() {
		this._applyPackeryDebounce = Debouncer.debounce(
			this._applyPackeryDebounce,
			timeOut.after(10),
			() => {
				if (this._packeryInitialized) {
					this._packery.layout();
				}
			},
		);
	}

	shiftPackery() {
		if (!this.usePackery) {
			return;
		}

		// Called when anything in #panels receives a click or tap event.
		// There's probably a lot of room to optimize this and not call
		// this routine for every single click,
		// but this was just the easiest way to ensure that mutations
		// caused by clicks are caught, because those mutations might
		// have changed the vertical size of the panel.

		this._shiftPackeryDebounce = Debouncer.debounce(
			this._shiftPackeryDebounce,
			timeOut.after(100),
			() => {
				if (this._packeryInitialized) {
					// See http://packery.metafizzy.co/methods.html#shiftlayout for more details
					this._packery.shiftLayout();
				}
			},
		);
	}

	_fixPackery() {
		this.applyPackery();
	}

	_computePanels(workspace: NodeCG.Workspace) {
		const workspaceName = workspace.route === "" ? "default" : workspace.name;
		const { bundles } = window.__renderData__;
		const panels: NodeCG.Bundle.Panel[] = [];
		bundles.forEach((bundle) => {
			bundle.dashboard.panels.forEach((panel) => {
				if (panel.dialog) {
					return;
				}

				if (panel.fullbleed) {
					if (
						workspaceName === `__nodecg_fullbleed__${bundle.name}_${panel.name}`
					) {
						return panels.push(panel);
					}

					return;
				}

				if (panel.workspace === workspaceName) {
					panels.push(panel);
				}

				return undefined;
			});
		});
		return panels;
	}

	_computeFullbleed(workspace: NodeCG.Workspace) {
		return workspace.fullbleed;
	}

	_computeUsePackery(fullbleed: boolean) {
		return !fullbleed;
	}

	_routeChanged(route: { path: string }) {
		if (this.usePackery) {
			// This is a hack to fix packery when the viewport size is changed
			// when the workspace is not visible.
			if (route.path === (this as any).parentNode.route) {
				this._fixPackeryDebounce = Debouncer.debounce(
					this._fixPackeryDebounce,
					timeOut.after(10),
					this._fixPackery.bind(this),
				);
			}
		}
	}

	_computePanelSortOrderStorageKey(workspace: NodeCG.Workspace) {
		return (
			(workspace.route === "" ? "default" : workspace.name) +
			"_workspace_panel_sort_order"
		);
	}

	_handlePanelCollapseTransition(e: any) {
		// Whenever a panel finishes transitioning, shiftPackery.
		if (e.detail.value === false) {
			this.shiftPackery();
		}
	}

	_debouncedMutationHandler() {
		this._panelMutationObserver.disconnect();
		this.shiftPackery();
		this.startObservingPanelMutations();
	}

	_calcIframeScrolling(fullbleed: boolean) {
		return fullbleed ? "yes" : "no";
	}
}

customElements.define("ncg-workspace", NcgWorkspace);

function arrayUnique<T>(array: T[]): T[] {
	const a = array.concat();
	for (let i = 0; i < a.length; ++i) {
		for (let j = i + 1; j < a.length; ++j) {
			if (a[i] === a[j]) {
				a.splice(j--, 1);
			}
		}
	}

	return a;
}