import { Tray, type BrowserWindow } from "electrobun/bun";
import { BRANDING } from "../shared/branding";
import type { WorkspaceSyncInfo } from "../shared/rpc";
import type { TransferEngine } from "./transfers/engine";

const BASE_IMAGE = "views://assets/tray/tray-44-template.png";
const PROGRESS_IMAGE = (pct: number) => `views://assets/tray/progress/p${pct}.png`;
const REFRESH_THROTTLE_MS = 500;

/**
 * Menu-bar icon: the app glyph when idle; while transfers run the icon swaps
 * to pre-rendered frames (faded arrows + fill bar = queue doneBytes/totalBytes).
 * The menu lists the tabs (synced from the webview) with per-tab job info.
 */
export class AppTray {
	private tray: Tray;
	private tabs: WorkspaceSyncInfo = { workspaces: [], activeId: 0 };
	private lastRefresh = 0;
	private refreshTimer: ReturnType<typeof setTimeout> | null = null;
	private currentImage = BASE_IMAGE;
	/** Forwards tray menu actions the UI must handle (activate-tab:<id>). */
	onAction: (action: string) => void = () => {};

	constructor(
		private win: BrowserWindow,
		private engine: TransferEngine,
	) {
		this.tray = new Tray({
			title: "",
			image: BASE_IMAGE,
			template: true,
			width: 22,
			height: 22,
		});

		this.tray.on("tray-clicked", (event) => {
			const { action } = (event as { data: { action: string } }).data;
			if (!action) return; // icon click with a menu set -> macOS opens the menu
			if (action === "show-app") {
				this.win.activate();
			} else if (action === "quit") {
				process.exit(0); // electrobun's clean-quit override
			} else if (action.startsWith("activate-tab:")) {
				this.win.activate();
				this.onAction(action);
			}
		});

		this.rebuildMenu();
	}

	updateTabs(sync: WorkspaceSyncInfo): void {
		this.tabs = sync;
		this.scheduleRefresh();
	}

	/** Called on every engine update; throttled internally. */
	updateProgress(): void {
		this.scheduleRefresh();
	}

	private scheduleRefresh(): void {
		const now = Date.now();
		const wait = Math.max(0, REFRESH_THROTTLE_MS - (now - this.lastRefresh));
		if (this.refreshTimer) return;
		this.refreshTimer = setTimeout(() => {
			this.refreshTimer = null;
			this.lastRefresh = Date.now();
			this.refresh();
		}, wait);
	}

	private refresh(): void {
		const progress = this.engine.aggregateProgress();

		// icon: nearest 5% frame while transferring, base glyph when idle
		let image = BASE_IMAGE;
		if (progress.activeCount > 0 && progress.totalBytes > 0) {
			const pct = Math.round(((progress.doneBytes / progress.totalBytes) * 100) / 5) * 5;
			image = PROGRESS_IMAGE(Math.max(0, Math.min(100, pct)));
		}
		if (image !== this.currentImage) {
			this.currentImage = image;
			this.tray.setImage(image);
		}

		this.rebuildMenu(progress);
	}

	private rebuildMenu(progress = this.engine.aggregateProgress()): void {
		const items: Parameters<Tray["setMenu"]>[0] = [];

		for (const ws of this.tabs.workspaces) {
			const jobs = ws.sessionIds
				.map((id) => progress.bySession[id])
				.filter((v): v is NonNullable<typeof v> => !!v);
			const count = jobs.reduce((n, j) => n + j.count, 0);
			const total = jobs.reduce((n, j) => n + j.total, 0);
			const done = jobs.reduce((n, j) => n + j.done, 0);
			const suffix = count
				? ` — ${count} transfer${count === 1 ? "" : "s"} · ${total ? Math.round((done / total) * 100) : 0}%`
				: "";
			items.push({
				type: "normal",
				label: `${ws.name}${suffix}`,
				action: `activate-tab:${ws.id}`,
				checked: ws.id === this.tabs.activeId,
			});
		}

		if (progress.activeCount > 0) {
			items.push({ type: "divider" });
			const pct = progress.totalBytes
				? Math.round((progress.doneBytes / progress.totalBytes) * 100)
				: 0;
			items.push({
				type: "normal",
				label: `${progress.activeCount} active transfer${progress.activeCount === 1 ? "" : "s"} · ${pct}%`,
				action: "noop",
				enabled: false,
			});
		}

		items.push({ type: "divider" });
		items.push({ type: "normal", label: `Show ${BRANDING.appName}`, action: "show-app" });
		items.push({ type: "normal", label: "Quit", action: "quit" });

		this.tray.setMenu(items);
	}
}