import * as vscode from 'vscode';
import { getVisitorCount } from './http';
import { initStatusBar, refresh } from './statusBar';

const OPEN = 4;
const CLOSE = 23;
const INTERVAL_MS = 2 * 60 * 1000;

let timer: NodeJS.Timeout | undefined;

export async function activate(context: vscode.ExtensionContext) {
	const subscriptions = context.subscriptions;
	const commandId = 'vsc-adda.refresh';

	const item = initStatusBar(getVisitorCount, commandId);
	subscriptions.push(item);

	subscriptions.push(
		vscode.commands.registerCommand(commandId, async () => {
			await refresh();
		})
	);

	await refresh();
	scheduleNext();

	subscriptions.push({ dispose: () => timer && clearTimeout(timer) });
}

export function deactivate() {
	if (timer) {
		clearTimeout(timer);
	}
}

function isOpen(d: Date = new Date()): boolean {
	return d.getHours() >= OPEN && d.getHours() < CLOSE;
}

function timeUntilOpenMs(from: Date = new Date()): number {
	const next = new Date(from);
	if (from.getHours() < OPEN) {
		next.setHours(OPEN, 0, 0, 0);
	} else {
		next.setDate(next.getDate() + 1);
		next.setHours(OPEN, 0, 0, 0);
	}
	return next.getTime() - from.getTime();
}

function scheduleNext(): void {
	if (timer) {
		clearTimeout(timer);
	}

	if (isOpen()) {
		timer = setTimeout(() => {
			refresh().finally(scheduleNext);
		}, INTERVAL_MS);
	} else {
		timer = setTimeout(() => {
			refresh().finally(scheduleNext);
		}, timeUntilOpenMs());
	}
}