uptime-monitoring/src/worker/notifications/webhook.ts

import { eq } from "drizzle-orm";
import type { CheckResult, Monitor } from "../checks/run-check";
import { getDb } from "../db/client";
import { notificationSettings } from "../db/schema";

export type IncidentAlert = {
	monitor: Monitor;
	kind: "opened" | "resolved";
	result: CheckResult;
	at: Date;
};

type WebhookPayload = {
	event: "down" | "recovered" | "test";
	monitor: { id: number; name: string; url: string };
	statusCode: number | null;
	error: string | null;
	at: string;
};

async function postWebhook(url: string, payload: WebhookPayload): Promise<boolean> {
	const response = await fetch(url, {
		method: "POST",
		headers: {
			"Content-Type": "application/json",
			"User-Agent": "Upwatch/1.0 (+incident webhook)",
		},
		body: JSON.stringify(payload),
	});
	await response.body?.cancel();
	return response.ok;
}

export async function sendTestWebhook(url: string): Promise<boolean> {
	try {
		return await postWebhook(url, {
			event: "test",
			monitor: { id: 0, name: "Upwatch test", url: "https://example.com/health" },
			statusCode: 200,
			error: null,
			at: new Date().toISOString(),
		});
	} catch (error) {
		console.error(JSON.stringify({
			message: "test webhook failed",
			error: error instanceof Error ? error.message : String(error),
		}));
		return false;
	}
}

export async function sendIncidentAlert(
	env: Env,
	alert: IncidentAlert,
): Promise<boolean> {
	if (!alert.monitor.alertsEnabled) return false;

	try {
		const [settings] = await getDb(env)
			.select()
			.from(notificationSettings)
			.where(eq(notificationSettings.id, 1))
			.limit(1);
		if (!settings?.webhookEnabled || !settings.webhookUrl) return false;

		const ok = await postWebhook(settings.webhookUrl, {
				event: alert.kind === "opened" ? "down" : "recovered",
				monitor: {
					id: alert.monitor.id,
					name: alert.monitor.name,
					url: alert.monitor.url,
				},
				statusCode: alert.result.statusCode,
				error: alert.result.error,
				at: alert.at.toISOString(),
		});
		if (!ok) {
			console.warn(JSON.stringify({
				message: "incident webhook returned an error",
				monitorId: alert.monitor.id,
			}));
		}
		return ok;
	} catch (error) {
		console.error(JSON.stringify({
			message: "incident webhook failed",
			error: error instanceof Error ? error.message : String(error),
			monitorId: alert.monitor.id,
		}));
		return false;
	}
}