mailflare/worker.ts

// @ts-ignore — generated at build time
import { default as nextHandler } from "./.open-next/worker.js";
import {
	processInboundMessage,
	storeRawToR2,
	type InboundQueueMessage,
} from "./src/lib/email/inbound";
import { processOutboundQueue, type OutboundQueueMessage } from "./src/lib/email/send";
import { isInboundQueueMessage, isWebhookRetryMessage } from "./worker-utils";
import { processWebhookRetry, type WebhookRetryMessage } from "./src/lib/email/webhooks";
import { resolveIncomingMail, forwardMessage } from "./src/lib/email/incoming";
import { getUserFromSession } from "./src/lib/auth/session";
import { getSessionTokenFromRequest } from "./src/lib/realtime/utils";
import {
	getAccountForwardingDestination,
	MAILFLARE_FORWARDED_HEADER,
} from "./src/lib/email/account-forwarding";
export { RealtimeHub } from "./src/lib/realtime/hub";
export { DatabaseBackupWorkflow } from "./src/lib/backups/workflow";

export default {
	async fetch(request: Request, env: CloudflareEnv, ctx: ExecutionContext) {
		const url = new URL(request.url);
		if (url.pathname === "/api/realtime") {
			if (request.headers.get("Upgrade")?.toLowerCase() !== "websocket") {
				return new Response("Expected WebSocket upgrade", { status: 426 });
			}

			const user = await getUserFromSession(env, getSessionTokenFromRequest(request));
			if (!user || user.disabled) {
				return new Response("Unauthorized", { status: 401 });
			}

			const hub = env.REALTIME.getByName(user.id);
			return hub.fetch(new Request("https://mailflare-realtime/connect", request));
		}

		return nextHandler.fetch(request, env, ctx);
	},

	async email(message: ForwardableEmailMessage, env: CloudflareEnv, ctx: ExecutionContext) {
		try {
			// Domain routing rules are resolved here rather than in the queue because reject and
			// forward can only be actioned on the live ForwardableEmailMessage.
			const decision = await resolveIncomingMail(env, message.from, message.to);

			if (decision?.action === "reject") {
				message.setReject(decision.rejectReason ?? "Message rejected by routing rule");
				return;
			}

			if (decision?.action === "forward" && decision.forwardTo) {
				const forwarded = await forwardMessage(message, decision.forwardTo);
				// A forward rule drops the message unless it was explicitly asked to keep a copy.
				// If the forward itself failed we still store it, so mail is never silently lost.
				if (forwarded && !decision.keepCopy) return;
			}

			if (message.headers.get(MAILFLARE_FORWARDED_HEADER) !== "1") {
				const forwardingDestination = await getAccountForwardingDestination(env, message.to);
				if (forwardingDestination) {
					await forwardMessage(message, forwardingDestination);
				}
			}
			const rawR2Key = await storeRawToR2(env, message.from, message.to, message.raw);
			const payload: InboundQueueMessage = {
				from: message.from,
				to: message.to,
				rawR2Key,
				headers: Object.fromEntries(message.headers),
			};
			await env.INBOUND_QUEUE.send(payload);
		} catch (err) {
			console.error("Inbound enqueue failed", err);
			message.setReject("Processing failed");
		}
	},

	async queue(batch: MessageBatch, env: CloudflareEnv): Promise<void> {
		for (const msg of batch.messages) {
			try {
				if (isInboundQueueMessage(msg.body)) {
					await processInboundMessage(env, msg.body);
				} else if (isWebhookRetryMessage(msg.body)) {
					await processWebhookRetry(env, msg.body as WebhookRetryMessage);
				} else {
					await processOutboundQueue(env, msg.body as OutboundQueueMessage);
				}
				msg.ack();
			} catch (err) {
				console.error("Queue processing failed", err);
				msg.retry({ delaySeconds: 10 });
			}
		}
	},
} satisfies ExportedHandler<CloudflareEnv>;