import { eventBus, type PMEvent } from "@/lib/events/bus";
import { requireAuth } from "@/lib/auth/middleware";

export const runtime = "nodejs";
export const dynamic = "force-dynamic";

export async function GET(req: Request) {
  const auth = await requireAuth(req);
  if (!auth.ok) return new Response("unauthorized", { status: auth.status });

  const stream = new ReadableStream({
    start(controller) {
      const encoder = new TextEncoder();
      const send = (event: PMEvent) => {
        try {
          controller.enqueue(encoder.encode(`event: ${event.type}\ndata: ${JSON.stringify(event)}\n\n`));
        } catch { /* controller closed */ }
      };
      const heartbeat = setInterval(() => {
        try {
          controller.enqueue(encoder.encode(`: heartbeat\n\n`));
        } catch { clearInterval(heartbeat); }
      }, 25_000);
      const unsub = eventBus.subscribe(send);
      try {
        controller.enqueue(encoder.encode(`event: hello\ndata: {"ok":true}\n\n`));
      } catch { /* ignore */ }

      const abort = () => {
        clearInterval(heartbeat);
        unsub();
        try { controller.close(); } catch { /* already closed */ }
      };
      req.signal.addEventListener("abort", abort);
    },
  });

  return new Response(stream, {
    headers: {
      "Content-Type": "text/event-stream",
      "Cache-Control": "no-cache, no-transform",
      Connection: "keep-alive",
      "X-Accel-Buffering": "no",
    },
  });
}