pr-monitor/server/index.ts

import { loadConfig } from './config.js';
import { Db } from './db.js';
import { runPoll } from './poller.js';
import { getLastRateLimit } from './github/client.js';
import { createApp, buildSyncPayload } from './routes.js';
import { broadcast } from './sse.js';

const config = loadConfig();
const db = new Db();

let polling = false;

async function poll(): Promise<void> {
  if (polling) return;
  polling = true;
  try {
    const result = await runPoll(config, db);
    console.log(
      `[poll] ${result.prCount} PRs, ${result.changedPrIds.length} changed, ${result.newEventCount} new events`,
    );
    broadcast(buildSyncPayload(db, result.changedPrIds, result.newEventCount));
  } catch (err) {
    const message = err instanceof Error ? err.message : String(err);
    console.error(`[poll] failed: ${message}`);
    db.setMeta('last_sync_error', message);
    broadcast(buildSyncPayload(db));
  } finally {
    polling = false;
  }
}

function scheduleNext(): void {
  // Back off to 5 minutes when the rate-limit budget runs low.
  const remaining = getLastRateLimit()?.remaining;
  const intervalMs =
    remaining !== undefined && remaining < 500 ? 5 * 60_000 : config.pollIntervalSeconds * 1000;
  setTimeout(async () => {
    await poll();
    scheduleNext();
  }, intervalMs);
}

const app = createApp({ db, triggerSync: poll });
app.listen(config.port, () => {
  console.log(`pr-monitor listening on http://localhost:${config.port}`);
});

await poll();
scheduleNext();