import "dotenv/config";
import { ENV } from "./_core/env";
import * as db from "./db";
import { processBackgroundTask } from "./taskWorker";

const workerId = `app-worker-${process.pid}`;

function sleep(ms: number) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

async function workOnce() {
  await db.requeueStaleBackgroundTasks(new Date(Date.now() - ENV.backgroundTaskStaleMs));

  const task = await db.claimNextBackgroundTask(workerId);
  if (!task) {
    return false;
  }

  try {
    const result = await processBackgroundTask(task);
    if (result !== null) {
      await db.completeBackgroundTask(task.id, result, "任务执行完成");
    }
  } catch (error) {
    const message = error instanceof Error ? error.message : "Unknown background task error";
    await db.failBackgroundTask(task.id, message);
    console.error(`[worker] task ${task.id} failed:`, error);
  }

  return true;
}

async function main() {
  console.log(`[worker] ${workerId} started`);
  for (;;) {
    const hasWorked = await workOnce();
    if (!hasWorked) {
      await sleep(ENV.backgroundTaskPollMs);
    }
  }
}

main().catch((error) => {
  console.error("[worker] fatal error", error);
  process.exit(1);
});