import { io, Socket } from "socket.io-client";
import { WorkerQueue } from "./modules/workers/queues";
import { setupEventDebugger } from "./modules/logging/eventDebugger";
import { boss, getBoss } from "./boss-instance";

let bossStartPromise: Promise<void> | null = null;
let reservationQueueReady = false;
let managerSocket: Socket | null = null;
let managerSocketReadyPromise: Promise<Socket> | null = null;

async function ensureBossStarted(): Promise<void> {
  if (bossStartPromise) return bossStartPromise;
  bossStartPromise = boss.start().then(() => undefined);
  await bossStartPromise;
}

async function ensureReservationQueue(): Promise<void> {
  if (reservationQueueReady) return;

  try {
    await boss.createQueue(WorkerQueue.WORKER_NAMESPACE_RESERVATION);
  } catch {
    // Queue may already exist; ignore to keep this idempotent.
  }

  reservationQueueReady = true;
}

export function ensureManagerSocketReady(): Promise<Socket> {
  if (managerSocket && managerSocket.connected)
    return Promise.resolve(managerSocket);
  if (managerSocketReadyPromise) return managerSocketReadyPromise;

  const managerUrl = process.env.MANAGER_SOCKET_URL ?? "http://localhost:8671";
  managerSocket = io(managerUrl, {
    reconnection: true,
    reconnectionDelay: 1000,
    reconnectionDelayMax: 5000,
    reconnectionAttempts: Infinity,
  });

  managerSocket.on("connect", () => {
    console.log("[worker] Connected to manager socket on :8671");
  });

  managerSocket.on("disconnect", (reason) => {
    console.warn(`[worker] Manager socket disconnected: ${reason}`);
  });

  managerSocket.on("connect_error", (err) => {
    console.error("[worker] Manager socket connect_error", err.message);
  });

  managerSocket.on("reconnect_attempt", () => {
    console.log("[worker] Attempting to reconnect to manager socket...");
  });

  managerSocketReadyPromise = new Promise<Socket>((resolve) => {
    const socket = managerSocket!;

    const onConnect = () => {
      socket.off("connect_error", onConnectError);
      resolve(socket);
    };

    const onConnectError = (err: Error) => {
      // Log the error but don't reject - let Socket.IO handle reconnection
      console.warn("[worker] Connection attempt failed:", err.message, "- retrying...");
    };

    socket.once("connect", onConnect);
    socket.on("connect_error", onConnectError);
  });

  return managerSocketReadyPromise;
}

/**
 * Ask PgBoss to generate a durable job ID we can reuse as a worker namespace ID.
 *
 * A short-lived reservation job is created and immediately canceled to avoid
 * growing the queue while still obtaining a PgBoss-generated ID.
 */
export async function reserveWorkerId(queueType: WorkerQueue): Promise<string> {
  await ensureBossStarted();
  await ensureReservationQueue();

  const workerId = await boss.send(WorkerQueue.WORKER_NAMESPACE_RESERVATION, {
    queueType,
    requestedAt: new Date().toISOString(),
  });

  if (!workerId) {
    throw new Error("Failed to reserve PgBoss job ID for worker namespace");
  }

  try {
    await boss.cancel(WorkerQueue.WORKER_NAMESPACE_RESERVATION, workerId);
  } catch {
    // Best-effort cleanup only.
  }

  return workerId;
}

async function ensureDalpuriSyncQueue(): Promise<void> {
  try {
    console.log("[worker] Creating DALPURI_FULL_SYNC queue...");
    await boss.createQueue(WorkerQueue.DALPURI_FULL_SYNC);
    console.log("[worker] DALPURI_FULL_SYNC queue ready");
  } catch (err) {
    console.log("[worker] DALPURI_FULL_SYNC queue already exists (or error):", (err as Error).message);
  }
  try {
    console.log("[worker] Creating DALPURI_INCREMENTAL_SYNC queue...");
    await boss.createQueue(WorkerQueue.DALPURI_INCREMENTAL_SYNC);
    console.log("[worker] DALPURI_INCREMENTAL_SYNC queue ready");
  } catch (err) {
    console.log("[worker] DALPURI_INCREMENTAL_SYNC queue already exists (or error):", (err as Error).message);
  }
  try {
    console.log("[worker] Creating REFRESH_SALES_METRICS queue...");
    await boss.createQueue(WorkerQueue.REFRESH_SALES_METRICS);
    console.log("[worker] REFRESH_SALES_METRICS queue ready");
  } catch (err) {
    console.log("[worker] REFRESH_SALES_METRICS queue already exists (or error):", (err as Error).message);
  }
}

/**
 * Initialize the worker system. Must be called before enqueueing jobs.
 * Starts PgBoss connection to PostgreSQL.
 */
export async function initializeWorkerSystem(): Promise<void> {
  await ensureBossStarted();
  await ensureReservationQueue();
  await ensureDalpuriSyncQueue();
  console.log("[worker] Worker system initialized - ready for job enqueueing");
}

if (import.meta.main) {
  // if (Bun.env.NODE_ENV === "development") {
  //   setupEventDebugger({ processLabel: "WORKER" });
  // }

  console.log("[worker] Worker process starting...");
  console.log(
    `[worker] Connecting to PgBoss on DATABASE_URL and SocketIO on ${process.env.MANAGER_SOCKET_URL ?? "http://localhost:8671"}`
  );
  console.log(`[worker] DATABASE_URL set: ${!!process.env.DATABASE_URL}`);

  // Ensure PgBoss is connected and queues exist
  console.log("[worker] Starting PgBoss...");
  try {
    await Promise.race([
      ensureBossStarted(),
      new Promise<never>((_, reject) =>
        setTimeout(() => reject(new Error("boss.start() timed out after 30s")), 30_000)
      ),
    ]);
  } catch (err) {
    console.error("[worker] FATAL: PgBoss failed to start:", err);
    process.exit(1);
  }
  console.log("[worker] PgBoss started successfully");
  console.log("[worker] Ensuring sync queues...");
  await ensureDalpuriSyncQueue();
  console.log("[worker] Sync queues ready");

  // Register job handler for DALPURI_FULL_SYNC
  console.log("[worker] Importing sync-manager...");
  const { enqueueDalpuriFullSync } = await import("./modules/workers/sync-manager");
  console.log("[worker] Importing dalpuri-sync...");
  const { executeIncrementalSync } = await import("./modules/workers/dalpuri-sync");
  console.log("[worker] Importing incremental-sync...");
  const { enqueueIncrementalSync } = await import("./modules/workers/incremental-sync");
  await boss.work(WorkerQueue.DALPURI_FULL_SYNC, async () => {
    const socket = await ensureManagerSocketReady();
    await enqueueDalpuriFullSync(socket);
  });
  console.log("[worker] Registered DALPURI_FULL_SYNC job handler");

  await boss.work(WorkerQueue.DALPURI_INCREMENTAL_SYNC, async () => {
    const startedAt = Date.now();
    console.log("[worker] DALPURI_INCREMENTAL_SYNC started");
    try {
      await executeIncrementalSync();
      console.log(
        `[worker] DALPURI_INCREMENTAL_SYNC completed in ${Date.now() - startedAt}ms`
      );
    } catch (err) {
      console.error(
        `[worker] DALPURI_INCREMENTAL_SYNC failed in ${Date.now() - startedAt}ms`,
        err
      );
      throw err;
    }
  });
  console.log("[worker] Registered DALPURI_INCREMENTAL_SYNC job handler");

  const enqueueIncrementalWithLogging = () => {
    enqueueIncrementalSync().catch((err) => {
      console.error(
        `[worker] interval enqueueIncrementalSync failed: ${err?.message ?? err}`
      );
    });
  };

  // Keep a worker-local 5s scheduler so incremental sync continues even when
  // API interval scheduling is unavailable.
  enqueueIncrementalWithLogging();
  setInterval(enqueueIncrementalWithLogging, 5_000);
  console.log("[worker] Started 5-second incremental enqueue interval");

  // Register job handler for REFRESH_SALES_METRICS
  const { executeSalesMetricsRefresh } = await import("./modules/workers/sales-metrics");
  await boss.work(WorkerQueue.REFRESH_SALES_METRICS, async (jobs) => {
    const job = Array.isArray(jobs) ? jobs[0] : jobs;
    const data = job?.data as { forceColdLoad?: boolean } | undefined;
    const forceColdLoad = data?.forceColdLoad ?? false;
    await executeSalesMetricsRefresh({ forceColdLoad });
  });
  console.log("[worker] Registered REFRESH_SALES_METRICS job handler");

  // Initiate manager socket connection (will reconnect automatically if it fails)
  ensureManagerSocketReady().catch((err) => {
    console.error("[worker] Failed to establish manager socket:", err.message);
    console.log("[worker] Will continue retrying in background...");
  });

  console.log("[worker] Worker process ready - waiting for job requests");

  // Keep process alive
  process.on("SIGTERM", async () => {
    console.log("[worker] SIGTERM received, shutting down gracefully");
    await boss.stop();
    process.exit(0);
  });
}