import { Worker, type Job } from "bullmq";
import { getConnection, BULLMQ_PREFIX } from "./client";
import { INDEX_QUEUE } from "./queue";
import { indexContentFile, runFullIndex } from "@mcpedia/core";

export function createWorker(): Worker {
  const worker = new Worker(
    INDEX_QUEUE,
    async (job: Job) => {
      switch (job.name) {
        case "index-doc": {
          const { relPath, reason } = job.data as {
            relPath: string;
            reason: string;
          };
          await job.log(`indexing ${relPath}`);
          const r = await indexContentFile(relPath, reason);
          return r;
        }
        case "index-all": {
          const { reason } = job.data as { reason: string };
          await job.log(`full index (${reason})`);
          return await runFullIndex(reason);
        }
        default:
          throw new Error(`unknown job type: ${job.name}`);
      }
    },
    {
      connection: getConnection(),
      prefix: BULLMQ_PREFIX,
      concurrency: 4,
    },
  );

  worker.on("completed", (job) => {
    console.log(`[worker] completed ${job.name} (${job.id})`);
  });
  worker.on("failed", (job, err) => {
    console.error(`[worker] failed ${job?.name} (${job?.id}): ${err.message}`);
  });
  worker.on("error", (err) => {
    console.error(`[worker] error:`, err.message);
  });

  return worker;
}

/** Start the worker and wire graceful shutdown. */
export async function startWorker(): Promise<Worker> {
  const worker = createWorker();
  console.log("[worker] indexing worker started");

  const shutdown = async (sig: string) => {
    console.log(`[worker] ${sig} received, closing...`);
    await worker.close();
    process.exit(0);
  };
  process.on("SIGINT", () => void shutdown("SIGINT"));
  process.on("SIGTERM", () => void shutdown("SIGTERM"));

  return worker;
}