import { Worker, Job } from "bullmq";
import { redisConnection } from "../connection";
import { OcrJobData } from "../queues";
import { io } from "../../socket";
import { runOcrProcessor } from "../processors/ocrProcessor";

function emitJobUpdate(
  socketId: string | undefined,
  jobId: string,
  status: "active" | "completed" | "failed",
  payload: Record<string, any>
) {
  const event = "job:update";
  const data = { jobId, jobType: "ocr", status, ...payload };
  if (socketId && io) {
    io.to(socketId).emit(event, data);
  } else if (io) {
    io.emit(event, data);
  }
}

async function processOcrJob(job: Job<OcrJobData>) {
  const { socketId, files } = job.data;
  const jobId = job.id ?? job.name;

  emitJobUpdate(socketId, jobId, "active", { message: "OCR processing started…" });

  try {
    const rows = await runOcrProcessor({ files });
    emitJobUpdate(socketId, jobId, "completed", { result: { rows } });
    return rows;
  } catch (err: any) {
    const errorMsg = err?.message ?? String(err);
    emitJobUpdate(socketId, jobId, "failed", { error: errorMsg });
    throw err;
  }
}

export function startOcrWorker() {
  const worker = new Worker<OcrJobData>("ocr-jobs", processOcrJob, {
    connection: redisConnection,
    concurrency: 2, // OCR service allows 2 concurrent
  });

  worker.on("completed", (job) => {
    console.log(`[ocrWorker] job ${job.id} completed`);
  });

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

  console.log("[ocrWorker] started");
  return worker;
}