const { Queue, Worker } = require("bullmq");
const { registerCleanupTask } = require("../../utils/cleanupManager");
const getBullMQPrefix = require("../../utils/getBullMQPrefix");
const devDebugLogger = require("../../utils/devDebugLogger");
const moment = require("moment-timezone");
const { sendServerEmail } = require("../../email/sendemail");

let chatterApiQueue;
let chatterApiWorker;

/**
 * Initializes the Chatter API queue and worker.
 *
 * @param {Object} options - Configuration options for queue initialization.
 * @param {Object} options.pubClient - Redis client instance for queue communication.
 * @param {Object} options.logger - Logger instance for logging events and debugging.
 * @param {Function} options.processJob - Function to process the Chatter API job.
 * @param {Function} options.getChatterToken - Function to get Chatter token from Redis.
 * @param {Function} options.setChatterToken - Function to set Chatter token in Redis.
 * @returns {Queue} The initialized `chatterApiQueue` instance.
 */
const loadChatterApiQueue = async ({ pubClient, logger, processJob, getChatterToken, setChatterToken }) => {
  if (!chatterApiQueue) {
    const prefix = getBullMQPrefix();

    devDebugLogger(`Initializing Chatter API Queue with prefix: ${prefix}`);

    chatterApiQueue = new Queue("chatterApi", {
      prefix,
      connection: pubClient,
      defaultJobOptions: {
        removeOnComplete: true,
        removeOnFail: false,
        attempts: 3,
        backoff: {
          type: "exponential",
          delay: 60000 // 1 minute base delay
        }
      }
    });

    chatterApiWorker = new Worker(
      "chatterApi",
      async (job) => {
        const { start, end, bodyshopIds, skipUpload } = job.data;

        logger.log("chatter-api-queue-job-start", "INFO", "api", null, {
          jobId: job.id,
          start,
          end,
          bodyshopIds,
          skipUpload
        });

        try {
          // Provide sessionUtils-like object with token caching functions
          const sessionUtils = {
            getChatterToken,
            setChatterToken
          };

          const result = await processJob({
            start,
            end,
            bodyshopIds,
            skipUpload,
            sessionUtils
          });

          logger.log("chatter-api-queue-job-complete", "INFO", "api", null, {
            jobId: job.id,
            totals: result.totals
          });

          // Send email summary
          await sendServerEmail({
            subject: `Chatter API Report ${moment().format("MM-DD-YY")}`,
            text:
              `Totals:\n${JSON.stringify(result.totals, null, 2)}\n\n` +
              `Shop summaries:\n${JSON.stringify(result.allShopSummaries, null, 2)}\n\n` +
              `Errors:\n${JSON.stringify(result.allErrors, null, 2)}\n`
          });

          return result;
        } catch (error) {
          logger.log("chatter-api-queue-job-error", "ERROR", "api", null, {
            jobId: job.id,
            error: error.message,
            stack: error.stack
          });

          // Send error email
          await sendServerEmail({
            subject: `Chatter API Error ${moment().format("MM-DD-YY")}`,
            text: `Job failed:\n${error.message}\n\n${error.stack}`
          });

          throw error;
        }
      },
      {
        prefix,
        connection: pubClient,
        concurrency: 1, // Process one job at a time
        lockDuration: 14400000 // 4 hours - allow long-running jobs
      }
    );

    // Event handlers
    chatterApiWorker.on("completed", (job) => {
      devDebugLogger(`Chatter API job ${job.id} completed`);
    });

    chatterApiWorker.on("failed", (job, err) => {
      logger.log("chatter-api-queue-job-failed", "ERROR", "api", null, {
        jobId: job?.id,
        message: err?.message,
        stack: err?.stack
      });
    });

    chatterApiWorker.on("progress", (job, progress) => {
      devDebugLogger(`Chatter API job ${job.id} progress: ${progress}%`);
    });

    // Register cleanup task
    const shutdown = async () => {
      devDebugLogger("Closing Chatter API queue worker...");
      await chatterApiWorker.close();
      devDebugLogger("Chatter API queue worker closed");
    };
    registerCleanupTask(shutdown);
  }

  return chatterApiQueue;
};

/**
 * Retrieves the initialized `chatterApiQueue` instance.
 *
 * @returns {Queue} The `chatterApiQueue` instance.
 * @throws {Error} If `chatterApiQueue` is not initialized.
 */
const getQueue = () => {
  if (!chatterApiQueue) {
    throw new Error("Chatter API queue not initialized. Ensure loadChatterApiQueue is called during bootstrap.");
  }
  return chatterApiQueue;
};

/**
 * Dispatches a Chatter API job to the queue.
 *
 * @param {Object} options - Options for the job.
 * @param {string} options.start - Start date for the delivery window.
 * @param {string} options.end - End date for the delivery window.
 * @param {Array<string>} options.bodyshopIds - Optional specific shops to process.
 * @param {boolean} options.skipUpload - Dry-run flag.
 * @returns {Promise<void>} Resolves when the job is added to the queue.
 */
const dispatchChatterApiJob = async ({ start, end, bodyshopIds, skipUpload }) => {
  const queue = getQueue();

  const jobData = {
    start: start || moment().subtract(1, "days").startOf("day").toISOString(),
    end: end || moment().endOf("day").toISOString(),
    bodyshopIds: bodyshopIds || [],
    skipUpload: skipUpload || false
  };

  await queue.add("process-chatter-api", jobData, {
    jobId: `chatter-api-${moment().format("YYYY-MM-DD-HHmmss")}`
  });

  devDebugLogger(`Added Chatter API job to queue: ${JSON.stringify(jobData)}`);
};

module.exports = { loadChatterApiQueue, getQueue, dispatchChatterApiJob };