import { Job, Queue, QueueEvents, Worker } from "bullmq";
import dotenv from "dotenv";
import { Request, Response } from "express";
import fs from "fs-extra";
import multer from "multer";
import path from "path";
import { logger } from "../server.js";
import GenerateThumbnail from "../util/generateThumbnail.js";
import generateUniqueFilename from "../util/generateUniqueFilename.js";
import { convertHeicFiles } from "../util/heicConverter.js";
import { PathToRoFolder } from "../util/pathGenerators.js";
import { JobsListMedia } from "./jobsListMedia.js";

dotenv.config({
  path: path.resolve(process.cwd(), `.env.${process.env.NODE_ENV || "development"}`)
});

const UPLOAD_QUEUE_NAME = "uploadProcessingQueue";

const connectionOpts = {
  host: "localhost",
  port: 6379,
  maxRetriesPerRequest: 3,
  enableReadyCheck: true,
  reconnectOnError: (err: Error) => err.message.includes("READONLY")
};

const uploadProcessingQueue = new Queue(UPLOAD_QUEUE_NAME, {
  connection: connectionOpts,
  defaultJobOptions: {
    removeOnComplete: true,
    removeOnFail: true,
    attempts: 3,
    backoff: { type: "exponential", delay: 1000 }
  }
});

const uploadQueueEvents = new QueueEvents(UPLOAD_QUEUE_NAME, {
  connection: connectionOpts
});

// Upload processing worker
const uploadWorker = new Worker(
  UPLOAD_QUEUE_NAME,
  async (
    job: Job<{
      files: Express.Multer.File[];
      jobid: string;
      skipThumbnails: boolean;
    }>
  ) => {
    const { files, jobid, skipThumbnails } = job.data;
    try {
      logger.debug(`Processing upload for job ${jobid} with ${files.length} files, skipThumbnails: ${skipThumbnails}`);
      await job.updateProgress(10);

      // Convert HEIC files if any
      await convertHeicFiles(files);
      await job.updateProgress(40);

      if (!skipThumbnails) {
        // Log file states after conversion for debugging
        logger.debug("File states after HEIC conversion:", files.map(f => ({
          filename: f.filename,
          mimetype: f.mimetype,
          path: f.path
        })));

        // Check if converted files actually exist on disk
        for (const file of files) {
          const exists = await fs.pathExists(file.path);
          logger.debug(`File existence check: ${file.filename} at ${file.path} - exists: ${exists}`);
        }

        // After HEIC conversion, all files should be ready for thumbnail generation
        // Only exclude files that are still HEIC (which shouldn't happen after conversion)
        const filesToThumbnail = [];
        for (const file of files) {
          const isStillHeic =
            file.mimetype === "image/heic" ||
            file.mimetype === "image/heif" ||
            /\.heic$/i.test(file.filename) ||
            /\.heif$/i.test(file.filename);
          
          logger.debug(`File ${file.filename} - mimetype: ${file.mimetype}, isStillHeic: ${isStillHeic}, including: ${!isStillHeic}`);
          
          if (!isStillHeic) {
            filesToThumbnail.push(file);
          }
        }

        logger.debug(
          `Generating thumbnails for ${filesToThumbnail.length} files (excluding HEIC)`,
          filesToThumbnail.map((f) => f.filename)
        );

        // Generate thumbnails
        logger.debug(`About to generate thumbnails for ${filesToThumbnail.length} files`);
        const thumbnailPromises = filesToThumbnail.map((file, index) => {
          logger.debug(`Starting thumbnail generation for file ${index + 1}/${filesToThumbnail.length}: ${file.filename} at ${file.path}`);
          return GenerateThumbnail(file.path);
        });
        const thumbnailResults = await Promise.all(thumbnailPromises);
        logger.debug(`Thumbnail generation completed. Results:`, thumbnailResults);
        await job.updateProgress(90);
      }

      logger.debug(`Upload processing completed for job ${jobid}`);
      await job.updateProgress(100);

      return { success: true, filesProcessed: files.length };
    } catch (error) {
      logger.error(`Error processing upload for job ${jobid}:`, error);
      throw error;
    }
  },
  {
    connection: connectionOpts,
    concurrency: 2 // Allow 2 upload processing jobs to run concurrently
  }
);

// Event listeners for upload queue and worker
uploadProcessingQueue.on("waiting", (job) => {
  logger.debug(`[UploadQueue] Job waiting: ${job.data.jobid}`);
});
uploadProcessingQueue.on("error", (error) => {
  logger.error(`[UploadQueue] Queue error:`, error);
});

uploadWorker.on("ready", () => {
  logger.debug("[UploadWorker] Worker ready");
});
uploadWorker.on("active", (job, prev) => {
  logger.debug(`[UploadWorker] Job ${job.id} active (previous: ${prev})`);
});
uploadWorker.on("completed", async (job) => {
  logger.debug(`[UploadWorker] Job ${job.id} completed`);
  await job.remove();
  logger.debug(`[UploadWorker] Job ${job.id} removed from Redis`);
});
uploadWorker.on("failed", (jobId, reason) => {
  logger.error(`[UploadWorker] Job ${jobId} failed: ${reason}`);
});
uploadWorker.on("error", (error) => {
  logger.error(`[UploadWorker] Worker error:`, error);
});
uploadWorker.on("stalled", (job) => {
  logger.error(`[UploadWorker] Worker stalled: ${job}`);
});
uploadWorker.on("ioredis:close", () => {
  logger.error("[UploadWorker] Redis connection closed");
});

export const JobMediaUploadMulter = multer({
  storage: multer.diskStorage({
    destination: function (req, file, cb) {
      const jobid: string = (req.body.jobid || "").trim();
      const DestinationFolder: string = PathToRoFolder(jobid);
      fs.ensureDirSync(DestinationFolder);
      cb(jobid === "" || jobid === null ? new Error("Job ID not specified.") : null, DestinationFolder);
    },
    filename: function (req, file, cb) {
      logger.debug("Uploading file: ", {
        file: path.basename(file.originalname)
      });
      cb(null, generateUniqueFilename(file));
    }
  })
});

export async function jobsUploadMedia(req: Request, res: Response) {
  const jobid: string = (req.body.jobid || "").trim();

  try {
    const files = req.files as Express.Multer.File[] | undefined;
    if (!files || files.length === 0) {
      logger.warning("Upload contained no files.");
      res.status(400).send({
        status: false,
        message: "No file uploaded"
      });
      return;
    }

    // Check if client wants to skip waiting for response but still do processing
    if (req.body.skip_thumbnail) {
      logger.debug("Client requested skip_thumbnail - responding immediately but processing in background");
      // Set header to indicate we're skipping the response wait
      req.headers.skipResponse = "true";
      res.sendStatus(200);
      
      // Continue with background processing (conversion + thumbnails)
      const job = await uploadProcessingQueue.add("processUpload", {
        files,
        jobid,
        skipThumbnails: false // Always do thumbnails, just don't wait for completion
      });
      return;
    }

    // Add upload processing job to queue and wait for completion
    logger.debug(`Adding upload processing job for ${files.length} files with thumbnails enabled`);
    const job = await uploadProcessingQueue.add("processUpload", {
      files,
      jobid,
      skipThumbnails: false
    });

    // Wait for the job to complete
    await job.waitUntilFinished(uploadQueueEvents);
    logger.debug(`Upload processing job completed for job ${jobid}`);

    // Return the updated media list
    JobsListMedia(req, res);
  } catch (error) {
    logger.error("Error uploading job media.", {
      jobid,
      error: (error as Error).message
    });
    res.status(500).json((error as Error).message);
  }
}