import { Request, Response } from "express";
import fs from "fs-extra";
import JSZip from "jszip";
import path from "path";
import { logger } from "../server.js";
import ListableChecker from "../util/listableChecker.js";
import { PathToRoBillsFolder, PathToRoFolder } from "../util/pathGenerators.js";
import { BillsRelativeFilePath, JobRelativeFilePath } from "../util/serverInit.js";

//param: files: string[] | array of filenames.
export async function jobsDownloadMedia(req: Request, res: Response) {
  const jobid: string = (req.body.jobid || "").trim();

  try {
    const files: string[] = req.body.files || [];
    const zip: JSZip = new JSZip();
    await fs.ensureDir(PathToRoFolder(jobid));

    logger.debug(`Generating batch download for Job ID ${jobid}`, files);

    const jobFileList: fs.Dirent[] = (
      await fs.readdir(PathToRoFolder(jobid), { withFileTypes: true })
    ).filter((f) => f.isFile() && ListableChecker(f));
    const billFileList: fs.Dirent[] = (
      await fs.readdir(PathToRoBillsFolder(jobid), { withFileTypes: true })
    ).filter((f) => f.isFile() && ListableChecker(f));

    // Helper to add files to the zip
    const addFilesToZip = async (
      fileList: fs.Dirent[],
      relativePathFn: (jobid: string, filename: string) => string
    ) => {
      await Promise.all(
        fileList.map(async (file) => {
          const baseName = path.basename(file.name);
          if (files.length === 0 || files.includes(baseName)) {
            try {
              const fileOnDisk: Buffer = await fs.readFile(relativePathFn(jobid, file.name));
              zip.file(baseName, fileOnDisk);
            } catch (err) {
              logger.warning(`Could not add file to zip: ${file.name}`, err);
            }
          }
        })
      );
    };

    await addFilesToZip(jobFileList, JobRelativeFilePath);
    await addFilesToZip(billFileList, BillsRelativeFilePath);

    // Set headers for download
    res.setHeader("Content-Disposition", `attachment; filename="${jobid}.zip"`);
    res.setHeader("Content-Type", "application/zip");

    zip
      .generateNodeStream({
        type: "nodebuffer",
        streamFiles: true
      })
      .pipe(res)
      .on("finish", () => {
        logger.debug(`Zip stream finished for Job ID ${jobid}`);
      });
  } catch (error) {
    logger.error("Error downloading job media.", {
      jobid,
      error: (error as Error).message
    });
    if (!res.headersSent) res.status(500).json((error as Error).message);
  }
}