import express from "express";
import path from "node:path";
import fs from "node:fs";
import { promises as fsp } from "node:fs";
import fsExtra from "fs-extra";
import multer from "multer";
import archiver from "archiver";
import extract from "extract-zip";
import tar from "tar";
import axios from "axios";
import os from "node:os";
import { pipeline } from "node:stream/promises";
import { fileURLToPath } from "node:url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const app = express();
app.use(express.json({ limit: "50mb" }));
app.use(express.urlencoded({ extended: true }));

// ROOT_DIR default: os.tmpdir() (bisa override via env ROOT_DIR)
const ROOT_DIR = path.resolve(process.env.ROOT_DIR || os.tmpdir());
fsExtra.ensureDirSync(ROOT_DIR);

// Multer temp dir juga pakai tmp
const uploadTmpDir = path.join(os.tmpdir(), "filemgr_uploads");
fsExtra.ensureDirSync(uploadTmpDir);
const upload = multer({ dest: uploadTmpDir });

// ===== Utils (tanpa regex untuk normalisasi path) =====
const toPosix = (p) => String(p).split("\\").join("/");

function stripLeadingSlashes(s) {
  if (!s) return "";
  let i = 0;
  while (i < s.length && (s[i] === "/" || s[i] === "\\")) i++;
  return s.slice(i);
}
const badName = (name) =>
  !name || String(name).includes("..") || String(name).includes("/") || String(name).includes("\\");

function safeResolve(rel = "") {
  const relNorm = stripLeadingSlashes(String(rel));
  const full = path.resolve(ROOT_DIR, relNorm);
  const relToRoot = path.relative(ROOT_DIR, full);
  if (relToRoot.startsWith("..") || path.isAbsolute(relToRoot)) {
    const err = new Error("Path outside ROOT_DIR");
    err.status = 400;
    throw err;
  }
  return full;
}

function buildBreadcrumb(rel = "") {
  const parts = toPosix(rel).split("/").filter(Boolean);
  let acc = "";
  const crumbs = [{ name: "root", path: "" }];
  for (const p of parts) {
    acc = acc ? `${acc}/${p}` : p;
    crumbs.push({ name: p, path: acc });
  }
  return crumbs;
}

// Deteksi format arsip (tanpa regex)
function detectExtFull(name) {
  const lower = String(name).toLowerCase();
  if (lower.endsWith(".tar.gz")) return "tar.gz";
  if (lower.endsWith(".tgz")) return "tgz";
  return path.extname(lower).slice(1); // zip/tar dll
}
function archiveFormatFromName(name) {
  const e = detectExtFull(name);
  if (e === "zip") return "zip";
  if (e === "tar") return "tar";
  if (e === "tgz" || e === "tar.gz") return "tgz";
  return null;
}
function stripArchiveExt(baseName) {
  let b = String(baseName);
  const lower = b.toLowerCase();
  if (lower.endsWith(".tar.gz")) return b.slice(0, -7);
  if (lower.endsWith(".tgz")) return b.slice(0, -4);
  if (lower.endsWith(".zip")) return b.slice(0, -4);
  if (lower.endsWith(".tar")) return b.slice(0, -4);
  return b;
}
function guessArchiveFormat(name, contentType = "") {
  const byName = archiveFormatFromName(name);
  if (byName) return byName;
  const ct = String(contentType).toLowerCase();
  if (ct.includes("zip")) return "zip";
  if (ct.includes("x-tar") || ct === "application/tar") return "tar";
  if (ct.includes("gzip")) return "tgz";
  return null;
}
function parseContentDispositionFilename(cd) {
  if (!cd) return null;
  // Contoh: attachment; filename="file.zip"; filename*=UTF-8''file.zip
  const parts = cd.split(";").map((s) => s.trim());
  let fname = null;
  for (const p of parts) {
    if (p.toLowerCase().startsWith("filename*=")) {
      let v = p.substring(9).trim(); // setelah 'filename*='
      if ((v.startsWith('"') && v.endsWith('"')) || (v.startsWith("'") && v.endsWith("'"))) {
        v = v.slice(1, -1);
      }
      const idx = v.indexOf("''");
      if (idx !== -1) v = v.slice(idx + 2);
      try { fname = decodeURIComponent(v); } catch { fname = v; }
      break;
    } else if (p.toLowerCase().startsWith("filename=")) {
      let v = p.substring(9).trim();
      if ((v.startsWith('"') && v.endsWith('"')) || (v.startsWith("'") && v.endsWith("'"))) {
        v = v.slice(1, -1);
      }
      try { fname = decodeURIComponent(v); } catch { fname = v; }
      // Jangan break dulu, utamakan filename* kalau ada (RFC)
    }
  }
  return fname;
}

// ===== Routes =====
app.get("/api/list", async (req, res, next) => {
  try {
    const rel = req.query.path ? String(req.query.path) : "";
    const dirFull = safeResolve(rel);
    const stat = await fsExtra.stat(dirFull);
    if (!stat.isDirectory()) return res.status(400).json({ error: "Not a directory" });

    const items = await fsp.readdir(dirFull, { withFileTypes: true });
    const details = await Promise.all(
      items.map(async (d) => {
        const full = path.join(dirFull, d.name);
        const s = await fsExtra.stat(full);
        const isDir = s.isDirectory();
        const ext = isDir ? "" : path.extname(d.name).slice(1).toLowerCase();
        const extFull = isDir ? "" : detectExtFull(d.name);
        const archFormat = isDir ? null : archiveFormatFromName(d.name);
        return {
          name: d.name,
          relPath: toPosix(path.join(rel, d.name)),
          isDir,
          size: isDir ? null : s.size,
          mtime: s.mtimeMs,
          ext,
          extFull,
          archFormat
        };
      })
    );

    details.sort((a, b) => {
      if (a.isDir && !b.isDir) return -1;
      if (!a.isDir && b.isDir) return 1;
      return a.name.localeCompare(b.name);
    });

    res.json({ path: toPosix(rel), breadcrumb: buildBreadcrumb(rel), items: details });
  } catch (err) {
    next(err);
  }
});

// Create folder
app.post("/api/folder", async (req, res, next) => {
  try {
    const { parent = "", name } = req.body;
    if (badName(name)) return res.status(400).json({ error: "Invalid folder name" });
    const dirFull = safeResolve(parent);
    await fsExtra.ensureDir(path.join(dirFull, name));
    res.json({ ok: true });
  } catch (err) {
    next(err);
  }
});

// Create file
app.post("/api/file", async (req, res, next) => {
  try {
    const { parent = "", name, content = "" } = req.body;
    if (badName(name)) return res.status(400).json({ error: "Invalid file name" });
    const dirFull = safeResolve(parent);
    const dest = path.join(dirFull, name);
    await fsExtra.ensureDir(path.dirname(dest));
    await fsp.writeFile(dest, content, "utf8");
    res.json({ ok: true });
  } catch (err) {
    next(err);
  }
});

// Update text file
app.put("/api/file", async (req, res, next) => {
  try {
    const { path: rel, content = "" } = req.body;
    if (!rel) return res.status(400).json({ error: "Missing path" });
    const full = safeResolve(rel);
    const s = await fsExtra.stat(full);
    if (!s.isFile()) return res.status(400).json({ error: "Not a file" });
    await fsp.writeFile(full, content, "utf8");
    res.json({ ok: true });
  } catch (err) {
    next(err);
  }
});

// Read small text file
app.get("/api/file", async (req, res, next) => {
  try {
    const rel = String(req.query.path || "");
    const full = safeResolve(rel);
    const s = await fsExtra.stat(full);
    if (!s.isFile()) return res.status(400).json({ error: "Not a file" });
    if (s.size > 2 * 1024 * 1024) return res.status(400).json({ error: "File too large to view" });
    const buf = await fsp.readFile(full);
    res.json({ content: buf.toString("utf8") });
  } catch (err) {
    next(err);
  }
});

// Rename
app.post("/api/rename", async (req, res, next) => {
  try {
    const { path: rel, newName } = req.body;
    if (!rel || badName(newName)) return res.status(400).json({ error: "Invalid input" });
    const full = safeResolve(rel);
    const parentRel = toPosix(path.dirname(rel));
    const dest = path.join(safeResolve(parentRel), newName);
    await fsExtra.move(full, dest, { overwrite: false });
    res.json({ ok: true, newPath: toPosix(path.join(parentRel, newName)) });
  } catch (err) {
    next(err);
  }
});

// Move
app.post("/api/move", async (req, res, next) => {
  try {
    const { from, toDir } = req.body;
    if (!from) return res.status(400).json({ error: "Missing from" });
    const srcFull = safeResolve(from);
    const toDirFull = safeResolve(toDir || "");
    const base = path.basename(srcFull);
    const destFull = path.join(toDirFull, base);
    await fsExtra.move(srcFull, destFull, { overwrite: false });
    res.json({ ok: true, newPath: toPosix(path.join(toDir || "", base)) });
  } catch (err) {
    next(err);
  }
});

// Delete
app.delete("/api/entry", async (req, res, next) => {
  try {
    const rel = String(req.query.path || "");
    const full = safeResolve(rel);
    await fsExtra.remove(full);
    res.json({ ok: true });
  } catch (err) {
    next(err);
  }
});

// Upload
app.post("/api/upload", upload.array("files"), async (req, res, next) => {
  try {
    const rel = String(req.query.path || "");
    const destDir = safeResolve(rel);
    await fsExtra.ensureDir(destDir);
    const moved = [];
    for (const file of req.files || []) {
      const target = path.join(destDir, file.originalname);
      await fsExtra.move(file.path, target, { overwrite: true });
      moved.push({ name: file.originalname });
    }
    res.json({ ok: true, files: moved });
  } catch (err) {
    next(err);
  }
});

// Download dari URL + auto-extract (ZIP/TAR/TGZ)
app.post("/api/fetch-url", async (req, res, next) => {
  try {
    const { url, destDir = "", filename, autoExtract = true, removeArchive = false, extractTo } = req.body;
    if (!url) return res.status(400).json({ error: "Missing url" });
    const destDirFull = safeResolve(destDir);
    await fsExtra.ensureDir(destDirFull);

    const resp = await axios.get(url, {
      responseType: "stream",
      validateStatus: (s) => s >= 200 && s < 400
    });

    let name = filename;
    if (!name) {
      const cd = resp.headers["content-disposition"];
      name = parseContentDispositionFilename(cd);
      if (!name) {
        try {
          const u = new URL(url);
          const base = path.basename(u.pathname);
          name = base || "downloaded.file";
        } catch {
          name = "downloaded.file";
        }
      }
    }
    if (badName(name)) name = `downloaded-${Date.now()}`;
    const savedRel = toPosix(path.join(destDir, name));
    const savedFull = path.join(destDirFull, name);

    // Simpan file
    const ws = fs.createWriteStream(savedFull);
    await pipeline(resp.data, ws);

    let extractedTo = null;
    if (autoExtract) {
      const format = guessArchiveFormat(name, resp.headers["content-type"]);
      if (format) {
        let destRel = extractTo;
        if (!destRel) {
          const base = stripArchiveExt(path.basename(name));
          destRel = toPosix(path.join(destDir, base));
        }
        const destFull = safeResolve(destRel);
        await fsExtra.ensureDir(destFull);

        if (format === "zip") {
          await extract(savedFull, { dir: destFull });
        } else if (format === "tar") {
          await tar.x({ file: savedFull, cwd: destFull, gzip: false });
        } else if (format === "tgz") {
          await tar.x({ file: savedFull, cwd: destFull, gzip: true });
        }
        extractedTo = destRel;

        if (removeArchive) {
          await fsExtra.remove(savedFull);
        }
      }
    }

    res.json({ ok: true, savedAs: savedRel, extractedTo });
  } catch (err) {
    next(err);
  }
});

// Archive (zip/tar/tgz)
app.post("/api/archive", async (req, res, next) => {
  try {
    const { path: rel = "", entries = [], name, format = "zip" } = req.body;
    const dirFull = safeResolve(rel);
    if (!Array.isArray(entries) || entries.length === 0) {
      return res.status(400).json({ error: "No entries to archive" });
    }

    const fmt = String(format).toLowerCase();
    let extName, archiverType, archiverOpts;
    if (fmt === "zip") {
      extName = "zip";
      archiverType = "zip";
      archiverOpts = { zlib: { level: 9 } };
    } else if (fmt === "tar") {
      extName = "tar";
      archiverType = "tar";
      archiverOpts = { gzip: false };
    } else if (fmt === "tgz" || fmt === "tar.gz") {
      extName = "tar.gz";
      archiverType = "tar";
      archiverOpts = { gzip: true, gzipOptions: { level: 9 } };
    } else {
      return res.status(400).json({ error: "Unsupported format" });
    }

    let outName = name;
    if (!outName) {
      const ts = new Date().toISOString().replaceAll(":", "-").replaceAll(".", "-");
      outName = `archive-${ts}.${extName}`;
    } else {
      const lower = outName.toLowerCase();
      const needExt =
        (extName === "zip" && !lower.endsWith(".zip")) ||
        (extName === "tar" && !lower.endsWith(".tar")) ||
        (extName === "tar.gz" && !(lower.endsWith(".tar.gz") || lower.endsWith(".tgz")));
      if (needExt) outName += `.${extName}`;
    }
    if (badName(outName)) return res.status(400).json({ error: "Invalid archive name" });

    const outFull = path.join(dirFull, outName);

    await new Promise((resolve, reject) => {
      const output = fs.createWriteStream(outFull);
      const archive = archiver(archiverType, archiverOpts);
      output.on("close", resolve);
      output.on("error", reject);
      archive.on("error", reject);
      archive.pipe(output);

      for (const nm of entries) {
        if (badName(path.basename(nm))) {
          archive.destroy(new Error("Invalid entry name"));
          return;
        }
        const full = path.join(dirFull, nm);
        const nameInArchive = path.basename(nm);
        if (fs.existsSync(full)) {
          const stat = fs.lstatSync(full);
          if (stat.isDirectory()) archive.directory(full, nameInArchive);
          else archive.file(full, { name: nameInArchive });
        }
      }
      archive.finalize();
    });

    res.json({ ok: true, archive: toPosix(path.join(rel, outName)) });
  } catch (err) {
    next(err);
  }
});

// Unarchive (zip/tar/tgz)
app.post("/api/unarchive", async (req, res, next) => {
  try {
    const { zipPath, destDir } = req.body;
    if (!zipPath) return res.status(400).json({ error: "archive path required" });
    const archiveFull = safeResolve(zipPath);
    const format = archiveFormatFromName(archiveFull);
    if (!format) return res.status(400).json({ error: "Unsupported archive format" });

    let destRel = destDir;
    if (!destRel) {
      const base = stripArchiveExt(path.basename(archiveFull));
      destRel = toPosix(path.join(path.dirname(zipPath), base));
    }
    const destFull = safeResolve(destRel);
    await fsExtra.ensureDir(destFull);

    if (format === "zip") {
      await extract(archiveFull, { dir: destFull });
    } else if (format === "tar") {
      await tar.x({ file: archiveFull, cwd: destFull, gzip: false });
    } else if (format === "tgz") {
      await tar.x({ file: archiveFull, cwd: destFull, gzip: true });
    }

    res.json({ ok: true, extractedTo: destRel });
  } catch (err) {
    next(err);
  }
});

// Download file ke client
app.get("/api/download", async (req, res, next) => {
  try {
    const rel = String(req.query.path || "");
    const full = safeResolve(rel);
    const s = await fsExtra.stat(full);
    if (!s.isFile()) return res.status(400).json({ error: "Not a file" });
    res.download(full, path.basename(full));
  } catch (err) {
    next(err);
  }
});

// Serve UI
app.use("/", express.static(path.join(__dirname, "public")));

app.use((err, req, res, next) => {
  console.error(err);
  const status = err.status || 500;
  res.status(status).json({ error: err.message || "Internal error" });
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`File Manager (ESM) at http://localhost:${PORT}`);
  console.log(`ROOT_DIR = ${ROOT_DIR}`);
});