import express from "express";
import multer from "multer";
import axios from "axios";
import sharp from "sharp";
import Link from "../models/Link.js";
import { authMiddleware } from "../middleware/auth.js";
import { parseICO } from "icojs";

const router = express.Router();

// Multer in-memory (niente filesystem)
const upload = multer({ storage: multer.memoryStorage() });

router.use(authMiddleware);

// Scarica immagine remota come Buffer
async function downloadImageAsBuffer(url) {
  const response = await axios.get(url, {
    responseType: "arraybuffer",
    maxRedirects: 5,
    headers: {
      "User-Agent": "Mozilla/5.0",
      "Accept": "image/*"
  }
  });

  return {
    buffer: Buffer.from(response.data),
    mime: response.headers["content-type"] || ""
  };
}

// Converte immagine → WebP 128x128 contain
async function processIcon(buffer, mime) {
  let inputBuffer = buffer;

  // Se è ICO → converti in PNG
  if (mime === "image/x-icon" || mime === "image/vnd.microsoft.icon") {
    const images = await parseICO(buffer);

    if (!images.length) {
      throw new Error("ICO non valido");
    }

    // Prendiamo l’immagine più grande dentro l’ICO
    const best = images.reduce((a, b) => (a.width > b.width ? a : b));

    inputBuffer = Buffer.from(best.buffer);
  }

  // Ora Sharp può lavorare
  return await sharp(inputBuffer)
    .resize(128, 128, {
      fit: "contain",
      background: { r: 0, g: 0, b: 0, alpha: 0 }
    })
    .webp({ quality: 90 })
    .toBuffer();
}

// ===============================
// GET LINKS
// ===============================
router.get("/", async (req, res) => {
  const links = await Link.find({ owner: req.userId });
  res.json(links);
});

// ===============================
// CREATE LINK
// ===============================
router.post("/", upload.single("icon"), async (req, res) => {
  const { url, name, iconURL } = req.body;

  let originalBuffer = null;

  // Caso 1: upload file
  if (req.file) {
    originalBuffer = req.file.buffer;
  }

  // Caso 2: URL remoto
  else if (iconURL) {
    originalBuffer = await downloadImageAsBuffer(iconURL);
  }

  let processedIcon = null;

  if (originalBuffer) {
    processedIcon = await processIcon(originalBuffer.buffer, originalBuffer.mime);
  }


  const link = await Link.create({
    url,
    name,
    owner: req.userId,
    icon: processedIcon
      ? {
          data: processedIcon,
          mime: "image/webp",
          size: processedIcon.length
        }
      : null
  });

  res.json(link);
});

// ===============================
// UPDATE LINK
// ===============================
router.put("/:id", upload.single("icon"), async (req, res) => {
  const { id } = req.params;
  const { name, url, iconURL } = req.body;

  const link = await Link.findOne({ _id: id, owner: req.userId });
  if (!link) return res.status(404).json({ error: "Link non trovato" });

  let originalBuffer = null;

  if (req.file) {
    originalBuffer = req.file.buffer;
  } else if (iconURL) {
    originalBuffer = await downloadImageAsBuffer(iconURL);
  }

  const update = { name, url };

  if (originalBuffer) {
    const processedIcon = await processIcon(originalBuffer.buffer, originalBuffer.mime);
    update.icon = {
      data: processedIcon,
      mime: "image/webp",
      size: processedIcon.length
    };
  }

  const updated = await Link.findOneAndUpdate(
    { _id: id, owner: req.userId },
    update,
    { new: true }
  );

  res.json(updated);
});

// ===============================
// DELETE LINK
// ===============================
router.delete("/:id", async (req, res) => {
  const link = await Link.findOneAndDelete({
    _id: req.params.id,
    owner: req.userId
  });

  if (!link) return res.status(404).json({ error: "Link non trovato" });

  res.json({ success: true });
});

export default router;