const express = require('express');
const multer = require('multer');
const axios = require('axios');
const fs = require('fs-extra');
const FormData = require('form-data');
const path = require('path');
const { v4: uuidv4 } = require('uuid');

const app = express();
const PORT = 7860;
const DATA_FILE = './data/files.json';
const MAX_CATBOX_SIZE = 200 * 1024 * 1024; // 200 MB

const upload = multer({ dest: 'uploads/' });

// Load or initialize DB
let db = fs.existsSync(DATA_FILE) ? JSON.parse(fs.readFileSync(DATA_FILE)) : {};
fs.ensureFileSync(DATA_FILE);
app.use(express.static(path.join(__dirname, 'public')));

// Optional: Serve index.html at root
app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, 'public/index.html'));
});

// 📤 Upload to Catbox or Litterbox
async function uploadToCatboxOrLitterbox(filepath, originalname) {
    const fileSize = (await fs.stat(filepath)).size;
    const formData = new FormData();
    const fileStream = fs.createReadStream(filepath);

    if (fileSize <= MAX_CATBOX_SIZE) {
        formData.append('reqtype', 'fileupload');
        formData.append('fileToUpload', fileStream, originalname);
        const res = await axios.post('https://catbox.moe/user/api.php', formData, {
            headers: formData.getHeaders()
        });
        return { url: res.data, type: 'catbox' };
    } else {
        formData.append('reqtype', 'fileupload');
        formData.append('time', '72h');
        formData.append('fileToUpload', fileStream, originalname);
        const res = await axios.post('https://litterbox.catbox.moe/resources/internals/api.php', formData, {
            headers: formData.getHeaders()
        });
        return { url: res.data, type: 'litterbox' };
    }
}

// 📤 Upload Route
app.post('/upload', upload.single('file'), async (req, res) => {
    const file = req.file;
    const id = uuidv4();

    try {
        const { url, type } = await uploadToCatboxOrLitterbox(file.path, file.originalname);

        db[id] = {
            id,
            filename: file.originalname,
            localPath: file.path,
            externalUrl: url,
            source: type,
            expiresAt: type === 'litterbox' ? Date.now() + 1000 * 60 * 60 * 24 * 3 : null
        };

        fs.writeFileSync(DATA_FILE, JSON.stringify(db, null, 2));
        res.json({
            id,
            viewLink: `https://nexusv1-uploadx.hf.space/view/${id}`,
            externalUrl: url,
            source: type
        });
    } catch (e) {
        res.status(500).json({ error: 'Upload failed', details: e.message });
    }
});

// 🔗 View Route – No Redirect
app.get('/view/:id', async (req, res) => {
    const id = req.params.id;
    const file = db[id];

    if (!file || !(await fs.pathExists(file.localPath))) {
        return res.status(404).send('File not found');
    }

    res.download(file.localPath, file.filename);
});

// 🔄 Periodic Reupload for Litterbox files
setInterval(async () => {
    for (let id in db) {
        const file = db[id];
        if (file.source === 'litterbox' && file.expiresAt && (file.expiresAt - Date.now() < 1000 * 60 * 60 * 6)) {
            try {
                console.log(`♻️ Reuploading ${file.filename} (${id})`);
                const { url, type } = await uploadToCatboxOrLitterbox(file.localPath, file.filename);
                db[id].externalUrl = url;
                db[id].source = type;
                db[id].expiresAt = type === 'litterbox' ? Date.now() + 1000 * 60 * 60 * 24 * 3 : null;
                fs.writeFileSync(DATA_FILE, JSON.stringify(db, null, 2));
                console.log(`✅ Reuploaded: ${url}`);
            } catch (err) {
                console.error(`❌ Failed to reupload ${file.filename}:`, err.message);
            }
        }
    }
}, 1000 * 60 * 30); // every 30 mins

app.listen(PORT, () => console.log(`🟢 Server running on http://localhost:${PORT}`));