const express = require('express');
const bodyParser = require('body-parser');
const rateLimit = require('express-rate-limit');
const fs = require('fs');
const path = require('path');

const app = express();
const PORT = process.env.PORT || 3000; // User preferred default
const DATA_FILE = path.join(__dirname, '../data/ressentis.json');
const APP_PASSWORD = process.env.APP_PASSWORD || 'parox'; // Default password

app.use(bodyParser.json());
app.use(express.static(path.join(__dirname, 'public')));

// Middleware to check authentication
const checkAuth = (req, res, next) => {
    // For simplicity, we'll check a custom header 'x-auth-token' or query param
    const token = req.headers['x-auth-token'];
    if (token === APP_PASSWORD) {
        next();
    } else {
        res.status(401).json({ error: 'Unauthorized' });
    }
};

// GCS Setup
const { Storage } = require('@google-cloud/storage');
const GCS_BUCKET_NAME = process.env.GCS_BUCKET_NAME;

// HF Spaces / General Secret support: Write key from ENV to file if available
if (process.env.GCS_KEY_JSON && !fs.existsSync('/app/gcs-key.json')) {
    try {
        console.log("> Writing GCS Key from ENV (GCS_KEY_JSON) to file...");
        fs.writeFileSync('/app/gcs-key.json', process.env.GCS_KEY_JSON);
        process.env.GOOGLE_APPLICATION_CREDENTIALS = '/app/gcs-key.json';
    } catch (e) {
        console.error("! Failed to write GCS Key from ENV:", e);
    }
}

let gcsBucket = null;
if (GCS_BUCKET_NAME) {
    try {
        const storage = new Storage();
        gcsBucket = storage.bucket(GCS_BUCKET_NAME);
        console.log(`> GCS Enabled: Using bucket '${GCS_BUCKET_NAME}'`);
    } catch (e) {
        console.error("! GCS config found but failed to init:", e);
    }
} else {
    console.log("> GCS Disabled: Using local filesystem");
    // Ensure data file exists locally
    if (!fs.existsSync(DATA_FILE)) {
        try {
            fs.mkdirSync(path.dirname(DATA_FILE), { recursive: true });
            fs.writeFileSync(DATA_FILE, JSON.stringify([], null, 2));
        } catch (e) { console.error("FS Init Error:", e); }
    }
}

// Data Handling Functions
async function readData() {
    if (gcsBucket) {
        try {
            const [contents] = await gcsBucket.file('ressentis.json').download();
            return JSON.parse(contents.toString());
        } catch (e) {
            if (e.code === 404) return []; // Auto-create on first write
            throw e;
        }
    } else {
        if (fs.existsSync(DATA_FILE)) {
            return JSON.parse(fs.readFileSync(DATA_FILE, 'utf8'));
        }
        return [];
    }
}

async function writeData(data) {
    const jsonStr = JSON.stringify(data, null, 2);
    if (gcsBucket) {
        await gcsBucket.file('ressentis.json').save(jsonStr, {
            contentType: 'application/json',
            resumable: false
        });
    } else {
        fs.writeFileSync(DATA_FILE, jsonStr);
    }
}

// API Routes

// Login check
const loginLimiter = rateLimit({
    windowMs: 15 * 60 * 1000, // 15 minutes
    max: 5, // Limit each IP to 5 requests per windowMs
    messsage: { error: 'Too many login attempts, please try again after 15 minutes' },
    standardHeaders: true,
    legacyHeaders: false,
});

app.post('/api/login', loginLimiter, (req, res) => {
    const { password } = req.body;
    if (password === APP_PASSWORD) {
        res.json({ success: true, token: password });
    } else {
        res.status(401).json({ success: false, error: 'Invalid Password' });
    }
});

// Get Data
app.get('/api/data', checkAuth, async (req, res) => {
    try {
        const data = await readData();
        res.json(data);
    } catch (e) {
        console.error("Read Error:", e);
        res.status(500).json({ error: 'Failed to read data' });
    }
});

// Save Data
app.post('/api/data', checkAuth, async (req, res) => {
    const newData = req.body;
    try {
        await writeData(newData);
        res.json({ success: true });
    } catch (e) {
        console.error("Save Error:", e);
        res.status(500).json({ error: 'Failed to save data' });
    }
});

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