require('dotenv').config();

const express = require('express');
const mongoose = require('mongoose');
const session = require('express-session');
const path = require('path');
const fetch = require('node-fetch');
const cors = require('cors');
const logger = require('./logger');
const bcrypt = require('bcryptjs');
const User = require('./models/User');  // Assuming User model is defined for your MongoDB users

const app = express();
const port = process.env.PORT || 3001;

// MongoDB connection setup
const mongoUri = process.env.MONGO_URI;

mongoose.connect(mongoUri)
    .then(() => logger.info('Connected to MongoDB successfully'))
    .catch(err => logger.error('Failed to connect to MongoDB:', err));

// Configuration and constants setup
const config = {
    SESSION_SECRET: process.env.SESSION_SECRET || "default-session-secret"
};

const STREMIO_API = {
    BASE_URL: "https://api.strem.io/api",
    LOGIN: "/login",
    REGISTER: "/register",
    ADDON_COLLECTION_GET: "/addonCollectionGet",
    ADDON_COLLECTION_SET: "/addonCollectionSet",
    LOGOUT: "/logout"
};

const corsOptions = {
    origin: "*",
    methods: ["GET", "POST", "DELETE", "PUT", "PATCH"],
    allowedHeaders: ["Content-Type", "Authorization"],
    credentials: true,
    maxAge: 86400
};

// Process error handlers
process.on("uncaughtException", (error) => {
    logger.error("Uncaught Exception:", error);
    process.exit(1);
});

process.on("unhandledRejection", (reason, promise) => {
    logger.error("Unhandled Rejection at:", promise, "reason:", reason);
});

// Middleware setup
app.use(cors(corsOptions));
app.options("*", cors(corsOptions));
app.use(express.json({ limit: "50mb" }));
app.use(express.static("public"));
app.use(session({
    secret: config.SESSION_SECRET,
    resave: false,
    saveUninitialized: true,
    cookie: { 
        secure: false,
        maxAge: 24 * 60 * 60 * 1000
    }
}));

// POST login route
app.post('/api/login', async (req, res) => {
    const { email, password } = req.body;
    try {
        logger.info('Attempting login for email:', email);
        
        const user = await User.findOne({ email });
        if (!user) {
            logger.info('User not found');
            return res.status(401).send('User not found');
        }

        const isMatch = await bcrypt.compare(password, user.password);
        if (!isMatch) {
            logger.info('Invalid credentials');
            return res.status(401).send('Invalid credentials');
        }

        // Session handling
        req.session.user = user;  // Save user to session
        res.status(200).send({ message: 'Login successful' });
    } catch (error) {
        logger.error('Login error:', error);

        // Send generic error message if unexpected token error occurs
        if (error.message && error.message.startsWith('Unexpected token')) {
            return res.status(500).send('Internal server error: invalid response format');
        } else {
            return res.status(500).send('Internal server error');
        }
    }
});

// Register route for user creation with bcrypt hashing
app.post('/api/register', async (req, res) => {
    const { email, password } = req.body;
    try {
        const hashedPassword = await bcrypt.hash(password, 10);
        const newUser = new User({ email, password: hashedPassword });

        await newUser.save();
        res.status(201).send({ message: 'User registered successfully' });
    } catch (error) {
        logger.error('Registration error:', error);
        res.status(500).send('Internal server error');
    }
});

// Hugging Face API Example Function (to demonstrate API interaction)
async function fetchHuggingFaceData(apiUrl) {
    try {
        const response = await fetch(apiUrl);
        if (!response.ok) {
            throw new Error(`HTTP Error: ${response.status}`);
        }
        const data = await response.json();
        logger.info('Hugging Face API response:', data);
        return data;
    } catch (error) {
        logger.error('Failed to fetch Hugging Face API:', error);
        throw error;
    }
}

// Server initialization
async function startServer() {
    try {
        app.listen(port, () => {
            logger.info(`Server started on port ${port}`);
        });
    } catch (error) {
        logger.error('Failed to initialize:', error);
        process.exit(1);
    }
}

startServer();

module.exports = app;