const express = require('express');
const Stripe = require('stripe');
require('dotenv').config();

const app = express();
app.use(express.json());

const config = {
    STRIPE_SECRET_KEY: process.env.STRIPE_SECRET_KEY,
    STRIPE_WEBHOOK_SECRET: process.env.STRIPE_WEBHOOK_SECRET,
    APP_HOST: process.env.APP_HOST || 'http://localhost:3000',
    PORT: process.env.PORT || 8080
};

// Stripe service
class StripeService {
    constructor() {
        this.client = new Stripe(config.STRIPE_SECRET_KEY);
        this.prices = {
            STANDARD: {
                monthly: process.env.STRIPE_STANDARD_SUBSCRIPTION_PRICE_ID,
                yearly: process.env.STRIPE_STANDARD_ANNUAL_SUBSCRIPTION_PRICE_ID
            },
            UNLIMITED: {
                monthly: process.env.STRIPE_UNLIMITED_SUBSCRIPTION_PRICE_ID,
                yearly: process.env.STRIPE_UNLIMITED_ANNUAL_SUBSCRIPTION_PRICE_ID
            }
        };
    }

    // Only for test
    async createTestSubscription() {
        try {
            const customer = await this.client.customers.create({
                email: 'test@example.com',
                description: 'Client test',
                source: 'tok_visa'
            });

            const priceId = this.prices.STANDARD.monthly;
            const price = await this.client.prices.retrieve(priceId);

            const subscription = await this.client.subscriptions.create({
                customer: customer.id,
                items: [{ price: price.id }],
                payment_behavior: 'default_incomplete',
                expand: ['latest_invoice.payment_intent']
            });

            return {
                subscriptionId: subscription.id,
                customerId: customer.id,
                status: subscription.status,
                priceId: price.id
            };

        } catch (error) {
            throw error;
        }
    }

    async createCheckoutSession(subscription, frequency) {
        const priceId = this.getPriceId(subscription.type, frequency);

        return await this.client.checkout.sessions.create({
            mode: 'subscription',
            payment_method_types: ['card', 'sepa_debit'],
            billing_address_collection: 'auto',
            line_items: [{
                price: priceId,
                quantity: subscription.type === 'STANDARD' ? subscription.seats : 1,
            }],
            success_url: `${config.APP_HOST}/subscription/success`, // Success page (frontend)
            cancel_url: `${config.APP_HOST}/subscription/error`, // Error page (frontend)
            metadata: {
                subscription: JSON.stringify(subscription),
            },
            allow_promotion_codes: true,
            automatic_tax: { enabled: true }
        });
    }

    getPriceId(type, frequency) {
        return this.prices[type][frequency];
    }

    async getSubscription(subscriptionId) {
        return await this.client.subscriptions.retrieve(subscriptionId);
    }

    async createPortalSession(subscriptionId) {
        const subscription = await this.getSubscription(subscriptionId);
        return await this.client.billingPortal.sessions.create({
            customer: subscription.customer,
            return_url: `${config.APP_HOST}/subscription/manage`
        });
    }
}

const stripeService = new StripeService();

// Validation middleware
const validateSubscription = (req, res, next) => {
    const { type, seats, frequency } = req.body;
    
    if (!type || !['STANDARD', 'UNLIMITED'].includes(type)) {
        return res.status(400).json({
            success: false,
            message: 'Type d\'abonnement invalide'
        });
    }

    if (type === 'STANDARD' && (!seats || seats < 1)) {
        return res.status(400).json({
            success: false,
            message: 'Nombre de sièges invalide'
        });
    }

    if (!frequency || !['monthly', 'yearly'].includes(frequency)) {
        return res.status(400).json({
            success: false,
            message: 'Fréquence invalide'
        });
    }

    next();
};

// Routes

// Only for test
app.post('/api/test/create-subscription', async (req, res) => {
    try {
        const result = await stripeService.createTestSubscription();
        res.json({
            success: true,
            data: result
        });
    } catch (error) {
        res.status(500).json({
            success: false,
            message: 'Erreur lors de la création de l\'abonnement de test',
            error: {
                message: error.message,
                type: error.type,
                code: error.code
            }
        });
    }
});

app.post('/api/subscriptions/checkout', validateSubscription, async (req, res) => {
    try {
        const session = await stripeService.createCheckoutSession(req.body, req.body.frequency);
        res.json({ success: true, sessionId: session.id });
    } catch (error) {
        console.error('Erreur création checkout:', error);
        res.status(500).json({
            success: false,
            message: 'Erreur lors de la création de la session de paiement'
        });
    }
});

app.get('/api/subscriptions/:id', async (req, res) => {
    try {
        const subscription = await stripeService.getSubscription(req.params.id);
        res.json({ success: true, subscription });
    } catch (error) {
        res.status(500).json({
            success: false,
            message: 'Erreur lors de la récupération de l\'abonnement'
        });
    }
});

app.post('/api/subscriptions/:id/portal', async (req, res) => {
    try {
        const session = await stripeService.createPortalSession(req.params.id);
        res.json({ success: true, url: session.url });
    } catch (error) {
        res.status(500).json({
            success: false,
            message: 'Erreur lors de la création de la session du portail'
        });
    }
});

// Webhook Stripe
app.post('/api/webhooks/stripe', express.raw({type: 'application/json'}), async (req, res) => {
    const sig = req.headers['stripe-signature'];
    let event;

    try {
        event = Stripe.webhooks.constructEvent(req.body, sig, config.STRIPE_WEBHOOK_SECRET);
    } catch (err) {
        return res.status(400).send(`Webhook Error: ${err.message}`);
    }

    try {
        switch (event.type) {
            case 'checkout.session.completed':
                const session = event.data.object;
                if (session.status === 'complete') {
                    const subscription = JSON.parse(session.metadata.subscription);
                    // Stock subscription (create process)
                    console.log('Nouvel abonnement:', subscription);
                }
                break;

            case 'invoice.payment_succeeded':
                const invoice = event.data.object;
                if (['subscription_update', 'subscription_cycle'].includes(invoice.billing_reason)) {
                    const subscription = await stripeService.getSubscription(invoice.subscription);
                    // Update subscription (update process)
                    console.log('Mise à jour abonnement:', subscription);
                }
                break;

            case 'customer.subscription.deleted':
                const deletedSubscription = event.data.object;
                // Delete subscription (update process to delete)
                console.log('Suppression abonnement:', deletedSubscription.id);
                break;
        }

        res.json({received: true});
    } catch (error) {
        console.error('Erreur webhook:', error);
        res.status(500).json({
            success: false,
            message: 'Erreur lors du traitement du webhook'
        });
    }
});

app.listen(config.PORT, () => {
    console.log(`Serveur démarré sur le port ${config.PORT}`);
});