Premium Purchase Webhooks

{
  "event": "premium_purchase",
  "purchaseId": "1732525200000-987654321098765432",
  "timestamp": "2025-11-25T10:00:00.000Z",
  "buyer": {
    "userId": "987654321098765432",
    "username": "exampleuser"
  },
  "tier": {
    "id": "pro-monthly",
    "name": "Pro Plan",
    "duration": "monthly",
    "planType": "user"
  },
  "serverId": null
}

const crypto = require('crypto');
const express = require('express');

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

const WEBHOOK_SECRET = process.env.RANKLY_PREMIUM_WEBHOOK_SECRET;

function verifyWebhookSignature(payload, signature, secret) {
  if (!signature || !secret) {
    return false;
  }

  const expectedSignature = crypto
    .createHmac('sha256', secret)
    .update(JSON.stringify(payload))
    .digest('hex');

  try {
    return crypto.timingSafeEqual(
      Buffer.from(signature),
      Buffer.from(expectedSignature)
    );
  } catch {
    return false;
  }
}

function calculateExpiry(duration) {
  const now = new Date();

  switch (duration) {
    case 'weekly':
      return new Date(now.getTime() + 7 * 24 * 60 * 60 * 1000);
    case 'monthly':
      const monthly = new Date(now);
      monthly.setMonth(monthly.getMonth() + 1);
      return monthly;
    case 'lifetime':
      return null;
    default:
      throw new Error(`Unknown duration: ${duration}`);
  }
}

app.post('/webhook/premium', async (req, res) => {
  const signature = req.headers['x-webhook-signature'];
  const payload = req.body;

  // Verify signature before processing
  if (!verifyWebhookSignature(payload, signature, WEBHOOK_SECRET)) {
    console.error('Webhook signature verification failed');
    return res.status(401).json({ error: 'Invalid signature' });
  }

  const { purchaseId, buyer, tier, serverId } = payload;

  // Check for duplicates
  const existingPurchase = await database.purchases.findOne({ purchaseId });
  if (existingPurchase) {
    return res.status(200).json({ received: true, duplicate: true });
  }

  // Calculate expiry
  const expiresAt = calculateExpiry(tier.duration);

  console.log(`Premium purchase: ${tier.name} by ${buyer.username} (${buyer.userId})`);

  try {
    // Record the purchase
    await database.purchases.insertOne({ 
      purchaseId, 
      processedAt: new Date() 
    });

    // Activate premium based on plan type
    if (tier.planType === 'user') {
      await activateUserPremium({
        discordId: buyer.userId,
        tierId: tier.id,
        tierName: tier.name,
        expiresAt,
        purchaseId
      });
    } else if (tier.planType === 'server') {
      await activateServerPremium({
        guildId: serverId,
        tierId: tier.id,
        tierName: tier.name,
        expiresAt,
        purchaseId,
        purchasedBy: buyer.userId
      });
    }

    return res.status(200).json({ received: true, purchaseId });
  } catch (error) {
    console.error('Error processing premium purchase:', error);
    return res.status(500).json({ error: 'Processing failed' });
  }
});

async function activateUserPremium(data) {
  // Insert or update in your database
  console.log(`Activated ${data.tierName} for user ${data.discordId}`);
}

async function activateServerPremium(data) {
  // Insert or update in your database
  console.log(`Activated ${data.tierName} for server ${data.guildId}`);
}

app.listen(3000, () => {
  console.log('Premium webhook server running on port 3000');
});