lnurl verify, first impl

src/pages/api/lightning-address/callback/[slug].js

@@ -76,7 +76,7 @@ export default async function handler(req, res) {
                             'Authorization': PLEBDEVS_API_KEY
                         }
                     });
-                    res.status(200).json({ pr: response.data });
+                    res.status(200).json({ pr: response.data, verify: `${BACKEND_URL}/api/lightning-address/verify/${slug}/${response.data.payment_hash}` });
                 } catch (error) {
                     console.error(error);
                     res.status(500).json({ error: 'Failed to generate invoice' });

src/pages/api/lightning-address/verify/[name]/[slug].js

@@ -0,0 +1,56 @@
+import axios from "axios";
+import { getLightningAddressByName } from "@/db/models/lightningAddressModels";
+import appConfig from "@/config/appConfig";
+
+export default async function handler(req, res) {
+    try {
+        const { name, slug } = req.query;
+
+        // Find the lightning address
+        let foundAddress = null;
+        const customAddress = appConfig.customLightningAddresses.find(addr => addr.name === name);
+
+        if (customAddress) {
+            foundAddress = customAddress;
+        } else {
+            foundAddress = await getLightningAddressByName(name);
+        }
+
+        if (!foundAddress) {
+            res.status(404).json({ error: 'Lightning address not found' });
+            return;
+        }
+
+        // Convert hex payment hash to base64
+        const paymentHashBuffer = Buffer.from(slug, 'hex');
+        const paymentHashBase64 = paymentHashBuffer.toString('base64');
+
+        // Call LND to check payment status
+        const response = await axios.get(
+            `https://${foundAddress.lndHost}/v1/invoice/${paymentHashBase64}`,
+            {
+                headers: {
+                    'Grpc-Metadata-macaroon': foundAddress.invoiceMacaroon,
+                }
+            }
+        );
+
+        // According to LNURL-pay spec, we should return { status: "OK" } if paid
+        // or { status: "ERROR", reason: "error message" } if not paid or error
+        if (response.data.state === 'SETTLED') {
+            res.status(200).json({ status: "OK" });
+        } else {
+            res.status(200).json({ 
+                status: "ERROR", 
+                reason: "Invoice not paid" 
+            });
+        }
+
+    } catch (error) {
+        console.error('Error verifying payment:', error.message);
+        res.status(200).json({ 
+            status: "ERROR", 
+            reason: error.message || "Error verifying payment"
+        });
+    }
+}