feat(extensions): add LNURL-withdraw extension (LUD-03)

src/extensions/context.ts

@@ -20,6 +20,17 @@ export interface MainHandlerInterface {
   // Application management
   applicationManager: {
     getById(id: string): Promise<any>
+    PayAppUserInvoice(appId: string, req: {
+      amount: number
+      invoice: string
+      user_identifier: string
+      debit_npub?: string
+    }): Promise<{
+      preimage: string
+      amount_paid: number
+      network_fee: number
+      service_fee: number
+    }>
   }
 
   // Payment operations
@@ -41,6 +52,7 @@ export interface MainHandlerInterface {
       applicationId: string
       paymentRequest: string
       maxFeeSats?: number
+      userPubkey?: string
     }): Promise<{
       paymentHash: string
       feeSats: number
@@ -156,16 +168,19 @@ export class ExtensionContextImpl implements ExtensionContext {
 
   /**
    * Pay a Lightning invoice
+   * If userPubkey is provided, pays from that user's balance instead of app.owner
    */
   async payInvoice(
     applicationId: string,
     paymentRequest: string,
-    maxFeeSats?: number
+    maxFeeSats?: number,
+    userPubkey?: string
   ): Promise<{ paymentHash: string; feeSats: number }> {
     return this.mainHandler.paymentManager.payInvoice({
       applicationId,
       paymentRequest,
-      maxFeeSats
+      maxFeeSats,
+      userPubkey
     })
   }
 

src/extensions/mainHandlerAdapter.ts

@@ -0,0 +1,155 @@
+/**
+ * MainHandler Adapter for Extension System
+ *
+ * Wraps the Lightning.Pub mainHandler to provide the MainHandlerInterface
+ * required by the extension system.
+ */
+
+import { MainHandlerInterface } from './context.js'
+import { LnurlPayInfo } from './types.js'
+import type Main from '../services/main/index.js'
+
+/**
+ * Create an adapter that wraps mainHandler for extension use
+ */
+export function createMainHandlerAdapter(mainHandler: Main): MainHandlerInterface {
+  return {
+    applicationManager: {
+      async getById(id: string) {
+        // The applicationManager stores apps internally
+        // We need to access it through the storage layer
+        try {
+          const app = await mainHandler.storage.applicationStorage.GetApplication(id)
+          if (!app) return null
+
+          return {
+            id: app.app_id,
+            name: app.name,
+            nostr_public: app.nostr_public_key || '',
+            balance: app.owner?.balance_sats || 0
+          }
+        } catch (e) {
+          // GetApplication throws if not found
+          return null
+        }
+      },
+
+      async PayAppUserInvoice(appId, req) {
+        return mainHandler.applicationManager.PayAppUserInvoice(appId, req)
+      }
+    },
+
+    paymentManager: {
+      async createInvoice(params: {
+        applicationId: string
+        amountSats: number
+        memo?: string
+        expiry?: number
+        metadata?: Record<string, any>
+      }) {
+        // Get the app to find the user ID
+        const app = await mainHandler.storage.applicationStorage.GetApplication(params.applicationId)
+        if (!app) {
+          throw new Error(`Application not found: ${params.applicationId}`)
+        }
+
+        // Create invoice using the app owner's user ID
+        const result = await mainHandler.paymentManager.NewInvoice(
+          app.owner.user_id,
+          {
+            amountSats: params.amountSats,
+            memo: params.memo || ''
+          },
+          {
+            expiry: params.expiry || 3600
+          }
+        )
+
+        return {
+          id: result.invoice.split(':')[0] || result.invoice, // Extract ID if present
+          paymentRequest: result.invoice,
+          paymentHash: '', // Not directly available from NewInvoice response
+          expiry: Date.now() + (params.expiry || 3600) * 1000
+        }
+      },
+
+      async payInvoice(params: {
+        applicationId: string
+        paymentRequest: string
+        maxFeeSats?: number
+        userPubkey?: string
+      }) {
+        // Get the app to find the user ID and app reference
+        const app = await mainHandler.storage.applicationStorage.GetApplication(params.applicationId)
+        if (!app) {
+          throw new Error(`Application not found: ${params.applicationId}`)
+        }
+
+        if (params.userPubkey) {
+          // Resolve the Nostr user's ApplicationUser to get their identifier
+          const appUser = await mainHandler.storage.applicationStorage.GetOrCreateNostrAppUser(app, params.userPubkey)
+          console.log(`[MainHandlerAdapter] Paying via PayAppUserInvoice from Nostr user ${params.userPubkey.slice(0, 8)}... (identifier: ${appUser.identifier})`)
+
+          // Use applicationManager.PayAppUserInvoice so notifyAppUserPayment fires
+          // This sends LiveUserOperation events via Nostr for real-time balance updates
+          const result = await mainHandler.applicationManager.PayAppUserInvoice(
+            params.applicationId,
+            {
+              invoice: params.paymentRequest,
+              amount: 0, // Use invoice amount
+              user_identifier: appUser.identifier
+            }
+          )
+
+          return {
+            paymentHash: result.preimage || '',
+            feeSats: result.network_fee || 0
+          }
+        }
+
+        // Fallback: pay from app owner's balance (no Nostr user context)
+        const result = await mainHandler.paymentManager.PayInvoice(
+          app.owner.user_id,
+          {
+            invoice: params.paymentRequest,
+            amount: 0
+          },
+          app,
+          {}
+        )
+
+        return {
+          paymentHash: result.preimage || '',
+          feeSats: result.network_fee || 0
+        }
+      },
+
+      async getLnurlPayInfoByPubkey(pubkeyHex: string, options?: {
+        metadata?: string
+        description?: string
+      }): Promise<LnurlPayInfo> {
+        // This would need implementation based on how Lightning.Pub handles LNURL-pay
+        // For now, throw not implemented
+        throw new Error('getLnurlPayInfoByPubkey not yet implemented')
+      }
+    },
+
+    async sendNostrEvent(event: any): Promise<string | null> {
+      // The mainHandler doesn't directly expose nostrSend
+      // This would need to be implemented through the nostrMiddleware
+      // For now, return null (not implemented)
+      console.warn('[MainHandlerAdapter] sendNostrEvent not fully implemented')
+      return null
+    },
+
+    async sendEncryptedDM(
+      applicationId: string,
+      recipientPubkey: string,
+      content: string
+    ): Promise<string> {
+      // This would need implementation using NIP-44 encryption
+      // For now, throw not implemented
+      throw new Error('sendEncryptedDM not yet implemented')
+    }
+  }
+}

src/extensions/types.ts

@@ -140,8 +140,9 @@ export interface ExtensionContext {
 
   /**
    * Pay a Lightning invoice (requires sufficient balance)
+   * If userPubkey is provided, pays from that user's balance instead of app.owner
    */
-  payInvoice(applicationId: string, paymentRequest: string, maxFeeSats?: number): Promise<{
+  payInvoice(applicationId: string, paymentRequest: string, maxFeeSats?: number, userPubkey?: string): Promise<{
     paymentHash: string
     feeSats: number
   }>