feat: Send payment from webapp

webapp/frontend/lib/wallet/send_screen.dart

@@ -17,7 +17,10 @@ class SendScreen extends StatefulWidget {
 
 class _SendScreenState extends State<SendScreen> {
   final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
+
   final TextEditingController _addressController = TextEditingController();
+  final TextEditingController _amountController = TextEditingController();
+  final TextEditingController _feeController = TextEditingController();
 
   String? address;
   Amount? amount;
@@ -72,6 +75,7 @@ class _SendScreenState extends State<SendScreen> {
                 AmountInputField(
                   value: amount != null ? amount! : Amount.zero(),
                   label: "Amount in sats",
+                  controller: _amountController,
                   validator: (value) {
                     return null;
                   },
@@ -86,6 +90,7 @@ class _SendScreenState extends State<SendScreen> {
                 AmountInputField(
                   value: fee != null ? fee! : Amount.zero(),
                   label: "Sats/vb",
+                  controller: _feeController,
                   validator: (value) {
                     if (value == null || value == "0") {
                       return "The fee rate must be greater than 0";
@@ -111,6 +116,20 @@ class _SendScreenState extends State<SendScreen> {
                                   await context
                                       .read<WalletService>()
                                       .sendPayment(address!, amount!, fee!);
+
+                                  setState(() {
+                                    _formKey.currentState!.reset();
+                                    _addressController.clear();
+                                    address = null;
+                                    _amountController.clear();
+                                    amount = null;
+                                    _feeController.clear();
+                                    fee = null;
+
+                                    _formKey.currentState!.validate();
+                                  });
+
+                                  showSnackBar(messenger, "Payment has been sent.");
                                 } catch (e) {
                                   showSnackBar(messenger, "Failed to send payment. $e");
                                 }
@@ -150,8 +169,13 @@ class _SendScreenState extends State<SendScreen> {
       ],
     );
   }
-}
 
-/*
-,
- */
+  @override
+  void dispose() {
+    super.dispose();
+
+    _addressController.dispose();
+    _amountController.dispose();
+    _feeController.dispose();
+  }
+}

webapp/frontend/lib/wallet/wallet_service.dart

@@ -45,7 +45,31 @@ class WalletService {
   }
 
   Future<void> sendPayment(String address, Amount amount, Amount fee) async {
-    // todo: send payment
-    throw UnimplementedError("todo");
+    // TODO(holzeis): this should come from the config
+    const port = "3001";
+    const host = "localhost";
+
+    try {
+      final response = await http.post(Uri.http('$host:$port', '/api/sendpayment'),
+          headers: <String, String>{
+            'Content-Type': 'application/json; charset=UTF-8',
+          },
+          body: jsonEncode(
+              <String, dynamic>{'address': address, 'amount': amount.sats, 'fee': fee.sats}));
+
+      if (response.statusCode != 200) {
+        throw FlutterError("Failed to send payment");
+      }
+    } catch (e) {
+      throw FlutterError("Failed to send payment. $e");
+    }
   }
 }
+
+class Payment {
+  final String address;
+  final int amount;
+  final int fee;
+
+  const Payment({required this.address, required this.amount, required this.fee});
+}

webapp/src/api.rs

@@ -6,6 +6,10 @@ use axum::response::IntoResponse;
 use axum::response::Response;
 use axum::Json;
 use native::api;
+use native::api::Fee;
+use native::api::SendPayment;
+use native::ln_dlc;
+use serde::Deserialize;
 use serde::Serialize;
 use std::sync::Arc;
 
@@ -68,3 +72,21 @@ pub async fn get_balance(
 
     Ok(Json(balance))
 }
+
+#[derive(Deserialize)]
+pub struct Payment {
+    address: String,
+    amount: u64,
+    fee: u64,
+}
+
+pub async fn send_payment(params: Json<Payment>) -> Result<(), AppError> {
+    ln_dlc::send_payment(SendPayment::OnChain {
+        address: params.0.address,
+        amount: params.0.amount,
+        fee: Fee::FeeRate { sats: params.0.fee },
+    })
+    .await?;
+
+    Ok(())
+}

webapp/src/main.rs

@@ -5,6 +5,7 @@ mod subscribers;
 
 use crate::api::get_balance;
 use crate::api::get_unused_address;
+use crate::api::send_payment;
 use crate::api::version;
 use crate::cli::Opts;
 use crate::subscribers::AppSubscribers;
@@ -18,6 +19,7 @@ use axum::response::Html;
 use axum::response::IntoResponse;
 use axum::response::Response;
 use axum::routing::get;
+use axum::routing::post;
 use axum::Router;
 use rust_embed::RustEmbed;
 use std::net::SocketAddr;
@@ -88,6 +90,7 @@ fn using_serve_dir(subscribers: Arc<AppSubscribers>) -> Router {
         .route("/api/version", get(version))
         .route("/api/balance", get(get_balance))
         .route("/api/newaddress", get(get_unused_address))
+        .route("/api/sendpayment", post(send_payment))
         .route("/main.dart.js", get(main_dart_handler))
         .route("/flutter.js", get(flutter_js))
         .route("/index.html", get(index_handler))