Receive Chain Swaps (#310)

* Implement Chain Swaps for receiving

* Send: validate if we have sufficient funds (#321)

* Implement Chain Swaps for receiving

* Fix rebase of flutter_rust_bridge version

* Send: validate if we have sufficient funds

* Re-generate FRB

---------

Co-authored-by: Ross Savage <hello@satimoto.com>

* Chaim swap claim: remove refund_tx arg (#328)

---------

Co-authored-by: ok300 <106775972+ok300@users.noreply.github.com>

packages/dart/lib/src/model.dart

@@ -409,6 +409,12 @@ enum PaymentState {
   /// This covers the case when the swap state is still Created and the swap fails to reach the
   /// Pending state in time. The TimedOut state indicates the lockup tx should never be broadcast.
   timedOut,
+
+  /// ## Incoming Chain Swaps
+  ///
+  /// This covers the case when the swap failed for any reason and there is a user lockup tx.
+  /// The swap in this case has to be manually refunded with a provided Bitcoin address
+  refundable,
   ;
 }
 
@@ -455,6 +461,45 @@ class PreparePayOnchainResponse {
           feesSat == other.feesSat;
 }
 
+class PrepareReceiveOnchainRequest {
+  final BigInt amountSat;
+
+  const PrepareReceiveOnchainRequest({
+    required this.amountSat,
+  });
+
+  @override
+  int get hashCode => amountSat.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is PrepareReceiveOnchainRequest &&
+          runtimeType == other.runtimeType &&
+          amountSat == other.amountSat;
+}
+
+class PrepareReceiveOnchainResponse {
+  final BigInt amountSat;
+  final BigInt feesSat;
+
+  const PrepareReceiveOnchainResponse({
+    required this.amountSat,
+    required this.feesSat,
+  });
+
+  @override
+  int get hashCode => amountSat.hashCode ^ feesSat.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is PrepareReceiveOnchainResponse &&
+          runtimeType == other.runtimeType &&
+          amountSat == other.amountSat &&
+          feesSat == other.feesSat;
+}
+
 class PrepareReceiveRequest {
   final BigInt payerAmountSat;
 
@@ -494,6 +539,51 @@ class PrepareReceiveResponse {
           feesSat == other.feesSat;
 }
 
+class PrepareRefundRequest {
+  final String swapAddress;
+  final String refundAddress;
+  final int satPerVbyte;
+
+  const PrepareRefundRequest({
+    required this.swapAddress,
+    required this.refundAddress,
+    required this.satPerVbyte,
+  });
+
+  @override
+  int get hashCode => swapAddress.hashCode ^ refundAddress.hashCode ^ satPerVbyte.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is PrepareRefundRequest &&
+          runtimeType == other.runtimeType &&
+          swapAddress == other.swapAddress &&
+          refundAddress == other.refundAddress &&
+          satPerVbyte == other.satPerVbyte;
+}
+
+class PrepareRefundResponse {
+  final int refundTxVsize;
+  final BigInt refundTxFeeSat;
+
+  const PrepareRefundResponse({
+    required this.refundTxVsize,
+    required this.refundTxFeeSat,
+  });
+
+  @override
+  int get hashCode => refundTxVsize.hashCode ^ refundTxFeeSat.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is PrepareRefundResponse &&
+          runtimeType == other.runtimeType &&
+          refundTxVsize == other.refundTxVsize &&
+          refundTxFeeSat == other.refundTxFeeSat;
+}
+
 class PrepareSendRequest {
   final String invoice;
 
@@ -531,6 +621,43 @@ class PrepareSendResponse {
           feesSat == other.feesSat;
 }
 
+class ReceiveOnchainRequest {
+  final PrepareReceiveOnchainResponse prepareRes;
+
+  const ReceiveOnchainRequest({
+    required this.prepareRes,
+  });
+
+  @override
+  int get hashCode => prepareRes.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is ReceiveOnchainRequest && runtimeType == other.runtimeType && prepareRes == other.prepareRes;
+}
+
+class ReceiveOnchainResponse {
+  final String address;
+  final String bip21;
+
+  const ReceiveOnchainResponse({
+    required this.address,
+    required this.bip21,
+  });
+
+  @override
+  int get hashCode => address.hashCode ^ bip21.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is ReceiveOnchainResponse &&
+          runtimeType == other.runtimeType &&
+          address == other.address &&
+          bip21 == other.bip21;
+}
+
 class ReceivePaymentResponse {
   final String id;
   final String invoice;
@@ -552,6 +679,70 @@ class ReceivePaymentResponse {
           invoice == other.invoice;
 }
 
+class RefundRequest {
+  final String swapAddress;
+  final String refundAddress;
+  final int satPerVbyte;
+
+  const RefundRequest({
+    required this.swapAddress,
+    required this.refundAddress,
+    required this.satPerVbyte,
+  });
+
+  @override
+  int get hashCode => swapAddress.hashCode ^ refundAddress.hashCode ^ satPerVbyte.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is RefundRequest &&
+          runtimeType == other.runtimeType &&
+          swapAddress == other.swapAddress &&
+          refundAddress == other.refundAddress &&
+          satPerVbyte == other.satPerVbyte;
+}
+
+class RefundResponse {
+  final String refundTxId;
+
+  const RefundResponse({
+    required this.refundTxId,
+  });
+
+  @override
+  int get hashCode => refundTxId.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is RefundResponse && runtimeType == other.runtimeType && refundTxId == other.refundTxId;
+}
+
+class RefundableSwap {
+  final String swapAddress;
+  final int timestamp;
+  final BigInt amountSat;
+
+  const RefundableSwap({
+    required this.swapAddress,
+    required this.timestamp,
+    required this.amountSat,
+  });
+
+  @override
+  int get hashCode => swapAddress.hashCode ^ timestamp.hashCode ^ amountSat.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is RefundableSwap &&
+          runtimeType == other.runtimeType &&
+          swapAddress == other.swapAddress &&
+          timestamp == other.timestamp &&
+          amountSat == other.amountSat;
+}
+
 class RestoreRequest {
   final String? backupPath;