From 952932c24b9c23389fb7286ea5f2e22e8dc5f479 Mon Sep 17 00:00:00 2001
From: thunderbiscuit <thunderbiscuit@protonmail.com>
Date: Thu, 19 Oct 2023 14:18:03 -0400
Subject: [PATCH] feat: add Transaction and PartiallySignedTransaction types

---
 bdk-ffi/src/bdk.udl                           |  30 +-
 bdk-ffi/src/bitcoin.rs                        | 320 ++++++++++++++++++
 bdk-ffi/src/lib.rs                            | 201 +----------
 bdk-ffi/src/psbt.rs                           | 119 -------
 bdk-ffi/src/wallet.rs                         |  14 +-
 .../kotlin/org/bitcoindevkit/JvmLibTest.kt    |  40 +--
 6 files changed, 386 insertions(+), 338 deletions(-)
 create mode 100644 bdk-ffi/src/bitcoin.rs
 delete mode 100644 bdk-ffi/src/psbt.rs

diff --git a/bdk-ffi/src/bdk.udl b/bdk-ffi/src/bdk.udl
index f73dc3a9..b689ab54 100644
--- a/bdk-ffi/src/bdk.udl
+++ b/bdk-ffi/src/bdk.udl
@@ -94,7 +94,7 @@ interface TxBuilder {
   TxBuilder fee_rate(float sat_per_vbyte);
 
   [Throws=BdkError]
-  string finish([ByRef] Wallet wallet);
+  PartiallySignedTransaction finish([ByRef] Wallet wallet);
 };
 
 // ------------------------------------------------------------------------
@@ -231,3 +231,31 @@ interface Script {
 
   sequence<u8> to_bytes();
 };
+
+interface Transaction {
+  [Throws=BdkError]
+  constructor(sequence<u8> transaction_bytes);
+
+  string txid();
+
+  u64 size();
+
+  u64 vsize();
+
+  boolean is_coin_base();
+
+  boolean is_explicitly_rbf();
+
+  boolean is_lock_time_enabled();
+
+  i32 version();
+};
+
+interface PartiallySignedTransaction {
+  [Throws=BdkError]
+  constructor(string psbt_base64);
+
+  string serialize();
+
+  Transaction extract_tx();
+};
diff --git a/bdk-ffi/src/bitcoin.rs b/bdk-ffi/src/bitcoin.rs
new file mode 100644
index 00000000..efc0c6b5
--- /dev/null
+++ b/bdk-ffi/src/bitcoin.rs
@@ -0,0 +1,320 @@
+use bdk::bitcoin::address::{NetworkChecked, NetworkUnchecked};
+use bdk::bitcoin::blockdata::script::ScriptBuf as BdkScriptBuf;
+use bdk::bitcoin::blockdata::transaction::Transaction as BdkTransaction;
+use bdk::bitcoin::consensus::Decodable;
+use bdk::bitcoin::psbt::PartiallySignedTransaction as BdkPartiallySignedTransaction;
+use bdk::bitcoin::Address as BdkAddress;
+use bdk::bitcoin::Network as BdkNetwork;
+use bdk::Error as BdkError;
+use std::io::Cursor;
+use std::str::FromStr;
+use std::sync::{Arc, Mutex};
+
+pub enum Network {
+    /// Mainnet Bitcoin.
+    Bitcoin,
+    /// Bitcoin's testnet network.
+    Testnet,
+    /// Bitcoin's signet network.
+    Signet,
+    /// Bitcoin's regtest network.
+    Regtest,
+}
+
+impl From<Network> for BdkNetwork {
+    fn from(network: Network) -> Self {
+        match network {
+            Network::Bitcoin => BdkNetwork::Bitcoin,
+            Network::Testnet => BdkNetwork::Testnet,
+            Network::Signet => BdkNetwork::Signet,
+            Network::Regtest => BdkNetwork::Regtest,
+        }
+    }
+}
+
+impl From<BdkNetwork> for Network {
+    fn from(network: BdkNetwork) -> Self {
+        match network {
+            BdkNetwork::Bitcoin => Network::Bitcoin,
+            BdkNetwork::Testnet => Network::Testnet,
+            BdkNetwork::Signet => Network::Signet,
+            BdkNetwork::Regtest => Network::Regtest,
+            _ => panic!("Network {} not supported", network),
+        }
+    }
+}
+
+/// A Bitcoin address.
+#[derive(Debug, PartialEq, Eq)]
+pub struct Address {
+    inner: BdkAddress<NetworkChecked>,
+}
+
+impl Address {
+    pub fn new(address: String, network: Network) -> Result<Self, BdkError> {
+        Ok(Address {
+            inner: address
+                .parse::<bdk::bitcoin::Address<NetworkUnchecked>>()
+                .unwrap() // TODO 11: Handle error correctly by rethrowing it as a BdkError
+                .require_network(network.into())
+                .map_err(|e| BdkError::Generic(e.to_string()))?,
+        })
+    }
+
+    /// alternative constructor
+    // fn from_script(script: Arc<Script>, network: Network) -> Result<Self, BdkError> {
+    //     BdkAddress::from_script(&script.inner, network)
+    //         .map(|a| Address { inner: a })
+    //         .map_err(|e| BdkError::Generic(e.to_string()))
+    // }
+    //
+    // fn payload(&self) -> Payload {
+    //     match &self.inner.payload.clone() {
+    //         BdkPayload::PubkeyHash(pubkey_hash) => Payload::PubkeyHash {
+    //             pubkey_hash: pubkey_hash.to_vec(),
+    //         },
+    //         BdkPayload::ScriptHash(script_hash) => Payload::ScriptHash {
+    //             script_hash: script_hash.to_vec(),
+    //         },
+    //         BdkPayload::WitnessProgram { version, program } => Payload::WitnessProgram {
+    //             version: *version,
+    //             program: program.clone(),
+    //         },
+    //     }
+    // }
+
+    pub fn network(&self) -> Network {
+        self.inner.network.into()
+    }
+
+    pub fn script_pubkey(&self) -> Arc<Script> {
+        Arc::new(Script {
+            inner: self.inner.script_pubkey(),
+        })
+    }
+
+    pub fn to_qr_uri(&self) -> String {
+        self.inner.to_qr_uri()
+    }
+
+    pub fn as_string(&self) -> String {
+        self.inner.to_string()
+    }
+}
+
+impl From<Address> for BdkAddress {
+    fn from(address: Address) -> Self {
+        address.inner
+    }
+}
+
+impl From<BdkAddress> for Address {
+    fn from(address: BdkAddress) -> Self {
+        Address { inner: address }
+    }
+}
+
+/// A Bitcoin script.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Script {
+    pub(crate) inner: BdkScriptBuf,
+}
+
+impl Script {
+    pub fn new(raw_output_script: Vec<u8>) -> Self {
+        let script: BdkScriptBuf = BdkScriptBuf::from(raw_output_script);
+        Script { inner: script }
+    }
+
+    pub fn to_bytes(&self) -> Vec<u8> {
+        self.inner.to_bytes()
+    }
+}
+
+/// A Bitcoin transaction.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Transaction {
+    inner: BdkTransaction,
+}
+
+impl Transaction {
+    pub fn new(transaction_bytes: Vec<u8>) -> Result<Self, BdkError> {
+        let mut decoder = Cursor::new(transaction_bytes);
+        let tx: BdkTransaction = BdkTransaction::consensus_decode(&mut decoder)
+            .map_err(|e| BdkError::Generic(e.to_string()))?;
+        Ok(Transaction { inner: tx })
+    }
+
+    pub fn txid(&self) -> String {
+        self.inner.txid().to_string()
+    }
+
+    // fn weight(&self) -> u64 {
+    //     self.inner.weight() as u64
+    // }
+
+    pub fn size(&self) -> u64 {
+        self.inner.size() as u64
+    }
+
+    pub fn vsize(&self) -> u64 {
+        self.inner.vsize() as u64
+    }
+
+    // fn serialize(&self) -> Vec<u8> {
+    //     self.inner.serialize()
+    // }
+
+    pub fn is_coin_base(&self) -> bool {
+        self.inner.is_coin_base()
+    }
+
+    pub fn is_explicitly_rbf(&self) -> bool {
+        self.inner.is_explicitly_rbf()
+    }
+
+    pub fn is_lock_time_enabled(&self) -> bool {
+        self.inner.is_lock_time_enabled()
+    }
+
+    pub fn version(&self) -> i32 {
+        self.inner.version
+    }
+
+    // fn lock_time(&self) -> u32 {
+    //     self.inner.lock_time.0
+    // }
+
+    // fn input(&self) -> Vec<TxIn> {
+    //     self.inner.input.iter().map(|x| x.into()).collect()
+    // }
+    //
+    // fn output(&self) -> Vec<TxOut> {
+    //     self.inner.output.iter().map(|x| x.into()).collect()
+    // }
+}
+
+impl From<BdkTransaction> for Transaction {
+    fn from(tx: BdkTransaction) -> Self {
+        Transaction { inner: tx }
+    }
+}
+
+pub(crate) struct PartiallySignedTransaction {
+    pub(crate) inner: Mutex<BdkPartiallySignedTransaction>,
+}
+
+impl PartiallySignedTransaction {
+    pub(crate) fn new(psbt_base64: String) -> Result<Self, BdkError> {
+        let psbt: BdkPartiallySignedTransaction =
+            BdkPartiallySignedTransaction::from_str(&psbt_base64)
+                .map_err(|e| BdkError::Generic(e.to_string()))?;
+
+        Ok(PartiallySignedTransaction {
+            inner: Mutex::new(psbt),
+        })
+    }
+
+    pub(crate) fn serialize(&self) -> String {
+        let psbt = self.inner.lock().unwrap().clone();
+        psbt.to_string()
+    }
+
+    // pub(crate) fn txid(&self) -> String {
+    //     let tx = self.inner.lock().unwrap().clone().extract_tx();
+    //     let txid = tx.txid();
+    //     txid.to_hex()
+    // }
+
+    /// Return the transaction.
+    pub(crate) fn extract_tx(&self) -> Arc<Transaction> {
+        let tx = self.inner.lock().unwrap().clone().extract_tx();
+        Arc::new(tx.into())
+    }
+
+    // /// Combines this PartiallySignedTransaction with other PSBT as described by BIP 174.
+    // ///
+    // /// In accordance with BIP 174 this function is commutative i.e., `A.combine(B) == B.combine(A)`
+    // pub(crate) fn combine(
+    //     &self,
+    //     other: Arc<PartiallySignedTransaction>,
+    // ) -> Result<Arc<PartiallySignedTransaction>, BdkError> {
+    //     let other_psbt = other.inner.lock().unwrap().clone();
+    //     let mut original_psbt = self.inner.lock().unwrap().clone();
+    //
+    //     original_psbt.combine(other_psbt)?;
+    //     Ok(Arc::new(PartiallySignedTransaction {
+    //         inner: Mutex::new(original_psbt),
+    //     }))
+    // }
+
+    // /// The total transaction fee amount, sum of input amounts minus sum of output amounts, in Sats.
+    // /// If the PSBT is missing a TxOut for an input returns None.
+    // pub(crate) fn fee_amount(&self) -> Option<u64> {
+    //     self.inner.lock().unwrap().fee_amount()
+    // }
+
+    // /// The transaction's fee rate. This value will only be accurate if calculated AFTER the
+    // /// `PartiallySignedTransaction` is finalized and all witness/signature data is added to the
+    // /// transaction.
+    // /// If the PSBT is missing a TxOut for an input returns None.
+    // pub(crate) fn fee_rate(&self) -> Option<Arc<FeeRate>> {
+    //     self.inner.lock().unwrap().fee_rate().map(Arc::new)
+    // }
+
+    // /// Serialize the PSBT data structure as a String of JSON.
+    // pub(crate) fn json_serialize(&self) -> String {
+    //     let psbt = self.inner.lock().unwrap();
+    //     serde_json::to_string(psbt.deref()).unwrap()
+    // }
+}
+
+impl From<BdkPartiallySignedTransaction> for PartiallySignedTransaction {
+    fn from(psbt: BdkPartiallySignedTransaction) -> Self {
+        PartiallySignedTransaction {
+            inner: Mutex::new(psbt),
+        }
+    }
+}
+
+// // The goal of these tests to to ensure `bdk-ffi` intermediate code correctly calls `bdk` APIs.
+// // These tests should not be used to verify `bdk` behavior that is already tested in the `bdk`
+// // crate.
+// #[cfg(test)]
+// mod test {
+//     use crate::wallet::{TxBuilder, Wallet};
+//     use bdk::wallet::get_funded_wallet;
+//     use std::sync::Mutex;
+//
+//     #[test]
+//     fn test_psbt_fee() {
+//         let test_wpkh = "wpkh(cVpPVruEDdmutPzisEsYvtST1usBR3ntr8pXSyt6D2YYqXRyPcFW)";
+//         let (funded_wallet, _, _) = get_funded_wallet(test_wpkh);
+//         let test_wallet = Wallet {
+//             inner_mutex: Mutex::new(funded_wallet),
+//         };
+//         let drain_to_address = "tb1ql7w62elx9ucw4pj5lgw4l028hmuw80sndtntxt".to_string();
+//         let drain_to_script = crate::Address::new(drain_to_address)
+//             .unwrap()
+//             .script_pubkey();
+//
+//         let tx_builder = TxBuilder::new()
+//             .fee_rate(2.0)
+//             .drain_wallet()
+//             .drain_to(drain_to_script.clone());
+//         //dbg!(&tx_builder);
+//         assert!(tx_builder.drain_wallet);
+//         assert_eq!(tx_builder.drain_to, Some(drain_to_script.inner.clone()));
+//
+//         let tx_builder_result = tx_builder.finish(&test_wallet).unwrap();
+//
+//         assert!(tx_builder_result.psbt.fee_rate().is_some());
+//         assert_eq!(
+//             tx_builder_result.psbt.fee_rate().unwrap().as_sat_per_vb(),
+//             2.682927
+//         );
+//
+//         assert!(tx_builder_result.psbt.fee_amount().is_some());
+//         assert_eq!(tx_builder_result.psbt.fee_amount().unwrap(), 220);
+//     }
+// }
diff --git a/bdk-ffi/src/lib.rs b/bdk-ffi/src/lib.rs
index 05d3a7ba..caed7931 100644
--- a/bdk-ffi/src/lib.rs
+++ b/bdk-ffi/src/lib.rs
@@ -1,13 +1,9 @@
+mod bitcoin;
 mod descriptor;
 mod esplora;
 mod keys;
-mod psbt;
 mod wallet;
 
-use bdk::bitcoin::address::{NetworkChecked, NetworkUnchecked};
-use bdk::bitcoin::blockdata::script::ScriptBuf as BdkScriptBuf;
-use bdk::bitcoin::Address as BdkAddress;
-use bdk::bitcoin::Network as BdkNetwork;
 use bdk::wallet::AddressIndex as BdkAddressIndex;
 use bdk::wallet::AddressInfo as BdkAddressInfo;
 use bdk::wallet::Balance as BdkBalance;
@@ -16,6 +12,11 @@ use bdk::KeychainKind;
 use std::sync::Arc;
 
 // TODO 6: Why are these imports required?
+use crate::bitcoin::Address;
+use crate::bitcoin::Network;
+use crate::bitcoin::PartiallySignedTransaction;
+use crate::bitcoin::Script;
+use crate::bitcoin::Transaction;
 use crate::descriptor::Descriptor;
 use crate::esplora::EsploraClient;
 use crate::keys::DerivationPath;
@@ -26,44 +27,9 @@ use crate::wallet::TxBuilder;
 use crate::wallet::Update;
 use crate::wallet::Wallet;
 use bdk::keys::bip39::WordCount;
-// use bdk_esplora::EsploraExt;
 
 uniffi::include_scaffolding!("bdk");
 
-pub enum Network {
-    /// Mainnet Bitcoin.
-    Bitcoin,
-    /// Bitcoin's testnet network.
-    Testnet,
-    /// Bitcoin's signet network.
-    Signet,
-    /// Bitcoin's regtest network.
-    Regtest,
-}
-
-impl From<Network> for BdkNetwork {
-    fn from(network: Network) -> Self {
-        match network {
-            Network::Bitcoin => BdkNetwork::Bitcoin,
-            Network::Testnet => BdkNetwork::Testnet,
-            Network::Signet => BdkNetwork::Signet,
-            Network::Regtest => BdkNetwork::Regtest,
-        }
-    }
-}
-
-impl From<BdkNetwork> for Network {
-    fn from(network: BdkNetwork) -> Self {
-        match network {
-            BdkNetwork::Bitcoin => Network::Bitcoin,
-            BdkNetwork::Testnet => Network::Testnet,
-            BdkNetwork::Signet => Network::Signet,
-            BdkNetwork::Regtest => Network::Regtest,
-            _ => panic!("Network {} not supported", network),
-        }
-    }
-}
-
 // /// A output script and an amount of satoshis.
 // pub struct ScriptAmount {
 //     pub script: Arc<Script>,
@@ -342,144 +308,6 @@ impl Balance {
 //         }
 //     }
 // }
-//
-// /// A Bitcoin transaction.
-// #[derive(Debug, Clone, PartialEq, Eq)]
-// pub struct Transaction {
-//     inner: BdkTransaction,
-// }
-//
-// impl Transaction {
-//     fn new(transaction_bytes: Vec<u8>) -> Result<Self, BdkError> {
-//         let mut decoder = Cursor::new(transaction_bytes);
-//         let tx: BdkTransaction = BdkTransaction::consensus_decode(&mut decoder)?;
-//         Ok(Transaction { inner: tx })
-//     }
-//
-//     fn txid(&self) -> String {
-//         self.inner.txid().to_string()
-//     }
-//
-//     fn weight(&self) -> u64 {
-//         self.inner.weight() as u64
-//     }
-//
-//     fn size(&self) -> u64 {
-//         self.inner.size() as u64
-//     }
-//
-//     fn vsize(&self) -> u64 {
-//         self.inner.vsize() as u64
-//     }
-//
-//     fn serialize(&self) -> Vec<u8> {
-//         self.inner.serialize()
-//     }
-//
-//     fn is_coin_base(&self) -> bool {
-//         self.inner.is_coin_base()
-//     }
-//
-//     fn is_explicitly_rbf(&self) -> bool {
-//         self.inner.is_explicitly_rbf()
-//     }
-//
-//     fn is_lock_time_enabled(&self) -> bool {
-//         self.inner.is_lock_time_enabled()
-//     }
-//
-//     fn version(&self) -> i32 {
-//         self.inner.version
-//     }
-//
-//     fn lock_time(&self) -> u32 {
-//         self.inner.lock_time.0
-//     }
-//
-//     fn input(&self) -> Vec<TxIn> {
-//         self.inner.input.iter().map(|x| x.into()).collect()
-//     }
-//
-//     fn output(&self) -> Vec<TxOut> {
-//         self.inner.output.iter().map(|x| x.into()).collect()
-//     }
-// }
-
-// impl From<BdkTransaction> for Transaction {
-//     fn from(tx: BdkTransaction) -> Self {
-//         Transaction { inner: tx }
-//     }
-// }
-
-/// A Bitcoin address.
-#[derive(Debug, PartialEq, Eq)]
-pub struct Address {
-    inner: BdkAddress<NetworkChecked>,
-}
-
-impl Address {
-    fn new(address: String, network: Network) -> Result<Self, BdkError> {
-        Ok(Address {
-            inner: address
-                .parse::<bdk::bitcoin::Address<NetworkUnchecked>>()
-                .unwrap() // TODO 11: Handle error correctly by rethrowing it as a BdkError
-                .require_network(network.into())
-                .map_err(|e| BdkError::Generic(e.to_string()))?,
-        })
-    }
-
-    /// alternative constructor
-    // fn from_script(script: Arc<Script>, network: Network) -> Result<Self, BdkError> {
-    //     BdkAddress::from_script(&script.inner, network)
-    //         .map(|a| Address { inner: a })
-    //         .map_err(|e| BdkError::Generic(e.to_string()))
-    // }
-    //
-    // fn payload(&self) -> Payload {
-    //     match &self.inner.payload.clone() {
-    //         BdkPayload::PubkeyHash(pubkey_hash) => Payload::PubkeyHash {
-    //             pubkey_hash: pubkey_hash.to_vec(),
-    //         },
-    //         BdkPayload::ScriptHash(script_hash) => Payload::ScriptHash {
-    //             script_hash: script_hash.to_vec(),
-    //         },
-    //         BdkPayload::WitnessProgram { version, program } => Payload::WitnessProgram {
-    //             version: *version,
-    //             program: program.clone(),
-    //         },
-    //     }
-    // }
-
-    fn network(&self) -> Network {
-        self.inner.network.into()
-    }
-
-    fn script_pubkey(&self) -> Arc<Script> {
-        Arc::new(Script {
-            inner: self.inner.script_pubkey(),
-        })
-    }
-
-    fn to_qr_uri(&self) -> String {
-        self.inner.to_qr_uri()
-    }
-
-    fn as_string(&self) -> String {
-        self.inner.to_string()
-    }
-}
-
-impl From<BdkAddress> for Address {
-    fn from(address: BdkAddress) -> Self {
-        Address { inner: address }
-    }
-}
-
-impl From<Address> for BdkAddress {
-    fn from(address: Address) -> Self {
-        address.inner
-    }
-}
 
 // /// The method used to produce an address.
 // #[derive(Debug)]
@@ -497,23 +325,6 @@ impl From<Address> for BdkAddress {
 //     },
 // }
 
-/// A Bitcoin script.
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Script {
-    inner: BdkScriptBuf,
-}
-
-impl Script {
-    fn new(raw_output_script: Vec<u8>) -> Self {
-        let script: BdkScriptBuf = BdkScriptBuf::from(raw_output_script);
-        Script { inner: script }
-    }
-
-    fn to_bytes(&self) -> Vec<u8> {
-        self.inner.to_bytes()
-    }
-}
-
 // impl From<BdkScript> for Script {
 //     fn from(bdk_script: BdkScript) -> Self {
 //         Script { inner: bdk_script }
diff --git a/bdk-ffi/src/psbt.rs b/bdk-ffi/src/psbt.rs
deleted file mode 100644
index e150db5d..00000000
--- a/bdk-ffi/src/psbt.rs
+++ /dev/null
@@ -1,119 +0,0 @@
-// use bdk::bitcoin::hashes::hex::ToHex;
-// use bdk::bitcoin::util::psbt::PartiallySignedTransaction as BdkPartiallySignedTransaction;
-// use bdk::bitcoincore_rpc::jsonrpc::serde_json;
-// use bdk::psbt::PsbtUtils;
-// use std::ops::Deref;
-// use std::str::FromStr;
-// use std::sync::{Arc, Mutex};
-//
-// use crate::{BdkError, FeeRate, Transaction};
-//
-// #[derive(Debug)]
-// pub(crate) struct PartiallySignedTransaction {
-//     pub(crate) inner: Mutex<BdkPartiallySignedTransaction>,
-// }
-//
-// impl PartiallySignedTransaction {
-//     pub(crate) fn new(psbt_base64: String) -> Result<Self, BdkError> {
-//         let psbt: BdkPartiallySignedTransaction =
-//             BdkPartiallySignedTransaction::from_str(&psbt_base64)?;
-//         Ok(PartiallySignedTransaction {
-//             inner: Mutex::new(psbt),
-//         })
-//     }
-//
-//     pub(crate) fn serialize(&self) -> String {
-//         let psbt = self.inner.lock().unwrap().clone();
-//         psbt.to_string()
-//     }
-//
-//     pub(crate) fn txid(&self) -> String {
-//         let tx = self.inner.lock().unwrap().clone().extract_tx();
-//         let txid = tx.txid();
-//         txid.to_hex()
-//     }
-//
-//     /// Return the transaction.
-//     pub(crate) fn extract_tx(&self) -> Arc<Transaction> {
-//         let tx = self.inner.lock().unwrap().clone().extract_tx();
-//         Arc::new(tx.into())
-//     }
-//
-//     /// Combines this PartiallySignedTransaction with other PSBT as described by BIP 174.
-//     ///
-//     /// In accordance with BIP 174 this function is commutative i.e., `A.combine(B) == B.combine(A)`
-//     pub(crate) fn combine(
-//         &self,
-//         other: Arc<PartiallySignedTransaction>,
-//     ) -> Result<Arc<PartiallySignedTransaction>, BdkError> {
-//         let other_psbt = other.inner.lock().unwrap().clone();
-//         let mut original_psbt = self.inner.lock().unwrap().clone();
-//
-//         original_psbt.combine(other_psbt)?;
-//         Ok(Arc::new(PartiallySignedTransaction {
-//             inner: Mutex::new(original_psbt),
-//         }))
-//     }
-//
-//     /// The total transaction fee amount, sum of input amounts minus sum of output amounts, in Sats.
-//     /// If the PSBT is missing a TxOut for an input returns None.
-//     pub(crate) fn fee_amount(&self) -> Option<u64> {
-//         self.inner.lock().unwrap().fee_amount()
-//     }
-//
-//     /// The transaction's fee rate. This value will only be accurate if calculated AFTER the
-//     /// `PartiallySignedTransaction` is finalized and all witness/signature data is added to the
-//     /// transaction.
-//     /// If the PSBT is missing a TxOut for an input returns None.
-//     pub(crate) fn fee_rate(&self) -> Option<Arc<FeeRate>> {
-//         self.inner.lock().unwrap().fee_rate().map(Arc::new)
-//     }
-//
-//     /// Serialize the PSBT data structure as a String of JSON.
-//     pub(crate) fn json_serialize(&self) -> String {
-//         let psbt = self.inner.lock().unwrap();
-//         serde_json::to_string(psbt.deref()).unwrap()
-//     }
-// }
-//
-// // The goal of these tests to to ensure `bdk-ffi` intermediate code correctly calls `bdk` APIs.
-// // These tests should not be used to verify `bdk` behavior that is already tested in the `bdk`
-// // crate.
-// #[cfg(test)]
-// mod test {
-//     use crate::wallet::{TxBuilder, Wallet};
-//     use bdk::wallet::get_funded_wallet;
-//     use std::sync::Mutex;
-//
-//     #[test]
-//     fn test_psbt_fee() {
-//         let test_wpkh = "wpkh(cVpPVruEDdmutPzisEsYvtST1usBR3ntr8pXSyt6D2YYqXRyPcFW)";
-//         let (funded_wallet, _, _) = get_funded_wallet(test_wpkh);
-//         let test_wallet = Wallet {
-//             inner_mutex: Mutex::new(funded_wallet),
-//         };
-//         let drain_to_address = "tb1ql7w62elx9ucw4pj5lgw4l028hmuw80sndtntxt".to_string();
-//         let drain_to_script = crate::Address::new(drain_to_address)
-//             .unwrap()
-//             .script_pubkey();
-//
-//         let tx_builder = TxBuilder::new()
-//             .fee_rate(2.0)
-//             .drain_wallet()
-//             .drain_to(drain_to_script.clone());
-//         //dbg!(&tx_builder);
-//         assert!(tx_builder.drain_wallet);
-//         assert_eq!(tx_builder.drain_to, Some(drain_to_script.inner.clone()));
-//
-//         let tx_builder_result = tx_builder.finish(&test_wallet).unwrap();
-//
-//         assert!(tx_builder_result.psbt.fee_rate().is_some());
-//         assert_eq!(
-//             tx_builder_result.psbt.fee_rate().unwrap().as_sat_per_vb(),
-//             2.682927
-//         );
-//
-//         assert!(tx_builder_result.psbt.fee_amount().is_some());
-//         assert_eq!(tx_builder_result.psbt.fee_amount().unwrap(), 220);
-//     }
-// }
diff --git a/bdk-ffi/src/wallet.rs b/bdk-ffi/src/wallet.rs
index 2f26beed..47beddcf 100644
--- a/bdk-ffi/src/wallet.rs
+++ b/bdk-ffi/src/wallet.rs
@@ -1,11 +1,12 @@
+use crate::bitcoin::PartiallySignedTransaction;
 use crate::descriptor::Descriptor;
 use crate::{AddressIndex, AddressInfo, Network};
 use crate::{Balance, Script};
+use bdk::bitcoin::blockdata::script::ScriptBuf as BdkScriptBuf;
 use bdk::wallet::Update as BdkUpdate;
 use bdk::Wallet as BdkWallet;
 use bdk::{Error as BdkError, FeeRate};
 use std::sync::{Arc, Mutex, MutexGuard};
-use bdk::bitcoin::blockdata::script::ScriptBuf as BdkScriptBuf;
 
 #[derive(Debug)]
 pub struct Wallet {
@@ -503,7 +504,10 @@ impl TxBuilder {
     //
     /// Finish building the transaction. Returns the BIP174 PSBT.
     /// TODO: The TxBuilder in bdk returns a Psbt type
-    pub(crate) fn finish(&self, wallet: &Wallet) -> Result<String, BdkError> {
+    pub(crate) fn finish(
+        &self,
+        wallet: &Wallet,
+    ) -> Result<Arc<PartiallySignedTransaction>, BdkError> {
         // TODO: I had to change the wallet here to be mutable. Why is that now required with the 1.0 API?
         let mut wallet = wallet.get_wallet();
         let mut tx_builder = wallet.build_tx();
@@ -552,7 +556,11 @@ impl TxBuilder {
         //     tx_builder.add_data(self.data.as_slice());
         // }
 
-        tx_builder.finish().map(|psbt| psbt.serialize_hex())
+        // tx_builder.finish().map(|psbt| psbt.serialize_hex())
+        // tx_builder.finish().into()
+        let psbt = tx_builder.finish()?;
+
+        Ok(Arc::new(psbt.into()))
     }
 }
 //
diff --git a/bdk-jvm/lib/src/test/kotlin/org/bitcoindevkit/JvmLibTest.kt b/bdk-jvm/lib/src/test/kotlin/org/bitcoindevkit/JvmLibTest.kt
index 60c83ed5..709238d8 100644
--- a/bdk-jvm/lib/src/test/kotlin/org/bitcoindevkit/JvmLibTest.kt
+++ b/bdk-jvm/lib/src/test/kotlin/org/bitcoindevkit/JvmLibTest.kt
@@ -47,24 +47,24 @@ class WalletTest {
     //     println("Balance: ${wallet.getBalance().total()}")
     // }
 
-    // @Test
-    // fun testTxBuilder() {
-    //     val descriptor = Descriptor("wpkh(tprv8ZgxMBicQKsPf2qfrEygW6fdYseJDDrVnDv26PH5BHdvSuG6ecCbHqLVof9yZcMoM31z9ur3tTYbSnr1WBqbGX97CbXcmp5H6qeMpyvx35B/84h/1h/0h/0/*)", Network.TESTNET)
-    //     val wallet = Wallet.newNoPersist(descriptor, null, Network.TESTNET)
-    //     val esploraClient = EsploraClient("https://mempool.space/testnet/api")
-    //     // val esploraClient = EsploraClient("https://blockstream.info/testnet/api")
-    //     val update = esploraClient.scan(wallet, 10uL, 1uL)
-    //     wallet.applyUpdate(update)
-    //     println("Balance: ${wallet.getBalance().total()}")
-    //
-    //     assert(wallet.getBalance().total() > 0uL)
-    //
-    //     val recipient: Address = Address("tb1qrnfslnrve9uncz9pzpvf83k3ukz22ljgees989", Network.TESTNET)
-    //     val psbt: String = TxBuilder()
-    //         .addRecipient(recipient.scriptPubkey(), 4200uL)
-    //         .feeRate(2.0f)
-    //         .finish(wallet)
-    //
-    //     println(psbt)
-    // }
+    @Test
+    fun testTxBuilder() {
+        val descriptor = Descriptor("wpkh(tprv8ZgxMBicQKsPf2qfrEygW6fdYseJDDrVnDv26PH5BHdvSuG6ecCbHqLVof9yZcMoM31z9ur3tTYbSnr1WBqbGX97CbXcmp5H6qeMpyvx35B/84h/1h/0h/0/*)", Network.TESTNET)
+        val wallet = Wallet.newNoPersist(descriptor, null, Network.TESTNET)
+        val esploraClient = EsploraClient("https://mempool.space/testnet/api")
+        // val esploraClient = EsploraClient("https://blockstream.info/testnet/api")
+        val update = esploraClient.scan(wallet, 10uL, 1uL)
+        wallet.applyUpdate(update)
+        println("Balance: ${wallet.getBalance().total()}")
+
+        assert(wallet.getBalance().total() > 0uL)
+
+        val recipient: Address = Address("tb1qrnfslnrve9uncz9pzpvf83k3ukz22ljgees989", Network.TESTNET)
+        val psbt: PartiallySignedTransaction = TxBuilder()
+            .addRecipient(recipient.scriptPubkey(), 4200uL)
+            .feeRate(2.0f)
+            .finish(wallet)
+
+        println(psbt.serialize())
+    }
 }