Merge pull request #75 from bitcoindevkit/update-readme-with-deployed-package-versions

Update README with latest published package information

.editorconfig

@@ -0,0 +1,29 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.rs]
+indent_size = 4
+
+[*.kt]
+indent_size = 4
+
+[*.gradle]
+indent_size = 4
+
+[tests/**/*.rs]
+charset = utf-8
+end_of_line = unset
+indent_size = unset
+indent_style = unset
+trim_trailing_whitespace = unset
+insert_final_newline = unset

.gitignore

@@ -1,4 +1,19 @@
-/target
-*.h
-/main
-/Cargo.lock
+target
+build
+Cargo.lock
+/bindings/bdk-kotlin/local.properties
+/bindings/bdk-swift
+/bindings/bdk-swift.swiftdoc
+/bindings/bdk-swift.swiftsourceinfo
+.gradle
+wallet_db
+bdk_ffi_test
+local.properties
+*.log
+*.dylib
+*.so
+.DS_Store
+testdb
+xcuserdata
+.lsp
+.clj-kondo

Cargo.toml

@@ -1,16 +1,19 @@
 [package]
-name = "bdk_ffi"
+name = "bdk-ffi"
 version = "0.1.0"
-authors = ["Steve Myers <steve@notmandatory.org>"]
+authors = ["Steve Myers <steve@notmandatory.org>", "Sudarsan Balaji <sudarsan.balaji@artfuldev.com>"]
 edition = "2018"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [lib]
-crate-type = ["staticlib"]
+crate-type = ["staticlib", "cdylib"]
+name = "bdkffi"
 
 [dependencies]
-bdk = { version = "^0.7", feature = ["all-keys"] }
-safer-ffi = { version = "*", features = ["proc_macros"]}
+bdk = { version = "0.13", features = ["all-keys", "use-esplora-ureq"] }
+uniffi_macros = "0.14.1"
+uniffi = "0.14.1"
+thiserror = "1.0"
 
-[features]
-c-headers = ["safer-ffi/headers"]
+[build-dependencies]
+uniffi_build = "0.14.1"

README.md

@@ -0,0 +1,112 @@
+# Foreign language bindings for BDK (bdk-ffi)
+
+This repository contains source code for generating foreign language bindings
+for the rust library bdk for the Bitcoin Dev Kit (BDK) project.
+
+## Supported target languages and platforms
+
+| Language | Platform | Status |
+| --- | --- | --- |
+| Kotlin | JVM | WIP |
+| Kotlin | Android | WIP |
+| Swift | iOS | WIP |
+
+
+## Getting Started (User)
+
+If you just want to consume the language bindings:
+
+### Kotlin (JVM)
+
+Just add the dependency `org.bitcoindevkit:bdk-jvm:0.1.1`. The package is `org.bitcoindevkit.bdk`.
+
+### Kotlin (Android)
+
+Just add the dependency `org.bitcoindevkit:bdk-android:0.1.1`. The package is `org.bitcoindevkit.bdk`.
+
+## Getting Started (Developer)
+
+This project uses rust. A basic knowledge of the rust ecosystem is helpful.
+
+### General
+1. Install `uniffi-bindgen`
+    ```sh
+    cargo install uniffi_bindgen
+    ```
+1. See the [UniFFI User Guide](https://mozilla.github.io/uniffi-rs/) for more info
+
+### Kotlin Bindings for JVM (OSX / Linux)
+
+1. Install required targets
+    ```sh
+      rustup target add x86_64-apple-darwin x86_64-unknown-linux-gnu
+    ```
+1. Build kotlin (JVM) bindings
+    ```sh
+      ./build.sh -k
+    ```
+1. Generated kotlin bindings are available at `/bindings/bdk-kotlin/`
+1. A demo app is available at `/bindings/bdk-kotlin/demo/`. It uses stdin for
+inputs and can be run from gradle.
+    ```sh
+    cd bindings/bdk-kotlin
+    ./gradlew :demo:run
+    ```
+
+### Kotlin bindings for Android
+
+1. Install required targets
+    ```sh
+    rustup target add x86_64-linux-android aarch64-linux-android
+    armv7-linux-androideabi i686-linux-android
+    ```
+1. Install Android SDK and Build-Tools for API level 30+
+1. Setup `$ANDROID_NDK_HOME` and `$ANDROID_SDK_ROOT` path variables (which are
+required by the build scripts)
+1. Build kotlin (Android) bindings
+    ```sh
+    ./build.sh -a
+    ```
+2. A demo android app is available at [notmandatory/bdk-sample-app](https://github.com/notmandatory/bitcoindevkit-android-sample-app/tree/upgrade-to-bdk-ffi/)
+
+### Swift bindings for iOS
+
+1. Install the latest version of xcode, download and install the advanced tools.
+1. Ensure Swift is installed
+1. Install required targets
+    ```sh
+    rustup target add aarch64-apple-ios x86_64-apple-ios
+    ```
+1. Build swift (iOS) bindings
+    ```sh
+    ./build.sh -s
+    ```
+1. Example iOS app can be found in `/examples/iOS` which can be run by xcode.
+
+## Notes
+
+### Adding new structs and functions
+
+See the [UniFFI User Guide](https://mozilla.github.io/uniffi-rs/)
+
+#### For pass by value objects
+
+1. create new rust struct with only fields that are supported UniFFI types
+1. update mapping `bdk.udl` file with new `dictionary`
+
+#### For pass by reference values 
+
+1. create wrapper rust struct/impl with only fields that are `Sync + Send`
+1. update mapping `bdk.udl` file with new `interface`
+
+## Goals
+
+1. Language bindings should feel idiomatic in target languages/platforms
+1. Adding new targets should be easy
+1. Getting up and running should be easy
+1. Contributing should be easy
+1. Get it right, then automate
+
+## Thanks
+
+This project is made possible thanks to the wonderful work on [mozilla/uniffi-rs](https://github.com/mozilla/uniffi-rs)

build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    uniffi_build::generate_scaffolding("src/bdk.udl").unwrap();
+}

build.sh

@@ -0,0 +1,145 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# functions
+
+## help
+help()
+{
+   # Display Help
+   echo "Build bdk-ffi and related libraries."
+   echo
+   echo "Syntax: build [-a|h|k|s]"
+   echo "options:"
+   echo "-a     Android."
+   echo "-h     Print this Help."
+   echo "-k     Kotlin."
+   echo "-s     Swift."
+   echo
+}
+
+## rust
+build_rust() {
+  echo "Build Rust library"
+  cargo fmt
+  cargo build
+  cargo test
+}
+
+## copy to bdk-bdk-kotlin
+copy_lib_kotlin() {
+  echo -n "Copy "
+  case $OS in
+    "Darwin")
+      echo -n "darwin "
+      mkdir -p bindings/bdk-kotlin/jvm/src/main/resources/darwin-x86-64
+      cp target/debug/libbdkffi.dylib bindings/bdk-kotlin/jvm/src/main/resources/darwin-x86-64
+      ;;
+    "Linux")
+      echo -n "linux "
+      mkdir -p bindings/bdk-kotlin/jvm/src/main/resources/linux-x86-64
+      cp target/debug/libbdkffi.so bindings/bdk-kotlin/jvm/src/main/resources/linux-x86-64
+      ;;
+  esac
+  echo "libs to kotlin sub-project"
+}
+
+## bdk-bdk-kotlin jar
+build_kotlin() {
+  copy_lib_kotlin
+  uniffi-bindgen generate src/bdk.udl --no-format --out-dir bindings/bdk-kotlin/jvm/src/main/kotlin --language kotlin
+}
+
+## bdk swift
+build_swift() {
+  uniffi-bindgen generate src/bdk.udl --no-format --out-dir bindings/bdk-swift/ --language swift
+  swiftc -module-name bdk -emit-library -o libbdkffi.dylib -emit-module -emit-module-path ./bindings/bdk-swift/ -parse-as-library -L ./target/debug/ -lbdkffi -Xcc -fmodule-map-file=./bindings/bdk-swift/bdkFFI.modulemap ./bindings/bdk-swift/bdk.swift
+  TARGETDIR=target
+  RELDIR=debug
+  STATIC_LIB_NAME=libbdkffi.a
+
+  # We can't use cargo lipo because we can't link to universal libraries :(
+  # https://github.com/rust-lang/rust/issues/55235
+  LIBS_ARCHS=("x86_64" "arm64")
+  IOS_TRIPLES=("x86_64-apple-ios" "aarch64-apple-ios")
+  for i in "${!LIBS_ARCHS[@]}"; do
+      cargo build --target "${IOS_TRIPLES[${i}]}"
+  done
+
+  UNIVERSAL_BINARY=./${TARGETDIR}/ios/universal/${RELDIR}/${STATIC_LIB_NAME}
+  NEED_LIPO=
+
+  # if the universal binary doesnt exist, or if it's older than the static libs,
+  # we need to run `lipo` again.
+  if [[ ! -f "${UNIVERSAL_BINARY}" ]]; then
+      NEED_LIPO=1
+  elif [[ "$(stat -f "%m" "./${TARGETDIR}/x86_64-apple-ios/${RELDIR}/${STATIC_LIB_NAME}")" -gt "$(stat -f "%m" "${UNIVERSAL_BINARY}")" ]]; then
+      NEED_LIPO=1
+  elif [[ "$(stat -f "%m" "./${TARGETDIR}/aarch64-apple-ios/${RELDIR}/${STATIC_LIB_NAME}")" -gt "$(stat -f "%m" "${UNIVERSAL_BINARY}")" ]]; then
+      NEED_LIPO=1
+  fi
+  if [[ "${NEED_LIPO}" = "1" ]]; then
+      mkdir -p "${TARGETDIR}/ios/universal/${RELDIR}"
+      lipo -create -output "${UNIVERSAL_BINARY}" \
+          "${TARGETDIR}/x86_64-apple-ios/${RELDIR}/${STATIC_LIB_NAME}" \
+          "${TARGETDIR}/aarch64-apple-ios/${RELDIR}/${STATIC_LIB_NAME}"
+  fi
+}
+
+## rust android
+build_android() {
+  build_kotlin
+
+  # If ANDROID_NDK_HOME is not set then set it to github actions default
+  [ -z "$ANDROID_NDK_HOME" ] && export ANDROID_NDK_HOME=$ANDROID_HOME/ndk-bundle
+
+  # Update this line accordingly if you are not building *from* darwin-x86_64 or linux-x86_64
+  export PATH=$PATH:$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/`uname | tr '[:upper:]' '[:lower:]'`-x86_64/bin
+
+  # Required for 'ring' dependency to cross-compile to Android platform, must be at least 21
+  export CFLAGS="-D__ANDROID_API__=21"
+
+  # IMPORTANT: make sure every target is not a substring of a different one. We check for them with grep later on
+  BUILD_TARGETS="${BUILD_TARGETS:-aarch64,x86_64,i686}"
+
+  mkdir -p bindings/bdk-kotlin/android/src/main/jniLibs/ bindings/bdk-kotlin/android/src/main/jniLibs/arm64-v8a bindings/bdk-kotlin/android/src/main/jniLibs/x86_64 bindings/bdk-kotlin/android/src/main/jniLibs/x86
+
+  if echo $BUILD_TARGETS | grep "aarch64"; then
+      CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER="aarch64-linux-android21-clang" CC="aarch64-linux-android21-clang" cargo build --target=aarch64-linux-android
+      cp target/aarch64-linux-android/debug/libbdkffi.so bindings/bdk-kotlin/android/src/main/jniLibs/arm64-v8a
+  fi
+  if echo $BUILD_TARGETS | grep "x86_64"; then
+      CARGO_TARGET_X86_64_LINUX_ANDROID_LINKER="x86_64-linux-android21-clang" CC="x86_64-linux-android21-clang" cargo build --target=x86_64-linux-android
+      cp target/x86_64-linux-android/debug/libbdkffi.so bindings/bdk-kotlin/android/src/main/jniLibs/x86_64
+  fi
+  if echo $BUILD_TARGETS | grep "i686"; then
+      CARGO_TARGET_I686_LINUX_ANDROID_LINKER="i686-linux-android21-clang" CC="i686-linux-android21-clang" cargo build --target=i686-linux-android
+      cp target/i686-linux-android/debug/libbdkffi.so bindings/bdk-kotlin/android/src/main/jniLibs/x86
+  fi
+
+  # copy sources
+  cp -R bindings/bdk-kotlin/jvm/src/main/kotlin bindings/bdk-kotlin/android/src/main
+
+  # bdk-kotlin aar
+  (cd bindings/bdk-kotlin && ./gradlew :android:build)
+}
+
+OS=$(uname)
+
+if [ "$1" == "-h" ]
+then
+  help
+else
+  build_rust
+
+  while [ -n "$1" ]; do # while loop starts
+    case "$1" in
+      -a) build_android ;;
+      -k) build_kotlin ;;
+      -s) build_swift ;;
+      -h) help ;;
+      *) echo "Option $1 not recognized" ;;
+    esac
+    shift
+  done
+fi

main.c

@@ -1,13 +0,0 @@
-#include <stdlib.h>
-
-#include "bdk_ffi.h"
-
-int main (int argc, char const * const argv[])
-{
-    Point_t * a = new_point(84,45);
-    Point_t * b = new_point(0.0,39.0);
-    Point_t * m = mid_point(a, b);
-    print_point(m);
-    print_point(NULL);
-    return EXIT_SUCCESS;
-}

src/bdk.udl

@@ -0,0 +1,167 @@
+namespace bdk {
+  [Throws=BdkError]
+  ExtendedKeyInfo generate_extended_key(Network network, MnemonicType mnemonic_type, string? password);
+  [Throws=BdkError]
+  ExtendedKeyInfo restore_extended_key(Network network, string mnemonic, string? password);
+};
+
+[Error]
+enum BdkError {
+  "InvalidU32Bytes",
+  "Generic",
+  "ScriptDoesntHaveAddressForm",
+  "NoRecipients",
+  "NoUtxosSelected",
+  "OutputBelowDustLimit",
+  "InsufficientFunds",
+  "BnBTotalTriesExceeded",
+  "BnBNoExactMatch",
+  "UnknownUtxo",
+  "TransactionNotFound",
+  "TransactionConfirmed",
+  "IrreplaceableTransaction",
+  "FeeRateTooLow",
+  "FeeTooLow",
+  "FeeRateUnavailable",
+  "MissingKeyOrigin",
+  "Key",
+  "ChecksumMismatch",
+  "SpendingPolicyRequired",
+  "InvalidPolicyPathError",
+  "Signer",
+  "InvalidNetwork",
+  "InvalidProgressValue",
+  "ProgressUpdateError",
+  "InvalidOutpoint",
+  "Descriptor",
+  "AddressValidator",
+  "Encode",
+  "Miniscript",
+  "Bip32",
+  "Secp256k1",
+  "Json",
+  "Hex",
+  "Psbt",
+  "PsbtParse",
+  "Electrum",
+  "Esplora",
+  "Sled",
+};
+
+enum Network {
+  "Bitcoin",
+  "Testnet",
+  "Signet",
+  "Regtest",
+};
+
+dictionary SledDbConfiguration {
+  string path;
+  string tree_name;
+};
+
+[Enum]
+interface DatabaseConfig {
+  Memory(string junk);
+  Sled(SledDbConfiguration config);
+};
+
+dictionary TransactionDetails {
+    u64? fees;
+    u64 received;
+    u64 sent;
+    string id;
+};
+
+dictionary Confirmation {
+    u32 height;
+    u64 timestamp;
+};
+
+[Enum]
+interface Transaction {
+  Unconfirmed(TransactionDetails details);
+  Confirmed(TransactionDetails details, Confirmation confirmation);
+};
+
+interface OfflineWallet {
+  [Throws=BdkError]
+  constructor(string descriptor, Network network, DatabaseConfig database_config);
+
+  // OfflineWalletOperations
+  string get_new_address();
+  string get_last_unused_address();
+  [Throws=BdkError]
+  u64 get_balance();
+  [Throws=BdkError]
+  void sign([ByRef] PartiallySignedBitcoinTransaction psbt);
+  [Throws=BdkError]
+  sequence<Transaction> get_transactions();
+};
+
+dictionary ElectrumConfig {
+  string url;
+  string? socks5;
+  u8 retry;
+  u8? timeout;
+  u64 stop_gap;
+};
+
+dictionary EsploraConfig {
+  string base_url;
+  string? proxy;
+  u64 timeout_read;
+  u64 timeout_write;
+  u64 stop_gap;
+};
+
+[Enum]
+interface BlockchainConfig {
+  Electrum(ElectrumConfig config);
+  Esplora(EsploraConfig config);
+};
+
+callback interface BdkProgress {
+  void update(f32 progress, string? message);
+};
+
+interface OnlineWallet {
+  [Throws=BdkError]
+  constructor(string descriptor, string? change_descriptor, Network network, DatabaseConfig database_config, BlockchainConfig blockchain_config);
+
+  // OfflineWalletOperations
+  string get_new_address();
+  string get_last_unused_address();
+  [Throws=BdkError]
+  u64 get_balance();
+  [Throws=BdkError]
+  void sign([ByRef] PartiallySignedBitcoinTransaction psbt);
+  [Throws=BdkError]
+  sequence<Transaction> get_transactions();
+
+  // OnlineWalletInterface
+  Network get_network();
+  [Throws=BdkError]
+  void sync(BdkProgress progress_update, u32? max_address_param);
+  [Throws=BdkError]
+  Transaction broadcast([ByRef] PartiallySignedBitcoinTransaction psbt);
+};
+
+interface PartiallySignedBitcoinTransaction {
+  [Throws=BdkError]
+  constructor([ByRef] OnlineWallet wallet, string recipient, u64 amount, float? fee_rate);
+};
+
+dictionary ExtendedKeyInfo {
+  string mnemonic;
+  string xprv;
+  string fingerprint;
+};
+
+enum MnemonicType {
+  "Words12",
+  "Words15",
+  "Words18",
+  "Words21",
+  "Words24",
+};

src/lib.rs

@@ -1,47 +1,340 @@
-use ::safer_ffi::prelude::*;
+use bdk::bitcoin::secp256k1::Secp256k1;
+use bdk::bitcoin::util::psbt::PartiallySignedTransaction;
+use bdk::bitcoin::{Address, Network};
+use bdk::blockchain::any::{AnyBlockchain, AnyBlockchainConfig};
+use bdk::blockchain::Progress;
+use bdk::blockchain::{
+    electrum::ElectrumBlockchainConfig, esplora::EsploraBlockchainConfig, ConfigurableBlockchain,
+};
+use bdk::database::any::{AnyDatabase, SledDbConfiguration};
+use bdk::database::{AnyDatabaseConfig, ConfigurableDatabase};
+use bdk::keys::bip39::{Language, Mnemonic, MnemonicType};
+use bdk::keys::{DerivableKey, ExtendedKey, GeneratableKey, GeneratedKey};
+use bdk::miniscript::BareCtx;
+use bdk::wallet::AddressIndex;
+use bdk::{ConfirmationTime, Error, FeeRate, SignOptions, Wallet};
+use std::convert::TryFrom;
+use std::str::FromStr;
+use std::sync::{Mutex, MutexGuard};
 
-/// A `struct` usable from both Rust and C
-#[derive_ReprC]
-#[repr(C)]
-#[derive(Debug, Clone, Copy)]
-pub struct Point {
-    x: f64,
-    y: f64,
+uniffi_macros::include_scaffolding!("bdk");
+
+type BdkError = Error;
+
+pub enum DatabaseConfig {
+    Memory { junk: String },
+    Sled { config: SledDbConfiguration },
 }
 
-/* Export a Rust function to the C world. */
-/// Returns the middle point of `[a, b]`.
-#[ffi_export]
-fn mid_point(a: Option<repr_c::Box<Point>>, b: Option<repr_c::Box<Point>>) -> repr_c::Box<Point> {
-    let a = a.unwrap();
-    let b = b.unwrap();
-    repr_c::Box::new(Point {
-        x: (a.x + b.x) / 2.,
-        y: (a.y + b.y) / 2.,
+pub struct ElectrumConfig {
+    pub url: String,
+    pub socks5: Option<String>,
+    pub retry: u8,
+    pub timeout: Option<u8>,
+    pub stop_gap: u64,
+}
+
+pub struct EsploraConfig {
+    pub base_url: String,
+    pub proxy: Option<String>,
+    pub timeout_read: u64,
+    pub timeout_write: u64,
+    pub stop_gap: u64,
+}
+
+pub enum BlockchainConfig {
+    Electrum { config: ElectrumConfig },
+    Esplora { config: EsploraConfig },
+}
+
+trait WalletHolder<B> {
+    fn get_wallet(&self) -> MutexGuard<Wallet<B, AnyDatabase>>;
+}
+
+struct OfflineWallet {
+    wallet: Mutex<Wallet<(), AnyDatabase>>,
+}
+
+impl WalletHolder<()> for OfflineWallet {
+    fn get_wallet(&self) -> MutexGuard<Wallet<(), AnyDatabase>> {
+        self.wallet.lock().unwrap()
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub struct TransactionDetails {
+    pub fees: Option<u64>,
+    pub received: u64,
+    pub sent: u64,
+    pub id: String,
+}
+
+type Confirmation = ConfirmationTime;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Transaction {
+    Unconfirmed {
+        details: TransactionDetails,
+    },
+    Confirmed {
+        details: TransactionDetails,
+        confirmation: Confirmation,
+    },
+}
+
+impl From<&bdk::TransactionDetails> for TransactionDetails {
+    fn from(x: &bdk::TransactionDetails) -> TransactionDetails {
+        TransactionDetails {
+            fees: x.fee,
+            id: x.txid.to_string(),
+            received: x.received,
+            sent: x.sent,
+        }
+    }
+}
+
+impl From<&bdk::TransactionDetails> for Transaction {
+    fn from(x: &bdk::TransactionDetails) -> Transaction {
+        match x.confirmation_time.clone() {
+            Some(confirmation) => Transaction::Confirmed {
+                details: TransactionDetails::from(x),
+                confirmation,
+            },
+            None => Transaction::Unconfirmed {
+                details: TransactionDetails::from(x),
+            },
+        }
+    }
+}
+
+trait OfflineWalletOperations<B>: WalletHolder<B> {
+    fn get_new_address(&self) -> String {
+        self.get_wallet()
+            .get_address(AddressIndex::New)
+            .unwrap()
+            .address
+            .to_string()
+    }
+
+    fn get_last_unused_address(&self) -> String {
+        self.get_wallet()
+            .get_address(AddressIndex::LastUnused)
+            .unwrap()
+            .address
+            .to_string()
+    }
+
+    fn get_balance(&self) -> Result<u64, Error> {
+        self.get_wallet().get_balance()
+    }
+
+    fn sign<'a>(&self, psbt: &'a PartiallySignedBitcoinTransaction) -> Result<(), Error> {
+        let mut psbt = psbt.internal.lock().unwrap();
+        let finalized = self.get_wallet().sign(&mut psbt, SignOptions::default())?;
+        match finalized {
+            true => Ok(()),
+            false => Err(BdkError::Generic(format!(
+                "transaction signing not finalized {:?}",
+                psbt
+            ))),
+        }
+    }
+
+    fn get_transactions(&self) -> Result<Vec<Transaction>, Error> {
+        let transactions = self.get_wallet().list_transactions(true)?;
+        Ok(transactions.iter().map(Transaction::from).collect())
+    }
+}
+
+impl OfflineWallet {
+    fn new(
+        descriptor: String,
+        network: Network,
+        database_config: DatabaseConfig,
+    ) -> Result<Self, BdkError> {
+        let any_database_config = match database_config {
+            DatabaseConfig::Memory { .. } => AnyDatabaseConfig::Memory(()),
+            DatabaseConfig::Sled { config } => AnyDatabaseConfig::Sled(config),
+        };
+        let database = AnyDatabase::from_config(&any_database_config)?;
+        let wallet = Mutex::new(Wallet::new_offline(&descriptor, None, network, database)?);
+        Ok(OfflineWallet { wallet })
+    }
+}
+
+impl OfflineWalletOperations<()> for OfflineWallet {}
+
+struct OnlineWallet {
+    wallet: Mutex<Wallet<AnyBlockchain, AnyDatabase>>,
+}
+
+pub trait BdkProgress: Send + Sync {
+    fn update(&self, progress: f32, message: Option<String>);
+}
+
+struct BdkProgressHolder {
+    progress_update: Box<dyn BdkProgress>,
+}
+
+impl Progress for BdkProgressHolder {
+    fn update(&self, progress: f32, message: Option<String>) -> Result<(), Error> {
+        self.progress_update.update(progress, message);
+        Ok(())
+    }
+}
+
+struct PartiallySignedBitcoinTransaction {
+    internal: Mutex<PartiallySignedTransaction>,
+    details: bdk::TransactionDetails,
+}
+
+impl PartiallySignedBitcoinTransaction {
+    fn new(
+        online_wallet: &OnlineWallet,
+        recipient: String,
+        amount: u64,
+        fee_rate: Option<f32>, // satoshis per vbyte
+    ) -> Result<Self, Error> {
+        let wallet = online_wallet.get_wallet();
+        match Address::from_str(&recipient) {
+            Ok(address) => {
+                let (psbt, details) = {
+                    let mut builder = wallet.build_tx();
+                    builder.add_recipient(address.script_pubkey(), amount);
+                    if let Some(sat_per_vb) = fee_rate {
+                        builder.fee_rate(FeeRate::from_sat_per_vb(sat_per_vb));
+                    }
+                    builder.finish()?
+                };
+                Ok(PartiallySignedBitcoinTransaction {
+                    internal: Mutex::new(psbt),
+                    details,
+                })
+            }
+            Err(..) => Err(BdkError::Generic(
+                "failed to read wallet address".to_string(),
+            )),
+        }
+    }
+}
+
+impl OnlineWallet {
+    fn new(
+        descriptor: String,
+        change_descriptor: Option<String>,
+        network: Network,
+        database_config: DatabaseConfig,
+        blockchain_config: BlockchainConfig,
+    ) -> Result<Self, BdkError> {
+        let any_database_config = match database_config {
+            DatabaseConfig::Memory { .. } => AnyDatabaseConfig::Memory(()),
+            DatabaseConfig::Sled { config } => AnyDatabaseConfig::Sled(config),
+        };
+        let any_blockchain_config = match blockchain_config {
+            BlockchainConfig::Electrum { config } => {
+                AnyBlockchainConfig::Electrum(ElectrumBlockchainConfig {
+                    retry: config.retry,
+                    socks5: config.socks5,
+                    timeout: config.timeout,
+                    url: config.url,
+                    stop_gap: usize::try_from(config.stop_gap).unwrap(),
+                })
+            }
+            BlockchainConfig::Esplora { config } => {
+                AnyBlockchainConfig::Esplora(EsploraBlockchainConfig {
+                    base_url: config.base_url,
+                    proxy: config.proxy,
+                    timeout_read: config.timeout_read,
+                    timeout_write: config.timeout_write,
+                    stop_gap: usize::try_from(config.stop_gap).unwrap(),
+                })
+            }
+        };
+        let database = AnyDatabase::from_config(&any_database_config)?;
+        let blockchain = AnyBlockchain::from_config(&any_blockchain_config)?;
+        let wallet = Mutex::new(Wallet::new(
+            &descriptor,
+            change_descriptor.to_owned().as_ref(),
+            network,
+            database,
+            blockchain,
+        )?);
+        Ok(OnlineWallet { wallet })
+    }
+
+    fn get_network(&self) -> Network {
+        self.wallet.lock().unwrap().network()
+    }
+
+    fn sync(
+        &self,
+        progress_update: Box<dyn BdkProgress>,
+        max_address_param: Option<u32>,
+    ) -> Result<(), BdkError> {
+        progress_update.update(21.0, Some("message".to_string()));
+        self.wallet
+            .lock()
+            .unwrap()
+            .sync(BdkProgressHolder { progress_update }, max_address_param)
+    }
+
+    fn broadcast<'a>(
+        &self,
+        psbt: &'a PartiallySignedBitcoinTransaction,
+    ) -> Result<Transaction, Error> {
+        let tx = psbt.internal.lock().unwrap().clone().extract_tx();
+        self.get_wallet().broadcast(tx)?;
+        Ok(Transaction::from(&psbt.details))
+    }
+}
+
+impl WalletHolder<AnyBlockchain> for OnlineWallet {
+    fn get_wallet(&self) -> MutexGuard<Wallet<AnyBlockchain, AnyDatabase>> {
+        self.wallet.lock().unwrap()
+    }
+}
+
+impl OfflineWalletOperations<AnyBlockchain> for OnlineWallet {}
+
+pub struct ExtendedKeyInfo {
+    mnemonic: String,
+    xprv: String,
+    fingerprint: String,
+}
+
+fn generate_extended_key(
+    network: Network,
+    mnemonic_type: MnemonicType,
+    password: Option<String>,
+) -> Result<ExtendedKeyInfo, Error> {
+    let mnemonic: GeneratedKey<_, BareCtx> =
+        Mnemonic::generate((mnemonic_type, Language::English)).unwrap();
+    let mnemonic = mnemonic.into_key();
+    let xkey: ExtendedKey = (mnemonic.clone(), password).into_extended_key()?;
+    let xprv = xkey.into_xprv(network).unwrap();
+    let fingerprint = xprv.fingerprint(&Secp256k1::new());
+    Ok(ExtendedKeyInfo {
+        mnemonic: mnemonic.to_string(),
+        xprv: xprv.to_string(),
+        fingerprint: fingerprint.to_string(),
     })
 }
 
-/// Pretty-prints a point using Rust's formatting logic.
-#[ffi_export]
-fn print_point(point: Option<repr_c::Box<Point>>) {
-    println!("{:?}", point);
+fn restore_extended_key(
+    network: Network,
+    mnemonic: String,
+    password: Option<String>,
+) -> Result<ExtendedKeyInfo, Error> {
+    let mnemonic = Mnemonic::from_phrase(mnemonic.as_ref(), Language::English).unwrap();
+    let xkey: ExtendedKey = (mnemonic.clone(), password).into_extended_key()?;
+    let xprv = xkey.into_xprv(network).unwrap();
+    let fingerprint = xprv.fingerprint(&Secp256k1::new());
+    Ok(ExtendedKeyInfo {
+        mnemonic: mnemonic.to_string(),
+        xprv: xprv.to_string(),
+        fingerprint: fingerprint.to_string(),
+    })
 }
 
-#[ffi_export]
-fn new_point(x: f64, y: f64) -> repr_c::Box<Point> {
-    repr_c::Box::new(Point { x, y })
-}
-
-#[ffi_export]
-fn free_point(point: Option<repr_c::Box<Point>>) {
-    drop(point)
-}
-
-/// The following test function is necessary for the header generation.
-#[::safer_ffi::cfg_headers]
-#[test]
-fn generate_headers() -> ::std::io::Result<()> {
-    ::safer_ffi::headers::builder()
-        .to_file("bdk_ffi.h")?
-        .generate()
-}
+uniffi::deps::static_assertions::assert_impl_all!(OfflineWallet: Sync, Send);
+uniffi::deps::static_assertions::assert_impl_all!(OnlineWallet: Sync, Send);

test.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# functions
+
+## help
+help()
+{
+   # Display Help
+   echo "Test bdk-uniffi and related libraries."
+   echo
+   echo "Syntax: build [-a|h|k]"
+   echo "options:"
+   echo "-a     Android connected device tests."
+   echo "-h     Print this Help."
+   echo "-k     Kotlin tests."
+   echo
+}
+
+test_kotlin() {
+  (cd bindings/bdk-kotlin && ./gradlew :jvm:test -Djna.debug_load=true)
+}
+
+test_android() {
+  (cd bindings/bdk-kotlin && ./gradlew :android:connectedDebugAndroidTest)
+}
+
+if [ $1 = "-h" ]
+then
+  help
+else
+  cargo test
+
+  # optional tests
+  while [ -n "$1" ]; do # while loop starts
+    case "$1" in
+      -a) test_android ;;
+      -h) help ;;
+      -k) test_kotlin ;;
+      *) echo "Option $1 not recognized" ;;
+    esac
+    shift
+  done
+fi

uniffi.toml

@@ -0,0 +1,12 @@
+[bindings.kotlin]
+package_name = "org.bitcoindevkit"
+cdylib_name = "bdkffi"
+
+[bindings.python]
+cdylib_name = "bdkffi"
+
+[bindings.ruby]
+cdylib_name = "bdkffi"
+
+[bindings.swift]
+cdylib_name = "bdkffi"