BDK UniFFI Language Bindings

Setup Android build environment

1. Add Android rust targets

rustup target add x86_64-apple-darwin x86_64-unknown-linux-gnu x86_64-linux-android aarch64-linux-android armv7-linux-androideabi i686-linux-android

2. Set ANDROID_NDK_HOME

export ANDROID_NDK_HOME=/home/<user>/Android/Sdk/ndk/<NDK version, ie. 21.4.7075529>

Setup Swift build environment

1. install Swift, see ["Download Swift"](https://swift.org/download/) page  
   (or on Mac OSX install the latest Xcode)

Setup UniFFI

1. `cargo install uniffi_bindgen`

Adding new structs and functions

See the UniFFI User Guide

For pass by value objects

1. create new rust struct with only fields that are supported UniFFI types
2. 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
2. update mapping bdk.udl file with new interface

Build and test

1. Use build.sh script (TODO do it all in build.rs instead)
2. Create tests in bindings/bdk-kotlin and/or bindings/bdk-swift
3. Use test.sh to run all bindings tests