# bdk-kotlin

This project builds .jar and .aar packages for the `jvm` and `android` platforms that provide 
[Kotlin] language bindings for the [`bdk`] library. The Kotlin language bindings are created by the 
[`bdk-ffi`] project which is included as a git submodule of this repository.

## How to Use

To use the Kotlin language bindings for [`bdk`] in your `jvm` or `android` project add the 
following to your gradle dependencies:
```groovy
repositories {
    mavenCentral()
}

dependencies {
  
  // for jvm
  implementation 'org.bitcoindevkit:bdk-jvm:<version>'
  // OR for android
  implementation 'org.bitcoindevkit:bdk-android:<version>'
  
}
```

You may then import and use the `org.bitcoindevkit` library in your Kotlin code. For example:

```kotlin
import org.bitcoindevkit.*

// ...

val externalDescriptor = "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)"
val internalDescriptor = "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"

val databaseConfig = DatabaseConfig.Memory

val blockchainConfig =
  BlockchainConfig.Electrum(
    ElectrumConfig("ssl://electrum.blockstream.info:60002", null, 5u, null, 10u)
  )
val wallet = Wallet(externalDescriptor, internalDescriptor, Network.TESTNET, databaseConfig, blockchainConfig)
val newAddress = wallet.getNewAddress()
```

### Example Projects

#### `bdk-android`
* [Devkit Wallet](https://github.com/thunderbiscuit/devkit-wallet)  
* [Padawan Wallet](https://github.com/thunderbiscuit/padawan-wallet)

#### `bdk-jvm`
* [Tatooine Faucet](https://github.com/thunderbiscuit/tatooine)

### How to build
_Note that Kotlin version `1.6.10` or later is required to build the library._

1. Clone this repository and initialize and update its [`bdk-ffi`] submodule.
```shell
git clone https://github.com/bitcoindevkit/bdk-kotlin
git submodule update --init
```
2. Follow the "General" bdk-ffi ["Getting Started (Developer)"] instructions.
3. If building on MacOS install required intel and m1 jvm targets
```sh
rustup target add x86_64-apple-darwin aarch64-apple-darwin
```
4. Install required targets
 ```sh
 rustup target add x86_64-linux-android aarch64-linux-android armv7-linux-androideabi
 ```
5. Install Android SDK and Build-Tools for API level 30+
6. Setup `$ANDROID_SDK_ROOT` and `$ANDROID_NDK_ROOT` path variables (which are required by the 
   build tool), for example (NDK major version 21 is required):
 ```shell
 export ANDROID_SDK_ROOT=~/Android/Sdk
 export ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/21.<NDK_VERSION>
 ```
7. Build kotlin bindings
 ```sh
 # build JVM library
 ./gradlew :jvm:buildJvmLib
 
 # build Android library
 ./gradlew :android:buildAndroidLib
 ```
8. Start android emulator (must be x86_64) and run tests
```sh
./gradlew connectedAndroidTest 
```

## How to publish

### Publish to your local maven repo

1. Set your `~/.gradle/gradle.properties` signing key values
```properties
signing.gnupg.keyName=<YOUR_GNUPG_ID>
signing.gnupg.passphrase=<YOUR_GNUPG_PASSPHRASE>
```
2. Publish   
```shell
./gradlew :jvm:publishToMavenLocal
./gradlew :android:publishToMavenLocal
```

Note that if you do not have gpg keys set up to sign the publication, the task will fail. If you wish to publish to your local Maven repository for local testing without signing the release, you can do so by excluding the `signMavenPublication` subtask like so:
```shell
./gradlew :jvm:publishToMavenLocal --exclude-task signMavenPublication
./gradlew :android:publishToMavenLocal --exclude-task signMavenPublication
```

### Publish to maven central with [Gradle Nexus Publish Plugin] (project maintainers only)

1. Set your `~/.gradle/gradle.properties` signing key values and SONATYPE login
```properties
signing.gnupg.keyName=<YOUR_GNUPG_ID>
signing.gnupg.passphrase=<YOUR_GNUPG_PASSPHRASE>

ossrhUserName=<YOUR_SONATYPE_USERNAME>
ossrhPassword=<YOUR_SONATYPE_PASSWORD>
```
2. Publish
```shell
./gradlew :jvm:publishToSonatype closeAndReleaseSonatypeStagingRepository
./gradlew :android:publishToSonatype closeAndReleaseSonatypeStagingRepository
```

[Kotlin]: https://kotlinlang.org/
[Android Studio]: https://developer.android.com/studio/
[`bdk`]: https://github.com/bitcoindevkit/bdk
[`bdk-ffi`]: https://github.com/bitcoindevkit/bdk-ffi
["Getting Started (Developer)"]: https://github.com/bitcoindevkit/bdk-ffi#getting-started-developer
[Gradle Nexus Publish Plugin]: https://github.com/gradle-nexus/publish-plugin