Move bdk-jvm and bdk-android out of subdirectory after ffi merge

bdk-android/build.gradle.kts

@@ -0,0 +1,33 @@
+buildscript {
+    repositories {
+        google()
+    }
+    dependencies {
+        classpath("com.android.tools.build:gradle:7.1.2")
+    }
+}
+
+plugins {
+    id("io.github.gradle-nexus.publish-plugin") version "1.1.0"
+}
+
+// These properties are required here so that the nexus publish-plugin
+// finds a staging profile with the correct group (group is otherwise set as "")
+// and knows whether to publish to a SNAPSHOT repository or not
+// https://github.com/gradle-nexus/publish-plugin#applying-the-plugin
+group = "org.bitcoindevkit"
+version = "0.12.0-SNAPSHOT"
+
+nexusPublishing {
+    repositories {
+        create("sonatype") {
+            nexusUrl.set(uri("https://s01.oss.sonatype.org/service/local/"))
+            snapshotRepositoryUrl.set(uri("https://s01.oss.sonatype.org/content/repositories/snapshots/"))
+
+            val ossrhUsername: String? by project
+            val ossrhPassword: String? by project
+            username.set(ossrhUsername)
+            password.set(ossrhPassword)
+        }
+    }
+}

bdk-android/gradle.properties

@@ -0,0 +1,4 @@
+org.gradle.jvmargs=-Xmx1536m
+android.useAndroidX=true
+android.enableJetifier=true
+kotlin.code.style=official

bdk-android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.2-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

bdk-android/gradlew

@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

bdk-android/gradlew.bat

@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

bdk-android/lib/build.gradle.kts

@@ -0,0 +1,106 @@
+plugins {
+    id("com.android.library")
+    id("org.jetbrains.kotlin.android") version "1.6.10"
+    id("maven-publish")
+    id("signing")
+
+    // Custom plugin to generate the native libs and bindings file
+    id("org.bitcoindevkit.plugins.generate-android-bindings")
+}
+
+repositories {
+    mavenCentral()
+    google()
+}
+
+android {
+    compileSdk = 31
+
+    defaultConfig {
+        minSdk = 21
+        targetSdk = 31
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles("consumer-rules.pro")
+    }
+
+    buildTypes {
+        getByName("release") {
+            isMinifyEnabled = false
+            proguardFiles(file("proguard-android-optimize.txt"), file("proguard-rules.pro"))
+        }
+    }
+
+    publishing {
+        singleVariant("release") {
+            withSourcesJar()
+            withJavadocJar()
+        }
+    }
+}
+
+dependencies {
+    implementation("net.java.dev.jna:jna:5.8.0@aar")
+    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk7")
+    implementation("androidx.appcompat:appcompat:1.4.0")
+    implementation("androidx.core:core-ktx:1.7.0")
+    api("org.slf4j:slf4j-api:1.7.30")
+
+    androidTestImplementation("com.github.tony19:logback-android:2.0.0")
+    androidTestImplementation("androidx.test.ext:junit:1.1.3")
+    androidTestImplementation("androidx.test.espresso:espresso-core:3.4.0")
+    androidTestImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.4.1")
+}
+
+afterEvaluate {
+    publishing {
+        publications {
+            create<MavenPublication>("maven") {
+                groupId = "org.bitcoindevkit"
+                artifactId = "bdk-android"
+                version = "0.12.0-SNAPSHOT"
+
+                from(components["release"])
+                pom {
+                    name.set("bdk-android")
+                    description.set("Bitcoin Dev Kit Kotlin language bindings.")
+                    url.set("https://bitcoindevkit.org")
+                    licenses {
+                        license {
+                            name.set("APACHE 2.0")
+                            url.set("https://github.com/bitcoindevkit/bdk/blob/master/LICENSE-APACHE")
+                        }
+                        license {
+                            name.set("MIT")
+                            url.set("https://github.com/bitcoindevkit/bdk/blob/master/LICENSE-MIT")
+                        }
+                    }
+                    developers {
+                        developer {
+                            id.set("notmandatory")
+                            name.set("Steve Myers")
+                            email.set("notmandatory@noreply.github.org")
+                        }
+                        developer {
+                            id.set("artfuldev")
+                            name.set("Sudarsan Balaji")
+                            email.set("sudarsan.balaji@artfuldev.com")
+                        }
+                    }
+                    scm {
+                        connection.set("scm:git:github.com/bitcoindevkit/bdk-ffi.git")
+                        developerConnection.set("scm:git:ssh://github.com/bitcoindevkit/bdk-ffi.git")
+                        url.set("https://github.com/bitcoindevkit/bdk-ffi/tree/master")
+                    }
+                }
+            }
+        }
+    }
+}
+
+signing {
+    val signingKeyId: String? by project
+    val signingKey: String? by project
+    val signingPassword: String? by project
+    useInMemoryPgpKeys(signingKeyId, signingKey, signingPassword)
+    sign(publishing.publications)
+}

bdk-android/lib/proguard-rules.pro

@@ -0,0 +1,28 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
+
+# for JNA
+-dontwarn java.awt.*
+-keep class com.sun.jna.* { *; }
+-keep class org.bitcoindevkit.* { *; }
+-keepclassmembers class * extends org.bitcoindevkit.* { public *; }
+-keepclassmembers class * extends com.sun.jna.* { public *; }

bdk-android/lib/src/androidTest/assets/logback.xml

@@ -0,0 +1,14 @@
+<configuration>
+  <appender name="logcat" class="ch.qos.logback.classic.android.LogcatAppender">
+    <tagEncoder>
+      <pattern>%logger{12}</pattern>
+    </tagEncoder>
+    <encoder>
+      <pattern>[%-20thread] %msg</pattern>
+    </encoder>
+  </appender>
+
+  <root level="DEBUG">
+    <appender-ref ref="logcat" />
+  </root>
+</configuration>

bdk-android/lib/src/androidTest/kotlin/org/bitcoindevkit/AndroidLibTest.kt

@@ -0,0 +1,81 @@
+package org.bitcoindevkit
+
+import org.junit.Assert.*
+import org.junit.Test
+import android.app.Application
+import android.content.Context.MODE_PRIVATE
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.runner.RunWith
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+import java.io.File
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class AndroidLibTest {
+
+    private fun getTestDataDir(): String {
+        val context = ApplicationProvider.getApplicationContext<Application>()
+        return context.getDir("bdk-test", MODE_PRIVATE).toString()
+    }
+
+    private fun cleanupTestDataDir(testDataDir: String) {
+        File(testDataDir).deleteRecursively()
+    }
+
+    class LogProgress : Progress {
+        private val log: Logger = LoggerFactory.getLogger(AndroidLibTest::class.java)
+
+        override fun update(progress: Float, message: String?) {
+            log.debug("Syncing...")
+        }
+    }
+
+    private val descriptor =
+        "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)"
+
+    private val databaseConfig = DatabaseConfig.Memory
+
+    private val blockchainConfig = BlockchainConfig.Electrum(
+        ElectrumConfig(
+            "ssl://electrum.blockstream.info:60002",
+            null,
+            5u,
+            null,
+            100u
+        )
+    )
+
+    @Test
+    fun memoryWalletNewAddress() {
+        val wallet = Wallet(descriptor, null, Network.TESTNET, databaseConfig)
+        val address = wallet.getAddress(AddressIndex.NEW).address
+        assertEquals("tb1qzg4mckdh50nwdm9hkzq06528rsu73hjxxzem3e", address)
+    }
+
+    @Test
+    fun memoryWalletSyncGetBalance() {
+        val wallet = Wallet(descriptor, null, Network.TESTNET, databaseConfig)
+        val blockchain = Blockchain(blockchainConfig)
+        wallet.sync(blockchain, LogProgress())
+        val balance: Balance = wallet.getBalance()
+        assertTrue(balance.total > 0u)
+    }
+
+    @Test
+    fun sqliteWalletSyncGetBalance() {
+        val testDataDir = getTestDataDir() + "/bdk-wallet.sqlite"
+        val databaseConfig = DatabaseConfig.Sqlite(SqliteDbConfiguration(testDataDir))
+        val wallet = Wallet(descriptor, null, Network.TESTNET, databaseConfig)
+        val blockchain = Blockchain(blockchainConfig)
+        wallet.sync(blockchain, LogProgress())
+        val balance: Balance = wallet.getBalance()
+        assertTrue(balance.total > 0u)
+        cleanupTestDataDir(testDataDir)
+    }
+}

bdk-android/lib/src/main/AndroidManifest.xml

@@ -0,0 +1,6 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  package="org.bitcoindevkit">
+
+  <uses-permission android:name="android.permission.INTERNET" />
+
+</manifest>

bdk-android/plugins/README.md

@@ -0,0 +1,17 @@
+# Readme
+The purpose of this directory is to host the Gradle plugin that adds tasks for building the native binaries required by `bdk-android`, and building the language bindings files.
+
+The plugin is applied to the `build.gradle.kts` file in `bdk-android` through the `plugins` block:
+```kotlin
+// bdk-android
+plugins {
+    id("org.bitcoindevkit.plugins.generate-android-bindings")
+}
+```
+
+It adds a series of tasks which are brought together into an aggregate task called `buildAndroidLib`. 
+
+This aggregate task:
+1. Builds the native libraries using `bdk-ffi`
+2. Places them in the correct resource directories
+3. Builds the bindings file

bdk-android/plugins/build.gradle.kts

@@ -0,0 +1,13 @@
+plugins {
+    id("java-gradle-plugin")
+    `kotlin-dsl`
+}
+
+gradlePlugin {
+    plugins {
+        create("uniFfiAndroidBindings") {
+            id = "org.bitcoindevkit.plugins.generate-android-bindings"
+            implementationClass = "org.bitcoindevkit.plugins.UniFfiAndroidPlugin"
+        }
+    }
+}

bdk-android/plugins/settings.gradle.kts

@@ -0,0 +1,8 @@
+dependencyResolutionManagement {
+    repositories {
+        mavenCentral()
+        google()
+    }
+}
+
+// include(":plugins")

bdk-android/plugins/src/main/kotlin/org/bitcoindevkit/plugins/Enums.kt

@@ -0,0 +1,14 @@
+package org.bitcoindevkit.plugins
+
+
+val operatingSystem: OS = when {
+    System.getProperty("os.name").contains("mac", ignoreCase = true) -> OS.MAC
+    System.getProperty("os.name").contains("linux", ignoreCase = true) -> OS.LINUX
+    else -> OS.OTHER
+}
+
+enum class OS {
+    MAC,
+    LINUX,
+    OTHER,
+}

bdk-android/plugins/src/main/kotlin/org/bitcoindevkit/plugins/UniFfiAndroidPlugin.kt

@@ -0,0 +1,180 @@
+package org.bitcoindevkit.plugins
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.tasks.Copy
+import org.gradle.api.tasks.Exec
+import org.gradle.kotlin.dsl.environment
+import org.gradle.kotlin.dsl.getValue
+import org.gradle.kotlin.dsl.provideDelegate
+import org.gradle.kotlin.dsl.register
+
+internal class UniFfiAndroidPlugin : Plugin<Project> {
+    override fun apply(target: Project): Unit = target.run {
+        val llvmArchPath = when (operatingSystem) {
+            OS.MAC -> "darwin-x86_64"
+            OS.LINUX -> "linux-x86_64"
+            OS.OTHER -> throw Error("Cannot build Android library from current architecture")
+        }
+
+        // arm64-v8a is the most popular hardware architecture for Android
+        val buildAndroidAarch64Binary by tasks.register<Exec>("buildAndroidAarch64Binary") {
+
+            workingDir("${projectDir}/../../bdk-ffi")
+            val cargoArgs: MutableList<String> =
+                mutableListOf("build", "--profile", "release-smaller", "--target", "aarch64-linux-android")
+
+            executable("cargo")
+            args(cargoArgs)
+
+            // if ANDROID_NDK_ROOT is not set then set it to github actions default
+            if (System.getenv("ANDROID_NDK_ROOT") == null) {
+                environment(
+                    Pair("ANDROID_NDK_ROOT", "${System.getenv("ANDROID_SDK_ROOT")}/ndk-bundle")
+                )
+            }
+
+            environment(
+                // add build toolchain to PATH
+                Pair("PATH",
+                    "${System.getenv("PATH")}:${System.getenv("ANDROID_NDK_ROOT")}/toolchains/llvm/prebuilt/$llvmArchPath/bin"),
+
+                Pair("CFLAGS", "-D__ANDROID_API__=21"),
+                Pair("CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER", "aarch64-linux-android21-clang"),
+                Pair("CC", "aarch64-linux-android21-clang")
+            )
+
+            doLast {
+                println("Native library for bdk-android on aarch64 built successfully")
+            }
+        }
+
+        // the x86_64 version of the library is mostly used by emulators
+        val buildAndroidX86_64Binary by tasks.register<Exec>("buildAndroidX86_64Binary") {
+
+            workingDir("${project.projectDir}/../../bdk-ffi")
+            val cargoArgs: MutableList<String> =
+                mutableListOf("build", "--profile", "release-smaller", "--target", "x86_64-linux-android")
+
+            executable("cargo")
+            args(cargoArgs)
+
+            // if ANDROID_NDK_ROOT is not set then set it to github actions default
+            if (System.getenv("ANDROID_NDK_ROOT") == null) {
+                environment(
+                    Pair("ANDROID_NDK_ROOT", "${System.getenv("ANDROID_SDK_ROOT")}/ndk-bundle")
+                )
+            }
+
+            environment(
+                // add build toolchain to PATH
+                Pair("PATH",
+                    "${System.getenv("PATH")}:${System.getenv("ANDROID_NDK_ROOT")}/toolchains/llvm/prebuilt/$llvmArchPath/bin"),
+
+                Pair("CFLAGS", "-D__ANDROID_API__=21"),
+                Pair("CARGO_TARGET_X86_64_LINUX_ANDROID_LINKER", "x86_64-linux-android21-clang"),
+                Pair("CC", "x86_64-linux-android21-clang")
+            )
+
+            doLast {
+                println("Native library for bdk-android on x86_64 built successfully")
+            }
+        }
+
+        // armeabi-v7a version of the library for older 32-bit Android hardware
+        val buildAndroidArmv7Binary by tasks.register<Exec>("buildAndroidArmv7Binary") {
+
+            workingDir("${project.projectDir}/../../bdk-ffi")
+            val cargoArgs: MutableList<String> =
+                mutableListOf("build", "--profile", "release-smaller", "--target", "armv7-linux-androideabi")
+
+            executable("cargo")
+            args(cargoArgs)
+
+            // if ANDROID_NDK_ROOT is not set then set it to github actions default
+            if (System.getenv("ANDROID_NDK_ROOT") == null) {
+                environment(
+                    Pair("ANDROID_NDK_ROOT", "${System.getenv("ANDROID_SDK_ROOT")}/ndk-bundle")
+                )
+            }
+
+            environment(
+                // add build toolchain to PATH
+                Pair("PATH",
+                    "${System.getenv("PATH")}:${System.getenv("ANDROID_NDK_ROOT")}/toolchains/llvm/prebuilt/$llvmArchPath/bin"),
+
+                Pair("CFLAGS", "-D__ANDROID_API__=21"),
+                Pair("CARGO_TARGET_ARMV7_LINUX_ANDROIDEABI_LINKER",
+                    "armv7a-linux-androideabi21-clang"),
+                Pair("CC", "armv7a-linux-androideabi21-clang")
+            )
+
+            doLast {
+                println("Native library for bdk-android on armv7 built successfully")
+            }
+        }
+
+        // move the native libs build by cargo from bdk-ffi/target/<architecture>/release/
+        // to their place in the bdk-android library
+        // the task only copies the available binaries built using the buildAndroid<architecture>Binary tasks
+        val moveNativeAndroidLibs by tasks.register<Copy>("moveNativeAndroidLibs") {
+
+            dependsOn(buildAndroidAarch64Binary)
+
+            into("${project.projectDir}/../lib/src/main/jniLibs/")
+
+            into("arm64-v8a") {
+                from("${project.projectDir}/../../bdk-ffi/target/aarch64-linux-android/release-smaller/libbdkffi.so")
+            }
+
+            into("x86_64") {
+                from("${project.projectDir}/../../bdk-ffi/target/x86_64-linux-android/release-smaller/libbdkffi.so")
+            }
+
+            into("armeabi-v7a") {
+                from("${project.projectDir}/../../bdk-ffi/target/armv7-linux-androideabi/release-smaller/libbdkffi.so")
+            }
+
+            doLast {
+                println("Native binaries for Android moved to ./lib/src/main/jniLibs/")
+            }
+        }
+
+        // generate the bindings using the bdk-ffi-bindgen tool located in the bdk-ffi submodule
+        val generateAndroidBindings by tasks.register<Exec>("generateAndroidBindings") {
+            dependsOn(moveNativeAndroidLibs)
+
+            workingDir("${project.projectDir}/../../bdk-ffi")
+            executable("cargo")
+            args(
+                "run",
+                "--package",
+                "bdk-ffi-bindgen",
+                "--",
+                "--language",
+                "kotlin",
+                "--out-dir",
+                "../bdk-android/lib/src/main/kotlin"
+            )
+
+            doLast {
+                println("Android bindings file successfully created")
+            }
+        }
+
+        // create an aggregate task which will run the required tasks to build the Android libs in order
+        // the task will also appear in the printout of the ./gradlew tasks task with group and description
+        tasks.register("buildAndroidLib") {
+            group = "Bitcoindevkit"
+            description = "Aggregate task to build Android library"
+
+            dependsOn(
+                buildAndroidAarch64Binary,
+                buildAndroidX86_64Binary,
+                buildAndroidArmv7Binary,
+                moveNativeAndroidLibs,
+                generateAndroidBindings
+            )
+        }
+    }
+}

bdk-android/settings.gradle.kts

@@ -0,0 +1,4 @@
+rootProject.name = "bdk-android"
+
+include(":lib")
+includeBuild("plugins")