Add custom Gradle plugin to build bdk-android library

buildSrc/src/main/kotlin/org/bitcoindevkit/plugins/Enums.kt

@@ -1,5 +1,18 @@
 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
+}
+
+val architecture: Arch = when (System.getProperty("os.arch")) {
+    "x86_64" -> Arch.X86_64
+    "aarch64" -> Arch.AARCH64
+    else -> Arch.OTHER
+}
+
 enum class Arch {
     AARCH64,
     X86_64,

buildSrc/src/main/kotlin/org/bitcoindevkit/plugins/generate-android-bindings.gradle.kts

@@ -2,90 +2,117 @@ package org.bitcoindevkit.plugins
 
 import org.gradle.kotlin.dsl.register
 
-val operatingSystem: OS = when {
+val llvmArchPath = when (operatingSystem) {
-    System.getProperty("os.name").contains("mac", ignoreCase = true) -> OS.MAC
+    OS.MAC   -> "darwin-x86_64"
-    System.getProperty("os.name").contains("linux", ignoreCase = true) -> OS.LINUX
+    OS.LINUX -> "linux-x86_64"
-    else -> OS.OTHER
+    OS.OTHER -> throw Error("Cannot build Android library from current architecture")
-}
-val architecture: Arch = when (System.getProperty("os.arch")) {
-    "x86_64" -> Arch.X86_64
-    "aarch64" -> Arch.AARCH64
-    else -> Arch.OTHER
 }
 
-// register a task of type Exec called buildJvmBinary
+// arm64-v8a is the most popular hardware architecture for Android
-// which will run something like
+val buildAndroidAarch64Binary by tasks.register<Exec>("buildAndroidAarch64Binary") {
-// cargo build --release --target aarch64-apple-darwin
-val buildJvmBinary by tasks.register<Exec>("buildJvmBinary") {
-    // group = "Bitcoindevkit"
-    // description = "Build the JVM binaries for the bitcoindevkit"
 
     workingDir("${project.projectDir}/../bdk-ffi")
-    val cargoArgs: MutableList<String> = mutableListOf("build", "--release", "--target")
+    val cargoArgs: MutableList<String> = mutableListOf("build", "--release", "--target", "aarch64-linux-android")
-
-    if (operatingSystem == OS.MAC && architecture == Arch.X86_64) {
-        cargoArgs.add("x86_64-apple-darwin")
-    } else if (operatingSystem == OS.MAC && architecture == Arch.AARCH64) {
-        cargoArgs.add("aarch64-apple-darwin")
-    } else if (operatingSystem == OS.LINUX) {
-        cargoArgs.add("x86_64-unknown-linux-gnu")
-    }
 
     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-jvm on ${cargoArgs.last()} successfully built")
+        println("Native library for bdk-android on aarch64 built successfully")
     }
 }
-//
+
-// // move the native libs build by cargo from bdk-ffi/target/.../release/
+// the x86_64 version of the library is mostly used by emulators
-// // to their place in the bdk-jvm library
+val buildAndroidX86_64Binary by tasks.register<Exec>("buildAndroidX86_64Binary") {
-// val moveNativeJvmLib by tasks.register<Copy>("moveNativeJvmLib") {
+
-//     // group = "Bitcoindevkit"
+    workingDir("${project.projectDir}/../bdk-ffi")
-//     // description = "Move the native libraries to the bdk-jvm project"
+    val cargoArgs: MutableList<String> = mutableListOf("build", "--release", "--target", "x86_64-linux-android")
-//     dependsOn(buildJvmBinary)
+
-//
+    executable("cargo")
-//     var targetDir = ""
+    args(cargoArgs)
-//     var resDir = ""
+
-//     if (operatingSystem == OS.MAC && architecture == Arch.X86_64) {
+    // if ANDROID_NDK_ROOT is not set then set it to github actions default
-//         targetDir = "x86_64-apple-darwin"
+    if (System.getenv("ANDROID_NDK_ROOT") == null) {
-//         resDir = "darwin-x86-64"
+        environment(
-//     } else if (operatingSystem == OS.MAC && architecture == Arch.AARCH64) {
+            Pair("ANDROID_NDK_ROOT", "${System.getenv("ANDROID_SDK_ROOT")}/ndk-bundle")
-//         targetDir = "aarch64-apple-darwin"
+        )
-//         resDir = "darwin-aarch64"
+    }
-//     } else if (operatingSystem == OS.LINUX) {
+
-//         targetDir = "x86_64-unknown-linux-gnu"
+    environment(
-//         resDir = "linux-x86-64"
+        // add build toolchain to PATH
-//     }
+        Pair("PATH", "${System.getenv("PATH")}:${System.getenv("ANDROID_NDK_ROOT")}/toolchains/llvm/prebuilt/$llvmArchPath/bin"),
-//
+
-//     from("${project.projectDir}/../bdk-ffi/target/$targetDir/release/libbdkffi.dylib")
+        Pair("CFLAGS", "-D__ANDROID_API__=21"),
-//     into("${project.projectDir}/../jvm/src/main/resources/$resDir/")
+        Pair("CARGO_TARGET_X86_64_LINUX_ANDROID_LINKER", "x86_64-linux-android21-clang"),
-//
+        Pair("CC", "x86_64-linux-android21-clang")
-//     doLast {
+    )
-//         println("$targetDir native binaries for JVM moved to ./jvm/src/main/resources/$resDir/")
+
-//     }
+    doLast {
-// }
+        println("Native library for bdk-android on x86_64 built successfully")
-//
+    }
-// // generate the bindings using the bdk-ffi-bindgen tool
+}
-// // created in the bdk-ffi submodule
+
-// val generateJvmBindings by tasks.register<Exec>("generateJvmBindings") {
+// move the native libs build by cargo from bdk-ffi/target/<architecture>/release/
-//     // group = "Bitcoindevkit"
+// to their place in the bdk-android library
-//     // description = "Building the bindings file for the bitcoindevkit"
+// the task only copies the available binaries built using the buildAndroid<architecture>Binary tasks
-//     dependsOn(moveNativeJvmLib)
+val moveNativeAndroidLibs by tasks.register<Copy>("moveNativeAndroidLibs") {
-//
+
-//     workingDir("${project.projectDir}/../bdk-ffi")
+    dependsOn(buildAndroidAarch64Binary)
-//     executable("cargo")
+
-//     args("run", "--package", "bdk-ffi-bindgen", "--", "--language", "kotlin", "--out-dir", "../jvm/src/main/kotlin")
+    into("${project.projectDir}/../android/src/main/jniLibs/")
-//
+
-//     doLast {
+    into("arm64-v8a") {
-//         println("JVM bindings file successfully created")
+        from("${project.projectDir}/../bdk-ffi/target/aarch64-linux-android/release/libbdkffi.so")
-//     }
+    }
-// }
+
-//
+    into("x86_64") {
-//
+        from("${project.projectDir}/../bdk-ffi/target/x86_64-linux-android/release/libbdkffi.so")
-// tasks.register("buildAndroidLib") {
+    }
-//     group = "Bitcoindevkit"
+
-//     description = "Aggregate task to build Android library"
+    doLast {
-//     dependsOn(buildJvmBinary, moveNativeJvmLib, generateJvmBindings)
+        println("Native binaries for Android moved to ./android/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", "../android/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,
+        moveNativeAndroidLibs,
+        generateAndroidBindings
+    )
+}

buildSrc/src/main/kotlin/org/bitcoindevkit/plugins/generate-jvm-bindings.gradle.kts

@@ -1,22 +1,9 @@
 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
-}
-val architecture: Arch = when (System.getProperty("os.arch")) {
-    "x86_64" -> Arch.X86_64
-    "aarch64" -> Arch.AARCH64
-    else -> Arch.OTHER
-}
-
 // register a task of type Exec called buildJvmBinary
 // which will run something like
 // cargo build --release --target aarch64-apple-darwin
 val buildJvmBinary by tasks.register<Exec>("buildJvmBinary") {
-    // group = "Bitcoindevkit"
-    // description = "Build the JVM binaries for the bitcoindevkit"
 
     workingDir("${project.projectDir}/../bdk-ffi")
     val cargoArgs: MutableList<String> = mutableListOf("build", "--release", "--target")
@@ -40,8 +27,7 @@ val buildJvmBinary by tasks.register<Exec>("buildJvmBinary") {
 // move the native libs build by cargo from bdk-ffi/target/.../release/
 // to their place in the bdk-jvm library
 val moveNativeJvmLib by tasks.register<Copy>("moveNativeJvmLib") {
-    // group = "Bitcoindevkit"
+
-    // description = "Move the native libraries to the bdk-jvm project"
     dependsOn(buildJvmBinary)
 
     var targetDir = ""
@@ -68,8 +54,7 @@ val moveNativeJvmLib by tasks.register<Copy>("moveNativeJvmLib") {
 // generate the bindings using the bdk-ffi-bindgen tool
 // created in the bdk-ffi submodule
 val generateJvmBindings by tasks.register<Exec>("generateJvmBindings") {
-    // group = "Bitcoindevkit"
+
-    // description = "Building the bindings file for the bitcoindevkit"
     dependsOn(moveNativeJvmLib)
 
     workingDir("${project.projectDir}/../bdk-ffi")
@@ -81,8 +66,15 @@ val generateJvmBindings by tasks.register<Exec>("generateJvmBindings") {
     }
 }
 
+// create an aggregate task which will run the 3 required tasks to build the JVM libs in order
+// the task will also appear in the printout of the ./gradlew tasks task with group and description
 tasks.register("buildJvmLib") {
     group = "Bitcoindevkit"
     description = "Aggregate task to build JVM library"
-    dependsOn(buildJvmBinary, moveNativeJvmLib, generateJvmBindings)
+
+    dependsOn(
+        buildJvmBinary,
+        moveNativeJvmLib,
+        generateJvmBindings
+    )
 }