onionwire/android/sdk/build.gradle.kts

import org.jetbrains.kotlin.gradle.dsl.JvmTarget
import org.jetbrains.kotlin.gradle.tasks.KotlinCompile

plugins {
    alias(libs.plugins.android.library)
    alias(libs.plugins.kotlin.android)
}

// ---------------------------------------------------------------------------
// Rust: build crates/onionwire-sdk for the requested Android ABIs and generate
// the UniFFI Kotlin bindings from the host cdylib.
//
// Nothing here touches the Linux TUI crate's feature graph: the SDK crate is
// its own Cargo workspace that selects Arti's rustls backend.
// ---------------------------------------------------------------------------

val repoRoot: File = rootProject.projectDir.parentFile
val sdkCrateDir: File = repoRoot.resolve("crates/onionwire-sdk")

/** NDK version used for the Rust link step. Must match an installed NDK. */
val onionwireNdkVersion: String = (findProperty("onionwire.ndk") as String?)
    ?: "28.2.13676358"

/** Compile against this API level. Keep in sync with `minSdk`. */
val onionwireApiLevel: Int = ((findProperty("onionwire.api") as String?) ?: "26").toInt()

val androidSdkDir: File = sequenceOf(
    System.getenv("ANDROID_HOME"),
    System.getenv("ANDROID_SDK_ROOT"),
).filterNotNull().map(::File).firstOrNull()
    ?: rootProject.file("local.properties")
        .takeIf { it.exists() }
        ?.readLines()
        ?.firstOrNull { it.startsWith("sdk.dir=") }
        ?.substringAfter('=')
        ?.trim()
        ?.let(::File)
    ?: error("ANDROID_HOME / ANDROID_SDK_ROOT unset and no sdk.dir in android/local.properties")

val ndkDir: File = androidSdkDir.resolve("ndk/$onionwireNdkVersion")
require(ndkDir.isDirectory) {
    "NDK $onionwireNdkVersion not found at $ndkDir — run: sdkmanager --install \"ndk;$onionwireNdkVersion\""
}

val cargoExe: String = (findProperty("onionwire.cargo") as String?)
    ?: System.getenv("CARGO")
    ?: File(System.getProperty("user.home"), ".cargo/bin/cargo").takeIf { it.canExecute() }?.absolutePath
    ?: "cargo"

/** `-Ponionwire.abis=arm64-v8a,x86_64` to build more than one ABI. */
val onionwireAbis: List<String> = (findProperty("onionwire.abis") as String?)
    ?.split(',')?.map(String::trim)?.filter(String::isNotEmpty)
    ?: listOf("arm64-v8a")

val jniLibsDir = layout.buildDirectory.dir("rustJniLibs")
val uniffiKotlinDir = layout.buildDirectory.dir("generated/uniffi")

/** Host cdylib. UniFFI's `--library` mode dlopens it, so it must be host-arch. */
val cargoHostLib by tasks.registering(Exec::class) {
    group = "onionwire"
    description = "Builds libonionwire_sdk.so for the host (used only to emit bindings)."
    workingDir = sdkCrateDir
    environment("ANDROID_HOME", androidSdkDir.absolutePath)
    commandLine(cargoExe, "build", "--release", "--lib")
}

val uniffiBindgen by tasks.registering(Exec::class) {
    group = "onionwire"
    description = "Generates the Kotlin UniFFI bindings into build/generated/uniffi."
    dependsOn(cargoHostLib)
    workingDir = sdkCrateDir
    inputs.file(sdkCrateDir.resolve("src/lib.rs"))
    outputs.dir(uniffiKotlinDir)
    environment("ANDROID_HOME", androidSdkDir.absolutePath)
    doFirst { uniffiKotlinDir.get().asFile.mkdirs() }
    commandLine(
        cargoExe, "run", "--release", "--bin", "uniffi-bindgen", "--",
        "generate",
        "--library", "target/release/libonionwire_sdk.so",
        "--language", "kotlin",
        "--no-format",
        "--config", "uniffi.toml",
        "--out-dir", uniffiKotlinDir.get().asFile.absolutePath,
    )
}

val cargoBuildAndroid by tasks.registering(Exec::class) {
    group = "onionwire"
    description = "Cross-compiles crates/onionwire-sdk for ${onionwireAbis.joinToString()}."
    workingDir = sdkCrateDir
    inputs.dir(sdkCrateDir.resolve("src"))
    inputs.file(sdkCrateDir.resolve("Cargo.toml"))
    inputs.file(sdkCrateDir.resolve("Cargo.lock"))
    inputs.dir(repoRoot.resolve("src"))
    inputs.file(repoRoot.resolve("Cargo.toml"))
    outputs.dir(jniLibsDir)
    environment("ANDROID_HOME", androidSdkDir.absolutePath)
    environment("ANDROID_NDK_HOME", ndkDir.absolutePath)
    environment("NDK_HOME", ndkDir.absolutePath)
    commandLine(
        buildList {
            add(cargoExe); add("ndk")
            onionwireAbis.forEach { add("-t"); add(it) }
            add("--platform"); add(onionwireApiLevel.toString())
            add("-o"); add(jniLibsDir.get().asFile.absolutePath)
            add("build"); add("--release"); add("--lib")
        }
    )
}

// ---------------------------------------------------------------------------

android {
    namespace = "com.siriusdevops.onionwire.sdk"
    compileSdk = 36
    ndkVersion = onionwireNdkVersion

    defaultConfig {
        minSdk = onionwireApiLevel
        consumerProguardFiles("consumer-rules.pro")
        ndk {
            abiFilters += onionwireAbis
        }
    }

    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_17
        targetCompatibility = JavaVersion.VERSION_17
    }

    sourceSets["main"].jniLibs.srcDir(jniLibsDir)
    sourceSets["main"].kotlin.srcDir(uniffiKotlinDir)

    buildTypes {
        release {
            isMinifyEnabled = false
        }
    }
}

kotlin {
    compilerOptions {
        jvmTarget.set(JvmTarget.JVM_17)
    }
}

dependencies {
    // UniFFI's Kotlin backend talks to the Rust cdylib through JNA direct
    // mapping, and the async bindings need coroutines. Both are part of the
    // public API surface, so they are `api` — a consumer of the AAR needs them
    // on its own compile classpath. JNA's `aar` variant is what carries
    // libjnidispatch.so for each ABI.
    api(variantOf(libs.jna) { artifactType("aar") })
    api(libs.kotlinx.coroutines.core)
}

tasks.withType<KotlinCompile>().configureEach {
    dependsOn(uniffiBindgen)
}

tasks.matching { it.name == "preBuild" }.configureEach {
    dependsOn(cargoBuildAndroid, uniffiBindgen)
}