eng-pad/app/build.gradle.kts

import javax.inject.Inject

plugins {
    alias(libs.plugins.android.application)
    alias(libs.plugins.kotlin.compose)
    alias(libs.plugins.ksp)
}

android {
    namespace = "net.metacircular.engpad"
    compileSdk = 36

    defaultConfig {
        applicationId = "net.metacircular.engpad"
        minSdk = 30
        targetSdk = 36
        versionCode = 1
        versionName = "0.1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            isMinifyEnabled = true
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }

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

    buildFeatures {
        compose = true
    }

    lint {
        warningsAsErrors = true
        abortOnError = true
        checkDependencies = true
    }
}

kotlin {
    jvmToolchain(17)
}

// --- Protobuf / gRPC code generation via protoc ---
//
// The protobuf-gradle-plugin (0.9.6) does not yet support AGP 9, so we drive
// protoc directly. A custom task exposes DirectoryProperty outputs that the
// AGP Variant API can consume.

abstract class GenerateProtoTask : DefaultTask() {
    @get:Inject
    abstract val execOps: ExecOperations
    @get:InputDirectory
    abstract val protoSourceDir: DirectoryProperty

    @get:InputFiles
    abstract val protocFile: ConfigurableFileCollection

    @get:InputFiles
    abstract val grpcJavaPluginFile: ConfigurableFileCollection

    @get:InputFiles
    abstract val grpcKotlinPluginFile: ConfigurableFileCollection

    /** Protobuf JAR containing well-known type .proto files (google/protobuf/*.proto). */
    @get:InputFiles
    abstract val protobufIncludesJar: ConfigurableFileCollection

    /** Temp directory for extracting well-known proto includes. */
    @get:OutputDirectory
    abstract val includesExtractDir: DirectoryProperty

    /** Java sources generated by protoc (messages). */
    @get:OutputDirectory
    abstract val javaOutputDir: DirectoryProperty

    /** Kotlin sources generated by protoc (Kotlin DSL builders). */
    @get:OutputDirectory
    abstract val kotlinOutputDir: DirectoryProperty

    /** Java sources generated by protoc-gen-grpc-java (service stubs). */
    @get:OutputDirectory
    abstract val grpcOutputDir: DirectoryProperty

    /** Kotlin sources generated by protoc-gen-grpc-kotlin (coroutine stubs). */
    @get:OutputDirectory
    abstract val grpcKtOutputDir: DirectoryProperty

    @TaskAction
    fun generate() {
        val javaOut = javaOutputDir.get().asFile
        val kotlinOut = kotlinOutputDir.get().asFile
        val grpcOut = grpcOutputDir.get().asFile
        val grpcKtOut = grpcKtOutputDir.get().asFile

        listOf(javaOut, kotlinOut, grpcOut, grpcKtOut).forEach { it.mkdirs() }

        // Extract well-known .proto files from the protobuf JAR.
        val extractDir = includesExtractDir.get().asFile
        extractDir.mkdirs()
        val jar = protobufIncludesJar.singleFile
        java.util.zip.ZipFile(jar).use { zip ->
            zip.entries().asSequence()
                .filter { it.name.endsWith(".proto") }
                .forEach { entry ->
                    val outFile = File(extractDir, entry.name)
                    outFile.parentFile.mkdirs()
                    zip.getInputStream(entry).use { input ->
                        outFile.outputStream().use { output -> input.copyTo(output) }
                    }
                }
        }

        val protoc = protocFile.singleFile.also { it.setExecutable(true) }
        val grpcJava = grpcJavaPluginFile.singleFile.also { it.setExecutable(true) }
        val grpcKt = grpcKotlinPluginFile.singleFile.also { it.setExecutable(true) }

        val protoDir = protoSourceDir.get().asFile
        val protoFiles = protoDir.walkTopDown().filter { it.extension == "proto" }.toList()
        if (protoFiles.isEmpty()) return

        execOps.exec {
            commandLine(
                protoc.absolutePath,
                "--proto_path=${protoDir.absolutePath}",
                "--proto_path=${extractDir.absolutePath}",
                "--java_out=lite:${javaOut.absolutePath}",
                "--kotlin_out=lite:${kotlinOut.absolutePath}",
                "--plugin=protoc-gen-grpc=${grpcJava.absolutePath}",
                "--grpc_out=lite:${grpcOut.absolutePath}",
                "--plugin=protoc-gen-grpckt=${grpcKt.absolutePath}",
                "--grpckt_out=lite:${grpcKtOut.absolutePath}",
                *protoFiles.map { it.absolutePath }.toTypedArray(),
            )
        }
    }
}

val protobufIncludes: Configuration by configurations.creating {
    isTransitive = false
}
val protocArtifact: Configuration by configurations.creating {
    isTransitive = false
}
val grpcJavaPlugin: Configuration by configurations.creating {
    isTransitive = false
}
val grpcKotlinPlugin: Configuration by configurations.creating {
    isTransitive = false
}

// Determine the OS/arch classifier for native protoc binaries.
val protocClassifier: String = run {
    val os = System.getProperty("os.name").lowercase()
    val arch = System.getProperty("os.arch").lowercase()
    val osName = when {
        os.contains("mac") || os.contains("darwin") -> "osx"
        os.contains("linux") -> "linux"
        os.contains("windows") -> "windows"
        else -> error("Unsupported OS: $os")
    }
    val archName = when {
        arch.contains("aarch64") || arch.contains("arm64") -> "aarch_64"
        arch.contains("amd64") || arch.contains("x86_64") -> "x86_64"
        else -> error("Unsupported architecture: $arch")
    }
    "$osName-$archName"
}

dependencies {
    protobufIncludes("com.google.protobuf:protobuf-java:${libs.versions.protobuf.get()}")
    protocArtifact("com.google.protobuf:protoc:${libs.versions.protobuf.get()}:$protocClassifier@exe")
    grpcJavaPlugin("io.grpc:protoc-gen-grpc-java:${libs.versions.grpc.get()}:$protocClassifier@exe")
    grpcKotlinPlugin("io.grpc:protoc-gen-grpc-kotlin:${libs.versions.grpcKotlin.get()}:jdk8@jar")
}

val protoGenBase = layout.buildDirectory.dir("generated/source/proto/main")

val generateProto by tasks.registering(GenerateProtoTask::class) {
    description = "Generate Kotlin/gRPC sources from .proto files"
    group = "build"

    protoSourceDir.set(layout.projectDirectory.dir("src/main/proto"))
    protocFile.from(protocArtifact)
    grpcJavaPluginFile.from(grpcJavaPlugin)
    grpcKotlinPluginFile.from(grpcKotlinPlugin)

    protobufIncludesJar.from(protobufIncludes)
    includesExtractDir.set(protoGenBase.map { it.dir("includes") })

    javaOutputDir.set(protoGenBase.map { it.dir("java") })
    kotlinOutputDir.set(protoGenBase.map { it.dir("kotlin") })
    grpcOutputDir.set(protoGenBase.map { it.dir("grpc") })
    grpcKtOutputDir.set(protoGenBase.map { it.dir("grpckt") })
}

// Register generated directories with AGP via the Variant API (AGP 9+).
androidComponents {
    onVariants { variant ->
        variant.sources.java?.addGeneratedSourceDirectory(
            generateProto, GenerateProtoTask::javaOutputDir,
        )
        variant.sources.java?.addGeneratedSourceDirectory(
            generateProto, GenerateProtoTask::grpcOutputDir,
        )
        variant.sources.kotlin?.addGeneratedSourceDirectory(
            generateProto, GenerateProtoTask::kotlinOutputDir,
        )
        variant.sources.kotlin?.addGeneratedSourceDirectory(
            generateProto, GenerateProtoTask::grpcKtOutputDir,
        )
    }
}

// --- end protobuf generation ---

dependencies {
    implementation(libs.androidx.core.ktx)
    implementation(libs.androidx.activity.compose)

    implementation(platform(libs.compose.bom))
    implementation(libs.compose.ui)
    implementation(libs.compose.ui.tooling.preview)
    implementation(libs.compose.material3)
    debugImplementation(libs.compose.ui.tooling)

    implementation(libs.navigation.compose)

    implementation(libs.lifecycle.viewmodel.compose)
    implementation(libs.lifecycle.runtime.compose)

    implementation(libs.room.runtime)
    implementation(libs.room.ktx)
    ksp(libs.room.compiler)

    implementation(libs.coroutines.android)
    implementation(libs.reorderable)

    implementation(libs.protobuf.kotlin.lite)
    implementation(libs.grpc.okhttp)
    implementation(libs.grpc.protobuf.lite)
    implementation(libs.grpc.stub)
    implementation(libs.grpc.kotlin.stub)

    testImplementation(libs.junit)
    testImplementation(libs.coroutines.test)
    testImplementation(libs.room.testing)
}