flamenet-messenger-android/app/build.gradle.kts

import java.io.File
import java.util.Properties

// The Android app shell. Everything below it — the cryptography and the wire
// layer — lives in :engine and :client, which are plain JVM libraries so they
// can be tested without any of this.
plugins {
    id("com.android.application")
    kotlin("android")
    id("org.jetbrains.kotlin.plugin.compose")
}

android {
    namespace = "io.flamenet.messenger"
    compileSdk = 35

    defaultConfig {
        applicationId = "io.flamenet.messenger"
        // Android exposes the XDH algorithm from API 33. Below that a provider
        // such as BouncyCastle has to be registered at startup; the engine is
        // provider-agnostic, but nothing here does that registration yet, so
        // claiming a lower floor would be claiming something untrue.
        minSdk = 33
        targetSdk = 35
        versionCode = 1
        versionName = "0.1"
        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }

    sourceSets {
        getByName("main") { java.srcDir("src/main/kotlin") }
        getByName("androidTest") { java.srcDir("src/androidTest/kotlin") }
    }

    buildFeatures { compose = true }

    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_17
        targetCompatibility = JavaVersion.VERSION_17
    }
    kotlin { compilerOptions { jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17) } }

    // Read from a properties file outside the repository, so the keystore and
    // its password are never in git and a checkout without them still builds
    // (unsigned, which is exactly what an unsigned build should be).
    // 🔴 **This app's OWN key, not the one every Flamenet Android app shares.**
    // `.flamenet-android-signing.properties` was made for Flamenet Files, and
    // because the path is app-agnostic this app silently inherited it — every
    // release before 2026-08-25 went out as `CN=Flamenet Files`. Nobody chose
    // that for a messenger; it fell out of the layout.
    //
    // It matters because **an Android signing key is permanent**: once a device
    // installs a build signed with one key, it REFUSES every later build signed
    // with another. Sharing one key across products also means one compromised
    // keystore takes out both.
    //
    // So: prefer this app's own file, fall back to the shared one so a machine
    // that only has the old setup still produces a signed build rather than
    // failing confusingly.
    //
    // ⚠️ Both files live outside the repo and hold a password in the clear. They
    // are never in git, and a checkout without them still builds — unsigned,
    // which is exactly what an unsigned build should be.
    val signingProperties = Properties()
    val home = File(System.getProperty("user.home"))
    val signingFile = listOf(
        File(home, ".flamenet-messenger-signing.properties"),
        File(home, ".flamenet-android-signing.properties"),
    ).firstOrNull { it.exists() }
    signingFile?.inputStream()?.use { signingProperties.load(it) }

    signingConfigs {
        if (signingProperties.isNotEmpty()) {
            create("release") {
                storeFile = File(signingProperties.getProperty("storeFile"))
                storePassword = signingProperties.getProperty("storePassword")
                keyAlias = signingProperties.getProperty("keyAlias")
                keyPassword = signingProperties.getProperty("keyPassword")
            }
        }
    }

    buildTypes {
        release {
            // ⚠️ **WebRTC ships native libraries for four ABIs and they
            // dominate the APK** — about 41 MB uncompressed, of which x86 and
            // x86_64 are ~24 MB and exist only for emulators. Real phones are
            // arm64-v8a, with armeabi-v7a for old ones.
            //
            // Restricted here rather than split into per-ABI APKs on purpose:
            // this app is handed to testers as one file, and per-ABI outputs
            // turn "send them the APK" into "send them the right APK".
            //
            // Debug keeps all four, because that is what runs on an emulator.
            ndk { abiFilters += setOf("arm64-v8a", "armeabi-v7a") }
            isMinifyEnabled = true
            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
            signingConfig = signingConfigs.findByName("release")
        }
    }

    packaging {
        resources.excludes += setOf("META-INF/*.kotlin_module", "META-INF/DEPENDENCIES")
    }
}

dependencies {
    implementation(project(":engine"))
    implementation(project(":client"))
    implementation(platform("androidx.compose:compose-bom:2024.12.01"))
    implementation("androidx.compose.material3:material3")
    implementation("androidx.compose.material:material-icons-extended")
    implementation("androidx.compose.ui:ui")
    implementation("androidx.compose.ui:ui-tooling-preview")
    debugImplementation("androidx.compose.ui:ui-tooling")
    implementation("androidx.activity:activity-compose:1.9.3")
    implementation("androidx.core:core-ktx:1.15.0")
    implementation("androidx.lifecycle:lifecycle-viewmodel-compose:2.8.7")
    implementation("androidx.lifecycle:lifecycle-runtime-compose:2.8.7")
    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.9.0")

    // Voice calls (§8.10).
    //
    // The one third-party dependency in this app, and it is here because the
    // alternative is implementing ICE, DTLS-SRTP and an audio pipeline, which
    // is not a thing to hand-roll. `webrtc-sdk` is the maintained build of
    // Google's own libwebrtc — the upstream project stopped publishing usable
    // Android artifacts, and every Android client of consequence uses either
    // this or its own build of the same source.
    //
    // ⚠️ It is a large native blob: roughly 15-20 MB of the APK, and not
    // something that can be audited line by line. Worth stating rather than
    // absorbing quietly, because everything else in this app deliberately is
    // auditable.
    implementation("io.github.webrtc-sdk:android:125.6422.07")

    // On-device tests. The JVM suites cannot see a provider difference, and a
    // provider difference is what broke X25519 the first time this engine's
    // sibling ran on a phone.
    androidTestImplementation("androidx.test.ext:junit:1.2.1")
    androidTestImplementation("androidx.test:runner:1.6.2")
    androidTestImplementation(platform("androidx.compose:compose-bom:2024.12.01"))
    androidTestImplementation("androidx.compose.ui:ui-test-junit4")
    debugImplementation("androidx.compose.ui:ui-test-manifest")
    androidTestImplementation("androidx.tracing:tracing:1.2.0")
}