Android 多模块架构与 Gradle 优化

// feature/home 模块的 build.gradle.kts
dependencies {
    // implementation：只在当前模块可见，不传递给依赖本模块的人
    implementation("androidx.recyclerview:recyclerview:1.3.2")
    implementation(libs.kotlinx.coroutines.android)

    // api：会传递出去，依赖 :feature:home 的模块也能看到这些类型
    api(project(":core:model"))
    api(libs.androidx.lifecycle.viewmodel.ktx)

    compileOnly(libs.javax.inject)          // 仅编译期可见，不进入运行时
    debugImplementation(libs.leakcanary.android) // 仅 debug 构建可见
}

模块图示例：
  :app                     组装、导航、依赖注入聚合
   ├── :feature:home        首页业务
   ├── :feature:detail      详情页业务
   ├── :core:ui             通用 Compose 组件、主题
   ├── :core:model          领域模型（纯 Kotlin，无 Android 依赖）
   ├── :core:data           仓库实现、Room、Retrofit
   ├── :core:network        网络客户端、拦截器
   └── :core:common         工具类、扩展函数

依赖规则（必须写进 CI 检查）：
  feature 之间禁止互相依赖，只能依赖 core
  core 之间只允许单向依赖：data → network → common
  core 禁止依赖 feature

./gradlew :app:dependencies --configuration releaseRuntimeClasspath | grep "project :"   # 定位项目间依赖

[versions]
agp = "8.7.3"
kotlin = "2.1.0"
ksp = "2.1.0-1.0.29"
composeBom = "2024.12.01"
lifecycle = "2.8.7"
room = "2.6.1"
hilt = "2.52"

[libraries]
androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
androidx-compose-ui = { group = "androidx.compose.ui", name = "ui" }
androidx-room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }
hilt-compiler = { group = "com.google.dagger", name = "hilt-android-compiler", version.ref = "hilt" }

[plugins]
android-library = { id = "com.android.library", version.ref = "agp" }
kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }

// feature/home/build.gradle.kts
plugins {
    alias(libs.plugins.android.library)
    alias(libs.plugins.kotlin.android)
    alias(libs.plugins.ksp)
}

dependencies {
    implementation(platform(libs.androidx.compose.bom))
    implementation(libs.androidx.compose.ui)
    ksp(libs.androidx.room.compiler)
}

// build-logic/convention/src/main/kotlin/AndroidLibraryConventionPlugin.kt
import com.android.build.api.dsl.LibraryExtension
import org.gradle.api.Plugin
import org.gradle.api.Project
import org.gradle.kotlin.dsl.configure
import org.jetbrains.kotlin.gradle.dsl.KotlinAndroidProjectExtension

class AndroidLibraryConventionPlugin : Plugin<Project> {
    override fun apply(target: Project) = with(target) {
        pluginManager.apply("com.android.library")
        pluginManager.apply("org.jetbrains.kotlin.android")

        extensions.configure<LibraryExtension> {
            // AGP 8.x 起 namespace 必须显式声明，不再从 manifest 推断
            namespace = "com.example.${path.replace(":", ".").removePrefix(".")}"
            compileSdk = 35
            defaultConfig { minSdk = 24 }
            compileOptions {
                sourceCompatibility = JavaVersion.VERSION_17
                targetCompatibility = JavaVersion.VERSION_17
            }
            buildFeatures { compose = true; buildConfig = true }
        }

        extensions.configure<KotlinAndroidProjectExtension> { jvmToolchain(17) }
    }
}

// settings.gradle.kts
pluginManagement {
    includeBuild("build-logic")
    repositories { google(); mavenCentral(); gradlePluginPortal() }
}

org.gradle.parallel=true                 # 并行执行任务（多模块收益最大）
org.gradle.caching=true                  # 构建缓存：跨机器、跨分支复用任务输出
org.gradle.configureondemand=true        # 只配置本次构建真正用到的模块
org.gradle.jvmargs=-Xmx4g -XX:MaxMetaspaceSize=1g -XX:+UseParallelGC -Dfile.encoding=UTF-8
android.nonTransitiveRClass=true         # 非传递 R 类，减少膨胀与重编范围
org.gradle.configuration-cache=true      # 开启 Configuration Cache
org.gradle.configuration-cache.problems=warn
kotlin.incremental=true
kotlin.daemon.jvmargs=-Xmx3g
ksp.incremental=true

./gradlew :app:assembleDebug --scan    # 生成构建扫描，Build Cache 命中会显示 FROM-CACHE

// app/build.gradle.kts
dependencies {
    // Compose BOM：统一所有 androidx.compose.* 的版本，声明后无需写版本号
    implementation(platform(libs.androidx.compose.bom))
    implementation("androidx.compose.material3:material3")
    implementation("androidx.compose.ui:ui-tooling-preview")

    // 对非 BOM 库使用依赖约束，强制全工程统一版本
    constraints {
        implementation("com.squareup.okhttp3:okhttp") {
            version { strictly("4.12.0") }
            because("统一 OkHttp 版本，避免不同小版本导致的方法签名冲突")
        }
    }
}

plugins { alias(libs.plugins.ksp) }

dependencies {
    implementation(libs.androidx.room.runtime)
    ksp(libs.androidx.room.compiler)   // 原为 kapt(...)

    implementation(libs.hilt.android)
    ksp(libs.hilt.compiler)            // Hilt 2.48+ 已支持 KSP
}

ksp { arg("room.schemaLocation", "$projectDir/schemas") }

// 迁移前（AGP 7.x 风格）
android {
    compileSdkVersion 33
    composeOptions { kotlinCompilerExtensionVersion = "1.5.14" } // 极易与 Kotlin 版本错配
}

// 迁移后（AGP 8.x 风格）
android {
    namespace = "com.example.app"   // 必填，取代 manifest 的 package
    compileSdk = 35
    defaultConfig {
        applicationId = "com.example.app"
        targetSdk = 35
        minSdk = 24
    }
    buildFeatures {
        compose = true
        buildConfig = true          // AGP 8.0 起默认关闭，用到 BuildConfig 必须显式开
    }
}

plugins {
    alias(libs.plugins.kotlin.android)
    alias(libs.plugins.kotlin.compose)   // org.jetbrains.kotlin.plugin.compose
}