import org.gradle.api.GradleException

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

fun installArtifact(
    root: File,
    group: String,
    name: String,
    version: String,
    ext: String,
    src: File,
) {
    val dir = root.resolve("${group.replace('.', '/')}/$name/$version")
    dir.mkdirs()
    src.copyTo(dir.resolve("$name-$version.$ext"), overwrite = true)
}

fun googleMavenBases(group: String): List<String> =
    if (group.startsWith("com.android") || group.startsWith("androidx") || group.startsWith("com.google.android")) {
        listOf(
            "https://dl.google.com/dl/android/maven2",
            "https://dl.google.com/android/maven2",
            "https://maven.google.com",
        )
    } else {
        listOf(
            "https://repo.maven.apache.org/maven2",
            "https://dl.google.com/dl/android/maven2",
            "https://maven.google.com",
        )
    }

fun downloadUrl(url: String, dest: File) {
    dest.parentFile.mkdirs()
    exec {
        commandLine("curl", "-fsSL", url, "-o", dest.absolutePath)
    }
}

fun ensurePom(root: File, group: String, name: String, version: String) {
    val dir = root.resolve("${group.replace('.', '/')}/$name/$version")
    dir.mkdirs()
    val pom = dir.resolve("$name-$version.pom")
    if (pom.exists() && pom.length() > 0L) {
        return
    }

    val groupPath = group.replace('.', '/')
    for (base in googleMavenBases(group)) {
        val url = "$base/$groupPath/$name/$version/$name-$version.pom"
        try {
            downloadUrl(url, pom)
            if (pom.exists() && pom.length() > 0L) {
                return
            }
        } catch (_: Exception) {
            pom.delete()
        }
    }

    throw GradleException("POM not found: $group:$name:$version")
}

fun exportConfiguration(projectPath: String, configName: String, offlineRoot: File): Int {
    val target = project(projectPath)
    val configuration = target.configurations.getByName(configName)
    configuration.resolve()
    val modules = linkedSetOf<Triple<String, String, String>>()

    configuration.resolvedConfiguration.resolvedArtifacts.forEach { artifact ->
        val id = artifact.moduleVersion.id
        modules.add(Triple(id.group, id.name, id.version))
        installArtifact(
            offlineRoot,
            id.group,
            id.name,
            id.version,
            artifact.extension ?: "jar",
            artifact.file,
        )
    }

    modules.forEach { (group, name, version) ->
        ensurePom(offlineRoot, group, name, version)
    }

    println("Exported ${modules.size} modules from ${projectPath}:${configName}")
    return modules.size
}

fun exportAndroidRuntimeClasspath(offlineRoot: File): Int =
    exportConfiguration(":app", "releaseRuntimeClasspath", offlineRoot)

val agpVersion: String = providers.gradleProperty("agpVersion").orElse("8.11.0").get()

tasks.register("exportOfflineMaven") {
    dependsOn(":tools:compileJava")
    doLast {
        val offlineRoot = file("${rootProject.projectDir}/../offline-maven").apply { mkdirs() }
        val modules = exportConfiguration(":tools", "agp", offlineRoot)
        file("${offlineRoot.absolutePath}/.agp-offline-complete").writeText(
            "agpVersion=$agpVersion\nmodules=$modules\n",
        )
    }
}

tasks.register("exportAllOfflineMaven") {
    dependsOn(":tools:compileJava", ":app:preBuild")
    doLast {
        val offlineRoot = file("${rootProject.projectDir}/../offline-maven").apply { mkdirs() }
        var modules = 0
        modules += exportConfiguration(":tools", "agp", offlineRoot)
        modules += exportConfiguration(":tools", "buildPlugins", offlineRoot)
        modules += exportAndroidRuntimeClasspath(offlineRoot)

        file("${offlineRoot.absolutePath}/.agp-offline-complete").writeText(
            "agpVersion=$agpVersion\nmodules=$modules\n",
        )
        file("${offlineRoot.absolutePath}/.android-deps-offline-complete").writeText(
            "modules=$modules\n",
        )
        println("Exported ${modules} total modules to ${offlineRoot.absolutePath}")
    }
}