import org.gradle.api.GradleException

plugins {
    java
}

repositories {
    google()
    mavenCentral()
}

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

configurations {
    create("agp")
}

dependencies {
    add("agp", "com.android.tools.build:gradle:$agpVersion")
}

tasks.register("exportOfflineMaven") {
    dependsOn(configurations.named("agp"))
    doLast {
        val offlineRoot = file("${rootProject.projectDir}/../offline-maven").apply { mkdirs() }
        val configuration = configurations.getByName("agp")
        val resolved = configuration.resolvedConfiguration
        val modules = linkedSetOf<Triple<String, String, String>>()

        resolved.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)
        }

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

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 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('.', '/')
    val bases = when {
        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",
            )
    }

    for (base in bases) {
        val url = "$base/$groupPath/$name/$version/$name-$version.pom"
        try {
            exec {
                commandLine("curl", "-fsSL", url, "-o", pom.absolutePath)
            }
            if (pom.exists() && pom.length() > 0L) {
                return
            }
        } catch (_: Exception) {
            pom.delete()
        }
    }

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