Initial commit

buildSrc/src/main/kotlin/GradleVersionInfo.kt

@@ -0,0 +1,68 @@
+import java.net.URL
+import org.gradle.util.GradleVersion
+import groovy.json.JsonSlurper
+
+@Suppress("unused")
+class GradleVersionInfo(json: Map<String, Any>) {
+  val version: String by json
+
+  val gradleVersion: GradleVersion by lazy { GradleVersion.version(version) }
+
+  val isReleaseVersion: Boolean by lazy {
+    // for some reason, `gradleVersion == gradleVersion.baseVersion` is a compile error
+    gradleVersion.version == gradleVersion.baseVersion.version
+  }
+
+  val buildTime: String by json
+
+  val current: Boolean by json
+
+  val snapshot: Boolean by json
+
+  val nightly: Boolean by json
+
+  val releaseNightly: Boolean by json
+
+  val activeRc: Boolean by json
+
+  val rcFor: String by json
+
+  val milestoneFor: String by json
+
+  val broken: Boolean by json
+
+  val downloadUrl: String by json
+
+  val checksumUrl: String by json
+
+  val wrapperChecksumUrl: String by json
+
+  companion object {
+    private fun fetchAll(): List<GradleVersionInfo> = fetchMultiple("https://services.gradle.org/versions/all")
+
+    fun fetchReleases(): List<GradleVersionInfo> = fetchAll().filter { it.isReleaseVersion }
+
+    fun fetchCurrent(): GradleVersionInfo = fetchSingle("https://services.gradle.org/versions/current")
+
+    fun fetchRc(): GradleVersionInfo? = fetchSingleOrNull("https://services.gradle.org/versions/release-candidate")
+
+    fun fetchNightly(): GradleVersionInfo = fetchSingle("https://services.gradle.org/versions/nightly")
+
+    private fun fetchSingle(url: String): GradleVersionInfo {
+      @Suppress("UNCHECKED_CAST")
+      return GradleVersionInfo(JsonSlurper().parse(URL(url)) as Map<String, Any>)
+    }
+
+    private fun fetchSingleOrNull(url: String): GradleVersionInfo? {
+      @Suppress("UNCHECKED_CAST")
+      val json = JsonSlurper().parse(URL(url)) as Map<String, Any>
+      return if (json.isEmpty()) null else GradleVersionInfo(json)
+    }
+
+    private fun fetchMultiple(url: String): List<GradleVersionInfo> {
+      @Suppress("UNCHECKED_CAST")
+      return (JsonSlurper().parse(URL(url)) as List<Map<String, Any>>)
+        .map { GradleVersionInfo(it) }
+    }
+  }
+}