Gradle: Implement setupPaperServer action which downloads Paper and links plugin JARs.

.gitignore

@@ -116,3 +116,6 @@ run/
 
 # Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
 !gradle-wrapper.jar
+
+# Foundation Server
+/server

build.gradle.kts

@@ -5,9 +5,7 @@ import java.io.FileWriter
 
 plugins {
   java
-  id("org.jetbrains.kotlin.jvm") version "1.6.10" apply false
-  id("org.jetbrains.kotlin.plugin.serialization") version "1.6.10" apply false
-  id("com.github.johnrengelman.shadow") version "7.1.1" apply false
+  id("foundation-gradle")
 }
 
 fun Project.isFoundationPlugin() = name.startsWith("foundation-")
@@ -23,6 +21,7 @@ allprojects {
       name = "papermc-repo"
       url = uri("https://papermc.io/repo/repository/maven-public/")
     }
+
     maven {
       name = "sonatype"
       url = uri("https://oss.sonatype.org/content/groups/public/")
@@ -135,3 +134,8 @@ subprojects {
     dependsOn("shadowJar")
   }
 }
+
+tasks.setupPaperServer {
+  minecraftServerPath = "server"
+  paperVersionGroup = "1.18"
+}

buildSrc/build.gradle.kts

@@ -0,0 +1,18 @@
+plugins {
+  `kotlin-dsl`
+  kotlin("plugin.serialization") version "1.5.31"
+}
+
+repositories {
+  gradlePluginPortal()
+}
+
+dependencies {
+  implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.10")
+  implementation("org.jetbrains.kotlin:kotlin-serialization:1.6.10")
+  implementation("gradle.plugin.com.github.johnrengelman:shadow:7.1.1")
+  implementation("com.google.code.gson:gson:2.8.9")
+}
+
+java.sourceCompatibility = JavaVersion.VERSION_1_8
+java.targetCompatibility = JavaVersion.VERSION_1_8

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/FoundationGradlePlugin.kt

@@ -0,0 +1,10 @@
+package cloud.kubelet.foundation.gradle
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+
+class FoundationGradlePlugin : Plugin<Project> {
+  override fun apply(project: Project) {
+    project.tasks.create("setupPaperServer", SetupPaperServer::class.java)
+  }
+}

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/PaperVersionClient.kt

@@ -0,0 +1,44 @@
+package cloud.kubelet.foundation.gradle
+
+import com.google.gson.Gson
+import java.net.URI
+import java.net.http.HttpClient
+import java.net.http.HttpRequest
+import java.net.http.HttpResponse
+
+class PaperVersionClient(val client: HttpClient = HttpClient.newHttpClient()) {
+  private val apiBaseUrl = URI.create("https://papermc.io/api/v2/")
+  private val gson = Gson()
+
+  fun getVersionBuilds(group: String): List<PaperBuild> {
+    val response = client.send(
+      HttpRequest.newBuilder()
+        .GET()
+        .uri(apiBaseUrl.resolve("projects/paper/version_group/${group}/builds"))
+        .build(),
+      HttpResponse.BodyHandlers.ofString()
+    )
+
+    val body = response.body()
+    val root = gson.fromJson(body, PaperVersionRoot::class.java)
+    return root.builds
+  }
+
+  fun resolveDownloadUrl(build: PaperBuild, download: PaperVersionDownload): URI =
+    apiBaseUrl.resolve("projects/paper/versions/${build.version}/builds/${build.build}/downloads/${download.name}")
+
+  data class PaperVersionRoot(
+    val builds: List<PaperBuild>
+  )
+
+  data class PaperBuild(
+    val version: String,
+    val build: Int,
+    val downloads: Map<String, PaperVersionDownload>
+  )
+
+  data class PaperVersionDownload(
+    val name: String,
+    val sha256: String
+  )
+}

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/SetupPaperServer.kt

@@ -0,0 +1,55 @@
+package cloud.kubelet.foundation.gradle
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.TaskAction
+import java.nio.file.Files
+
+open class SetupPaperServer : DefaultTask() {
+  @get:Input
+  lateinit var paperVersionGroup: String
+
+  @get:Input
+  lateinit var minecraftServerPath: String
+
+  @TaskAction
+  fun downloadPaperTask() {
+    val minecraftServerDirectory = project.file(minecraftServerPath)
+    val client = PaperVersionClient()
+    val builds = client.getVersionBuilds(paperVersionGroup)
+    val build = builds.last()
+    val download = build.downloads["application"]!!
+    val url = client.resolveDownloadUrl(build, download)
+
+    if (!minecraftServerDirectory.exists()) {
+      minecraftServerDirectory.mkdirs()
+    }
+
+    ant.invokeMethod(
+      "get", mapOf(
+        "src" to url.toString(),
+        "dest" to project.file("${minecraftServerPath}/paper.jar").absolutePath
+      )
+    )
+
+    val paperPluginsDirectory = minecraftServerDirectory.resolve("plugins")
+
+    if (!paperPluginsDirectory.exists()) {
+      paperPluginsDirectory.mkdirs()
+    }
+
+    for (project in project.subprojects) {
+      if (!project.name.startsWith("foundation-")) {
+        continue
+      }
+
+      val pluginJarFile = project.buildDir.resolve("libs/${project.name}-DEV-plugin.jar")
+      val pluginLinkFile = paperPluginsDirectory.resolve("${project.name}.jar")
+      if (pluginLinkFile.exists()) {
+        pluginLinkFile.delete()
+      }
+
+      Files.createSymbolicLink(pluginLinkFile.toPath(), pluginJarFile.toPath())
+    }
+  }
+}

buildSrc/src/main/resources/META-INF/gradle-plugins/foundation-gradle.properties

@@ -0,0 +1 @@
+implementation-class=cloud.kubelet.foundation.gradle.FoundationGradlePlugin