add missing file

Author: vandonr

buildSrc/src/main/kotlin/datadog/gradle/plugin/muzzle/MuzzleExcludedDependencySupport.kt

@@ -0,0 +1,190 @@
+package datadog.gradle.plugin.muzzle
+
+import org.eclipse.aether.artifact.Artifact
+import org.gradle.api.Project
+import org.gradle.api.artifacts.Configuration
+import java.io.ByteArrayInputStream
+import java.io.FileNotFoundException
+import java.net.URI
+import java.nio.file.Files
+import java.nio.file.Path
+import javax.xml.parsers.DocumentBuilderFactory
+import javax.xml.transform.OutputKeys
+import javax.xml.transform.TransformerFactory
+import javax.xml.transform.dom.DOMSource
+import javax.xml.transform.stream.StreamResult
+import org.w3c.dom.Document
+import org.w3c.dom.Element
+
+internal object MuzzleExcludedDependencySupport {
+  fun applyTo(
+    project: Project,
+    configuration: Configuration,
+    directive: MuzzleDirective,
+    versionArtifact: Artifact?
+  ) {
+    if (versionArtifact == null || directive.excludedDependencies.isEmpty()) {
+      return
+    }
+
+    val repositoryUris = directive.getRepositories(MuzzleMavenRepoUtils.MUZZLE_REPOS).map { URI.create(it.url) }
+    val repoDir = project.layout.buildDirectory
+      .dir("generated/muzzle-excluded-dependencies/${configuration.name}")
+      .get()
+      .asFile
+      .toPath()
+    Files.createDirectories(repoDir)
+
+    materializeArtifactHierarchy(
+      repoDir = repoDir,
+      repositories = repositoryUris,
+      coordinates = Coordinates(versionArtifact.groupId, versionArtifact.artifactId, versionArtifact.version),
+      excludedDependencies = directive.excludedDependencies.map { it.split(":", limit = 2) }.map { it[0] to it[1] }.toSet(),
+      rootArtifact = versionArtifact,
+      seen = LinkedHashSet()
+    )
+
+    val generatedRepo = project.repositories.maven {
+      name = "${configuration.name}MuzzleExcludedDependencies"
+      url = repoDir.toUri()
+    }
+    project.repositories.remove(generatedRepo)
+    project.repositories.addFirst(generatedRepo)
+  }
+
+  private fun materializeArtifactHierarchy(
+    repoDir: Path,
+    repositories: List<URI>,
+    coordinates: Coordinates,
+    excludedDependencies: Set<Pair<String, String>>,
+    rootArtifact: Artifact?,
+    seen: MutableSet<Coordinates>
+  ) {
+    if (!seen.add(coordinates)) {
+      return
+    }
+
+    val pomBytes = downloadRequired(repositories, coordinates.pomRelativePath)
+    val pomDocument = parsePom(pomBytes)
+    removeExcludedDependencies(pomDocument, excludedDependencies)
+    writePom(repoDir.resolve(coordinates.pomRelativePath), pomDocument)
+
+    if (rootArtifact != null) {
+      downloadOptional(repositories, coordinates.artifactRelativePath(rootArtifact.extension, rootArtifact.classifier))
+        ?.let { artifactBytes ->
+          val artifactPath = repoDir.resolve(coordinates.artifactRelativePath(rootArtifact.extension, rootArtifact.classifier))
+          Files.createDirectories(artifactPath.parent)
+          Files.write(artifactPath, artifactBytes)
+        }
+    }
+
+    parseParentCoordinates(pomDocument)?.let { parent ->
+      materializeArtifactHierarchy(
+        repoDir = repoDir,
+        repositories = repositories,
+        coordinates = parent,
+        excludedDependencies = excludedDependencies,
+        rootArtifact = null,
+        seen = seen
+      )
+    }
+  }
+
+  private fun parsePom(bytes: ByteArray): Document =
+    DocumentBuilderFactory.newInstance().apply {
+      isNamespaceAware = false
+    }.newDocumentBuilder().parse(ByteArrayInputStream(bytes))
+
+  private fun parseParentCoordinates(document: Document): Coordinates? {
+    val project = document.documentElement ?: return null
+    val parent = childElements(project).firstOrNull { it.tagName == "parent" } ?: return null
+    val groupId = childText(parent, "groupId") ?: return null
+    val artifactId = childText(parent, "artifactId") ?: return null
+    val version = childText(parent, "version") ?: return null
+    return Coordinates(groupId, artifactId, version)
+  }
+
+  private fun removeExcludedDependencies(document: Document, excludedDependencies: Set<Pair<String, String>>) {
+    if (excludedDependencies.isEmpty()) {
+      return
+    }
+
+    val dependencies = document.getElementsByTagName("dependency")
+    val toRemove = mutableListOf<Element>()
+    for (index in 0 until dependencies.length) {
+      val dependency = dependencies.item(index) as? Element ?: continue
+      val groupId = childText(dependency, "groupId") ?: continue
+      val artifactId = childText(dependency, "artifactId") ?: continue
+      if (excludedDependencies.contains(groupId to artifactId)) {
+        toRemove.add(dependency)
+      }
+    }
+
+    toRemove.forEach { dependency ->
+      dependency.parentNode?.removeChild(dependency)
+    }
+  }
+
+  private fun writePom(path: Path, document: Document) {
+    Files.createDirectories(path.parent)
+    TransformerFactory.newInstance().newTransformer().apply {
+      setOutputProperty(OutputKeys.INDENT, "yes")
+      setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2")
+    }.transform(DOMSource(document), StreamResult(path.toFile()))
+  }
+
+  private fun downloadRequired(repositories: List<URI>, relativePath: String): ByteArray =
+    downloadOptional(repositories, relativePath)
+      ?: error("Could not download $relativePath from repositories ${repositories.joinToString()}")
+
+  private fun downloadOptional(repositories: List<URI>, relativePath: String): ByteArray? {
+    for (repository in repositories) {
+      try {
+        val resolvedUri = URI.create("${repository.toString().trimEnd('/')}/$relativePath")
+        val bytes = when (resolvedUri.scheme) {
+          "file" -> {
+            val path = Path.of(resolvedUri)
+            if (Files.exists(path)) Files.readAllBytes(path) else null
+          }
+          "http", "https" -> resolvedUri.toURL().openStream().use { it.readBytes() }
+          else -> null
+        }
+        if (bytes != null) {
+          return bytes
+        }
+      } catch (_: FileNotFoundException) {
+        // Try the next repository until one has the requested artifact.
+      }
+    }
+    return null
+  }
+
+  private fun childText(parent: Element, tagName: String): String? =
+    childElements(parent).firstOrNull { it.tagName == tagName }?.textContent?.trim()
+
+  private fun childElements(parent: Element): List<Element> {
+    val children = mutableListOf<Element>()
+    val nodeList = parent.childNodes
+    for (index in 0 until nodeList.length) {
+      val child = nodeList.item(index)
+      if (child is Element) {
+        children.add(child)
+      }
+    }
+    return children
+  }
+
+  private data class Coordinates(
+    val groupId: String,
+    val artifactId: String,
+    val version: String
+  ) {
+    val pomRelativePath: String
+      get() = "${groupId.replace('.', '/')}/$artifactId/$version/$artifactId-$version.pom"
+
+    fun artifactRelativePath(extension: String, classifier: String?): String {
+      val classifierSuffix = classifier?.takeIf { it.isNotBlank() }?.let { "-$it" } ?: ""
+      return "${groupId.replace('.', '/')}/$artifactId/$version/$artifactId-$version$classifierSuffix.$extension"
+    }
+  }
+}