Allow repos to provide maven-metadata.xml files to list known versions.

2 files changed, 29 insertions, 3 deletions

diff --git a/src/api/java/com/amadornes/artifactural/api/repository/Repository.java b/src/api/java/com/amadornes/artifactural/api/repository/Repository.java
index da8aa69..2e1de79 100644
--- a/src/api/java/com/amadornes/artifactural/api/repository/Repository.java
+++ b/src/api/java/com/amadornes/artifactural/api/repository/Repository.java
@@ -19,6 +19,8 @@
 
 package com.amadornes.artifactural.api.repository;
 
+import java.io.File;
+
 import com.amadornes.artifactural.api.artifact.Artifact;
 import com.amadornes.artifactural.api.artifact.ArtifactIdentifier;
 
@@ -26,4 +28,17 @@ public interface Repository {
 
     Artifact getArtifact(ArtifactIdentifier identifier);
 
+    /**
+     * Returns a file in maven-metadata.xml format for the specified artifact,
+     * this is used by gradle to list all known versions, so that it can resolve wildcard
+     * dependencies such as foo:bar:1.+
+     *
+     * @param group Group
+     * @param name Artifact name
+     * @return maven-metadata.xml file listing all versions of the artifact this repo can provide. Or null if you don't want to list any.
+     */
+    default File getMavenMetadata(String group, String name) {
+        return null;
+    }
+
 }
diff --git a/src/gradlecomp/java/com/amadornes/artifactural/gradle/GradleRepositoryAdapter.java b/src/gradlecomp/java/com/amadornes/artifactural/gradle/GradleRepositoryAdapter.java
index 834905c..64d6652 100644
--- a/src/gradlecomp/java/com/amadornes/artifactural/gradle/GradleRepositoryAdapter.java
+++ b/src/gradlecomp/java/com/amadornes/artifactural/gradle/GradleRepositoryAdapter.java
@@ -236,9 +236,7 @@ public class GradleRepositoryAdapter extends AbstractArtifactRepository implemen
                 String relative = path.substring(root.length());
                 debug("  Relative: " + relative);
                 Matcher matcher = URL_PATTERN.matcher(relative);
-                if (!matcher.matches()) {
-                    log("  Matcher Failed: " + relative);
-                } else {
+                if (matcher.matches()) {
                     ArtifactIdentifier identifier = new SimpleArtifactIdentifier(
                         matcher.group("group").replace('/', '.'),
                         matcher.group("name"),
@@ -247,6 +245,19 @@ public class GradleRepositoryAdapter extends AbstractArtifactRepository implemen
                         matcher.group("extension"));
                     Artifact artifact = repository.getArtifact(identifier);
                     return wrap(artifact, identifier);
+                } else if (relative.endsWith("maven-metadata.xml")) {
+                    String tmp = relative.substring(0, relative.length() - "maven-metadata.xml".length() - 1);
+                    int idx = tmp.lastIndexOf('/');
+                    if (idx != -1) {
+                        File ret = repository.getMavenMetadata(tmp.substring(0, idx - 1), tmp.substring(idx));
+                        if (ret != null) {
+                            return new LocalFileStandInExternalResource(ret, fileSystem);
+                        }
+                    }
+                } else if (relative.endsWith("/")) {
+                    debug("    Directory listing not supported");
+                } else {
+                    log("  Matcher Failed: " + relative);
                 }
             } else {
                 log("Unknown root: " + path);