1 files changed, 56 insertions, 0 deletions
diff --git a/routers/api/packages/maven/api.go b/routers/api/packages/maven/api.go
new file mode 100644
index 0000000000..b60a317814
--- /dev/null
+++ b/routers/api/packages/maven/api.go
@@ -0,0 +1,56 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package maven
+
+import (
+	"encoding/xml"
+	"sort"
+	"strings"
+
+	packages_model "code.gitea.io/gitea/models/packages"
+	maven_module "code.gitea.io/gitea/modules/packages/maven"
+)
+
+// MetadataResponse https://maven.apache.org/ref/3.2.5/maven-repository-metadata/repository-metadata.html
+type MetadataResponse struct {
+	XMLName    xml.Name `xml:"metadata"`
+	GroupID    string   `xml:"groupId"`
+	ArtifactID string   `xml:"artifactId"`
+	Release    string   `xml:"versioning>release,omitempty"`
+	Latest     string   `xml:"versioning>latest"`
+	Version    []string `xml:"versioning>versions>version"`
+}
+
+func createMetadataResponse(pds []*packages_model.PackageDescriptor) *MetadataResponse {
+	sort.Slice(pds, func(i, j int) bool {
+		// Maven and Gradle order packages by their creation timestamp and not by their version string
+		return pds[i].Version.CreatedUnix < pds[j].Version.CreatedUnix
+	})
+
+	var release *packages_model.PackageDescriptor
+
+	versions := make([]string, 0, len(pds))
+	for _, pd := range pds {
+		if !strings.HasSuffix(pd.Version.Version, "-SNAPSHOT") {
+			release = pd
+		}
+		versions = append(versions, pd.Version.Version)
+	}
+
+	latest := pds[len(pds)-1]
+
+	metadata := latest.Metadata.(*maven_module.Metadata)
+
+	resp := &MetadataResponse{
+		GroupID:    metadata.GroupID,
+		ArtifactID: metadata.ArtifactID,
+		Latest:     latest.Version.Version,
+		Version:    versions,
+	}
+	if release != nil {
+		resp.Release = release.Version.Version
+	}
+	return resp
+}