1 files changed, 93 insertions, 0 deletions
diff --git a/app/models/packages/go/module.rb b/app/models/packages/go/module.rb
new file mode 100644
index 00000000000..b38b691ed6c
--- /dev/null
+++ b/app/models/packages/go/module.rb
@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+module Packages
+  module Go
+    class Module
+      include Gitlab::Utils::StrongMemoize
+
+      attr_reader :project, :name, :path
+
+      def initialize(project, name, path)
+        @project = project
+        @name = name
+        @path = path
+      end
+
+      def versions
+        strong_memoize(:versions) { Packages::Go::VersionFinder.new(self).execute }
+      end
+
+      def version_by(ref: nil, commit: nil)
+        raise ArgumentError.new 'no filter specified' unless ref || commit
+        raise ArgumentError.new 'ref and commit are mutually exclusive' if ref && commit
+
+        if commit
+          return version_by_sha(commit) if commit.is_a? String
+
+          return version_by_commit(commit)
+        end
+
+        return version_by_name(ref) if ref.is_a? String
+
+        version_by_ref(ref)
+      end
+
+      def path_valid?(major)
+        m = /\/v(\d+)$/i.match(@name)
+
+        case major
+        when 0, 1
+          m.nil?
+        else
+          !m.nil? && m[1].to_i == major
+        end
+      end
+
+      def gomod_valid?(gomod)
+        if Feature.enabled?(:go_proxy_disable_gomod_validation, @project)
+          return gomod&.start_with?("module ")
+        end
+
+        gomod&.split("\n", 2)&.first == "module #{@name}"
+      end
+
+      private
+
+      def version_by_name(name)
+        # avoid a Gitaly call if possible
+        if strong_memoized?(:versions)
+          v = versions.find { |v| v.name == ref }
+          return v if v
+        end
+
+        ref = @project.repository.find_tag(name) || @project.repository.find_branch(name)
+        return unless ref
+
+        version_by_ref(ref)
+      end
+
+      def version_by_ref(ref)
+        # reuse existing versions
+        if strong_memoized?(:versions)
+          v = versions.find { |v| v.ref == ref }
+          return v if v
+        end
+
+        commit = ref.dereferenced_target
+        semver = Packages::SemVer.parse(ref.name, prefixed: true)
+        Packages::Go::ModuleVersion.new(self, :ref, commit, ref: ref, semver: semver)
+      end
+
+      def version_by_sha(sha)
+        commit = @project.commit_by(oid: sha)
+        return unless ref
+
+        version_by_commit(commit)
+      end
+
+      def version_by_commit(commit)
+        Packages::Go::ModuleVersion.new(self, :commit, commit)
+      end
+    end
+  end
+end