1 files changed, 48 insertions, 0 deletions
diff --git a/internal/gitutil/submodule.go b/internal/gitutil/submodule.go
new file mode 100644
index 00000000..e46f48a1
--- /dev/null
+++ b/internal/gitutil/submodule.go
@@ -0,0 +1,48 @@
+// Copyright 2020 The Gogs 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 gitutil
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+
+	"github.com/gogs/git-module"
+
+	"gogs.io/gogs/internal/lazyregexp"
+)
+
+var scpSyntax = lazyregexp.New(`^([a-zA-Z0-9_]+@)?([a-zA-Z0-9._-]+):(.*)$`)
+
+// InferSubmoduleURL returns the inferred external URL of the submodule at best effort.
+func InferSubmoduleURL(mod *git.Submodule) string {
+	raw := strings.TrimSuffix(mod.URL, "/")
+	raw = strings.TrimSuffix(raw, ".git")
+
+	parsed, err := url.Parse(raw)
+	if err != nil {
+		// Try parse as SCP syntax again
+		match := scpSyntax.FindAllStringSubmatch(raw, -1)
+		if len(match) == 0 {
+			return mod.URL
+		}
+		parsed = &url.URL{
+			Scheme: "http",
+			Host:   match[0][2],
+			Path:   match[0][3],
+		}
+	}
+
+	switch parsed.Scheme {
+	case "http", "https":
+		raw = parsed.String()
+	case "ssh":
+		raw = fmt.Sprintf("http://%s%s", parsed.Host, parsed.Path)
+	default:
+		return raw
+	}
+
+	return fmt.Sprintf("%s/commit/%s", raw, mod.Commit)
+}