1 files changed, 59 insertions, 0 deletions
diff --git a/internal/util/namestring.go b/internal/util/namestring.go
new file mode 100644
index 000000000..611a1c0eb
--- /dev/null
+++ b/internal/util/namestring.go
@@ -0,0 +1,59 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package util
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/superseriousbusiness/gotosocial/internal/regexes"
+)
+
+// ExtractNamestringParts extracts the username test_user and
+// the domain example.org from a string like @test_user@example.org.
+//
+// If nothing is matched, it will return an error.
+func ExtractNamestringParts(mention string) (username, host string, err error) {
+	matches := regexes.MentionName.FindStringSubmatch(mention)
+	switch len(matches) {
+	case 2:
+		return matches[1], "", nil
+	case 3:
+		return matches[1], matches[2], nil
+	default:
+		return "", "", fmt.Errorf("couldn't match mention %s", mention)
+	}
+}
+
+// ExtractWebfingerParts returns username test_user and
+// domain example.org from a string like acct:test_user@example.org,
+// or acct:@test_user@example.org.
+//
+// If nothing is extracted, it will return an error.
+func ExtractWebfingerParts(webfinger string) (username, host string, err error) {
+	// remove the acct: prefix if it's present
+	webfinger = strings.TrimPrefix(webfinger, "acct:")
+
+	// prepend an @ if necessary
+	if webfinger[0] != '@' {
+		webfinger = "@" + webfinger
+	}
+
+	return ExtractNamestringParts(webfinger)
+}