From 378e21a426781a9d41d34f96f222d7281a1ac87b Mon Sep 17 00:00:00 2001
From: oppiliappan <me@oppi.li>
Date: Fri, 5 Dec 2025 04:12:11 +0000
Subject: [PATCH] types: add utility to extract co-authors from a commit
Change-Id: qxwspuynkpoknnskvqktnomzkryqyzxu

uses a regex to detect & extract a object.Signature from the
Co-authored-by header.

Signed-off-by: oppiliappan <me@oppi.li>
---
 appview/repo/repo_util.go |  3 ---
 types/commit.go           | 26 ++++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/appview/repo/repo_util.go b/appview/repo/repo_util.go
index b6a9507a..5217500d 100644
--- a/appview/repo/repo_util.go
+++ b/appview/repo/repo_util.go
@@ -1,7 +1,6 @@
 package repo
 
 import (
-	"regexp"
 	"slices"
 	"sort"
 	"strings"
@@ -9,8 +8,6 @@ import (
 	"tangled.org/core/appview/db"
 	"tangled.org/core/appview/models"
 	"tangled.org/core/types"
-
-	"github.com/go-git/go-git/v5/plumbing/object"
 )
 
 func sortFiles(files []types.NiceTree) {
diff --git a/types/commit.go b/types/commit.go
index d52e2066..fd5bc595 100644
--- a/types/commit.go
+++ b/types/commit.go
@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"maps"
+	"regexp"
 	"strings"
 
 	"github.com/go-git/go-git/v5/plumbing"
@@ -166,3 +167,28 @@ func (c *Commit) Payload() string {
 
 	return payload.String()
 }
+
+var (
+	coAuthorRegex = regexp.MustCompile(`(?im)^Co-authored-by:\s*(.+?)\s*<([^>]+)>`)
+)
+
+func (commit *Commit) CoAuthors() []object.Signature {
+	var coAuthors []object.Signature
+
+	matches := coAuthorRegex.FindAllStringSubmatch(commit.Message, -1)
+
+	for _, match := range matches {
+		if len(match) >= 3 {
+			name := strings.TrimSpace(match[1])
+			email := strings.TrimSpace(match[2])
+
+			coAuthors = append(coAuthors, object.Signature{
+				Name:  name,
+				Email: email,
+				When:  commit.Committer.When,
+			})
+		}
+	}
+
+	return coAuthors
+}
-- 
2.43.0