From 943975c25ff6a34a3a1d6bdc5141bdb598948148 Mon Sep 17 00:00:00 2001
From: Anirudh Oppiliappan <x@icyphox.sh>
Date: Sun, 16 Mar 2025 19:39:05 +0200
Subject: [PATCH] knotserver/git/merge: merge options use git apply

---
 knotserver/git/merge.go | 61 ++++++++++++++++++++++++++++++++++++++---
 knotserver/routes.go    | 14 ++++++----
 types/merge.go          |  9 ++++++
 3 files changed, 75 insertions(+), 9 deletions(-)

diff --git a/knotserver/git/merge.go b/knotserver/git/merge.go
index 90fc462f..7dd2f654 100644
--- a/knotserver/git/merge.go
+++ b/knotserver/git/merge.go
@@ -24,6 +24,14 @@ type ConflictInfo struct {
 	Reason   string
 }
 
+// MergeOptions specifies the configuration for a merge operation
+type MergeOptions struct {
+	CommitMessage string
+	CommitBody    string
+	AuthorName    string
+	AuthorEmail   string
+}
+
 func (e ErrMerge) Error() string {
 	if e.HasConflict {
 		return fmt.Sprintf("merge failed due to conflicts: %s (%d conflicts)", e.Message, len(e.Conflicts))
@@ -74,7 +82,7 @@ func (g *GitRepo) cloneRepository(targetBranch string) (string, error) {
 	return tmpDir, nil
 }
 
-func (g *GitRepo) applyPatch(tmpDir, patchFile string, checkOnly bool) error {
+func (g *GitRepo) applyPatch(tmpDir, patchFile string, checkOnly bool, opts *MergeOptions) error {
 	var stderr bytes.Buffer
 	var cmd *exec.Cmd
 
@@ -82,7 +90,48 @@ func (g *GitRepo) applyPatch(tmpDir, patchFile string, checkOnly bool) error {
 		cmd = exec.Command("git", "-C", tmpDir, "apply", "--check", "-v", patchFile)
 	} else {
 		exec.Command("git", "-C", tmpDir, "config", "advice.mergeConflict", "false").Run()
-		cmd = exec.Command("git", "-C", tmpDir, "am", patchFile)
+
+		if opts != nil {
+			applyCmd := exec.Command("git", "-C", tmpDir, "apply", patchFile)
+			applyCmd.Stderr = &stderr
+			if err := applyCmd.Run(); err != nil {
+				return fmt.Errorf("patch application failed: %s", stderr.String())
+			}
+
+			stageCmd := exec.Command("git", "-C", tmpDir, "add", ".")
+			if err := stageCmd.Run(); err != nil {
+				return fmt.Errorf("failed to stage changes: %w", err)
+			}
+
+			commitArgs := []string{"-C", tmpDir, "commit"}
+
+			// Set author if provided
+			authorName := opts.AuthorName
+			authorEmail := opts.AuthorEmail
+
+			if authorEmail == "" {
+				authorEmail = "noreply@tangled.sh"
+			}
+
+			if authorName == "" {
+				authorName = "Tangled"
+			}
+
+			if authorName != "" {
+				commitArgs = append(commitArgs, "--author", fmt.Sprintf("%s <%s>", authorName, authorEmail))
+			}
+
+			commitArgs = append(commitArgs, "-m", opts.CommitMessage)
+
+			if opts.CommitBody != "" {
+				commitArgs = append(commitArgs, "-m", opts.CommitBody)
+			}
+
+			cmd = exec.Command("git", commitArgs...)
+		} else {
+			// If no commit message specified, use git-am which automatically creates a commit
+			cmd = exec.Command("git", "-C", tmpDir, "am", patchFile)
+		}
 	}
 
 	cmd.Stderr = &stderr
@@ -122,10 +171,14 @@ func (g *GitRepo) MergeCheck(patchData []byte, targetBranch string) error {
 	}
 	defer os.RemoveAll(tmpDir)
 
-	return g.applyPatch(tmpDir, patchFile, true)
+	return g.applyPatch(tmpDir, patchFile, true, nil)
 }
 
 func (g *GitRepo) Merge(patchData []byte, targetBranch string) error {
+	return g.MergeWithOptions(patchData, targetBranch, nil)
+}
+
+func (g *GitRepo) MergeWithOptions(patchData []byte, targetBranch string, opts *MergeOptions) error {
 	patchFile, err := g.createTempFileWithPatch(patchData)
 	if err != nil {
 		return &ErrMerge{
@@ -144,7 +197,7 @@ func (g *GitRepo) Merge(patchData []byte, targetBranch string) error {
 	}
 	defer os.RemoveAll(tmpDir)
 
-	if err := g.applyPatch(tmpDir, patchFile, false); err != nil {
+	if err := g.applyPatch(tmpDir, patchFile, false, opts); err != nil {
 		return err
 	}
 
diff --git a/knotserver/routes.go b/knotserver/routes.go
index 67e3e796..fb1a0546 100644
--- a/knotserver/routes.go
+++ b/knotserver/routes.go
@@ -559,10 +559,7 @@ func (h *Handle) RemoveRepo(w http.ResponseWriter, r *http.Request) {
 func (h *Handle) Merge(w http.ResponseWriter, r *http.Request) {
 	path, _ := securejoin.SecureJoin(h.c.Repo.ScanPath, didPath(r))
 
-	var data struct {
-		Patch  string `json:"patch"`
-		Branch string `json:"branch"`
-	}
+	data := types.MergeRequest{}
 
 	if err := json.NewDecoder(r.Body).Decode(&data); err != nil {
 		writeError(w, err.Error(), http.StatusBadRequest)
@@ -570,6 +567,13 @@ func (h *Handle) Merge(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	mo := &git.MergeOptions{
+		AuthorName:    data.AuthorName,
+		AuthorEmail:   data.AuthorEmail,
+		CommitBody:    data.CommitBody,
+		CommitMessage: data.CommitMessage,
+	}
+
 	patch := data.Patch
 	branch := data.Branch
 	gr, err := git.Open(path, branch)
@@ -577,7 +581,7 @@ func (h *Handle) Merge(w http.ResponseWriter, r *http.Request) {
 		notFound(w)
 		return
 	}
-	if err := gr.Merge([]byte(patch), branch); err != nil {
+	if err := gr.MergeWithOptions([]byte(patch), branch, mo); err != nil {
 		var mergeErr *git.ErrMerge
 		if errors.As(err, &mergeErr) {
 			conflicts := make([]types.ConflictInfo, len(mergeErr.Conflicts))
diff --git a/types/merge.go b/types/merge.go
index 73bccf0c..c9f25ec8 100644
--- a/types/merge.go
+++ b/types/merge.go
@@ -11,3 +11,12 @@ type MergeCheckResponse struct {
 	Message      string         `json:"message"`
 	Error        string         `json:"error"`
 }
+
+type MergeRequest struct {
+	Patch         string `json:"patch"`
+	AuthorName    string `json:"authorName,omitempty"`
+	AuthorEmail   string `json:"authorEmail,omitempty"`
+	CommitBody    string `json:"commitBody,omitempty"`
+	CommitMessage string `json:"commitMessage,omitempty"`
+	Branch        string `json:"branch"`
+}
-- 
2.51.2