feat: add feedback resolver

internal/repository/feedback_repo.go

@@ -32,16 +32,17 @@ func (r *FeedbackRepo) Create(ctx context.Context, userID *string, category, mes
 
 // FindByID returns one feedback row joined with the submitter's
 // handle + name + email if a user_id is present. Used after Create to
-// assemble the admin notification email with the proper author block.
+// assemble the admin notification email with the proper author block,
+// and after MarkResolved to assemble the author thank-you email.
 func (r *FeedbackRepo) FindByID(ctx context.Context, id string) (*model.Feedback, error) {
 	f := &model.Feedback{}
 	err := r.pg.Pool.QueryRow(ctx, `
-		SELECT f.id, f.user_id, f.category, f.message, f.contact_email, f.created_at,
+		SELECT f.id, f.user_id, f.category, f.message, f.contact_email, f.created_at, f.resolved_at,
 		       u.handle, u.name, u.email
 		FROM feedback f
 		LEFT JOIN users u ON u.id = f.user_id
 		WHERE f.id = $1`, id,
-	).Scan(&f.ID, &f.UserID, &f.Category, &f.Message, &f.ContactEmail, &f.CreatedAt,
+	).Scan(&f.ID, &f.UserID, &f.Category, &f.Message, &f.ContactEmail, &f.CreatedAt, &f.ResolvedAt,
 		&f.AuthorHandle, &f.AuthorName, &f.AuthorEmail)
 	if err != nil {
 		return nil, fmt.Errorf("find feedback: %w", err)
@@ -49,6 +50,23 @@ func (r *FeedbackRepo) FindByID(ctx context.Context, id string) (*model.Feedback
 	return f, nil
 }
 
+// MarkResolved stamps resolved_at = now() on a still-open row. The
+// `resolved_at IS NULL` guard makes this idempotent and one-way: the
+// first call returns true (newly resolved), any subsequent call — or a
+// call on an unknown id — returns false so the caller knows NOT to fire
+// the thank-you email a second time.
+func (r *FeedbackRepo) MarkResolved(ctx context.Context, id string) (resolved bool, err error) {
+	tag, err := r.pg.Pool.Exec(ctx, `
+		UPDATE feedback
+		SET resolved_at = now()
+		WHERE id = $1 AND resolved_at IS NULL`, id,
+	)
+	if err != nil {
+		return false, fmt.Errorf("mark feedback resolved: %w", err)
+	}
+	return tag.RowsAffected() == 1, nil
+}
+
 // Recent returns the most-recent N feedback rows joined with users
 // for display on /stats. NULL author columns mean anonymous (or the
 // original submitter's account was since deleted).
@@ -57,7 +75,7 @@ func (r *FeedbackRepo) Recent(ctx context.Context, limit int) ([]model.Feedback,
 		limit = 25
 	}
 	rows, err := r.pg.Pool.Query(ctx, `
-		SELECT f.id, f.user_id, f.category, f.message, f.contact_email, f.created_at,
+		SELECT f.id, f.user_id, f.category, f.message, f.contact_email, f.created_at, f.resolved_at,
 		       u.handle, u.name
 		FROM feedback f
 		LEFT JOIN users u ON u.id = f.user_id
@@ -71,7 +89,7 @@ func (r *FeedbackRepo) Recent(ctx context.Context, limit int) ([]model.Feedback,
 	out := []model.Feedback{}
 	for rows.Next() {
 		var f model.Feedback
-		if err := rows.Scan(&f.ID, &f.UserID, &f.Category, &f.Message, &f.ContactEmail, &f.CreatedAt,
+		if err := rows.Scan(&f.ID, &f.UserID, &f.Category, &f.Message, &f.ContactEmail, &f.CreatedAt, &f.ResolvedAt,
 			&f.AuthorHandle, &f.AuthorName); err != nil {
 			return nil, fmt.Errorf("scan feedback: %w", err)
 		}