feat(go-api): add chat update endpoints (#16378)

## Summary

- Added Go API route `PUT /api/v1/chats/:chat_id` to align with Python
`PUT /api/v1/chats/<chat_id>` chat update behavior.
- Added Go API route `PATCH /api/v1/chats/:chat_id` to align with Python
`PATCH /api/v1/chats/<chat_id>` partial chat update behavior.
- Added matching handler and service logic for owner checks, tenant
validation, persisted-field filtering, read-only field filtering,
`dataset_ids` to `kb_ids` conversion, and PATCH shallow merge semantics
for `prompt_config` and `llm_setting`.

internal/handler/chat.go

@@ -503,3 +503,57 @@ func (h *ChatHandler) GetChat(c *gin.Context) {
 		"message": "success",
 	})
 }
+
+// UpdateChat updates a chat by ID using REST PUT semantics.
+func (h *ChatHandler) UpdateChat(c *gin.Context) {
+	h.updateChatByMethod(c, false)
+}
+
+// PatchChat updates a chat by ID using REST PATCH semantics.
+func (h *ChatHandler) PatchChat(c *gin.Context) {
+	h.updateChatByMethod(c, true)
+}
+
+func (h *ChatHandler) updateChatByMethod(c *gin.Context, patch bool) {
+	user, errorCode, errorMessage := GetUser(c)
+	if errorCode != common.CodeSuccess {
+		jsonError(c, errorCode, errorMessage)
+		return
+	}
+
+	chatID := c.Param("chat_id")
+	if chatID == "" {
+		jsonError(c, common.CodeBadRequest, "chat_id is required")
+		return
+	}
+
+	var req map[string]interface{}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		jsonError(c, common.CodeDataError, err.Error())
+		return
+	}
+
+	var (
+		result map[string]interface{}
+		err    error
+	)
+	if patch {
+		result, err = h.chatService.PatchChat(user.ID, chatID, req)
+	} else {
+		result, err = h.chatService.UpdateChat(user.ID, chatID, req)
+	}
+	if err != nil {
+		if err.Error() == "no authorization" {
+			c.JSON(http.StatusOK, gin.H{
+				"code":    common.CodeAuthenticationError,
+				"data":    false,
+				"message": "No authorization.",
+			})
+			return
+		}
+		jsonError(c, common.CodeDataError, err.Error())
+		return
+	}
+
+	jsonResponse(c, common.CodeSuccess, result, "success")
+}

internal/handler/chat_test.go

@@ -25,7 +25,7 @@ func setupChatHandlerTestDB(t *testing.T) *gorm.DB {
 		t.Fatalf("failed to open sqlite: %v", err)
 	}
 
-	if err := db.AutoMigrate(&entity.Chat{}); err != nil {
+	if err := db.AutoMigrate(&entity.Chat{}, &entity.Tenant{}); err != nil {
 		t.Fatalf("failed to migrate test schema: %v", err)
 	}
 
@@ -33,6 +33,20 @@ func setupChatHandlerTestDB(t *testing.T) *gorm.DB {
 	dao.DB = db
 	t.Cleanup(func() { dao.DB = origDB })
 
+	status := string(entity.StatusValid)
+	if err := db.Create(&entity.Tenant{
+		ID:        "user-1",
+		LLMID:     "model-a",
+		EmbdID:    "embd-a",
+		ASRID:     "asr-a",
+		Img2TxtID: "img2txt-a",
+		RerankID:  "rerank-a",
+		ParserIDs: "naive",
+		Status:    &status,
+	}).Error; err != nil {
+		t.Fatalf("failed to create tenant: %v", err)
+	}
+
 	return db
 }
 
@@ -120,3 +134,68 @@ func TestBulkDeleteChatsHandlerPartialSuccess(t *testing.T) {
 		t.Fatalf("unexpected message: %v", resp["message"])
 	}
 }
+
+func TestPatchChatHandlerSuccess(t *testing.T) {
+	db := setupChatHandlerTestDB(t)
+	createChatHandlerTestChat(t, db, "chat-1", "user-1")
+
+	h := NewChatHandler(service.NewChatService(), service.NewUserService())
+	c, w := setupGinContextWithUser("PATCH", "/api/v1/chats/chat-1", `{"name":" updated chat "}`)
+	c.Params = []gin.Param{{Key: "chat_id", Value: "chat-1"}}
+
+	h.PatchChat(c)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
+	}
+
+	var resp map[string]interface{}
+	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("failed to decode response: %v", err)
+	}
+	if resp["code"] != float64(common.CodeSuccess) {
+		t.Fatalf("expected success code, got %v", resp["code"])
+	}
+	data, ok := resp["data"].(map[string]interface{})
+	if !ok {
+		t.Fatalf("expected object data, got %+v", resp["data"])
+	}
+	if data["name"] != "updated chat" {
+		t.Fatalf("expected trimmed name in response, got %+v", data["name"])
+	}
+	if _, ok := data["kb_ids"]; ok {
+		t.Fatalf("response must not expose kb_ids: %+v", data)
+	}
+	if _, ok := data["dataset_ids"]; !ok {
+		t.Fatalf("response should expose dataset_ids: %+v", data)
+	}
+}
+
+func TestUpdateChatHandlerRejectsNonOwner(t *testing.T) {
+	db := setupChatHandlerTestDB(t)
+	createChatHandlerTestChat(t, db, "chat-1", "tenant-2")
+
+	h := NewChatHandler(service.NewChatService(), service.NewUserService())
+	c, w := setupGinContextWithUser("PUT", "/api/v1/chats/chat-1", `{"name":"updated"}`)
+	c.Params = []gin.Param{{Key: "chat_id", Value: "chat-1"}}
+
+	h.UpdateChat(c)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
+	}
+
+	var resp map[string]interface{}
+	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("failed to decode response: %v", err)
+	}
+	if resp["code"] != float64(common.CodeAuthenticationError) {
+		t.Fatalf("expected auth error code, got %v", resp["code"])
+	}
+	if resp["data"] != false {
+		t.Fatalf("expected data=false, got %v", resp["data"])
+	}
+	if resp["message"] != "No authorization." {
+		t.Fatalf("unexpected message: %v", resp["message"])
+	}
+}