refactor(chat): centralize session persistence

src/routes/chat.ts

@@ -36,6 +36,7 @@ import {
   type ActiveRun,
   type RunStatus,
   type StreamSubscriber,
+  appendBackendToolArtifact,
   cancelBackendTodos,
   completeBackendProgress,
   createInitialStreamingMessages,
@@ -67,12 +68,6 @@ const forkPayloadSchema = z.object({
   keep_message_count: z.coerce.number().int().min(0),
 });
 
-const sessionStateSchema = z.object({
-  title: z.string().max(120).optional(),
-  is_title_manually_edited: z.boolean().optional(),
-  messages: z.array(z.unknown()).default([]),
-});
-
 const activeRuns = new Map<string, ActiveRun>();
 const lastRunStatuses = new Map<string, RunStatus>();
 
@@ -80,6 +75,20 @@ const toSessionUiStateContext = (sessionRecord: SessionRecord) => ({
   sessionId: sessionRecord.sessionId,
 });
 
+export const buildForkedSessionUiState = (
+  sourceState: { messages?: unknown[] } | null | undefined,
+  input: {
+    keepMessageCount: number;
+    targetSessionId: string;
+  },
+) => ({
+  sessionId: input.targetSessionId,
+  isTitleManuallyEdited: false,
+  messages: Array.isArray(sourceState?.messages)
+    ? sourceState.messages.slice(0, input.keepMessageCount)
+    : [],
+});
+
 const getSessionRunStatus = (sessionId: string) =>
   activeRuns.get(sessionId)?.status ?? lastRunStatuses.get(sessionId);
 
@@ -274,71 +283,6 @@ export const buildChatRouter = (
     res.on("close", cleanup);
   });
 
-  chatRouter.put("/session/:sessionId", async (req, res) => {
-    const sessionId = req.params.sessionId?.trim();
-    const parsed = sessionStateSchema.safeParse(req.body ?? {});
-    if (!parsed.success) {
-      res.status(400).json({
-        message: "invalid request payload",
-        detail: parsed.error.flatten(),
-      });
-      return;
-    }
-
-    const projectId = req.header("x-project-id") ?? undefined;
-    const userId = req.header("x-user-id") ?? undefined;
-    const actorKey = toActorKey(userId);
-    const projectKey = toProjectKey(projectId);
-    if (!sessionId) {
-      res.status(400).json({ message: "session_id is required" });
-      return;
-    }
-
-    const { record } = await sessionMetadataStore.ensure({
-      actorKey,
-      projectId,
-      projectKey,
-      sessionId,
-      userId,
-    });
-    const nextRecord = await sessionMetadataStore.touch(record, {
-      ...(parsed.data.title ? { title: parsed.data.title } : {}),
-    });
-    await sessionUiStateStore.write(toSessionUiStateContext(nextRecord), {
-      sessionId: nextRecord.sessionId,
-      isTitleManuallyEdited: parsed.data.is_title_manually_edited,
-      messages: parsed.data.messages,
-    });
-    const latestTurn = extractLatestFrontendTurn(parsed.data.messages);
-    if (latestTurn) {
-      void learningOrchestrator.onTurnCompleted({
-        ...latestTurn,
-        requestContext: {
-          actorKey,
-          clientSessionId: nextRecord.sessionId,
-          projectId,
-          projectKey,
-          traceId: req.header("x-trace-id") ?? `save-${nextRecord.sessionId}`,
-          userId,
-        },
-        sessionId: nextRecord.sessionId,
-      }).catch((error) => {
-        logger.warn(
-          { err: error, sessionId: nextRecord.sessionId },
-          "post-save learning failed",
-        );
-      });
-    }
-    res.json({
-      id: nextRecord.sessionId,
-      title: nextRecord.title ?? "新对话",
-      created_at: nextRecord.createdAt,
-      updated_at: nextRecord.updatedAt,
-      status: nextRecord.status,
-      session_id: nextRecord.sessionId,
-    });
-  });
-
   chatRouter.patch("/session/:sessionId/title", async (req, res) => {
     const sessionId = req.params.sessionId?.trim();
     const title =
@@ -469,7 +413,7 @@ export const buildChatRouter = (
       });
       const nextSessionId = targetSessionRecord.sessionId;
 
-      if (sourceSessionId && parsed.data.keep_message_count > 0) {
+      if (sourceSessionId) {
         await sessionTranscriptStore.cloneThread(
           {
             actorKey,
@@ -485,12 +429,24 @@ export const buildChatRouter = (
           },
           parsed.data.keep_message_count,
         );
-        if (sourceSessionRecord?.title) {
-          await sessionMetadataStore.touch(targetSessionRecord, {
-            title: sourceSessionRecord.title,
-          });
-        }
       }
+      const sourceState = sourceSessionRecord
+        ? await sessionUiStateStore.read(toSessionUiStateContext(sourceSessionRecord))
+        : null;
+      const forkTitle = sourceSessionRecord?.title
+        ? `${sourceSessionRecord.title} 副本`
+        : "新对话副本";
+      const titledTargetSessionRecord = await sessionMetadataStore.touch(
+        targetSessionRecord,
+        { title: forkTitle },
+      );
+      await sessionUiStateStore.write(
+        toSessionUiStateContext(titledTargetSessionRecord),
+        buildForkedSessionUiState(sourceState, {
+          keepMessageCount: parsed.data.keep_message_count,
+          targetSessionId: nextSessionId,
+        }),
+      );
 
       logger.info(
         {
@@ -789,6 +745,11 @@ export const buildChatRouter = (
             ...message,
             todos: upsertBackendTodoUpdate(message.todos, payload),
           }));
+        } else if (event === "tool_call") {
+          activeRun.messages = updateLastAssistantMessage(activeRun.messages, (message) => ({
+            ...message,
+            artifacts: appendBackendToolArtifact(message.artifacts, data),
+          }));
         }
 
         for (const subscriber of activeRun.subscribers) {
@@ -876,6 +837,19 @@ export const buildChatRouter = (
               logger.warn({ err: error, sessionId: clientSessionId }, "failed to persist chat stream state");
             });
           }
+          const latestTurn = extractLatestFrontendTurn(activeRun.messages);
+          if (latestTurn) {
+            void learningOrchestrator.onTurnCompleted({
+              ...latestTurn,
+              requestContext,
+              sessionId: clientSessionId,
+            }).catch((error) => {
+              logger.warn(
+                { err: error, sessionId: clientSessionId },
+                "stream-completed learning failed",
+              );
+            });
+          }
         }
       } finally {
         if (abortController.signal.aborted) {

src/routes/chatUiState.ts

@@ -22,6 +22,15 @@ export type ActiveRun = {
   subscribers: Set<StreamSubscriber>;
 };
 
+type ToolArtifactKind = "chart" | "map" | "panel" | "tool";
+
+type ToolCallPayload = {
+  session_id?: string;
+  tool?: string;
+  params?: unknown;
+  reason?: string;
+};
+
 export const isObjectRecord = (value: unknown): value is Record<string, unknown> =>
   typeof value === "object" && value !== null && !Array.isArray(value);
 
@@ -196,6 +205,59 @@ export const updateLastAssistantQuestion = (
     };
   });
 
+const getToolArtifactKind = (tool: string): ToolArtifactKind => {
+  if (tool === "show_chart" || tool === "chart") return "chart";
+  if (
+    tool === "locate_features" ||
+    tool === "zoom_to_map" ||
+    tool === "render_junctions" ||
+    tool === "apply_layer_style" ||
+    tool.startsWith("locate_")
+  ) {
+    return "map";
+  }
+  if (tool === "view_history" || tool === "view_scada") return "panel";
+  return "tool";
+};
+
+const getToolArtifactTitle = (tool: string, params: Record<string, unknown>) => {
+  if (typeof params.title === "string" && params.title.trim()) {
+    return params.title.trim();
+  }
+  if (tool === "show_chart" || tool === "chart") return "生成图表";
+  if (tool === "zoom_to_map") return "缩放到地图坐标";
+  if (tool === "render_junctions") return "渲染节点分区";
+  if (tool === "view_history") return "打开计算结果曲线";
+  if (tool === "view_scada") return "打开 SCADA 数据面板";
+  if (tool === "apply_layer_style") return "应用图层样式";
+  if (tool === "locate_features" || tool.startsWith("locate_")) return "地图定位";
+  return tool || "工具调用";
+};
+
+export const appendBackendToolArtifact = (
+  artifacts: unknown,
+  payload: ToolCallPayload,
+) => {
+  const tool = typeof payload.tool === "string" ? payload.tool.trim() : "";
+  if (!tool) {
+    return artifacts;
+  }
+  const params = isObjectRecord(payload.params) ? payload.params : {};
+  const next = Array.isArray(artifacts) ? [...artifacts] : [];
+  next.push({
+    id: `${tool}-${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 8)}`,
+    tool,
+    kind: getToolArtifactKind(tool),
+    title: getToolArtifactTitle(tool, params),
+    description:
+      typeof payload.reason === "string" && payload.reason.trim()
+        ? payload.reason.trim()
+        : undefined,
+    params,
+  });
+  return next;
+};
+
 export const toFrontendPermission = (
   payload: PermissionRequestPayload,
   status: "pending" | "approved_once" | "approved_always" | "rejected" | "error" = "pending",

tests/routes/chatSession.test.ts

@@ -1,5 +1,8 @@
 import { describe, expect, it } from "bun:test";
 
+import {
+  buildForkedSessionUiState,
+} from "../../src/routes/chat.js";
 import {
   buildPromptWithLearningContext,
   extractLatestFrontendTurn,
@@ -199,3 +202,79 @@ describe("extractLatestFrontendTurn", () => {
     });
   });
 });
+
+describe("buildForkedSessionUiState", () => {
+  it("copies truncated source messages and preserves tool artifacts", () => {
+    const forked = buildForkedSessionUiState(
+      {
+        messages: [
+          { role: "user", content: "画压力曲线" },
+          {
+            role: "assistant",
+            content: "已生成图表",
+            artifacts: [
+              {
+                id: "chart-1",
+                tool: "show_chart",
+                kind: "chart",
+                params: { chart_type: "line" },
+              },
+            ],
+          },
+          { role: "user", content: "继续分析" },
+        ],
+      },
+      {
+        keepMessageCount: 2,
+        targetSessionId: "forked-session",
+      },
+    );
+
+    expect(forked).toEqual({
+      sessionId: "forked-session",
+      isTitleManuallyEdited: false,
+      messages: [
+        { role: "user", content: "画压力曲线" },
+        {
+          role: "assistant",
+          content: "已生成图表",
+          artifacts: [
+            {
+              id: "chart-1",
+              tool: "show_chart",
+              kind: "chart",
+              params: { chart_type: "line" },
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("creates an empty branch state when source UI state is missing or keep count is zero", () => {
+    expect(
+      buildForkedSessionUiState(null, {
+        keepMessageCount: 3,
+        targetSessionId: "forked-without-source",
+      }),
+    ).toEqual({
+      sessionId: "forked-without-source",
+      isTitleManuallyEdited: false,
+      messages: [],
+    });
+
+    expect(
+      buildForkedSessionUiState(
+        { messages: [{ role: "user", content: "不保留" }] },
+        {
+          keepMessageCount: 0,
+          targetSessionId: "forked-empty",
+        },
+      ),
+    ).toEqual({
+      sessionId: "forked-empty",
+      isTitleManuallyEdited: false,
+      messages: [],
+    });
+  });
+});

tests/routes/chatUiState.test.ts

@@ -1,10 +1,45 @@
 import { describe, expect, it } from "bun:test";
 
 import {
+  appendBackendToolArtifact,
   cancelBackendTodos,
   upsertBackendQuestion,
 } from "../../src/routes/chatUiState.js";
 
+describe("appendBackendToolArtifact", () => {
+  it("persists show_chart tool calls as chart artifacts", () => {
+    const artifacts = appendBackendToolArtifact([], {
+      session_id: "session-1",
+      tool: "show_chart",
+      reason: "测试折线图渲染",
+      params: {
+        title: "压力曲线",
+        chart_type: "line",
+        x_data: ["00:00", "01:00"],
+        series: [{ name: "P-101", data: [0.42, 0.41] }],
+      },
+    }) as Array<Record<string, unknown>>;
+
+    expect(artifacts).toHaveLength(1);
+    expect(artifacts[0]).toMatchObject({
+      tool: "show_chart",
+      kind: "chart",
+      title: "压力曲线",
+      description: "测试折线图渲染",
+      params: {
+        chart_type: "line",
+        x_data: ["00:00", "01:00"],
+        series: [{ name: "P-101", data: [0.42, 0.41] }],
+      },
+    });
+    expect(artifacts[0]).toEqual(
+      expect.objectContaining({
+        id: expect.stringMatching(/^show_chart-/),
+      }),
+    );
+  });
+});
+
 describe("upsertBackendQuestion", () => {
   it("replaces a tool-call placeholder with the actionable question request", () => {
     const questions = upsertBackendQuestion(