feat: route canvas agent text updates

lib/canvas/agent-explicit-operations.ts

@@ -12,6 +12,7 @@ type ExplicitOperationKind =
   | "create_agent_slot"
   | "create_text_node"
   | "rename_node"
+  | "update_text"
   | "update_note";
 
 export type CanvasAgentExplicitOperationPlan = {
@@ -199,6 +200,60 @@ function buildCreateTextOperation(params: {
   };
 }
 
+function hasImageTextEditIntent(userText: string) {
+  return /(?:图片|图像|照片|主图|海报|画面|图中|图里|图片里|图片上|海报上).*(?:文字|文本|文案|字).*(?:改|换|替换|编辑|修改|去掉|删除)|(?:文字|文本|文案|字).*(?:图片|图像|照片|主图|海报|画面|图中|图里|图片里|图片上|海报上).*(?:改|换|替换|编辑|修改|去掉|删除)/.test(
+    userText
+  );
+}
+
+function buildUpdateTextOperation(params: {
+  context: CanvasAgentContext;
+  projectId: string;
+  messageId: string;
+  chatId: string;
+  userText: string;
+  requestedNodeIds?: string[];
+}): CanvasAgentExplicitOperationPlan | null {
+  const text = params.userText.trim();
+  const hasUpdateTextIntent =
+    /(?:选中|当前|这个|这段|该).*(?:文本|文字|文案|标语|说明|copy|text).*(?:改成|改为|修改为|更新为|设为|设置为|换成)|(?:文本|文字|文案|标语|说明|copy|text).*(?:改成|改为|修改为|更新为|设为|设置为|换成)/i.test(
+      text
+    );
+  if (!hasUpdateTextIntent || hasMediaMutationIntent(text)) return null;
+  if (hasImageTextEditIntent(text)) return null;
+
+  const textContent = extractContentFromPatterns(
+    text,
+    [
+      /(?:改成|改为|修改为|更新为|设为|设置为|换成)\s*[:：]?\s*([\s\S]+)$/i,
+      /(?:文本|文字|文案|标语|说明|copy|text)[^:：]*(?:改成|改为|修改为|更新为|设为|设置为|换成)\s*[:：]?\s*([\s\S]+)$/i,
+      /[:：]\s*([\s\S]+)$/i,
+    ],
+    4000
+  );
+  if (!textContent) return null;
+
+  const targetNodeIds = getTargetNodeIds({
+    context: params.context,
+    requestedNodeIds: params.requestedNodeIds,
+    allowedTypes: ["text"],
+  }).slice(0, 10);
+  if (targetNodeIds.length === 0) return null;
+
+  return {
+    operationPlan: {
+      ...buildPlanBase({ ...params, operation: "update_text" }),
+      targetNodeIds,
+      textContent,
+    },
+    reply: "已更新选中文本内容。",
+    progressTitle: "正在更新画布文本",
+    progressMessage: "我会只修改选中文本节点的内容，不移动画布节点。",
+    completedTitle: "画布文本已更新",
+    failedTitle: "画布文本更新失败",
+  };
+}
+
 function getSlotTypeLabel(slotType: "image" | "video" | "ui-screen") {
   if (slotType === "video") return "视频";
   if (slotType === "ui-screen") return "UI";
@@ -407,6 +462,7 @@ export function buildCanvasAgentExplicitOperationPlan(params: {
   return (
     buildCreateAgentSlotOperation(commonParams) ||
     buildCreateTextOperation(commonParams) ||
+    buildUpdateTextOperation(commonParams) ||
     buildRenameOperation(commonParams) ||
     buildUpdateNoteOperation(commonParams) ||
     buildAddAnnotationOperation(commonParams)

lib/canvas/agent-mutations.ts

@@ -1132,7 +1132,10 @@ function applyOperationToCanvasData(params: {
   if (
     existingOperationNodes.length > 0 &&
     (params.plan.operation === "replace_node_media" ||
-      params.plan.operation === "move_nodes")
+      params.plan.operation === "move_nodes" ||
+      params.plan.operation === "rename_node" ||
+      params.plan.operation === "update_note" ||
+      params.plan.operation === "update_text")
   ) {
     return {
       canvasData: params.canvasData,
@@ -1385,6 +1388,7 @@ function applyOperationToCanvasData(params: {
         content: textContent,
         metadata: {
           ...(data.metadata || {}),
+          ...(params.plan.metadata || {}),
           updatedByAgent: true,
           canvasAgentOperationId: params.plan.operationId,
           canvasAgentOperation: params.plan.operation,

tests/routes/canvas-agent-operations.test.ts

@@ -83,6 +83,23 @@ function buildImageNode(id = "image-1") {
   };
 }
 
+function buildTextNode(id = "text-1") {
+  return {
+    id,
+    type: "text",
+    position: { x: 160, y: 180 },
+    size: { width: 280, height: 120 },
+    data: {
+      content: "旧文案",
+      fontSize: 18,
+      color: "#111827",
+    },
+    connections: [],
+    createdAt: "2026-06-22T00:00:00.000Z",
+    updatedAt: "2026-06-22T00:00:00.000Z",
+  };
+}
+
 function buildAgentSlotNode(id = "slot-1", slotType: "image" | "video" = "image") {
   return {
     id,
@@ -751,6 +768,56 @@ test.describe("canvas agent operation mutation contract", () => {
     );
   });
 
+  test("updates selected text nodes with trace metadata and idempotency", () => {
+    const plan: CanvasOperationPlan = {
+      version: 1,
+      operationId: "op-update-text-node",
+      operation: "update_text",
+      projectId,
+      targetNodeIds: ["text-update"],
+      textContent: "轻盈强吸力，家务更省心",
+      metadata: {
+        messageId: "assistant-message-update-text",
+        chatId: "chat-1",
+      },
+    };
+
+    const first = applyCanvasOperationPlanToCanvasData({
+      canvasData: getCanvasData([buildTextNode("text-update")]),
+      plan,
+    });
+    const updatedText = getResultNodes(first.canvasData).find(
+      (node) => node.id === "text-update"
+    );
+
+    expect(first.createdNodeIds).toEqual([]);
+    expect(first.updatedNodeIds).toEqual(["text-update"]);
+    expect(updatedText).toMatchObject({
+      data: {
+        content: "轻盈强吸力，家务更省心",
+        metadata: {
+          updatedByAgent: true,
+          canvasAgentOperationId: "op-update-text-node",
+          canvasAgentOperation: "update_text",
+          previousContent: "旧文案",
+          messageId: "assistant-message-update-text",
+          chatId: "chat-1",
+        },
+      },
+    });
+
+    const retry = applyCanvasOperationPlanToCanvasData({
+      canvasData: first.canvasData,
+      plan,
+    });
+    const retryText = getResultNodes(retry.canvasData).find(
+      (node) => node.id === "text-update"
+    );
+
+    expect(retry.updatedNodeIds).toEqual(["text-update"]);
+    expect(retryText.data.metadata.previousContent).toBe("旧文案");
+  });
+
   test("fills an agent slot and returns media item node mappings", () => {
     const slot = buildAgentSlotNode();
     const result = applyCanvasOperationPlanToCanvasData({

tests/routes/canvas-chat-helpers.test.ts

@@ -1432,6 +1432,29 @@ test.describe("canvas chat pure helpers", () => {
     });
   });
 
+  test("builds deterministic text update plans for selected text nodes", () => {
+    const outcome = buildCanvasAgentExplicitOperationPlan({
+      context: plannerContext,
+      projectId: plannerContext.projectId || "",
+      messageId: "message-1",
+      chatId: "chat-1",
+      userText: "把选中文案改成：轻盈强吸力，家务更省心",
+    });
+
+    expect(outcome?.operationPlan).toMatchObject({
+      operation: "update_text",
+      targetNodeIds: ["text-1"],
+      textContent: "轻盈强吸力，家务更省心",
+      preserveOriginal: true,
+      metadata: {
+        messageId: "message-1",
+        chatId: "chat-1",
+        planner: "deterministic",
+      },
+    });
+    expect(outcome?.reply).toContain("文本");
+  });
+
   test("builds deterministic agent slot creation plans from explicit canvas prompts", () => {
     const context: CanvasAgentContext = {
       ...plannerContext,
@@ -1601,6 +1624,16 @@ test.describe("canvas chat pure helpers", () => {
         userText: "按这张图上的批注修改",
       })
     ).toBeNull();
+
+    expect(
+      buildCanvasAgentExplicitOperationPlan({
+        context: plannerContext,
+        projectId: plannerContext.projectId || "",
+        messageId: "message-1",
+        chatId: "chat-1",
+        userText: "把图片里的文字改成新品上市",
+      })
+    ).toBeNull();
   });
 
   test("normalizes model-planned annotations to selected media nodes", () => {