撤回转交: recall接口删除子任务恢复父WIP + 前端canRecall判断 + 红色撤回按钮

backend/app/services/task_service.py

@@ -306,6 +306,48 @@ async def end_task(
     return _to_response(task)
 
 
+# ============================================================
+# 核心业务 0.3：撤回转交
+# ============================================================
+
+async def recall_task(
+    db: AsyncSession, task_id: uuid.UUID, operator_id: str | None = None
+) -> TaskResponse:
+    """撤回 PENDING 转交任务，恢复父任务为 WIP。"""
+    task = await _get_task_or_404(db, task_id)
+
+    if task.status != TASK_STATUS_PENDING:
+        raise HTTPException(status_code=409, detail="只有待接收(PENDING)的任务可以撤回")
+
+    if not task.parent_task_id:
+        raise HTTPException(status_code=400, detail="顶层任务无法撤回")
+
+    parent = await _get_task_or_404(db, task.parent_task_id)
+    if parent.status != TASK_STATUS_COMPLETED:
+        raise HTTPException(status_code=409, detail="父任务状态异常，无法撤回")
+
+    # 恢复父任务
+    parent.status = TASK_STATUS_WIP
+    parent.completed_at = None
+
+    # 更新产品位置到父任务负责人
+    product_result = await db.execute(select(Product).where(Product.id == parent.product_id))
+    product = product_result.scalar_one_or_none()
+    if product and parent.assignee_id:
+        product.current_location_id = parent.assignee_id
+        product.overall_status = parent.task_name
+
+    # 删除 PENDING 子任务
+    await db.delete(task)
+
+    await _create_task_log(db, parent.id, action_type="recall", operator_id=operator_id,
+        remark=f"撤回转交「{task.task_name}」→ {task.assignee_id}，恢复父任务为 WIP")
+
+    await db.commit()
+    await db.refresh(parent)
+    return _to_response(parent)
+
+
 # ============================================================
 # 核心业务 0.5：派发协助分支（不改变父任务状态）
 # ============================================================