feat: new modul (stateflow)

api_v1/views/stateflow/process.py

@@ -0,0 +1,59 @@
+"""
+Process API ViewSet
+"""
+from rest_framework import viewsets, filters
+from rest_framework.pagination import LimitOffsetPagination
+from django_filters.rest_framework import DjangoFilterBackend
+from django.db.models import Count
+from stateflow import models
+from stateflow.serializers import (
+    ProcessListSerializer,
+    ProcessDetailSerializer,
+    ProcessCreateUpdateSerializer,
+)
+
+
+class ProcessViewSet(viewsets.ModelViewSet):
+    """
+    流程 CRUD 接口
+    
+    list: 获取流程列表
+    retrieve: 获取流程详情（包含节点）
+    create: 创建流程
+    update: 更新流程
+    partial_update: 部分更新流程
+    destroy: 删除流程
+    
+    查询参数:
+    - name: 按名称模糊查询
+    - search: 全文搜索（名称和描述）
+    - ordering: 排序字段，支持 id, name, node_count, created_at, updated_at
+    """
+    pagination_class = LimitOffsetPagination
+    filter_backends = [DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter]
+    filterset_fields = ['name']
+    search_fields = ['name', 'description']
+    ordering_fields = ['id', 'name', 'node_count', 'created_at', 'updated_at']
+    ordering = ['-created_at']
+    
+    def get_serializer_class(self):
+        """根据动作选择序列化器"""
+        if self.action == 'list':
+            return ProcessListSerializer
+        elif self.action in ['create', 'update', 'partial_update']:
+            return ProcessCreateUpdateSerializer
+        else:  # retrieve
+            return ProcessDetailSerializer
+    
+    def get_queryset(self):
+        """优化查询"""
+        queryset = models.Process.objects.all()
+        
+        if self.action == 'list':
+            # list 时添加节点计数注解
+            queryset = queryset.annotate(node_count=Count('process_nodes'))
+        elif self.action == 'retrieve':
+            # retrieve 时预加载节点和状态
+            queryset = queryset.prefetch_related('process_nodes__state')
+        
+        return queryset