"""
测试 step_back API 端点
"""
from django.test import TestCase
from rest_framework.test import APIClient
from rest_framework import status
from django.contrib.auth import get_user_model
from stateflow import models

User = get_user_model()


class StepBackAPITestCase(TestCase):
    """测试单步回退 API"""
    
    def setUp(self):
        self.client = APIClient()
        
        # 创建用户
        self.user = User.objects.create_user(username='testuser', password='testpass')
        self.client.force_authenticate(user=self.user)
        
        # 创建状态
        self.state1 = models.State.objects.create(name='状态1')
        self.state2 = models.State.objects.create(name='状态2')
        self.state3 = models.State.objects.create(name='状态3')
        
        # 创建流程
        self.process = models.Process.objects.create(name='测试流程')
        models.ProcessNode.objects.create(process=self.process, state=self.state1, order=0)
        models.ProcessNode.objects.create(process=self.process, state=self.state2, order=1)
        models.ProcessNode.objects.create(process=self.process, state=self.state3, order=2)
        
        # 创建业务对象
        self.business_object = models.BusinessObject.objects.create(
            name='测试对象',
            process=self.process
        )
    
    def test_step_back_api_success(self):
        """测试回退 API 成功"""
        # 先推进两步
        self.client.post(f'/api/v1/stateflow/business-objects/{self.business_object.id}/advance/')
        self.client.post(f'/api/v1/stateflow/business-objects/{self.business_object.id}/advance/')
        
        # 回退一步
        response = self.client.post(f'/api/v1/stateflow/business-objects/{self.business_object.id}/step_back/')
        
        self.assertEqual(response.status_code, status.HTTP_200_OK)
        self.assertTrue(response.data['success'])
        self.assertIn('状态2', response.data['message'])
        self.assertIn('business_object', response.data)
    
    def test_step_back_api_not_started(self):
        """测试未开始状态回退失败"""
        response = self.client.post(f'/api/v1/stateflow/business-objects/{self.business_object.id}/step_back/')
        
        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
        self.assertFalse(response.data['success'])
        self.assertIn('没有任何状态流转记录', response.data['message'])
    
    def test_advance_step_back_advance_cycle(self):
        """测试前进-回退-前进循环"""
        # 前进
        response1 = self.client.post(f'/api/v1/stateflow/business-objects/{self.business_object.id}/advance/')
        self.assertEqual(response1.status_code, status.HTTP_200_OK)
        
        # 回退
        response2 = self.client.post(f'/api/v1/stateflow/business-objects/{self.business_object.id}/step_back/')
        self.assertEqual(response2.status_code, status.HTTP_200_OK)
        
        # 再前进
        response3 = self.client.post(f'/api/v1/stateflow/business-objects/{self.business_object.id}/advance/')
        self.assertEqual(response3.status_code, status.HTTP_200_OK)
        
        # 验证数据库中有已撤销的记录
        cancelled_count = models.StateFlowRecord.objects.filter(
            business_object=self.business_object,
            is_cancelled=True
        ).count()
        self.assertEqual(cancelled_count, 1)