/**
 * 用户实体、DTO和服务的完整测试套件
 * 
 * 功能：
 * - 测试Users实体的结构和装饰器
 * - 测试CreateUserDto的验证规则
 * - 测试UsersService的所有CRUD操作
 * - 验证数据类型和约束条件
 * 
 * @author moyin
 * @version 1.0.0
 * @since 2025-12-17
 */

import { Test, TestingModule } from '@nestjs/testing';
import { getRepositoryToken } from '@nestjs/typeorm';
import { Repository, DataSource } from 'typeorm';
import { ConflictException, NotFoundException, BadRequestException } from '@nestjs/common';
import { validate } from 'class-validator';
import { plainToClass } from 'class-transformer';

import { Users } from './users.entity';
import { CreateUserDto } from './users.dto';
import { UsersService } from './users.service';

describe('Users Entity, DTO and Service Tests', () => {
  let service: UsersService;
  let repository: Repository<Users>;
  let module: TestingModule;

  // 模拟的Repository方法
  const mockRepository = {
    save: jest.fn(),
    find: jest.fn(),
    findOne: jest.fn(),
    delete: jest.fn(),
    softRemove: jest.fn(),
    count: jest.fn(),
    createQueryBuilder: jest.fn(),
  };

  // 测试数据
  const mockUser: Users = {
    id: BigInt(1),
    username: 'testuser',
    email: 'test@example.com',
    phone: '+8613800138000',
    password_hash: 'hashed_password',
    nickname: '测试用户',
    github_id: 'github_123',
    avatar_url: 'https://example.com/avatar.jpg',
    role: 1,
    email_verified: false,
    created_at: new Date(),
    updated_at: new Date(),
  };

  const createUserDto: CreateUserDto = {
    username: 'testuser',
    email: 'test@example.com',
    phone: '+8613800138000',
    password_hash: 'hashed_password',
    nickname: '测试用户',
    github_id: 'github_123',
    avatar_url: 'https://example.com/avatar.jpg',
    role: 1
  };

  beforeEach(async () => {
    module = await Test.createTestingModule({
      providers: [
        UsersService,
        {
          provide: getRepositoryToken(Users),
          useValue: mockRepository,
        },
      ],
    }).compile();

    service = module.get<UsersService>(UsersService);
    repository = module.get<Repository<Users>>(getRepositoryToken(Users));

    // 清理所有mock
    jest.clearAllMocks();
  });

  afterEach(async () => {
    await module.close();
  });

  describe('Users Entity Tests', () => {
    it('应该正确创建用户实体实例', () => {
      const user = new Users();
      user.username = 'testuser';
      user.email = 'test@example.com';
      user.phone = '+8613800138000';
      user.password_hash = 'hashed_password';
      user.nickname = '测试用户';
      user.github_id = 'github_123';
      user.avatar_url = 'https://example.com/avatar.jpg';
      user.role = 1;
      user.created_at = new Date();
      user.updated_at = new Date();

      expect(user.username).toBe('testuser');
      expect(user.email).toBe('test@example.com');
      expect(user.nickname).toBe('测试用户');
      expect(user.role).toBe(1);
    });

    it('应该能够设置和获取所有属性', () => {
      const user = new Users();
      
      // 验证可以设置和获取所有属性
      user.username = 'testuser';
      user.email = 'test@example.com';
      user.phone = '+8613800138000';
      user.password_hash = 'hashed_password';
      user.nickname = '测试用户';
      user.github_id = 'github_123';
      user.avatar_url = 'https://example.com/avatar.jpg';
      user.role = 1;
      user.created_at = new Date();
      user.updated_at = new Date();

      expect(user.username).toBe('testuser');
      expect(user.email).toBe('test@example.com');
      expect(user.phone).toBe('+8613800138000');
      expect(user.password_hash).toBe('hashed_password');
      expect(user.nickname).toBe('测试用户');
      expect(user.github_id).toBe('github_123');
      expect(user.avatar_url).toBe('https://example.com/avatar.jpg');
      expect(user.role).toBe(1);
      expect(user.created_at).toBeInstanceOf(Date);
      expect(user.updated_at).toBeInstanceOf(Date);
    });
  });

  describe('CreateUserDto Validation Tests', () => {
    it('应该通过有效数据的验证', async () => {
      const validData = {
        username: 'testuser',
        email: 'test@example.com',
        phone: '+8613800138000',
        password_hash: 'hashed_password',
        nickname: '测试用户',
        github_id: 'github_123',
        avatar_url: 'https://example.com/avatar.jpg',
        role: 1
      };

      const dto = plainToClass(CreateUserDto, validData);
      const errors = await validate(dto);

      expect(errors).toHaveLength(0);
    });

    it('应该拒绝缺少必填字段的数据', async () => {
      const invalidData = {
        email: 'test@example.com'
        // 缺少 username 和 nickname
      };

      const dto = plainToClass(CreateUserDto, invalidData);
      const errors = await validate(dto);

      expect(errors.length).toBeGreaterThan(0);
      
      const usernameError = errors.find(error => error.property === 'username');
      const nicknameError = errors.find(error => error.property === 'nickname');
      
      expect(usernameError).toBeDefined();
      expect(nicknameError).toBeDefined();
    });

    it('应该拒绝无效的邮箱格式', async () => {
      const invalidData = {
        username: 'testuser',
        nickname: '测试用户',
        email: 'invalid-email'
      };

      const dto = plainToClass(CreateUserDto, invalidData);
      const errors = await validate(dto);

      const emailError = errors.find(error => error.property === 'email');
      expect(emailError).toBeDefined();
    });

    it('应该拒绝超长的用户名', async () => {
      const invalidData = {
        username: 'a'.repeat(51), // 超过50字符
        nickname: '测试用户'
      };

      const dto = plainToClass(CreateUserDto, invalidData);
      const errors = await validate(dto);

      const usernameError = errors.find(error => error.property === 'username');
      expect(usernameError).toBeDefined();
    });

    it('应该拒绝无效的角色值', async () => {
      const invalidData = {
        username: 'testuser',
        nickname: '测试用户',
        role: 10 // 超出1-9范围
      };

      const dto = plainToClass(CreateUserDto, invalidData);
      const errors = await validate(dto);

      const roleError = errors.find(error => error.property === 'role');
      expect(roleError).toBeDefined();
    });
  });

  describe('UsersService CRUD Tests', () => {

    describe('create()', () => {
      it('应该成功创建新用户', async () => {
        mockRepository.findOne.mockResolvedValue(null); // 没有重复用户
        mockRepository.save.mockResolvedValue(mockUser);

        const result = await service.create(createUserDto);

        expect(mockRepository.save).toHaveBeenCalled();
        expect(result).toEqual(mockUser);
      });

      it('应该在用户名重复时抛出ConflictException', async () => {
        mockRepository.findOne.mockResolvedValue(mockUser); // 模拟用户名已存在

        await expect(service.createWithDuplicateCheck(createUserDto)).rejects.toThrow(ConflictException);
        expect(mockRepository.save).not.toHaveBeenCalled();
      });

      it('应该在数据验证失败时抛出BadRequestException', async () => {
        const invalidDto = { username: '', nickname: '' }; // 无效数据

        await expect(service.create(invalidDto as CreateUserDto)).rejects.toThrow(BadRequestException);
      });
    });

    describe('findAll()', () => {
      it('应该返回用户列表', async () => {
        const mockUsers = [mockUser];
        mockRepository.find.mockResolvedValue(mockUsers);

        const result = await service.findAll();

        expect(mockRepository.find).toHaveBeenCalledWith({
          take: 100,
          skip: 0,
          order: { created_at: 'DESC' }
        });
        expect(result).toEqual(mockUsers);
      });

      it('应该支持分页参数', async () => {
        mockRepository.find.mockResolvedValue([]);

        await service.findAll(50, 10);

        expect(mockRepository.find).toHaveBeenCalledWith({
          take: 50,
          skip: 10,
          order: { created_at: 'DESC' }
        });
      });
    });

    describe('findOne()', () => {
      it('应该根据ID返回用户', async () => {
        mockRepository.findOne.mockResolvedValue(mockUser);

        const result = await service.findOne(BigInt(1));

        expect(mockRepository.findOne).toHaveBeenCalledWith({
          where: { id: BigInt(1) }
        });
        expect(result).toEqual(mockUser);
      });

      it('应该在用户不存在时抛出NotFoundException', async () => {
        mockRepository.findOne.mockResolvedValue(null);

        await expect(service.findOne(BigInt(999))).rejects.toThrow(NotFoundException);
      });
    });

    describe('findByUsername()', () => {
      it('应该根据用户名返回用户', async () => {
        mockRepository.findOne.mockResolvedValue(mockUser);

        const result = await service.findByUsername('testuser');

        expect(mockRepository.findOne).toHaveBeenCalledWith({
          where: { username: 'testuser' }
        });
        expect(result).toEqual(mockUser);
      });

      it('应该在用户不存在时返回null', async () => {
        mockRepository.findOne.mockResolvedValue(null);

        const result = await service.findByUsername('nonexistent');

        expect(result).toBeNull();
      });
    });

    describe('findByEmail()', () => {
      it('应该根据邮箱返回用户', async () => {
        mockRepository.findOne.mockResolvedValue(mockUser);

        const result = await service.findByEmail('test@example.com');

        expect(mockRepository.findOne).toHaveBeenCalledWith({
          where: { email: 'test@example.com' }
        });
        expect(result).toEqual(mockUser);
      });
    });

    describe('update()', () => {
      it('应该成功更新用户信息', async () => {
        const updatedUser = { ...mockUser, nickname: '更新后的昵称' };
        
        mockRepository.findOne
          .mockResolvedValueOnce(mockUser) // findOne in update method
          .mockResolvedValueOnce(null); // 检查昵称是否重复
        mockRepository.save.mockResolvedValue(updatedUser);

        const result = await service.update(BigInt(1), { nickname: '更新后的昵称' });

        expect(mockRepository.save).toHaveBeenCalled();
        expect(result.nickname).toBe('更新后的昵称');
      });

      it('应该在更新不存在的用户时抛出NotFoundException', async () => {
        mockRepository.findOne.mockResolvedValue(null);

        await expect(service.update(BigInt(999), { nickname: '新昵称' })).rejects.toThrow(NotFoundException);
      });

      it('应该在更新数据冲突时抛出ConflictException', async () => {
        mockRepository.findOne
          .mockResolvedValueOnce(mockUser) // 找到要更新的用户
          .mockResolvedValueOnce(mockUser); // 发现用户名冲突

        await expect(service.update(BigInt(1), { username: 'conflictuser' })).rejects.toThrow(ConflictException);
      });
    });

    describe('remove()', () => {
      it('应该成功删除用户', async () => {
        mockRepository.findOne.mockResolvedValue(mockUser);
        mockRepository.delete.mockResolvedValue({ affected: 1 });

        const result = await service.remove(BigInt(1));

        expect(mockRepository.delete).toHaveBeenCalledWith({ id: BigInt(1) });
        expect(result.affected).toBe(1);
        expect(result.message).toContain('成功删除');
      });

      it('应该在删除不存在的用户时抛出NotFoundException', async () => {
        mockRepository.findOne.mockResolvedValue(null);

        await expect(service.remove(BigInt(999))).rejects.toThrow(NotFoundException);
      });
    });

    describe('count()', () => {
      it('应该返回用户总数', async () => {
        mockRepository.count.mockResolvedValue(10);

        const result = await service.count();

        expect(mockRepository.count).toHaveBeenCalled();
        expect(result).toBe(10);
      });
    });

    describe('exists()', () => {
      it('应该在用户存在时返回true', async () => {
        mockRepository.count.mockResolvedValue(1);

        const result = await service.exists(BigInt(1));

        expect(result).toBe(true);
      });

      it('应该在用户不存在时返回false', async () => {
        mockRepository.count.mockResolvedValue(0);

        const result = await service.exists(BigInt(999));

        expect(result).toBe(false);
      });
    });

    describe('search()', () => {
      it('应该根据关键词搜索用户', async () => {
        const mockQueryBuilder = {
          where: jest.fn().mockReturnThis(),
          orderBy: jest.fn().mockReturnThis(),
          limit: jest.fn().mockReturnThis(),
          getMany: jest.fn().mockResolvedValue([mockUser]),
        };

        mockRepository.createQueryBuilder.mockReturnValue(mockQueryBuilder);

        const result = await service.search('test');

        expect(mockRepository.createQueryBuilder).toHaveBeenCalledWith('user');
        expect(mockQueryBuilder.where).toHaveBeenCalled();
        expect(result).toEqual([mockUser]);
      });
    });

    describe('findByRole()', () => {
      it('应该根据角色查询用户', async () => {
        mockRepository.find.mockResolvedValue([mockUser]);

        const result = await service.findByRole(1);

        expect(mockRepository.find).toHaveBeenCalledWith({
          where: { role: 1 },
          order: { created_at: 'DESC' }
        });
        expect(result).toEqual([mockUser]);
      });
    });
  });

  describe('Integration Tests', () => {
    it('应该完成从DTO到Entity的完整流程', async () => {
      // 1. 验证DTO
      const dto = plainToClass(CreateUserDto, createUserDto);
      const validationErrors = await validate(dto);
      expect(validationErrors).toHaveLength(0);

      // 2. 创建匹配的mock用户数据
      const expectedUser = { ...mockUser, nickname: dto.nickname };
      
      // 3. 模拟服务创建用户
      mockRepository.findOne.mockResolvedValue(null);
      mockRepository.save.mockResolvedValue(expectedUser);

      const result = await service.create(dto);

      // 4. 验证结果
      expect(result).toBeDefined();
      expect(result.username).toBe(dto.username);
      expect(result.nickname).toBe(dto.nickname);
    });

    it('应该正确处理可选字段', async () => {
      const minimalDto: CreateUserDto = {
        username: 'minimaluser',
        nickname: '最小用户'
      };

      const dto = plainToClass(CreateUserDto, minimalDto);
      const validationErrors = await validate(dto);
      expect(validationErrors).toHaveLength(0);

      // 验证可选字段的默认值处理
      expect(dto.role).toBe(1); // 默认角色
      expect(dto.email).toBeUndefined();
      expect(dto.phone).toBeUndefined();
    });
  });

  describe('Error Handling Tests', () => {
    it('应该正确处理数据库连接错误', async () => {
      mockRepository.save.mockRejectedValue(new Error('Database connection failed'));

      await expect(service.create(createUserDto)).rejects.toThrow('Database connection failed');
    });

    it('应该正确处理并发创建冲突', async () => {
      // 模拟并发情况：检查时不存在，保存时出现唯一约束错误
      mockRepository.findOne.mockResolvedValue(null);
      mockRepository.save.mockRejectedValue(new Error('Duplicate entry'));

      await expect(service.create(createUserDto)).rejects.toThrow('Duplicate entry');
    });
  });
});