package service

import (
	"RelationshipManagement-backend/dao"
	"RelationshipManagement-backend/model"
	"errors"
)

// UserService 用户服务
type UserService struct {
	userDAO *dao.UserDAO
}

// NewUserService 创建用户服务实例
func NewUserService(userDAO *dao.UserDAO) *UserService {
	return &UserService{userDAO: userDAO}
}

// CreateUser 创建用户
func (s *UserService) CreateUser(user *model.User) error {
	// 检查用户名是否已存在
	_, err := s.userDAO.GetByUsername(user.Username)
	if err == nil {
		return errors.New("用户名已存在")
	}

	// 检查邮箱是否已存在
	_, err = s.userDAO.GetByEmail(user.Email)
	if err == nil {
		return errors.New("邮箱已存在")
	}

	// 创建用户
	return s.userDAO.Create(user)
}

// GetUserByID 根据ID获取用户
func (s *UserService) GetUserByID(id uint) (*model.User, error) {
	return s.userDAO.GetByID(id)
}

// GetUserByUsername 根据用户名获取用户
func (s *UserService) GetUserByUsername(username string) (*model.User, error) {
	return s.userDAO.GetByUsername(username)
}

// UpdateUser 更新用户
func (s *UserService) UpdateUser(user *model.User) error {
	return s.userDAO.Update(user)
}

// DeleteUser 删除用户
func (s *UserService) DeleteUser(id uint) error {
	return s.userDAO.Delete(id)
}

// ListUsers 获取用户列表
func (s *UserService) ListUsers(page, pageSize int) ([]*model.User, int64, error) {
	offset := (page - 1) * pageSize
	users, err := s.userDAO.List(offset, pageSize)
	if err != nil {
		return nil, 0, err
	}

	// 获取总数（这里简化处理，实际应该从DAO获取）
	total := int64(len(users))
	return users, total, nil
}