/**
 * package service
 * 作用：用户管理服务
 */
package service

import (
	"errors"
	"xk-websocket-v2/internal/model"
	"xk-websocket-v2/internal/utils"

	"gorm.io/gorm"
)

// UserService 用户服务结构体
type UserService struct {
	DB *gorm.DB
}

// UserSvc 全局单例
var UserSvc *UserService

/**
 * InitUserService
 * 功能：初始化用户服务
 */
func InitUserService(db *gorm.DB) {
	UserSvc = &UserService{DB: db}
}

/**
 * GetUserByID
 * 功能：根据ID获取用户
 */
func (s *UserService) GetUserByID(userID string) (*model.User, error) {
	var user model.User
	result := s.DB.Where("id = ?", userID).First(&user)
	if result.Error != nil {
		return nil, result.Error
	}
	user.Password = "" // 清除密码
	return &user, nil
}

/**
 * GetUserByEmail
 * 功能：根据邮箱获取用户
 */
func (s *UserService) GetUserByEmail(email string) (*model.User, error) {
	var user model.User
	result := s.DB.Where("email = ?", email).First(&user)
	if result.Error != nil {
		return nil, result.Error
	}
	user.Password = "" // 清除密码
	return &user, nil
}

/**
 * GetUserByPhone
 * 功能：根据手机号获取用户
 */
func (s *UserService) GetUserByPhone(phone string) (*model.User, error) {
	var user model.User
	result := s.DB.Where("phone = ?", phone).First(&user)
	if result.Error != nil {
		return nil, result.Error
	}
	user.Password = "" // 清除密码
	return &user, nil
}

/**
 * CreateUser
 * 功能：创建用户
 */
func (s *UserService) CreateUser(user *model.User) error {
	// 如果提供了密码，加密密码
	if user.Password != "" {
		hashedPassword, err := utils.HashPassword(user.Password)
		if err != nil {
			return err
		}
		user.Password = hashedPassword
	}
	return s.DB.Create(user).Error
}

/**
 * UpdateUser
 * 功能：更新用户信息
 */
func (s *UserService) UpdateUser(userID string, updates map[string]interface{}) error {
	// 如果更新密码，需要加密
	if password, ok := updates["password"].(string); ok && password != "" {
		hashedPassword, err := utils.HashPassword(password)
		if err != nil {
			return err
		}
		updates["password"] = hashedPassword
	}
	return s.DB.Model(&model.User{}).Where("id = ?", userID).Updates(updates).Error
}

/**
 * DeleteUser
 * 功能：删除用户
 */
func (s *UserService) DeleteUser(userID string) error {
	return s.DB.Where("id = ?", userID).Delete(&model.User{}).Error
}

/**
 * GetUserList
 * 功能：获取用户列表（分页）
 */
func (s *UserService) GetUserList(page, pageSize int) ([]model.User, int64, error) {
	var users []model.User
	var total int64

	// 获取总数
	s.DB.Model(&model.User{}).Count(&total)

	// 分页查询
	offset := (page - 1) * pageSize
	result := s.DB.Offset(offset).Limit(pageSize).Find(&users)
	if result.Error != nil {
		return nil, 0, result.Error
	}

	// 清除所有用户的密码
	for i := range users {
		users[i].Password = ""
	}

	return users, total, nil
}

/**
 * SearchUsers
 * 功能：搜索用户（按用户名、ID、邮箱、手机号）
 */
func (s *UserService) SearchUsers(keyword string, limit int) ([]model.User, error) {
	var users []model.User
	
	query := s.DB.Where("name LIKE ? OR id LIKE ? OR email LIKE ? OR phone LIKE ?",
		"%"+keyword+"%", "%"+keyword+"%", "%"+keyword+"%", "%"+keyword+"%")
	
	if limit > 0 {
		query = query.Limit(limit)
	}
	
	result := query.Find(&users)
	if result.Error != nil && !errors.Is(result.Error, gorm.ErrRecordNotFound) {
		return nil, result.Error
	}

	// 清除所有用户的密码
	for i := range users {
		users[i].Password = ""
	}

	return users, nil
}