package service

import (
	"errors"

	"affiliate_dash/internal/model"

	"golang.org/x/crypto/bcrypt"
	"gorm.io/gorm"
)

type UserService struct {
	db *gorm.DB
}

func NewUserService(db *gorm.DB) *UserService {
	return &UserService{db: db}
}

type UserListQuery struct {
	Page    int
	Size    int
	Keyword string
	Role    string
	Status  *int
}

func (s *UserService) List(q UserListQuery) ([]model.User, int64, error) {
	if q.Page < 1 {
		q.Page = 1
	}
	if q.Size < 1 || q.Size > 100 {
		q.Size = 20
	}
	tx := s.db.Model(&model.User{})
	if q.Keyword != "" {
		like := "%" + q.Keyword + "%"
		tx = tx.Where("username LIKE ? OR nickname LIKE ?", like, like)
	}
	if q.Role != "" {
		tx = tx.Where("role = ?", q.Role)
	}
	if q.Status != nil {
		tx = tx.Where("status = ?", *q.Status)
	}
	var total int64
	if err := tx.Count(&total).Error; err != nil {
		return nil, 0, err
	}
	var list []model.User
	err := tx.Order("id DESC").Offset((q.Page - 1) * q.Size).Limit(q.Size).Find(&list).Error
	return list, total, err
}

func (s *UserService) Create(username, password, nickname, role string, parentID *uint) (*model.User, error) {
	var count int64
	s.db.Model(&model.User{}).Where("username = ?", username).Count(&count)
	if count > 0 {
		return nil, errors.New("用户名已存在")
	}
	if role == "" {
		role = model.RoleDistributor
	}
	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return nil, err
	}
	user := &model.User{
		Username:     username,
		PasswordHash: string(hash),
		Nickname:     nickname,
		Role:         role,
		Status:       1,
		InviteCode:   generateInviteCode(),
		ParentID:     parentID,
	}
	if user.Nickname == "" {
		user.Nickname = username
	}
	if err := s.db.Create(user).Error; err != nil {
		return nil, err
	}
	return user, nil
}

func (s *UserService) UpdateStatus(id uint, status int) error {
	res := s.db.Model(&model.User{}).Where("id = ?", id).Update("status", status)
	if res.Error != nil {
		return res.Error
	}
	if res.RowsAffected == 0 {
		return errors.New("用户不存在")
	}
	return nil
}