package service

import (
	"errors"

	"github.com/mhsanaei/3x-ui/v2/database"
	"github.com/mhsanaei/3x-ui/v2/database/model"
	"github.com/mhsanaei/3x-ui/v2/logger"
	"github.com/mhsanaei/3x-ui/v2/util/crypto"
    ldaputil "github.com/mhsanaei/3x-ui/v2/util/ldap"
	"github.com/xlzd/gotp"
	"gorm.io/gorm"
)

// UserService provides business logic for user management and authentication.
// It handles user creation, login, password management, and 2FA operations.
type UserService struct {
	settingService SettingService
}

// GetFirstUser retrieves the first user from the database.
// This is typically used for initial setup or when there's only one admin user.
func (s *UserService) GetFirstUser() (*model.User, error) {
	db := database.GetDB()

	user := &model.User{}
	err := db.Model(model.User{}).
		First(user).
		Error
	if err != nil {
		return nil, err
	}
	return user, nil
}

func (s *UserService) CheckUser(username string, password string, twoFactorCode string) *model.User {
	db := database.GetDB()

	user := &model.User{}

	err := db.Model(model.User{}).
		Where("username = ?", username).
		First(user).
		Error
	if err == gorm.ErrRecordNotFound {
		return nil
	} else if err != nil {
		logger.Warning("check user err:", err)
		return nil
	}

    // If LDAP enabled and local password check fails, attempt LDAP auth
    if !crypto.CheckPasswordHash(user.Password, password) {
        ldapEnabled, _ := s.settingService.GetLdapEnable()
        if !ldapEnabled {
            return nil
        }

        host, _ := s.settingService.GetLdapHost()
        port, _ := s.settingService.GetLdapPort()
        useTLS, _ := s.settingService.GetLdapUseTLS()
        bindDN, _ := s.settingService.GetLdapBindDN()
        ldapPass, _ := s.settingService.GetLdapPassword()
        baseDN, _ := s.settingService.GetLdapBaseDN()
        userFilter, _ := s.settingService.GetLdapUserFilter()
        userAttr, _ := s.settingService.GetLdapUserAttr()

        cfg := ldaputil.Config{
            Host: host,
            Port: port,
            UseTLS: useTLS,
            BindDN: bindDN,
            Password: ldapPass,
            BaseDN: baseDN,
            UserFilter: userFilter,
            UserAttr: userAttr,
        }
        ok, err := ldaputil.AuthenticateUser(cfg, username, password)
        if err != nil || !ok {
            return nil
        }
        // On successful LDAP auth, continue 2FA checks below
    }

	twoFactorEnable, err := s.settingService.GetTwoFactorEnable()
	if err != nil {
		logger.Warning("check two factor err:", err)
		return nil
	}

	if twoFactorEnable {
		twoFactorToken, err := s.settingService.GetTwoFactorToken()

		if err != nil {
			logger.Warning("check two factor token err:", err)
			return nil
		}

		if gotp.NewDefaultTOTP(twoFactorToken).Now() != twoFactorCode {
			return nil
		}
	}

	return user
}

func (s *UserService) UpdateUser(id int, username string, password string) error {
	db := database.GetDB()
	hashedPassword, err := crypto.HashPasswordAsBcrypt(password)

	if err != nil {
		return err
	}

	twoFactorEnable, err := s.settingService.GetTwoFactorEnable()
	if err != nil {
		return err
	}

	if twoFactorEnable {
		s.settingService.SetTwoFactorEnable(false)
		s.settingService.SetTwoFactorToken("")
	}

	return db.Model(model.User{}).
		Where("id = ?", id).
		Updates(map[string]any{"username": username, "password": hashedPassword}).
		Error
}

func (s *UserService) UpdateFirstUser(username string, password string) error {
	if username == "" {
		return errors.New("username can not be empty")
	} else if password == "" {
		return errors.New("password can not be empty")
	}
	hashedPassword, er := crypto.HashPasswordAsBcrypt(password)

	if er != nil {
		return er
	}

	db := database.GetDB()
	user := &model.User{}
	err := db.Model(model.User{}).First(user).Error
	if database.IsNotFound(err) {
		user.Username = username
		user.Password = hashedPassword
		return db.Model(model.User{}).Create(user).Error
	} else if err != nil {
		return err
	}
	user.Username = username
	user.Password = hashedPassword
	return db.Save(user).Error
}