package member

import (
	"enaklo-pos-be/internal/common/logger"
	"enaklo-pos-be/internal/common/mycontext"
	"enaklo-pos-be/internal/constants"
	"enaklo-pos-be/internal/entity"
	"errors"
	"go.uber.org/zap"
	"golang.org/x/exp/rand"
	"time"
)

func (s *memberSvc) InitiateRegistration(
	ctx mycontext.Context,
	request *entity.MemberRegistrationRequest,
) (*entity.MemberRegistrationResponse, error) {
	customerResolution := &entity.CustomerResolutionRequest{
		Email:       request.Email,
		PhoneNumber: request.Phone,
	}

	checkResult, err := s.customerSvc.CustomerCheck(ctx, customerResolution)
	if checkResult.Exists {
		return nil, errors.New(checkResult.Message)
	}

	otp := generateOTP(6)

	token := constants.GenerateUUID()

	registration := &entity.MemberRegistration{
		ID:        constants.GenerateUUID(),
		Token:     token,
		Name:      request.Name,
		Email:     request.Email,
		Phone:     request.Phone,
		BirthDate: request.BirthDate,
		OTP:       otp,
		Status:    constants.RegistrationPending,
		ExpiresAt: constants.TimeNow().Add(10 * time.Minute),
		CreatedAt: constants.TimeNow(),
		UpdatedAt: constants.TimeNow(),
		BranchID:  request.BranchID,
		CashierID: request.CashierID,
		Password:  request.GetHashPassword(),
	}

	savedRegistration, err := s.repo.CreateRegistration(ctx, registration)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to create member registration", zap.Error(err))
		return nil, err
	}

	err = s.sendRegistrationOTP(ctx, savedRegistration)
	if err != nil {
		logger.ContextLogger(ctx).Warn("failed to send OTP", zap.Error(err))
	}

	return &entity.MemberRegistrationResponse{
		Token:     token,
		Status:    savedRegistration.Status.String(),
		ExpiresAt: savedRegistration.ExpiresAt,
		Message:   "Registration initiated. Please verify with OTP sent to your email.",
	}, nil
}

func (s *memberSvc) VerifyOTP(
	ctx mycontext.Context,
	token string,
	otp string,
) (*entity.MemberVerificationResponse, error) {
	logger.ContextLogger(ctx).Info("verifying OTP for member registration", zap.String("token", token))

	registration, err := s.repo.GetRegistrationByToken(ctx, token)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to get registration", zap.Error(err))
		return nil, errors.New("invalid registration token")
	}

	if registration.Status == constants.RegistrationSuccess {
		return nil, errors.New("registration already completed")
	}

	if registration.ExpiresAt.Before(constants.TimeNow()) {
		return nil, errors.New("registration expired")
	}

	if registration.OTP != otp {
		return nil, errors.New("invalid OTP")
	}

	customerResolution := &entity.CustomerResolutionRequest{
		Name:        registration.Name,
		Email:       registration.Email,
		PhoneNumber: registration.Phone,
		BirthDate:   registration.BirthDate,
		Password:    registration.Password,
	}

	customerID, err := s.customerSvc.ResolveCustomer(ctx, customerResolution)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to create customer", zap.Error(err))
		return nil, errors.New("failed to create member record")
	}

	err = s.repo.UpdateRegistrationStatus(ctx, token, constants.RegistrationSuccess)
	if err != nil {
		logger.ContextLogger(ctx).Warn("failed to update registration status", zap.Error(err))
	}

	customer, err := s.customerSvc.GetCustomer(ctx, customerID)
	if err != nil {
		logger.ContextLogger(ctx).Warn("failed to get created customer", zap.Error(err))

		return &entity.MemberVerificationResponse{
			CustomerID: customerID,
			Name:       registration.Name,
			Email:      registration.Email,
			Phone:      registration.Phone,
			Status:     "Registration completed successfully",
		}, nil
	}

	err = s.sendWelcomeEmail(ctx, customer)
	if err != nil {
		logger.ContextLogger(ctx).Warn("failed to send welcome email", zap.Error(err))
	}

	signedToken, err := s.crypt.GenerateJWTCustomer(customer)

	if err != nil {
		return nil, err
	}

	return &entity.MemberVerificationResponse{
		Auth:       customer.ToUserAuthenticate(signedToken),
		CustomerID: customer.ID,
		Name:       customer.Name,
		Email:      customer.Email,
		Phone:      customer.Phone,
		Points:     customer.Points,
		Status:     "Registration completed successfully",
	}, nil
}

func (s *memberSvc) GetRegistrationStatus(
	ctx mycontext.Context,
	token string,
) (*entity.MemberRegistrationStatus, error) {
	logger.ContextLogger(ctx).Info("checking registration status", zap.String("token", token))

	registration, err := s.repo.GetRegistrationByToken(ctx, token)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to get registration", zap.Error(err))
		return nil, errors.New("invalid registration token")
	}

	return &entity.MemberRegistrationStatus{
		Token:     registration.Token,
		Status:    registration.Status.String(),
		ExpiresAt: registration.ExpiresAt,
		IsExpired: registration.ExpiresAt.Before(constants.TimeNow()),
		CreatedAt: registration.CreatedAt,
	}, nil
}

func (s *memberSvc) ResendOTP(
	ctx mycontext.Context,
	token string,
) (*entity.ResendOTPResponse, error) {
	logger.ContextLogger(ctx).Info("resending OTP", zap.String("token", token))

	registration, err := s.repo.GetRegistrationByToken(ctx, token)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to get registration", zap.Error(err))
		return nil, errors.New("invalid registration token")
	}

	if registration.Status == constants.RegistrationSuccess {
		return nil, errors.New("registration already completed")
	}

	newOTP := generateOTP(6)
	newExpiresAt := constants.TimeNow().Add(10 * time.Minute)

	err = s.repo.UpdateRegistrationOTP(ctx, token, newOTP, newExpiresAt)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to update OTP", zap.Error(err))
		return nil, errors.New("failed to generate new OTP")
	}

	registration.OTP = newOTP
	registration.ExpiresAt = newExpiresAt

	err = s.sendRegistrationOTP(ctx, registration)
	if err != nil {
		logger.ContextLogger(ctx).Warn("failed to send OTP", zap.Error(err))
	}

	return &entity.ResendOTPResponse{
		Token:     token,
		ExpiresAt: newExpiresAt,
		Message:   "OTP has been resent to your email and phone",
	}, nil
}

func (s *memberSvc) sendRegistrationOTP(
	ctx mycontext.Context,
	registration *entity.MemberRegistration,
) error {
	emailData := map[string]interface{}{
		"UserName": registration.Name,
		"OTPCode":  registration.OTP,
	}

	err := s.notification.SendEmailTransactional(ctx, entity.SendEmailNotificationParam{
		Sender:       "noreply@enaklo.co.id",
		Recipient:    registration.Email,
		Subject:      "Enaklo - Registration Verification Code",
		TemplateName: "member_registration_otp",
		TemplatePath: "templates/member_registration_otp.html",
		Data:         emailData,
	})

	if err != nil {
		return err
	}

	//if registration.Phone != "" {
	//	smsMessage := fmt.Sprintf("Your Enaklo registration code is: %s. Please provide this code to our staff to complete your registration.", registration.OTP)
	//	_ = s.notification.SendSMS(ctx, registration.Phone, smsMessage)
	//}

	return nil
}

func (s *memberSvc) sendWelcomeEmail(
	ctx mycontext.Context,
	customer *entity.Customer,
) error {

	welcomeData := map[string]interface{}{
		"UserName":      customer.Name,
		"MemberID":      customer.CustomerID,
		"PointsName":    "ELP",
		"PointsBalance": customer.Points,
		"RedeemLink":    "https://enaklo.co.id/redeem",
		"CurrentDate":   time.Now().Format("01-2006"),
	}

	return s.notification.SendEmailTransactional(ctx, entity.SendEmailNotificationParam{
		Sender:       "noreply@enaklo.co.id",
		Recipient:    customer.Email,
		Subject:      "Welcome to Enaklo Membership Program",
		TemplateName: "welcome_member",
		TemplatePath: "/templates/welcome_member.html",
		Data:         welcomeData,
	})
}

func generateOTP(length int) string {
	rand.Seed(uint64(time.Now().Nanosecond()))
	digits := "0123456789"
	otp := ""
	for i := 0; i < length; i++ {
		otp += string(digits[rand.Intn(len(digits))])
	}
	return otp
}