package customer

import (
	"context"
	errors2 "enaklo-pos-be/internal/common/errors"
	"enaklo-pos-be/internal/common/logger"
	"enaklo-pos-be/internal/common/mycontext"
	"enaklo-pos-be/internal/constants"
	"enaklo-pos-be/internal/entity"
	"enaklo-pos-be/internal/utils"
	"github.com/pkg/errors"
	"go.uber.org/zap"
	"log"
	"strings"
	"time"
)

type Repository interface {
	Create(ctx mycontext.Context, customer *entity.Customer) (*entity.Customer, error)
	FindByID(ctx mycontext.Context, id int64) (*entity.Customer, error)
	FindByPhone(ctx mycontext.Context, phone string) (*entity.Customer, error)
	FindByEmail(ctx mycontext.Context, email string) (*entity.Customer, error)
	AddPoints(ctx mycontext.Context, id int64, points int, reference string) error
	GetPointsByCustomerID(
		ctx mycontext.Context,
		customerID int64,
	) (*entity.CustomerPoints, error)
	FindSequence(ctx mycontext.Context, partnerID int64) (int64, error)
	GetAllCustomers(ctx mycontext.Context, req entity.MemberSearch) (entity.MemberList, int, error)
	VerifyOTP(ctx mycontext.Context, verificationHash string, otpCode string) (int64, error)
}

type Service interface {
	ResolveCustomer(ctx mycontext.Context, req *entity.CustomerResolutionRequest) (int64, error)
	AddPoints(ctx mycontext.Context, customerID int64, points int, reference string) error
	GetCustomerPoints(ctx mycontext.Context, customerID int64) (*entity.CustomerPoints, error)
	GetCustomer(ctx mycontext.Context, id int64) (*entity.Customer, error)
	CustomerCheck(ctx mycontext.Context, req *entity.CustomerResolutionRequest) (*entity.CustomerCheckResponse, error)
	GetAllCustomers(ctx mycontext.Context, req *entity.MemberSearch) (*entity.MemberList, int, error)
	RegistrationMember(ctx mycontext.Context, req *entity.Customer) (*entity.Customer, error)
	VerifyOTP(ctx mycontext.Context, verificationID, otpCode string) error
}

type EmailService interface {
	SendEmailTransactional(ctx context.Context, param entity.SendEmailNotificationParam) error
}

type customerSvc struct {
	repo         Repository
	notification EmailService
}

func New(repo Repository, notification EmailService) Service {
	return &customerSvc{
		repo:         repo,
		notification: notification,
	}
}

func (s *customerSvc) ResolveCustomer(ctx mycontext.Context, req *entity.CustomerResolutionRequest) (int64, error) {
	if req.Email == "" && req.PhoneNumber == "" {
		return 0, nil
	}

	if req.ID != nil && *req.ID > 0 {
		customer, err := s.repo.FindByID(ctx, *req.ID)
		if err != nil {
			if !strings.Contains(err.Error(), "not found") {
				return 0, errors.Wrap(err, "failed to find customer by ID")
			}
		} else {
			return customer.ID, nil
		}
	}

	if req.PhoneNumber != "" {
		customer, err := s.repo.FindByPhone(ctx, req.PhoneNumber)
		if err != nil {
			if !strings.Contains(err.Error(), "not found") {
				return 0, errors.Wrap(err, "failed to find customer by phone")
			}
		} else {
			return customer.ID, nil
		}
	}

	if req.Email != "" {
		customer, err := s.repo.FindByEmail(ctx, req.Email)
		if err != nil {
			if !strings.Contains(err.Error(), "not found") {
				return 0, errors.Wrap(err, "failed to find customer by email")
			}
		} else {
			return customer.ID, nil
		}
	}

	if req.Name == "" {
		return 0, errors.New("customer name is required to create a new customer")
	}

	lastSeq, err := s.repo.FindSequence(ctx, 1)
	if err != nil {
		return 0, errors.New("failed to resolve customer sequence")
	}

	newCustomer := &entity.Customer{
		Name:       req.Name,
		Email:      req.Email,
		Phone:      req.PhoneNumber,
		Points:     0,
		CreatedAt:  constants.TimeNow(),
		UpdatedAt:  constants.TimeNow(),
		CustomerID: utils.GenerateMemberID(ctx, 1, lastSeq),
		BirthDate:  req.BirthDate,
		Password:   req.Password,
	}

	customer, err := s.repo.Create(ctx, newCustomer)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to create customer", zap.Error(err))
		return 0, errors.Wrap(err, "failed to create customer")
	}

	return customer.ID, nil
}

func (s *customerSvc) RegistrationMember(ctx mycontext.Context, req *entity.Customer) (*entity.Customer, error) {
	if req.Email == "" && req.PhoneNumber == "" {
		return nil, errors2.ErrorPhoneNumberEmailIsRequired
	}

	if req.PhoneNumber != "" {
		customer, err := s.repo.FindByPhone(ctx, req.PhoneNumber)
		if err != nil && !strings.Contains(err.Error(), "not found") {
			return nil, errors2.ErrorInternalServer
		}

		if customer != nil {
			return nil, errors2.ErrorPhoneNumberIsAlreadyRegistered
		}
	}

	if req.Email != "" {
		customer, err := s.repo.FindByEmail(ctx, req.Email)
		if err != nil && !strings.Contains(err.Error(), "not found") {
			return nil, errors2.ErrorInternalServer
		}

		if customer != nil {
			return nil, errors2.ErrorEmailIsAlreadyRegistered
		}
	}

	newCustomer := &entity.Customer{
		Name:      req.Name,
		Email:     req.Email,
		Phone:     req.PhoneNumber,
		CreatedAt: constants.TimeNow(),
		UpdatedAt: constants.TimeNow(),
		BirthDate: req.BirthDate,
		Password:  req.HashedPassword(),
	}

	customer, err := s.repo.Create(ctx, newCustomer)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to create customer", zap.Error(err))
		return nil, errors2.ErrorInternalServer
	}

	errs := s.sendRegistrationOTP(ctx, &entity.MemberRegistration{
		Name:  customer.Name,
		Email: customer.Email,
		OTP:   customer.OTP,
	})

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

	return customer, nil
}

func (s *customerSvc) AddPoints(ctx mycontext.Context, customerID int64, points int, reference string) error {
	if points <= 0 {
		return nil
	}

	err := s.repo.AddPoints(ctx, customerID, points, reference)
	if err != nil {
		return errors.Wrap(err, "failed to add points to customer")
	}

	return nil
}

func (s *customerSvc) GetCustomerPoints(ctx mycontext.Context, customerID int64) (*entity.CustomerPoints, error) {
	cp, err := s.repo.GetPointsByCustomerID(ctx, customerID)
	if err != nil {
		return nil, errors.Wrap(err, "failed to add points to customer")
	}

	return cp, nil
}

func (s *customerSvc) GetCustomer(ctx mycontext.Context, id int64) (*entity.Customer, error) {
	customer, err := s.repo.FindByID(ctx, id)
	if err != nil {
		return nil, errors.Wrap(err, "failed to get customer")
	}

	return customer, nil
}

func (s *customerSvc) CustomerCheck(ctx mycontext.Context, req *entity.CustomerResolutionRequest) (*entity.CustomerCheckResponse, error) {
	logger.ContextLogger(ctx).Info("checking customer existence before registration",
		zap.String("email", req.Email),
		zap.String("phone", req.PhoneNumber))

	if req.Email == "" && req.PhoneNumber == "" {
		return nil, errors.New("email dan phone number is mandatory")
	}

	response := &entity.CustomerCheckResponse{
		Exists:   false,
		Customer: nil,
	}

	if req.PhoneNumber != "" {
		customer, err := s.repo.FindByPhone(ctx, req.PhoneNumber)
		if err != nil {
			if !strings.Contains(err.Error(), "not found") {
				logger.ContextLogger(ctx).Error("error checking customer by phone", zap.Error(err))
				return nil, errors.Wrap(err, "failed to find customer by phone")
			}
		} else {
			logger.ContextLogger(ctx).Info("found existing customer by phone",
				zap.Int64("customerId", customer.ID))

			return &entity.CustomerCheckResponse{
				Exists:   true,
				Customer: customer,
				Message:  "Nomor telepon sudah terdaftar. Silakan gunakan nomor lain atau login.",
			}, nil
		}
	}

	if req.Email != "" {
		customer, err := s.repo.FindByEmail(ctx, req.Email)
		if err != nil {
			if !strings.Contains(err.Error(), "not found") {
				logger.ContextLogger(ctx).Error("error checking customer by email", zap.Error(err))
				return nil, errors.Wrap(err, "failed to find customer by email")
			}
		} else {
			logger.ContextLogger(ctx).Info("found existing customer by email",
				zap.Int64("customerId", customer.ID))

			return &entity.CustomerCheckResponse{
				Exists:   true,
				Customer: customer,
				Message:  "Email sudah terdaftar. Silakan gunakan email lain atau login.",
			}, nil
		}
	}

	return response, nil
}

func (s *customerSvc) GetAllCustomers(ctx mycontext.Context, req *entity.MemberSearch) (*entity.MemberList, int, error) {
	if req.Limit <= 0 {
		req.Limit = 10
	}
	if req.Offset < 0 {
		req.Offset = 0
	}

	customers, totalCount, err := s.repo.GetAllCustomers(ctx, *req)
	if err != nil {
		logger.ContextLogger(ctx).Error("failed to retrieve customers",
			zap.Error(err),
			zap.String("search", req.Search),
		)
		return nil, 0, errors.Wrap(err, "failed to get customers")
	}

	return &customers, totalCount, nil
}

func (s *customerSvc) 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
	}

	return nil
}

func (s *customerSvc) VerifyOTP(ctx mycontext.Context, verificationID, otpCode string) error {
	customerID, err := s.repo.VerifyOTP(ctx, verificationID, otpCode)
	if err != nil {
		return errors.Wrap(err, "verification failed")
	}

	customer, _ := s.repo.FindByID(ctx, customerID)

	go func(customer *entity.Customer) {
		newCtx := context.Background()

		defer func() {
			if r := recover(); r != nil {
				log.Printf("Recovered from panic in sendWelcomeEmail: %v", r)
			}
		}()

		s.sendWelcomeEmail(newCtx, customer)
	}(customer)

	return nil
}

func (s *customerSvc) sendWelcomeEmail(
	ctx context.Context,
	customer *entity.Customer,
) error {

	welcomeData := map[string]interface{}{
		"UserName":      customer.Name,
		"MemberID":      customer.CustomerID,
		"PointsName":    "EnakPoint",
		"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,
	})
}