package validator

import (
	"errors"
	"regexp"
	"strings"

	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/contract"
)

type CustomerAuthValidator interface {
	ValidateCheckPhoneRequest(req *contract.CheckPhoneRequest) (error, string)
	ValidateRegisterStartRequest(req *contract.RegisterStartRequest) (error, string)
	ValidateRegisterVerifyOtpRequest(req *contract.RegisterVerifyOtpRequest) (error, string)
	ValidateRegisterSetPasswordRequest(req *contract.RegisterSetPasswordRequest) (error, string)
	ValidateCustomerLoginRequest(req *contract.CustomerLoginRequest) (error, string)
	ValidateResendOtpRequest(req *contract.ResendOtpRequest) (error, string)
}

type CustomerAuthValidatorImpl struct{}

func NewCustomerAuthValidator() CustomerAuthValidator {
	return &CustomerAuthValidatorImpl{}
}

func (v *CustomerAuthValidatorImpl) ValidateCheckPhoneRequest(req *contract.CheckPhoneRequest) (error, string) {
	if req == nil {
		return errors.New("request is required"), constants.ValidationErrorCode
	}

	// Validate phone number
	if strings.TrimSpace(req.PhoneNumber) == "" {
		return errors.New("phone number is required"), constants.ValidationErrorCode
	}

	if !v.isValidPhoneNumber(req.PhoneNumber) {
		return errors.New("invalid phone number format"), constants.ValidationErrorCode
	}

	return nil, ""
}

func (v *CustomerAuthValidatorImpl) ValidateRegisterStartRequest(req *contract.RegisterStartRequest) (error, string) {
	if req == nil {
		return errors.New("request is required"), constants.ValidationErrorCode
	}

	// Validate phone number
	if strings.TrimSpace(req.PhoneNumber) == "" {
		return errors.New("phone number is required"), constants.ValidationErrorCode
	}

	if !v.isValidPhoneNumber(req.PhoneNumber) {
		return errors.New("invalid phone number format"), constants.ValidationErrorCode
	}

	// Validate name
	if strings.TrimSpace(req.Name) == "" {
		return errors.New("name is required"), constants.ValidationErrorCode
	}

	if len(req.Name) < 2 {
		return errors.New("name must be at least 2 characters long"), constants.ValidationErrorCode
	}

	if len(req.Name) > 100 {
		return errors.New("name cannot exceed 100 characters"), constants.ValidationErrorCode
	}

	// Validate birth date
	if strings.TrimSpace(req.BirthDate) == "" {
		return errors.New("birth date is required"), constants.ValidationErrorCode
	}

	if !v.isValidDateFormat(req.BirthDate) {
		return errors.New("invalid birth date format (YYYY-MM-DD)"), constants.ValidationErrorCode
	}

	return nil, ""
}

func (v *CustomerAuthValidatorImpl) ValidateRegisterVerifyOtpRequest(req *contract.RegisterVerifyOtpRequest) (error, string) {
	if req == nil {
		return errors.New("request is required"), constants.ValidationErrorCode
	}

	// Validate registration token
	if strings.TrimSpace(req.RegistrationToken) == "" {
		return errors.New("registration token is required"), constants.ValidationErrorCode
	}

	// Validate OTP code
	if strings.TrimSpace(req.OtpCode) == "" {
		return errors.New("OTP code is required"), constants.ValidationErrorCode
	}

	if !v.isValidOtpCode(req.OtpCode) {
		return errors.New("invalid OTP code format"), constants.ValidationErrorCode
	}

	return nil, ""
}

func (v *CustomerAuthValidatorImpl) ValidateRegisterSetPasswordRequest(req *contract.RegisterSetPasswordRequest) (error, string) {
	if req == nil {
		return errors.New("request is required"), constants.ValidationErrorCode
	}

	// Validate registration token
	if strings.TrimSpace(req.RegistrationToken) == "" {
		return errors.New("registration token is required"), constants.ValidationErrorCode
	}

	// Validate password
	if strings.TrimSpace(req.Password) == "" {
		return errors.New("password is required"), constants.ValidationErrorCode
	}

	if len(req.Password) < 8 {
		return errors.New("password must be at least 8 characters long"), constants.ValidationErrorCode
	}

	if len(req.Password) > 128 {
		return errors.New("password cannot exceed 128 characters"), constants.ValidationErrorCode
	}

	// Validate confirm password
	if strings.TrimSpace(req.ConfirmPassword) == "" {
		return errors.New("confirm password is required"), constants.ValidationErrorCode
	}

	if req.Password != req.ConfirmPassword {
		return errors.New("passwords do not match"), constants.ValidationErrorCode
	}

	// Validate password strength
	if !v.isStrongPassword(req.Password) {
		return errors.New("password must contain at least one uppercase letter, one lowercase letter, and one number"), constants.ValidationErrorCode
	}

	return nil, ""
}

func (v *CustomerAuthValidatorImpl) ValidateCustomerLoginRequest(req *contract.CustomerLoginRequest) (error, string) {
	if req == nil {
		return errors.New("request is required"), constants.ValidationErrorCode
	}

	// Validate phone number
	if strings.TrimSpace(req.PhoneNumber) == "" {
		return errors.New("phone number is required"), constants.ValidationErrorCode
	}

	if !v.isValidPhoneNumber(req.PhoneNumber) {
		return errors.New("invalid phone number format"), constants.ValidationErrorCode
	}

	// Validate password
	if strings.TrimSpace(req.Password) == "" {
		return errors.New("password is required"), constants.ValidationErrorCode
	}

	return nil, ""
}

// Helper validation functions
func (v *CustomerAuthValidatorImpl) isValidPhoneNumber(phoneNumber string) bool {
	// Basic phone number validation - adjust regex based on your requirements
	phoneRegex := regexp.MustCompile(`^\+?[1-9]\d{1,14}$`)
	return phoneRegex.MatchString(phoneNumber)
}

func (v *CustomerAuthValidatorImpl) isValidDateFormat(date string) bool {
	// Basic date format validation for YYYY-MM-DD
	dateRegex := regexp.MustCompile(`^\d{4}-\d{2}-\d{2}$`)
	if !dateRegex.MatchString(date) {
		return false
	}

	// You can add more sophisticated date validation here if needed
	return true
}

func (v *CustomerAuthValidatorImpl) isValidOtpCode(code string) bool {
	// OTP code should be 4-8 digits
	otpRegex := regexp.MustCompile(`^\d{4,8}$`)
	return otpRegex.MatchString(code)
}

func (v *CustomerAuthValidatorImpl) ValidateResendOtpRequest(req *contract.ResendOtpRequest) (error, string) {
	if req == nil {
		return errors.New("request is required"), constants.CustomerEntity
	}

	// Validate phone number
	if req.PhoneNumber == "" {
		return errors.New("phone number is required"), constants.CustomerEntity
	}

	// Validate phone number format
	if !v.isValidPhoneNumber(req.PhoneNumber) {
		return errors.New("invalid phone number format"), constants.CustomerEntity
	}

	// Validate purpose
	if req.Purpose == "" {
		return errors.New("purpose is required"), constants.CustomerEntity
	}

	// Validate purpose values
	validPurposes := []string{"login", "registration"}
	if !v.contains(validPurposes, req.Purpose) {
		return errors.New("purpose must be either 'login' or 'registration'"), constants.CustomerEntity
	}

	return nil, ""
}

func (v *CustomerAuthValidatorImpl) isStrongPassword(password string) bool {
	// Password must contain at least one uppercase, one lowercase, and one number
	hasUpper := regexp.MustCompile(`[A-Z]`).MatchString(password)
	hasLower := regexp.MustCompile(`[a-z]`).MatchString(password)
	hasNumber := regexp.MustCompile(`[0-9]`).MatchString(password)

	return hasUpper && hasLower && hasNumber
}

func (v *CustomerAuthValidatorImpl) contains(slice []string, item string) bool {
	for _, s := range slice {
		if s == item {
			return true
		}
	}
	return false
}