package useCases

import (
	"RenewCMS/internal/domain/hash"
	"RenewCMS/internal/domain/mail"
	"RenewCMS/internal/domain/user"
	"log"
	"time"

	"github.com/google/uuid"
)

const (
	verifyNewEmailTemplateName    = "verify-new-email"
	emailChangeNoticeTemplateName = "email-change-notice"
)

type MailVerifyNewEmailData struct {
	Host             string
	Username         string
	VerificationCode string
}

type MailEmailChangeNoticeData struct {
	Host     string
	Username string
	NewEmail string
}

type emailChangeIssuer struct {
	userRepository user.Repository
	hasher         hash.Hasher
	mailRepository mail.Repository
	dispatcher     mail.Dispatcher
	publicURL      string
	now            func() time.Time
}

func (i emailChangeIssuer) issue(account user.User, pendingEmail string) (user.User, error) {
	rawCode := uuid.NewString()
	hashedCode, err := i.hasher.Hash(rawCode)
	if err != nil {
		return user.User{}, err
	}
	updated, err := i.userRepository.SetPendingEmailChange(account.ID, pendingEmail, hashedCode, i.now().Add(user.EmailChangeLifetime))
	if err != nil {
		return user.User{}, err
	}
	i.dispatcher.Dispatch(func() { i.sendVerification(account, pendingEmail, rawCode) })
	return updated, nil
}

func (i emailChangeIssuer) sendVerification(account user.User, pendingEmail string, rawCode string) {
	taken, err := i.userRepository.IsEmailInUse(pendingEmail, account.ID)
	if err != nil {
		log.Println("error when checking whether the new email address is in use:", err)
		return
	}
	if taken {
		return
	}
	if err := i.mailRepository.Send(pendingEmail, verifyNewEmailTemplateName, MailVerifyNewEmailData{
		Host:             i.publicURL,
		Username:         account.Username,
		VerificationCode: rawCode,
	}); err != nil {
		log.Println("error when Send-ing the new email verification mail:", err)
	}
}

func (i emailChangeIssuer) sendNotice(account user.User, pendingEmail string) {
	i.dispatcher.Dispatch(func() {
		if err := i.mailRepository.Send(account.Email, emailChangeNoticeTemplateName, MailEmailChangeNoticeData{
			Host:     i.publicURL,
			Username: account.Username,
			NewEmail: pendingEmail,
		}); err != nil {
			log.Println("error when Send-ing the email change notice mail:", err)
		}
	})
}