package webui

import (
	"context"
	"errors"

	"cmroubao/backend-api/internal/usecase"
)

type AuthUsecaseAdapter struct {
	service *usecase.AuthService
}

func NewAuthUsecaseAdapter(
	service *usecase.AuthService,
) (*AuthUsecaseAdapter, error) {
	if service == nil {
		return nil, errors.New("admin auth use case is required")
	}
	return &AuthUsecaseAdapter{service: service}, nil
}

func (adapter *AuthUsecaseAdapter) LoginAdmin(
	ctx context.Context,
	input AdminLoginInput,
) (AdminLoginResult, error) {
	result, err := adapter.service.LoginAdmin(
		ctx,
		usecase.LoginAdminCommand{
			Username: input.Username,
			Password: input.Password,
		},
	)
	if err != nil {
		return AdminLoginResult{}, mapAuthUsecaseError(err)
	}
	return AdminLoginResult{
		Token:     result.Token,
		ExpiresAt: result.ExpiresAt,
	}, nil
}

func (adapter *AuthUsecaseAdapter) LogoutAdmin(
	ctx context.Context,
	token string,
) error {
	if err := adapter.service.LogoutAdmin(ctx, token); err != nil {
		return mapAuthUsecaseError(err)
	}
	return nil
}

func mapAuthUsecaseError(err error) error {
	var typed *usecase.Error
	if !errors.As(err, &typed) {
		return err
	}
	var public error
	switch typed.Kind {
	case usecase.ErrorKindUnauthorized,
		usecase.ErrorKindForbidden,
		usecase.ErrorKindInvalid:
		public = ErrInvalidCredentials
	case usecase.ErrorKindUnavailable:
		public = ErrUnavailable
	default:
		return err
	}
	return &adapterError{
		public: public,
		cause:  err,
	}
}

var _ AdminSessionService = (*AuthUsecaseAdapter)(nil)