package at.gv.egiz.moazs.service;

import at.gv.egiz.moazs.preprocess.DeliveryRequestAugmenter;
import at.gv.egiz.moazs.repository.DeliveryRepository;
import at.gv.egiz.moazs.scheme.Msg2MzsConverter;
import at.gv.egiz.moazs.scheme.RequestStatusResponse;
import at.gv.zustellung.app2mzs.xsd.App2MzsPortType;
import at.gv.zustellung.app2mzs.xsd.DeliveryRequestType;
import at.gv.zustellung.app2mzs.xsd.DeliveryResponseType;
import at.gv.zustellung.msg.xsd.DeliveryRequestStatusType;
import org.apache.cxf.annotations.SchemaValidation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.jws.WebParam;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Consumer;

import static at.gv.egiz.moazs.MoaZSException.moaZSException;
import static at.gv.zustellung.app2mzs.xsd.PartialSuccessType.partialSuccessTypeBuilder;
import static java.lang.String.format;
import static java.util.concurrent.CompletableFuture.supplyAsync;

//todo : validate Schema in both directions.
@Service
@SchemaValidation(type = SchemaValidation.SchemaValidationType.IN)
public class MzsService implements App2MzsPortType {

    private static final Logger logger = LoggerFactory.getLogger(MzsService.class);

    //TODO move timeout and namespaces to config
    private static final int TIMEOUT_FOR_ANWSER = 10;
    private static final String MZS_SERVICE_ERROR_MSG = "An error occurred while processing DeliveryRequest " +
            "with AppDeliveryID=%s.";
    private static final String RESPONSE_MISSING_ERROR_MSG = "Could not get a response for AppDeliveryID=%s.";

    private final DeliveryRepository repository;
    private final Consumer<String> backend;
    private final DeliveryRequestAugmenter augmenter;
    private final Msg2MzsConverter converter;

    @Autowired
    public MzsService(DeliveryRepository repository, Consumer<String> deliveryRequestBackend,
                      DeliveryRequestAugmenter augmenter, Msg2MzsConverter converter) {
        this.repository = repository;
        this.backend = deliveryRequestBackend;
        this.augmenter = augmenter;
        this.converter = converter;
    }

    @Override
    public DeliveryResponseType app2Mzs(
            @WebParam(partName = "DeliveryRequest",
                      name = "DeliveryRequest")
                    DeliveryRequestType deliveryRequest) {

        var appDeliveryID = deliveryRequest.getMetaData().getAppDeliveryID();
        var responseID = RequestStatusResponse.getResponseID(appDeliveryID);

        var future = supplyAsync(() -> augmenter.augment(deliveryRequest))
                .thenApply(this::process)
                .thenApply(status -> converter.convert(status, repository.retrieveBinaryResponse(responseID)));

        try {
            return future.get(TIMEOUT_FOR_ANWSER, TimeUnit.SECONDS);
        } catch (TimeoutException e) {
            logger.info("Answer Timed Out", e);

            //TODO: revise how notification should be sent
            //future.thenAccept(appClient::sendNotification);
            return generatePartialSuccessResponse(appDeliveryID);

        } catch (Exception e) {
            var message = format(MZS_SERVICE_ERROR_MSG, appDeliveryID);
            throw moaZSException(message, e);
        }

    }

    private DeliveryRequestStatusType process(DeliveryRequestType deliveryRequest) {

        var appDeliveryID = deliveryRequest.getMetaData().getAppDeliveryID();
        //TODO: fix too.
        logger.info("Receive request with appDeliveryID = {}.", appDeliveryID);

        repository.store(deliveryRequest);
        backend.accept(appDeliveryID);

        var statusId = RequestStatusResponse.getResponseID(appDeliveryID);
        var response = repository.retrieveResponse(statusId)
                .orElseThrow(() -> moaZSException(format(RESPONSE_MISSING_ERROR_MSG, appDeliveryID)));
        return (DeliveryRequestStatusType) response.getResponse();
    }

    private DeliveryResponseType generatePartialSuccessResponse(String appDeliveryId) {

        var partial = partialSuccessTypeBuilder()
                .withAppDeliveryID(appDeliveryId)
                .build();

        return DeliveryResponseType.deliveryResponseTypeBuilder()
                .withPartialSuccess(partial)
                .build();
    }

}