package at.gv.egiz.moazs.preprocess;

import at.gv.egiz.moazs.scheme.Marshaller;
import at.gv.zustellung.app2mzs.xsd.ConfigType;
import at.gv.zustellung.app2mzs.xsd.DeliveryRequestType;
import at.gv.zustellung.app2mzs.xsd.ObjectFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Component;

import java.util.Map;

import static at.gv.egiz.moazs.MoaZSException.moaZSException;
import static at.gv.egiz.moazs.util.NullCoalesce.coalesce;
import static at.gv.zustellung.app2mzs.xsd.DeliveryRequestType.deliveryRequestTypeBuilder;

@Component
public class DeliveryRequestAugmenter {

    private static final Logger log = LoggerFactory.getLogger(DeliveryRequestAugmenter.class);
    private static final ObjectFactory FACTORY = new ObjectFactory();

    private final ConfigUtil util;
    private final Map<String, ConfigType> configs;
    private final Marshaller mzsMarshaller;

    private static final String CONFIG_MISSING_ERROR_MSG = "Delivery request configuration is missing.";

    @Autowired
    public DeliveryRequestAugmenter(Map<String, ConfigType> deliveryRequestConfigs, ConfigUtil util,
                                    Marshaller mzsMarshaller) {
        this.configs = deliveryRequestConfigs;
        this.util = util;
        this.mzsMarshaller = mzsMarshaller;
    }

    /**
     * Augments an incoming {@code request} by filling gaps with config- or default parameters.
     *
     * @param request
     * @throws at.gv.egiz.moazs.MoaZSException
     * @return augmented request and validated
     */
    public DeliveryRequestType augment(DeliveryRequestType request) {

        var requestConfig = request.getConfig();
        var fallbackProfileId = determineProfileIdFrom(requestConfig);
        var fallbackConfig = configs.get(fallbackProfileId);

        trace("Request config", requestConfig);
        trace("Fallback config", fallbackConfig);

        var augmentedConfig = (requestConfig != null && fallbackConfig != null)
                ? util.merge(requestConfig, fallbackConfig)
                : coalesce(requestConfig, fallbackConfig)
                    .orElseThrow(()-> moaZSException(CONFIG_MISSING_ERROR_MSG));

        trace("Augmented config", augmentedConfig);

        var augmentedRequest = deliveryRequestTypeBuilder(request)
                .withConfig(augmentedConfig)
                .build();

        return augmentedRequest;

    }

    private String determineProfileIdFrom(@Nullable ConfigType requestConfig) {
        return (requestConfig == null
                || requestConfig.getProfileID() == null
                || isProfileMissing(requestConfig.getProfileID()))
                ? "default"
                : requestConfig.getProfileID();
    }

    private boolean isProfileMissing(String id) {
        return !configs.containsKey(id);
    }

    private void trace(String description, ConfigType config) {
        if (log.isTraceEnabled()) {
            log.trace("{} : {}", description, mzsMarshaller.marshallXml(FACTORY.createConfig(config)));
        }
    }


}