/*
 * Copyright 2018 A-SIT Plus GmbH
 * AT-specific eIDAS Connector has been developed in a cooperation between EGIZ,
 * A-SIT Plus GmbH, A-SIT, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "License");
 * You may not use this work except in compliance with the License.
 * You may obtain a copy of the License at:
 * https://joinup.ec.europa.eu/news/understanding-eupl-v12
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
*/

package at.asitplus.eidas.specific.modules.auth.eidas.v2.service;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import javax.annotation.PostConstruct;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Service;

import at.asitplus.eidas.specific.modules.auth.eidas.v2.Constants;
import at.asitplus.eidas.specific.modules.auth.eidas.v2.dao.ErnbEidData;
import at.asitplus.eidas.specific.modules.auth.eidas.v2.exception.EidasAttributeException;
import at.asitplus.eidas.specific.modules.auth.eidas.v2.exception.EidPostProcessingException;
import at.asitplus.eidas.specific.modules.auth.eidas.v2.handler.INationalEidProcessor;
import at.asitplus.eidas.specific.modules.auth.eidas.v2.utils.EidasResponseUtils;
import at.gv.egiz.eaaf.core.api.IRequest;
import at.gv.egiz.eaaf.core.impl.data.Trible;
import eu.eidas.auth.commons.light.impl.LightRequest.Builder;

@Service
public class CcSpecificEidProcessingService implements ICcSpecificEidProcessingService {
  private static final Logger log = LoggerFactory.getLogger(CcSpecificEidProcessingService.class);

  @Autowired
  private ApplicationContext context;

  private final List<INationalEidProcessor> handlers = new ArrayList<>();

  @PostConstruct
  private void initialize() {
    log.debug("Initialize eID PostProcessing-Service ... ");
    final Map<String, INationalEidProcessor> postProcessors = context.getBeansOfType(
        INationalEidProcessor.class);
    final Iterator<Entry<String, INationalEidProcessor>> iterator = postProcessors.entrySet().iterator();
    while (iterator.hasNext()) {
      final Entry<String, INationalEidProcessor> el = iterator.next();
      log.debug("Find eID-PostProcessor with name: " + el.getKey());
      handlers.add(el.getValue());

    }

    log.trace("Sorting eID-PostProcessors on priority ... ");
    Collections.sort(handlers, (thisAuthModule, otherAuthModule) -> {
      final int thisOrder = thisAuthModule.getPriority();
      final int otherOrder = otherAuthModule.getPriority();
      return thisOrder < otherOrder ? 1 : thisOrder == otherOrder ? 0 : -1;
    });

    log.info("# " + handlers.size() + " eID PostProcessing services are registrated");

  }

  @Override
  public void preProcess(String selectedCitizenCountry, IRequest pendingReq, Builder authnRequestBuilder)
      throws EidPostProcessingException {
    if (StringUtils.isEmpty(selectedCitizenCountry)) {
      log.info("No CountryCode for eID Pre-Processor. Default Pre-Processor will be used");
    }

    for (final INationalEidProcessor el : handlers) {
      if (el.canHandle(selectedCitizenCountry)) {
        log.debug("Pre-Process eIDAS request for " + selectedCitizenCountry + " by using:  " + el.getName());
        el.preProcess(pendingReq, authnRequestBuilder);
        return;

      }
    }

    log.error("NO eID PostProcessor FOUND. Looks like a depentency problem!");
    throw new EidPostProcessingException("internal.00", null);

  }

  @Override
  public ErnbEidData postProcess(Map<String, Object> eidasAttrMap) throws EidPostProcessingException,
      EidasAttributeException {
    // extract citizen country from eIDAS unique identifier
    final Object eIdentifierObj = eidasAttrMap.get(Constants.eIDAS_ATTR_PERSONALIDENTIFIER);
    if (eIdentifierObj == null || !(eIdentifierObj instanceof String)) {
      throw new EidasAttributeException(Constants.eIDAS_ATTR_PERSONALIDENTIFIER);
    }

    final Trible<String, String, String> eIdentifier =
        EidasResponseUtils.parseEidasPersonalIdentifier((String) eIdentifierObj);
    final String citizenCountry = eIdentifier.getFirst();

    if (StringUtils.isEmpty(citizenCountry)) {
      log.info("No CountryCode for eID PostProcessor. Default-PostProcessor will be used");
    }

    for (final INationalEidProcessor el : handlers) {
      if (el.canHandle(citizenCountry)) {
        log.debug("Post-Process eIDAS eID from " + citizenCountry + " by using:  " + el.getName());
        return el.postProcess(eidasAttrMap);

      }
    }

    log.error("NO eID PostProcessor FOUND. Looks like a depentency problem!");
    throw new EidPostProcessingException("internal.00", null);
  }

}