/*
 * 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.utils;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.annotation.Nullable;

import org.apache.commons.lang3.StringUtils;
import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.ImmutableList;

import at.asitplus.eidas.specific.modules.auth.eidas.v2.Constants;
import at.gv.egiz.eaaf.core.impl.data.Trible;
import eu.eidas.auth.commons.attribute.AttributeDefinition;
import eu.eidas.auth.commons.attribute.AttributeValue;
import eu.eidas.auth.commons.attribute.AttributeValueMarshaller;
import eu.eidas.auth.commons.attribute.AttributeValueMarshallingException;
import eu.eidas.auth.commons.attribute.AttributeValueTransliterator;
import eu.eidas.auth.commons.protocol.eidas.impl.PostalAddress;

public class EidasResponseUtils {
  private static final Logger log = LoggerFactory.getLogger(EidasResponseUtils.class);

  public static final String PERSONALIDENIFIER_VALIDATION_PATTERN = "^[A-Z,a-z]{2}/[A-Z,a-z]{2}/.*";

  /**
   * Validate a eIDAS PersonalIdentifier attribute value This validation is done
   * according to eIDAS SAML Attribute Profile - Section 2.2.3 Unique Identifier
   * 
   * @param uniqueID eIDAS attribute value of a unique identifier
   * @return true if the uniqueID matches to eIDAS to Unique Identifier
   *         specification, otherwise false
   */
  public static boolean validateEidasPersonalIdentifier(String uniqueID) {
    final Pattern pattern = Pattern.compile(PERSONALIDENIFIER_VALIDATION_PATTERN);
    final Matcher matcher = pattern.matcher(uniqueID);
    return matcher.matches();

  }

  /**
   * Parse an eIDAS PersonalIdentifier attribute value into it components. This
   * processing is done according to eIDAS SAML Attribute Profile - Section 2.2.3
   * Unique Identifier
   * 
   * @param uniqueID eIDAS attribute value of a unique identifier
   * @return {@link Trible} that contains: <br>
   *         First : citizen country <br>
   *         Second: destination country <br>
   *         Third : unique identifier <br>
   *         or null if the attribute value has a wrong format
   */
  public static Trible<String, String, String> parseEidasPersonalIdentifier(String uniqueID) {
    if (!validateEidasPersonalIdentifier(uniqueID)) {
      log.error("eIDAS attribute value for {} looks wrong formated. Value: {}", 
          Constants.eIDAS_ATTR_PERSONALIDENTIFIER, uniqueID);
      return null;

    }
    return Trible.newInstance(uniqueID.substring(0, 2), uniqueID.substring(3, 5), uniqueID.substring(6));

  }

  /**
   * Get eIDAS attribute-values from eIDAS Node attributes. 
   * 
   * @param attributeDefinition eIDAS attribute definition
   * @param attributeValues Attributes from eIDAS response
   * @return Set of attribute values. If more then one value than the first value contains the 'Latin' value. 
   */
  // TODO: check possible problem with nonLatinCharacters
  public static List<String> translateStringListAttribute(AttributeDefinition<?> attributeDefinition,
      ImmutableList<? extends AttributeValue<?>> attributeValues) {
    final List<String> stringListAttribute = new ArrayList<>();
    final AttributeValueMarshaller<?> attributeValueMarshaller = attributeDefinition
        .getAttributeValueMarshaller();
    for (final AttributeValue<?> attributeValue : attributeValues) {
      String valueString = null;
      try {
        valueString = attributeValueMarshaller.marshal((AttributeValue) attributeValue);

        log.trace("Find attr: {} with value: {} nonLatinFlag: {} needTransliteration: {}",
            attributeDefinition.getFriendlyName(), attributeValue.toString(),
            attributeValue.isNonLatinScriptAlternateVersion(), 
            AttributeValueTransliterator.needsTransliteration(valueString));

        // if (attributeValue.isNonLatinScriptAlternateVersion()) {
        if (!AttributeValueTransliterator.needsTransliteration(valueString)) {
          stringListAttribute.add(0, valueString);

        } else {
          log.trace("Find 'needsTransliteration' flag. Setting this value at last list element ... ");
          stringListAttribute.add(valueString);

        }

      } catch (final AttributeValueMarshallingException e) {
        throw new IllegalStateException(e);

      }
    }

    log.trace("Extract values: {} for attr: {}", 
        StringUtils.join(stringListAttribute, ","), attributeDefinition.getFriendlyName());

    return stringListAttribute;

  }

  /**
   * Convert eIDAS DateTime attribute to Java Object. 
   * 
   * @param attributeDefinition eIDAS attribute definition.
   * @param attributeValues eIDAS attribute value
   * @return
   */
  @Nullable
  public static DateTime translateDateAttribute(AttributeDefinition<?> attributeDefinition,
      ImmutableList<? extends AttributeValue<?>> attributeValues) {
    if (attributeValues.size() != 0) {
      final AttributeValue<?> firstAttributeValue = attributeValues.get(0);
      return (DateTime) firstAttributeValue.getValue();

    }

    return null;
  }

  /**
   * Concert eIDAS Address attribute to Java object.
   * 
   * @param attributeDefinition eIDAS attribute definition
   * @param attributeValues eIDAS attribute value
   * @return
   */
  @Nullable
  public static PostalAddress translateAddressAttribute(AttributeDefinition<?> attributeDefinition,
      ImmutableList<? extends AttributeValue<?>> attributeValues) {
    final AttributeValue<?> firstAttributeValue = attributeValues.get(0);
    return (PostalAddress) firstAttributeValue.getValue();

  }

}