/**
 * Copyright (c) Istituto Nazionale di Fisica Nucleare (INFN). 2006-2016
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 */
package it.infn.cnaf.voms.saml;

import it.infn.cnaf.voms.aa.VOMSAttributes;
import it.infn.cnaf.voms.aa.VOMSFQAN;
import it.infn.cnaf.voms.aa.VOMSGenericAttribute;
import it.infn.cnaf.voms.saml.emi.AttributeWizard;

import java.util.ArrayList;
import java.util.List;

import org.glite.security.voms.admin.configuration.VOMSConfiguration;
import org.opensaml.Configuration;
import org.opensaml.saml2.core.Attribute;
import org.opensaml.saml2.core.AttributeValue;
import org.opensaml.saml2.core.impl.AttributeBuilder;
import org.opensaml.xml.XMLObjectBuilderFactory;
import org.opensaml.xml.schema.XSString;
import org.opensaml.xml.schema.impl.XSStringBuilder;

/**
 * 
 * @author Andrea Ceccanti
 * @author Valerio Venturi
 *
 */
public class SAMLAttributeSerializer {

  public static final String ATTRIBUTE_NAME_FORMAT = Attribute.URI_REFERENCE;

  public static final String FQAN_ATTRIBUTE_NAME = "http://voms.forge.cnaf.infn.it/fqan";

  public static final String AUTHZ_INTEROP_FQAN_ATTRIBUTE_NAME = "http://authz-interop.org/xacml/subject/voms-fqan";

  static Attribute serializeFQAN(List<VOMSFQAN> fqans) {

    XMLObjectBuilderFactory builderFactory = Configuration.getBuilderFactory();

    AttributeBuilder attributeBuilder = (AttributeBuilder) builderFactory
      .getBuilder(Attribute.DEFAULT_ELEMENT_NAME);

    Attribute fqansAttribute = attributeBuilder.buildObject();

    fqansAttribute.setName(AUTHZ_INTEROP_FQAN_ATTRIBUTE_NAME);
    fqansAttribute.setNameFormat(ATTRIBUTE_NAME_FORMAT);

    XSStringBuilder attributeValueBuilder = (XSStringBuilder) builderFactory
      .getBuilder(XSString.TYPE_NAME);

    for (VOMSFQAN fqan : fqans) {

      XSString attributeValue = attributeValueBuilder.buildObject(
        AttributeValue.DEFAULT_ELEMENT_NAME, XSString.TYPE_NAME);
      attributeValue.setValue(fqan.getFQAN());
      fqansAttribute.getAttributeValues().add(attributeValue);
    }

    return fqansAttribute;

  }

  static Attribute serializeGenericAttribute(
    VOMSGenericAttribute genericAttribute) {

    XMLObjectBuilderFactory builderFactory = Configuration.getBuilderFactory();

    AttributeBuilder attributeBuilder = (AttributeBuilder) builderFactory
      .getBuilder(Attribute.DEFAULT_ELEMENT_NAME);

    Attribute gaAttribute = attributeBuilder.buildObject();

    // FIXME: find out a non-naive format for generic attributes names
    gaAttribute.setName(genericAttribute.getName());
    gaAttribute.setNameFormat(ATTRIBUTE_NAME_FORMAT);

    XSStringBuilder attributeValueBuilder = (XSStringBuilder) builderFactory
      .getBuilder(XSString.TYPE_NAME);

    XSString attributeValue = attributeValueBuilder.buildObject(
      AttributeValue.DEFAULT_ELEMENT_NAME, XSString.TYPE_NAME);

    // FIXME: gracefully forgot the context...
    attributeValue.setValue(genericAttribute.getValue());
    gaAttribute.getAttributeValues().add(attributeValue);

    return gaAttribute;

  }

  public static List<Attribute> serializeAllAttributes(VOMSAttributes attributes) {

    assert attributes != null : "Cannot serialize a NULL attribute!";

    List<Attribute> vomsSAMLAttributes = new ArrayList<Attribute>();

    // EMI profile
    String voName = VOMSConfiguration.instance().getVOName();

    vomsSAMLAttributes.add(AttributeWizard.createVOAttribute(voName));

    vomsSAMLAttributes.add(AttributeWizard.createGroupAttribute(attributes
      .getFqans()));

    // Find primary group
    for (VOMSFQAN f : attributes.getFqans()) {

      if (f.isGroup()) {
        vomsSAMLAttributes.add(AttributeWizard.createPrimaryGroupAttribute(f));
        break;
      }

    }

    vomsSAMLAttributes.add(AttributeWizard.createRoleAttribute(attributes
      .getFqans()));

    // Find primary role
    for (VOMSFQAN f : attributes.getFqans()) {

      if (f.isRole()) {
        vomsSAMLAttributes.add(AttributeWizard.createPrimaryRoleAttribute(f));
        break;
      }

    }

    // Serialize FQANs
    vomsSAMLAttributes.add(serializeFQAN(attributes.getFqans()));

    // Serialized Generic Attributes
    for (VOMSGenericAttribute ga : attributes.getGenericAttributes())
      vomsSAMLAttributes.add(serializeGenericAttribute(ga));

    return vomsSAMLAttributes;
  }
}