openaz-xacml-pdp/src/main/java/org/apache/openaz/xacml/pdp/std/functions/FunctionDefinitionBagIsIn.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.
 *
 */

/*
 *                        AT&T - PROPRIETARY
 *          THIS FILE CONTAINS PROPRIETARY INFORMATION OF
 *        AT&T AND IS NOT TO BE DISCLOSED OR USED EXCEPT IN
 *             ACCORDANCE WITH APPLICABLE AGREEMENTS.
 *
 *          Copyright (c) 2013 AT&T Knowledge Ventures
 *              Unpublished and Not for Publication
 *                     All Rights Reserved
 */
package org.apache.openaz.xacml.pdp.std.functions;

import java.util.Iterator;
import java.util.List;

import org.apache.openaz.xacml.api.AttributeValue;
import org.apache.openaz.xacml.api.DataType;
import org.apache.openaz.xacml.api.Identifier;
import org.apache.openaz.xacml.pdp.eval.EvaluationContext;
import org.apache.openaz.xacml.pdp.policy.Bag;
import org.apache.openaz.xacml.pdp.policy.ExpressionResult;
import org.apache.openaz.xacml.pdp.policy.FunctionArgument;
import org.apache.openaz.xacml.std.StdStatus;
import org.apache.openaz.xacml.std.StdStatusCode;
import org.apache.openaz.xacml.std.datatypes.DataTypes;

/**
 * FunctionDefinitionBagIsIn implements {@link org.apache.openaz.xacml.pdp.policy.FunctionDefinition} to
 * implement the XACML 'type'-is-in predicates as functions taking two arguments, the first of
 * <code>type</code> and the second of type <code>Bag</code>, and returning a <code>Boolean</code> for whether
 * the first argument is contained in the second. In the first implementation of XACML we had separate files
 * for each XACML Function. This release combines multiple Functions in fewer files to minimize code
 * duplication. This file supports the following XACML codes: string-is-in boolean-is-in integer-is-in
 * double-is-in time-is-in date-is-in dateTime-is-in anyURI-is-in hexBinary-is-in base64Binary-is-in
 * dayTimeDuration-is-in (version 1 and3) yearMonthDuration-is-in (version 1 and 3) x500Name-is-in
 * rfc822Name-is-in ipAddress-is-in dnsName-is-in
 *
 * @param <I> the java class for the data type of the elements in the Input argument Bag The Output for these
 *            functions is always a Boolean.
 */
public class FunctionDefinitionBagIsIn<I> extends FunctionDefinitionBase<Boolean, I> {

    /**
     * Constructor - need dataType input because of java Generic type-erasure during compilation.
     *
     * @param idIn
     * @param dataTypeArgsIn
     */
    public FunctionDefinitionBagIsIn(Identifier idIn, DataType<I> dataTypeArgsIn) {
        super(idIn, DataTypes.DT_BOOLEAN, dataTypeArgsIn, false);

    }

    /**
     * Evaluates this <code>FunctionDefinition</code> on the given <code>List</code> of
     * {@link org.apache.openaz.xacml.pdp.policy.FunctionArgument}s.
     *
     * @param evaluationContext the {@link org.apache.openaz.xacml.pdp.eval.EvaluationContext} to use in the
     *            evaluation
     * @param arguments the <code>List</code> of <code>FunctionArgument</code>s for the evaluation
     * @return an {@link org.apache.openaz.xacml.pdp.policy.ExpressionResult} with the results of the call
     */
    @Override
    public ExpressionResult evaluate(EvaluationContext evaluationContext, List<FunctionArgument> arguments) {

        if (arguments == null || arguments.size() != 2) {
            return ExpressionResult.newError(new StdStatus(StdStatusCode.STATUS_CODE_PROCESSING_ERROR,
                                                           this.getShortFunctionId()
                                                               + " Expected 2 arguments, got "
                                                               + ((arguments == null) ? "null" : arguments
                                                                   .size())));
        }

        // get the thing to look for in the bag
        FunctionArgument elementArgument = arguments.get(0);

        ConvertedArgument<I> convertedTargetArgument = new ConvertedArgument<I>(elementArgument,
                                                                                this.getDataTypeArgs(), false);
        if (!convertedTargetArgument.isOk()) {
            return ExpressionResult.newError(getFunctionStatus(convertedTargetArgument.getStatus()));
        }

        // Special case: Most methods want the value contained in the AttributeValue object inside the
        // FunctionArgument.
        // This one wants the AttributeValue itself.
        // We use the ConvertedArgument constructor to validate that the argument is ok, then use the
        // AttributeValue
        // from the FunctionArgument.
        AttributeValue<?> attributeValueElement = elementArgument.getValue();

        // now get the bag
        FunctionArgument bagArgument = arguments.get(1);
        ConvertedArgument<Bag> convertedBagArgument = new ConvertedArgument<Bag>(bagArgument, null, true);

        if (!convertedBagArgument.isOk()) {
            return ExpressionResult.newError(getFunctionStatus(convertedBagArgument.getStatus()));
        }

        Bag bag = convertedBagArgument.getBag();

        Iterator<AttributeValue<?>> iterBagContents = bag.getAttributeValues();
        while (iterBagContents.hasNext()) {
            AttributeValue<?> attributeValueBagContents = iterBagContents.next();

            /*
             * Should we be checking the type of the bag contents and returning an error if the bag contents
             * are not of the right type? The spec does not say this, so we just use the
             * AttributeValue.equals() method for now.
             */
            if (attributeValueElement.equals(attributeValueBagContents)) {
                return ER_TRUE;
            }
        }

        return ER_FALSE;
    }

}