/*
 *  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 *              Unpublished and Not for Publication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;

import java.util.Collection;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.openaz.xacml.api.IdReferenceMatch;
import org.apache.openaz.xacml.api.Request;
import org.apache.openaz.xacml.api.pip.PIPEngine;
import org.apache.openaz.xacml.api.pip.PIPException;
import org.apache.openaz.xacml.api.pip.PIPFinder;
import org.apache.openaz.xacml.api.pip.PIPRequest;
import org.apache.openaz.xacml.api.pip.PIPResponse;
import org.apache.openaz.xacml.api.trace.TraceEngine;
import org.apache.openaz.xacml.api.trace.TraceEngineFactory;
import org.apache.openaz.xacml.api.trace.TraceEvent;
import org.apache.openaz.xacml.pdp.eval.EvaluationContext;
import org.apache.openaz.xacml.pdp.policy.Policy;
import org.apache.openaz.xacml.pdp.policy.PolicyDef;
import org.apache.openaz.xacml.pdp.policy.PolicyFinder;
import org.apache.openaz.xacml.pdp.policy.PolicyFinderResult;
import org.apache.openaz.xacml.pdp.policy.PolicySet;
import org.apache.openaz.xacml.std.pip.engines.RequestEngine;
import org.apache.openaz.xacml.std.pip.finders.RequestFinder;
import org.apache.openaz.xacml.util.FactoryException;

/**
 * StdEvaluationContext implements the {@link org.apache.openaz.xacml.pdp.eval.EvaluationContext} interface
 * using default factories to load the XACML policies, and get the PIP engines.
 */
public class StdEvaluationContext implements EvaluationContext {
    private Log logger = LogFactory.getLog(this.getClass());
    private Request request;
    private RequestFinder requestFinder;
    private PolicyFinder policyFinder;
    private TraceEngine traceEngine;

    /**
     * Creates a new <code>StdEvaluationContext</code> with the given
     * {@link org.apache.openaz.xacml.api.Request} and {@link org.apache.openaz.xacml.pdp.policy.PolicyDef}.
     *
     * @param requestIn the <code>Request</code>
     * @param policyDef the <code>PolicyDef</code>
     */
    public StdEvaluationContext(Request requestIn, PolicyFinder policyFinderIn, PIPFinder pipFinder,
                                TraceEngine traceEngineIn) {
        this.request = requestIn;
        this.policyFinder = policyFinderIn;
        if (traceEngineIn != null) {
            this.traceEngine = traceEngineIn;
        } else {
            try {
                this.traceEngine = TraceEngineFactory.newInstance().getTraceEngine();
            } catch (FactoryException ex) {
                this.logger.error("FactoryException creating TraceEngine: " + ex.toString(), ex);
            }
        }

        if (pipFinder == null) {
            this.requestFinder = new RequestFinder(null, new RequestEngine(requestIn));
        } else {
            if (pipFinder instanceof RequestFinder) {
                this.requestFinder = (RequestFinder)pipFinder;
            } else {
                this.requestFinder = new RequestFinder(pipFinder, new RequestEngine(requestIn));
            }
        }
    }

    public StdEvaluationContext(Request requestIn, PolicyFinder policyFinderIn, PIPFinder pipFinder) {
        this(requestIn, policyFinderIn, pipFinder, null);
    }

    @Override
    public Request getRequest() {
        return this.request;
    }

    @Override
    public PIPResponse getAttributes(PIPRequest pipRequest) throws PIPException {
        return this.requestFinder.getAttributes(pipRequest, null);
    }

    @Override
    public PIPResponse getAttributes(PIPRequest pipRequest, PIPEngine exclude) throws PIPException {
        return this.requestFinder.getAttributes(pipRequest, exclude);
    }

    @Override
    public PIPResponse getAttributes(PIPRequest pipRequest, PIPEngine exclude, PIPFinder pipFinderRoot)
        throws PIPException {
        return this.requestFinder.getAttributes(pipRequest, exclude, pipFinderRoot);
    }

    @Override
    public PolicyFinderResult<PolicyDef> getRootPolicyDef() {
        return this.policyFinder.getRootPolicyDef(this);
    }

    @Override
    public PolicyFinderResult<Policy> getPolicy(IdReferenceMatch idReferenceMatch) {
        return this.policyFinder.getPolicy(idReferenceMatch);
    }

    @Override
    public PolicyFinderResult<PolicySet> getPolicySet(IdReferenceMatch idReferenceMatch) {
        return this.policyFinder.getPolicySet(idReferenceMatch);
    }

    @Override
    public void trace(TraceEvent<?> traceEvent) {
        if (this.traceEngine != null) {
            this.traceEngine.trace(traceEvent);
        }
    }

    @Override
    public boolean isTracing() {
        return (this.traceEngine == null ? false : this.traceEngine.isTracing());
    }

    @Override
    public PIPResponse getMatchingAttributes(PIPRequest pipRequest, PIPEngine exclude) throws PIPException {
        return this.requestFinder.getMatchingAttributes(pipRequest, exclude);
    }

    @Override
    public PIPResponse getMatchingAttributes(PIPRequest pipRequest, PIPEngine exclude,
                                             PIPFinder pipFinderParent) throws PIPException {
        return this.requestFinder.getMatchingAttributes(pipRequest, exclude, pipFinderParent);
    }

    @Override
    public Collection<PIPEngine> getPIPEngines() {
        return this.requestFinder.getPIPEngines();
    }
}