/*
 *  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 *              Unpublished and Not for Publication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.policy;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import org.apache.openaz.xacml.api.Advice;
import org.apache.openaz.xacml.api.IdReference;
import org.apache.openaz.xacml.api.IdReferenceMatch;
import org.apache.openaz.xacml.api.Identifier;
import org.apache.openaz.xacml.api.Obligation;
import org.apache.openaz.xacml.api.StatusCode;
import org.apache.openaz.xacml.api.Version;
import org.apache.openaz.xacml.api.VersionMatch;
import org.apache.openaz.xacml.pdp.eval.EvaluationContext;
import org.apache.openaz.xacml.pdp.eval.EvaluationException;
import org.apache.openaz.xacml.pdp.eval.EvaluationResult;
import org.apache.openaz.xacml.pdp.eval.MatchResult;
import org.apache.openaz.xacml.std.StdIdReference;
import org.apache.openaz.xacml.std.StdStatus;
import org.apache.openaz.xacml.std.StdStatusCode;
import org.apache.openaz.xacml.util.StringUtils;

/**
 * PolicyDef extends {@link org.apache.openaz.xacml.pdp.policy.PolicySetChild} with members and methods
 * common to XACML 3.0 Policies and PolicySets.
 */
public abstract class PolicyDef extends PolicySetChild {
    private String description;
    private PolicyIssuer policyIssuer;
    private Target target;
    private List<CombinerParameter> combinerParameters;
    private List<ObligationExpression> obligationExpressions;
    private List<AdviceExpression> adviceExpressions;
    private Version version;
    private Integer maxDelegationDepth;

    private IdReference idReference;

    private void ensureCombinerParameters() {
        if (this.combinerParameters == null) {
            this.combinerParameters = new ArrayList<CombinerParameter>();
        }
    }

    private void ensureObligationExpressions() {
        if (this.obligationExpressions == null) {
            this.obligationExpressions = new ArrayList<ObligationExpression>();
        }
    }

    private void ensureAdviceExpressions() {
        if (this.adviceExpressions == null) {
            this.adviceExpressions = new ArrayList<AdviceExpression>();
        }
    }

    protected List<CombinerParameter> getCombinerParameterList() {
        return this.combinerParameters;
    }

    protected List<ObligationExpression> getObligationExpressionList() {
        return this.obligationExpressions;
    }

    protected List<AdviceExpression> getAdviceExpressionList() {
        return this.adviceExpressions;
    }

    protected void updateResult(EvaluationResult evaluationResult, EvaluationContext evaluationContext)
        throws EvaluationException {
        List<ObligationExpression> thisObligationExpressions = this.getObligationExpressionList();
        if (thisObligationExpressions != null && thisObligationExpressions.size() > 0) {
            List<Obligation> listObligations = ObligationExpression.evaluate(evaluationContext,
                                                                             this.getPolicyDefaults(),
                                                                             evaluationResult.getDecision(),
                                                                             thisObligationExpressions);
            if (listObligations != null && listObligations.size() > 0) {
                evaluationResult.addObligations(listObligations);
            }
        }

        List<AdviceExpression> thisAdviceExpressions = this.getAdviceExpressionList();
        if (thisAdviceExpressions != null && thisAdviceExpressions.size() > 0) {
            List<Advice> listAdvices = AdviceExpression.evaluate(evaluationContext, this.getPolicyDefaults(),
                                                                 evaluationResult.getDecision(),
                                                                 thisAdviceExpressions);
            if (listAdvices != null && listAdvices.size() > 0) {
                evaluationResult.addAdvice(listAdvices);
            }
        }
    }

    @Override
    protected boolean validateComponent() {
        if (super.validateComponent()) {
            if (this.getVersion() == null) {
                this.setStatus(StdStatusCode.STATUS_CODE_SYNTAX_ERROR, "Missing version string");
                return false;
            } else if (this.getTarget() == null) {
                this.setStatus(StdStatusCode.STATUS_CODE_SYNTAX_ERROR, "Missing Target in policy "
                                                                       + this.getIdReference().getId()
                                                                           .stringValue());
                return false;
            } else {
                return true;
            }
        } else {
            return false;
        }
    }

    public PolicyDef(PolicySet policySetParent, StatusCode statusCodeIn, String statusMessageIn) {
        super(policySetParent, statusCodeIn, statusMessageIn);
    }

    public PolicyDef(StatusCode statusCodeIn, String statusMessageIn) {
        super(statusCodeIn, statusMessageIn);
    }

    public PolicyDef(StatusCode statusCodeIn) {
        super(statusCodeIn);
    }

    public PolicyDef(PolicySet policySetParent) {
        super(policySetParent);
    }

    public PolicyDef() {
        super();
    }

    @Override
    public void setIdentifier(Identifier identifierIn) {
        super.setIdentifier(identifierIn);
        this.idReference = null;
    }

    /**
     * Gets the <code>String</code> description of this <code>PolicyDef</code>.
     *
     * @return the <code>String</code> description of this <code>PolicyDef</code>.
     */
    public String getDescription() {
        return this.description;
    }

    /**
     * Sets the <code>String</code> description of this <code>PolicyDef</code>.
     *
     * @param s the <code>String</code> description of this <code>PolicyDef</code>
     */
    public void setDescription(String s) {
        this.description = s;
    }

    /**
     * Gets the {@link org.apache.openaz.xacml.pdp.policy.PolicyIssuer} for this <code>PolicyDef</code>.
     *
     * @return the <code>PolicyIssuer</code> for this <code>PolicyDef</code>
     */
    public PolicyIssuer getPolicyIssuer() {
        return this.policyIssuer;
    }

    /**
     * Sets the <code>PolicyIssuer</code> for this <code>PolicyDef</code>.
     *
     * @param policyIssuerIn the <code>PolicyIssuer</code> for this <code>PolicyDef</code>.
     */
    public void setPolicyIssuer(PolicyIssuer policyIssuerIn) {
        this.policyIssuer = policyIssuerIn;
    }

    /**
     * Gets the <code>Target</code> for this <code>PolicyDef</code>.
     *
     * @return the <code>Target</code> for this <code>PolicyDef</code>
     */
    public Target getTarget() {
        return this.target;
    }

    /**
     * Sets the <code>Target</code> for this <code>PolicyDef</code>.
     *
     * @param targetIn the <code>Target</code> for this <code>PolicyDef</code>
     */
    public void setTarget(Target targetIn) {
        this.target = targetIn;
    }

    /**
     * Gets an <code>Iterator</code> over the <code>CombinerParameter</code>s for this <code>Policy</code>.
     *
     * @return an <code>Iterator</code> over the <code>CombinerParameter</code>s for this <code>Policy</code>
     *         or null if there are none
     */
    public Iterator<CombinerParameter> getCombinerParameters() {
        return (this.combinerParameters == null ? null : this.combinerParameters.iterator());
    }

    /**
     * Sets the <code>CombinerParameter</code>s for this<code>Policy</code> to the contents of the given
     * <code>Collection</code>. If the <code>Collection</code> is null, the set of
     * <code>CombinerParameter</code>s for this <code>Policy</code> is set to null.
     *
     * @param combinerParametersIn the <code>Collection</code> of <code>CombinerParameter</code>s for this
     *            <code>PolicyDef</code>
     */
    public void setCombinerParameters(Collection<CombinerParameter> combinerParametersIn) {
        this.combinerParameters = null;
        if (combinerParametersIn != null) {
            this.addCombinerParameters(combinerParametersIn);
        }
    }

    /**
     * Adds the given <code>CombinerParameter</code> to the set of <code>CombinerParameter</code>s for this
     * <code>PolicyDef</code>>
     *
     * @param combinerParameter the <code>CombinerParameter</code> to add
     */
    public void add(CombinerParameter combinerParameter) {
        this.ensureCombinerParameters();
        this.combinerParameters.add(combinerParameter);
    }

    /**
     * Adds the given <code>Collection</code> of <code>CombinerParameter</code>s to this
     * <code>PolicyDef</code>>
     *
     * @param combinerParametersIn the <code>Collection</code> of <code>CombinerParameter</code>s to add
     */
    public void addCombinerParameters(Collection<CombinerParameter> combinerParametersIn) {
        this.ensureCombinerParameters();
        this.combinerParameters.addAll(combinerParametersIn);
    }

    /**
     * Gets an <code>Iterator</code> over the <code>ObligationExpression</code>s for this
     * <code>PolicyDef</code>.
     *
     * @return an <code>Iterator</code> over the <code>ObligationExpression</code>s for this
     *         <code>PolicyDef</code> or null if there are none.
     */
    public Iterator<ObligationExpression> getObligationExpressions() {
        return (this.obligationExpressions == null ? null : this.obligationExpressions.iterator());
    }

    /**
     * Sets the <code>ObligationExpression</code>s for this <code>PolicyDef</code> to the contents of the
     * given <code>Collection</code>. If the <code>Collection</code> is null, the
     * <code>ObligationExpression</code>s for this <code>PolicyDef</code> are set to null.
     *
     * @param obligationExpressionsIn the <code>Collection</code> of <code>ObligationExpression</code>s for
     *            this <code>PolicyDef</code>.
     */
    public void setObligationExpressions(Collection<ObligationExpression> obligationExpressionsIn) {
        this.obligationExpressions = null;
        if (obligationExpressionsIn != null) {
            this.addObligationExpressions(obligationExpressionsIn);
        }
    }

    /**
     * Adds the given <code>ObligationExpression</code> to the set of <code>ObligationExpression</code>s for
     * this <code>PolicyDef</code>.
     *
     * @param obligationExpression the <code>ObligationExpression</code> to add
     */
    public void add(ObligationExpression obligationExpression) {
        this.ensureObligationExpressions();
        this.obligationExpressions.add(obligationExpression);
    }

    /**
     * Adds the contents of the given <code>Collection</code> of <code>ObligationExpression</code>s to the set
     * of <code>ObligationExpression</code>s for this <code>PolicyDef</code>.
     *
     * @param obligationExpressionsIn the <code>Collection</code> of <code>ObligationExpression</code>s to add
     */
    public void addObligationExpressions(Collection<ObligationExpression> obligationExpressionsIn) {
        this.ensureObligationExpressions();
        this.obligationExpressions.addAll(obligationExpressionsIn);
    }

    /**
     * Gets an <code>Iterator</code> over the set of <code>AdviceExpression</code>s for this
     * <code>PolicyDef</code>.
     *
     * @return an <code>Iterator</code> over the set of <code>AdviceExpression</code>s for this
     *         <code>PolicyDef</code> or null if there are none.
     */
    public Iterator<AdviceExpression> getAdviceExpressions() {
        return (this.adviceExpressions == null ? null : this.adviceExpressions.iterator());
    }

    /**
     * Sets the set of <code>AdviceExpression</code>s for this <code>PolicyDef</code> to the contents of the
     * given <code>Collection</code>.
     *
     * @param adviceExpressionsIn the <code>Collection</code> of <code>AdviceExpression</code> to add
     */
    public void setAdviceExpressions(Collection<AdviceExpression> adviceExpressionsIn) {
        this.adviceExpressions = null;
        if (adviceExpressionsIn != null) {
            this.addAdviceExpressions(adviceExpressionsIn);
        }
    }

    /**
     * Adds the given <code>AdviceExpression</code> to the set of <code>AdviceExpression</code>s for this
     * <code>PolicyDef</code>.
     *
     * @param adviceExpression the <code>AdviceExpression</code> to add.
     */
    public void add(AdviceExpression adviceExpression) {
        this.ensureAdviceExpressions();
        this.adviceExpressions.add(adviceExpression);
    }

    /**
     * Adds the contents of the given <code>Collection</code> of <code>AdviceExpression</code>s to the set of
     * <code>AdviceExpression</code>s for this <code>PolicyDef</code>.
     *
     * @param adviceExpressionsIn the <code>Collection</code> of <code>AdviceExpression</code>s to add.
     */
    public void addAdviceExpressions(Collection<AdviceExpression> adviceExpressionsIn) {
        this.ensureAdviceExpressions();
        this.adviceExpressions.addAll(adviceExpressionsIn);
    }

    /**
     * Gets the <code>String</code> version for this <code>PolicyDef</code>.
     *
     * @return the <code>String</code> version for this <code>PolicyDef</code>.
     */
    public Version getVersion() {
        return this.version;
    }

    /**
     * Sets the version <code>String</code> for this <code>PolicyDef</code>>
     *
     * @param versionIn the <code>String</code> version for this <code>PolicyDef</code>
     */
    public void setVersion(Version versionIn) {
        this.version = versionIn;
        this.idReference = null;
    }

    /**
     * Creates the <code>IdReference</code> for this <code>PolicyDef</code> if needed and returns it.
     *
     * @return the <code>IdReference</code> for this <code>PolicyDef</code>
     */
    public IdReference getIdReference() {
        if (this.idReference == null) {
            this.idReference = new StdIdReference(this.getIdentifier(), this.getVersion());
        }
        return this.idReference;
    }

    public boolean matches(IdReferenceMatch idReferenceRequest) {
        IdReference thisIdReference = this.getIdReference();
        if (thisIdReference == null || thisIdReference.getId() == null || idReferenceRequest == null
            || idReferenceRequest.getId() == null) {
            return false;
        } else if (!thisIdReference.getId().equals(idReferenceRequest.getId())) {
            return false;
        }

        /*
         * Now do version number matching
         */
        VersionMatch idReferenceRequestVersion = idReferenceRequest.getVersion();
        if (idReferenceRequestVersion != null) {
            /*
             * Do exact version matching
             */
            Version thisVersion = thisIdReference.getVersion();
            if (thisVersion == null) {
                return false;
            } else {
                return idReferenceRequestVersion.match(thisVersion, 0);
            }
        } else {
            VersionMatch idReferenceRequestEarliestVersion = idReferenceRequest.getEarliestVersion();
            Version thisVersion = thisIdReference.getVersion();

            if (idReferenceRequestEarliestVersion != null) {
                if (thisVersion == null) {
                    return false;
                } else if (!idReferenceRequestEarliestVersion.match(thisVersion, 1)) {
                    return false;
                }
            }

            VersionMatch idReferenceRequestLatestVersion = idReferenceRequest.getLatestVersion();
            if (idReferenceRequestLatestVersion != null) {
                if (thisVersion == null) {
                    return false;
                } else if (!idReferenceRequestLatestVersion.match(thisVersion, -1)) {
                    return false;
                }
            }

            return true;
        }
    }

    /**
     * Gets the <code>Integer</code> maximum delegation depth for this <code>PolicyDef</code>.
     *
     * @return the <code>Integer</code> maximum delegation depth for this <code>PolicyDef</code>
     */
    public Integer getMaxDelegationDepth() {
        return this.maxDelegationDepth;
    }

    /**
     * Sets the <code>Integer</code> maximum delegation depth for this <code>PolicyDef</code>
     * 
     * @param i the <code>Integer</code> maximum delegation depth for this <code>PolicyDef</code>
     */
    public void setMaxDelegationDepth(Integer i) {
        this.maxDelegationDepth = i;
    }

    @Override
    public String toString() {
        StringBuilder stringBuilder = new StringBuilder("{");

        stringBuilder.append("super=");
        stringBuilder.append(super.toString());

        Object objectToDump;
        if ((objectToDump = this.getDescription()) != null) {
            stringBuilder.append(",description=");
            stringBuilder.append((String)objectToDump);
        }
        if ((objectToDump = this.getPolicyIssuer()) != null) {
            stringBuilder.append(",policyIssuer=");
            stringBuilder.append(objectToDump.toString());
        }
        if ((objectToDump = this.getTarget()) != null) {
            stringBuilder.append(",target=");
            stringBuilder.append(objectToDump.toString());
        }
        String iteratorToString;
        if ((iteratorToString = StringUtils.toString(this.getCombinerParameters())) != null) {
            stringBuilder.append(",combinerParameters=");
            stringBuilder.append(iteratorToString);
        }
        if ((iteratorToString = StringUtils.toString(this.getObligationExpressions())) != null) {
            stringBuilder.append(",obligationExpressions=");
            stringBuilder.append(iteratorToString);
        }
        if ((iteratorToString = StringUtils.toString(this.getAdviceExpressions())) != null) {
            stringBuilder.append(",adviceExpressions=");
            stringBuilder.append(iteratorToString);
        }
        if ((objectToDump = this.getVersion()) != null) {
            stringBuilder.append(",version=");
            stringBuilder.append(objectToDump.toString());
        }
        if ((objectToDump = this.getMaxDelegationDepth()) != null) {
            stringBuilder.append(",maxDelegationDepth=");
            stringBuilder.append(objectToDump.toString());
        }
        stringBuilder.append('}');
        return stringBuilder.toString();
    }

    @Override
    public MatchResult match(EvaluationContext evaluationContext) throws EvaluationException {
        if (!this.validate()) {
            return new MatchResult(new StdStatus(this.getStatusCode(), this.getStatusMessage()));
        }
        return this.getTarget().match(evaluationContext);
    }

}