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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package com.sun.xml.internal.ws.policy.sourcemodel;

import com.sun.xml.internal.ws.policy.privateutil.LocalizationMessages;
import com.sun.xml.internal.ws.policy.privateutil.PolicyLogger;
import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
import com.sun.xml.internal.ws.policy.sourcemodel.wspolicy.XmlToken;

import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;

The general representation of a single node within a PolicySourceModel instance. The model node is created via factory methods of the PolicySourceModel instance. It may also hold AssertionData instance in case its type is ModelNode.Type.ASSERTION. 
Author:
Marek Potociar/**
 * The general representation of a single node within a {@link com.sun.xml.internal.ws.policy.sourcemodel.PolicySourceModel} instance.
 * The model node is created via factory methods of the {@link com.sun.xml.internal.ws.policy.sourcemodel.PolicySourceModel} instance.
 * It may also hold {@link com.sun.xml.internal.ws.policy.sourcemodel.AssertionData} instance in case its type is {@code ModelNode.Type.ASSERTION}.
 *
 * @author Marek Potociar
 */
public final class ModelNode implements Iterable<ModelNode>, Cloneable {
    private static final PolicyLogger LOGGER = PolicyLogger.getLogger(ModelNode.class);

    
Policy source model node type enumeration
/**
     * Policy source model node type enumeration
     */
    public static enum Type {
        POLICY(XmlToken.Policy),
        ALL(XmlToken.All),
        EXACTLY_ONE(XmlToken.ExactlyOne),
        POLICY_REFERENCE(XmlToken.PolicyReference),
        ASSERTION(XmlToken.UNKNOWN),
        ASSERTION_PARAMETER_NODE(XmlToken.UNKNOWN);

        private XmlToken token;

        Type(XmlToken token) {
            this.token = token;
        }

        public XmlToken getXmlToken() {
            return token;
        }

        
Method checks the PSM state machine if the creation of new child of given type is plausible for a node element
with type set to this type instance.
Params:
childType – The type.
Returns:
True if the type is supported, false otherwise/**
         * Method checks the PSM state machine if the creation of new child of given type is plausible for a node element
         * with type set to this type instance.
         *
         * @param childType The type.
         * @return True if the type is supported, false otherwise
         */
        private boolean isChildTypeSupported(final Type childType) {
            switch (this) {
                case POLICY:
                case ALL:
                case EXACTLY_ONE:
                    switch (childType) {
                        case ASSERTION_PARAMETER_NODE:
                            return false;
                        default:
                            return true;
                    }
                case POLICY_REFERENCE:
                    return false;
                case ASSERTION:
                    switch (childType) {
                        case POLICY:
                        case POLICY_REFERENCE:
                        case ASSERTION_PARAMETER_NODE:
                            return true;
                        default:
                            return false;
                    }
                case ASSERTION_PARAMETER_NODE:
                    switch (childType) {
                        case ASSERTION_PARAMETER_NODE:
                            return true;
                        default:
                            return false;
                    }
                default:
                    throw LOGGER.logSevereException(new IllegalStateException(
                            LocalizationMessages.WSP_0060_POLICY_ELEMENT_TYPE_UNKNOWN(this)));
            }
        }
    }

    // comon model node attributes
    private LinkedList<ModelNode> children;
    private Collection<ModelNode> unmodifiableViewOnContent;
    private final ModelNode.Type type;
    private ModelNode parentNode;
    private PolicySourceModel parentModel;

    // attributes used only in 'POLICY_REFERENCE' model node
    private PolicyReferenceData referenceData;
    private PolicySourceModel referencedModel;

    // attibutes used only in 'ASSERTION' or 'ASSERTION_PARAMETER_NODE' model node
    private AssertionData nodeData;

    
The factory method creates and initializes the POLICY model node and sets it's parent model reference to point to the model supplied as an input parameter. This method is intended to be used ONLY from PolicySourceModel during the initialization of its own internal structures. 
Params:
model – policy source model to be used as a parent model of the newly created ModelNode. Must not be null
Throws:
IllegalArgumentException – if the model input parameter is null
Returns:
POLICY model node with the parent model reference initialized to the model supplied as an input parameter/**
     * The factory method creates and initializes the POLICY model node and sets it's parent model reference to point to
     * the model supplied as an input parameter. This method is intended to be used ONLY from {@link PolicySourceModel} during
     * the initialization of its own internal structures.
     *
     * @param model policy source model to be used as a parent model of the newly created {@link ModelNode}. Must not be {@code null}
     * @return POLICY model node with the parent model reference initialized to the model supplied as an input parameter
     * @throws IllegalArgumentException if the {@code model} input parameter is {@code null}
     */
    static ModelNode createRootPolicyNode(final PolicySourceModel model) throws IllegalArgumentException {
        if (model == null) {
            throw LOGGER.logSevereException(new IllegalArgumentException(LocalizationMessages.WSP_0039_POLICY_SRC_MODEL_INPUT_PARAMETER_MUST_NOT_BE_NULL()));
        }
        return new ModelNode(ModelNode.Type.POLICY, model);
    }

    private ModelNode(Type type, PolicySourceModel parentModel) {
        this.type = type;
        this.parentModel = parentModel;
        this.children = new LinkedList<ModelNode>();
        this.unmodifiableViewOnContent = Collections.unmodifiableCollection(this.children);
    }

    private ModelNode(Type type, PolicySourceModel parentModel, AssertionData data) {
        this(type, parentModel);

        this.nodeData = data;
    }

    private ModelNode(PolicySourceModel parentModel, PolicyReferenceData data) {
        this(Type.POLICY_REFERENCE, parentModel);

        this.referenceData = data;
    }

    private void checkCreateChildOperationSupportForType(final Type type) throws UnsupportedOperationException {
        if (!this.type.isChildTypeSupported(type)) {
            throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0073_CREATE_CHILD_NODE_OPERATION_NOT_SUPPORTED(type, this.type)));
        }
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Returns:
A new Policy node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @return A new Policy node.
     */
    public ModelNode createChildPolicyNode() {
        checkCreateChildOperationSupportForType(Type.POLICY);

        final ModelNode node = new ModelNode(ModelNode.Type.POLICY, parentModel);
        this.addChild(node);

        return node;
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Returns:
A new All node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @return A new All node.
     */
    public ModelNode createChildAllNode() {
        checkCreateChildOperationSupportForType(Type.ALL);

        final ModelNode node = new ModelNode(ModelNode.Type.ALL, parentModel);
        this.addChild(node);

        return node;
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Returns:
A new ExactlyOne node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @return A new ExactlyOne node.
     */
    public ModelNode createChildExactlyOneNode() {
        checkCreateChildOperationSupportForType(Type.EXACTLY_ONE);

        final ModelNode node = new ModelNode(ModelNode.Type.EXACTLY_ONE, parentModel);
        this.addChild(node);

        return node;
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Returns:
A new policy assertion node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @return A new policy assertion node.
     */
    public ModelNode createChildAssertionNode() {
        checkCreateChildOperationSupportForType(Type.ASSERTION);

        final ModelNode node = new ModelNode(ModelNode.Type.ASSERTION, parentModel);
        this.addChild(node);

        return node;
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Params:
nodeData – The policy assertion data.
Returns:
A new policy assertion node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @param nodeData The policy assertion data.
     * @return A new policy assertion node.
     */
    public ModelNode createChildAssertionNode(final AssertionData nodeData) {
        checkCreateChildOperationSupportForType(Type.ASSERTION);

        final ModelNode node = new ModelNode(Type.ASSERTION, parentModel, nodeData);
        this.addChild(node);

        return node;
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Returns:
A new assertion parameter node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @return A new assertion parameter node.
     */
    public ModelNode createChildAssertionParameterNode() {
        checkCreateChildOperationSupportForType(Type.ASSERTION_PARAMETER_NODE);

        final ModelNode node = new ModelNode(ModelNode.Type.ASSERTION_PARAMETER_NODE, parentModel);
        this.addChild(node);

        return node;
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Params:
nodeData – The assertion parameter data.
Returns:
A new assertion parameter node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @param nodeData The assertion parameter data.
     * @return A new assertion parameter node.
     */
    ModelNode createChildAssertionParameterNode(final AssertionData nodeData) {
        checkCreateChildOperationSupportForType(Type.ASSERTION_PARAMETER_NODE);

        final ModelNode node = new ModelNode(Type.ASSERTION_PARAMETER_NODE, parentModel, nodeData);
        this.addChild(node);

        return node;
    }

    
Factory method that creates new policy source model node as specified by a factory method name and input parameters.
Each node is created with respect to its enclosing policy source model.
Params:
referenceData – The PolicyReference data.
Returns:
A new PolicyReference node./**
     * Factory method that creates new policy source model node as specified by a factory method name and input parameters.
     * Each node is created with respect to its enclosing policy source model.
     *
     * @param referenceData The PolicyReference data.
     * @return A new PolicyReference node.
     */
    ModelNode createChildPolicyReferenceNode(final PolicyReferenceData referenceData) {
        checkCreateChildOperationSupportForType(Type.POLICY_REFERENCE);

        final ModelNode node = new ModelNode(parentModel, referenceData);
        this.parentModel.addNewPolicyReference(node);
        this.addChild(node);

        return node;
    }

    Collection<ModelNode> getChildren() {
        return unmodifiableViewOnContent;
    }

    
Sets the parent model reference on the node and its children. The method may be invoked only on the root node
of the policy source model (or - in general - on a model node that dose not reference a parent node). Otherwise an
exception is thrown.
Params:
model – new parent policy source model to be set.
Throws:
IllegalAccessException – in case this node references a parent node (i.e. is not a root node of the model)./**
     * Sets the parent model reference on the node and its children. The method may be invoked only on the root node
     * of the policy source model (or - in general - on a model node that dose not reference a parent node). Otherwise an
     * exception is thrown.
     *
     * @param model new parent policy source model to be set.
     * @throws IllegalAccessException in case this node references a parent node (i.e. is not a root node of the model).
     */
    void setParentModel(final PolicySourceModel model) throws IllegalAccessException {
        if (parentNode != null) {
            throw LOGGER.logSevereException(new IllegalAccessException(LocalizationMessages.WSP_0049_PARENT_MODEL_CAN_NOT_BE_CHANGED()));
        }

        this.updateParentModelReference(model);
    }

    
The method updates the parentModel reference on current model node instance and all of it's children
Params:
model – new policy source model reference./**
     * The method updates the parentModel reference on current model node instance and all of it's children
     *
     * @param model new policy source model reference.
     */
    private void updateParentModelReference(final PolicySourceModel model) {
        this.parentModel = model;

        for (ModelNode child : children) {
            child.updateParentModelReference(model);
        }
    }

    
Returns the parent policy source model that contains this model node.
Returns:
the parent policy source model/**
     * Returns the parent policy source model that contains this model node.
     *
     * @return the parent policy source model
     */
    public PolicySourceModel getParentModel() {
        return parentModel;
    }

    
Returns the type of this policy source model node.
Returns:
actual type of this policy source model node/**
     * Returns the type of this policy source model node.
     *
     * @return actual type of this policy source model node
     */
    public ModelNode.Type getType() {
        return type;
    }

    
Returns the parent referenced by this policy source model node.
Returns:
current parent of this policy source model node or null if the node does not have a parent currently./**
     * Returns the parent referenced by this policy source model node.
     *
     * @return current parent of this policy source model node or {@code null} if the node does not have a parent currently.
     */
    public ModelNode getParentNode() {
        return parentNode;
    }

    
Returns the data for this policy source model node (if any). The model node data are expected to be not null only in case the type of this node is ASSERTION or ASSERTION_PARAMETER_NODE. 
Returns:
the data of this policy source model node or null if the node does not have any data associated to it attached./**
     * Returns the data for this policy source model node (if any). The model node data are expected to be not {@code null} only in
     * case the type of this node is ASSERTION or ASSERTION_PARAMETER_NODE.
     *
     * @return the data of this policy source model node or {@code null} if the node does not have any data associated to it
     * attached.
     */
    public AssertionData getNodeData() {
        return nodeData;
    }

    
Returns the policy reference data for this policy source model node. The policy reference data are expected to be not null only in case the type of this node is POLICY_REFERENCE. 
Returns:
the policy reference data for this policy source model node or null if the node does not have any policy reference data attached./**
     * Returns the policy reference data for this policy source model node. The policy reference data are expected to be not {@code null} only in
     * case the type of this node is POLICY_REFERENCE.
     *
     * @return the policy reference data for this policy source model node or {@code null} if the node does not have any policy reference data
     * attached.
     */
    PolicyReferenceData getPolicyReferenceData() {
        return referenceData;
    }

    
The method may be used to set or replace assertion data set for this node. If there are assertion data set already,
those are replaced by a new reference and eventualy returned from the method.
 This method is supported only in case this model node instance's type is ASSERTION or ASSERTION_PARAMETER_NODE. If used from other node types, an exception is thrown. 
Params:
newData – new assertion data to be set.
Throws:
UnsupportedOperationException – in case this method is called on nodes of type other than ASSERTION or ASSERTION_PARAMETER_NODE
Returns:
old and replaced assertion data if any or null otherwise./**
     * The method may be used to set or replace assertion data set for this node. If there are assertion data set already,
     * those are replaced by a new reference and eventualy returned from the method.
     * <p/>
     * This method is supported only in case this model node instance's type is {@code ASSERTION} or {@code ASSERTION_PARAMETER_NODE}.
     * If used from other node types, an exception is thrown.
     *
     * @param newData new assertion data to be set.
     * @return old and replaced assertion data if any or {@code null} otherwise.
     *
     * @throws UnsupportedOperationException in case this method is called on nodes of type other than {@code ASSERTION}
     * or {@code ASSERTION_PARAMETER_NODE}
     */
    public AssertionData setOrReplaceNodeData(final AssertionData newData) {
        if (!isDomainSpecific()) {
            throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0051_OPERATION_NOT_SUPPORTED_FOR_THIS_BUT_ASSERTION_RELATED_NODE_TYPE(type)));
        }

        final AssertionData oldData = this.nodeData;
        this.nodeData = newData;

        return oldData;
    }

    
The method specifies whether the model node instance represents assertion related node, it means whether its type is 'ASSERTION' or 'ASSERTION_PARAMETER_NODE'. This is, for example, the way to determine whether the node supports setting a AssertionData object via setOrReplaceNodeData(AssertionData) method or not. 
Returns:
true or false according to whether the node instance represents assertion related node or not./**
     * The method specifies whether the model node instance represents assertion related node, it means whether its type
     * is 'ASSERTION' or 'ASSERTION_PARAMETER_NODE'. This is, for example, the way to determine whether the node supports
     * setting a {@link AssertionData} object via {@link #setOrReplaceNodeData(AssertionData)} method or not.
     *
     * @return {@code true} or {@code false} according to whether the node instance represents assertion related node or not.
     */
    boolean isDomainSpecific() {
        return type == Type.ASSERTION || type == Type.ASSERTION_PARAMETER_NODE;
    }

    
Appends the specified child node to the end of the children list of this node and sets it's parent to reference
this node.
Params:
child – node to be appended to the children list of this node.
Throws:
NullPointerException – if the specified node is null.
IllegalArgumentException – if child has a parent node set already to point to some node
Returns:
true (as per the general contract of the Collection.add method)./**
     * Appends the specified child node to the end of the children list of this node and sets it's parent to reference
     * this node.
     *
     * @param child node to be appended to the children list of this node.
     * @return {@code true} (as per the general contract of the {@code Collection.add} method).
     *
     * @throws NullPointerException if the specified node is {@code null}.
     * @throws IllegalArgumentException if child has a parent node set already to point to some node
     */
    private boolean addChild(final ModelNode child) {
        children.add(child);
        child.parentNode = this;

        return true;
    }

    void setReferencedModel(final PolicySourceModel model) {
        if (this.type != Type.POLICY_REFERENCE) {
            throw LOGGER.logSevereException(new UnsupportedOperationException(LocalizationMessages.WSP_0050_OPERATION_NOT_SUPPORTED_FOR_THIS_BUT_POLICY_REFERENCE_NODE_TYPE(type)));
        }

        referencedModel = model;
    }

    PolicySourceModel getReferencedModel() {
        return referencedModel;
    }

    
Returns the number of child policy source model nodes. If this model node contains more than Integer.MAX_VALUE children, returns Integer.MAX_VALUE. 
Returns:
the number of children of this node./**
     * Returns the number of child policy source model nodes. If this model node contains
     * more than {@code Integer.MAX_VALUE} children, returns {@code Integer.MAX_VALUE}.
     *
     * @return the number of children of this node.
     */
    public int childrenSize() {
        return children.size();
    }

    
Returns true if the node has at least one child node.
Returns:
true if the node has at least one child node, false otherwise./**
     * Returns true if the node has at least one child node.
     *
     * @return true if the node has at least one child node, false otherwise.
     */
    public boolean hasChildren() {
        return !children.isEmpty();
    }

    
Iterates through all child nodes.
Returns:
An iterator for the child nodes/**
     * Iterates through all child nodes.
     *
     * @return An iterator for the child nodes
     */
    public Iterator<ModelNode> iterator() {
        return children.iterator();
    }

    
An Object.equals(Object obj) method override. Method ignores the parent source model. It means that two model nodes may be the same even if they belong to different models. 
 If parent model comparison is desired, it must be accomplished separately. To perform that, the reference equality test is sufficient (nodeA.getParentModel() == nodeB.getParentModel()), since all model nodes are created for specific model instances. /**
     * An {@code Object.equals(Object obj)} method override. Method ignores the parent source model. It means that two
     * model nodes may be the same even if they belong to different models.
     * <p/>
     * If parent model comparison is desired, it must be accomplished separately. To perform that, the reference equality
     * test is sufficient ({@code nodeA.getParentModel() == nodeB.getParentModel()}), since all model nodes are created
     * for specific model instances.
     */
    @Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }

        if (!(obj instanceof ModelNode)) {
            return false;
        }

        boolean result = true;
        final ModelNode that = (ModelNode) obj;

        result = result && this.type.equals(that.type);
        // result = result && ((this.parentNode == null) ? that.parentNode == null : this.parentNode.equals(that.parentNode));
        result = result && ((this.nodeData == null) ? that.nodeData == null : this.nodeData.equals(that.nodeData));
        result = result && ((this.children == null) ? that.children == null : this.children.equals(that.children));

        return result;
    }

    
An Object.hashCode() method override. /**
     * An {@code Object.hashCode()} method override.
     */
    @Override
    public int hashCode() {
        int result = 17;

        result = 37 * result + this.type.hashCode();
        result = 37 * result + ((this.parentNode == null) ? 0 : this.parentNode.hashCode());
        result = 37 * result + ((this.nodeData == null) ? 0 : this.nodeData.hashCode());
        result = 37 * result + this.children.hashCode();

        return result;
    }

    
Returns a string representation of the object. In general, the toString method
returns a string that "textually represents" this object.
Returns:
 a string representation of the object./**
     * Returns a string representation of the object. In general, the <code>toString</code> method
     * returns a string that "textually represents" this object.
     *
     * @return  a string representation of the object.
     */
    @Override
    public String toString() {
        return toString(0, new StringBuffer()).toString();
    }

    
A helper method that appends indented string representation of this instance to the input string buffer.
Params:
indentLevel – indentation level to be used.
buffer – buffer to be used for appending string representation of this instance
Returns:
modified buffer containing new string representation of the instance/**
     * A helper method that appends indented string representation of this instance to the input string buffer.
     *
     * @param indentLevel indentation level to be used.
     * @param buffer buffer to be used for appending string representation of this instance
     * @return modified buffer containing new string representation of the instance
     */
    public StringBuffer toString(final int indentLevel, final StringBuffer buffer) {
        final String indent = PolicyUtils.Text.createIndent(indentLevel);
        final String innerIndent = PolicyUtils.Text.createIndent(indentLevel + 1);

        buffer.append(indent).append(type).append(" {").append(PolicyUtils.Text.NEW_LINE);
        if (type == Type.ASSERTION) {
            if (nodeData == null) {
                buffer.append(innerIndent).append("no assertion data set");
            } else {
                nodeData.toString(indentLevel + 1, buffer);
            }
            buffer.append(PolicyUtils.Text.NEW_LINE);
        } else if (type == Type.POLICY_REFERENCE) {
            if (referenceData == null) {
                buffer.append(innerIndent).append("no policy reference data set");
            } else {
                referenceData.toString(indentLevel + 1, buffer);
            }
            buffer.append(PolicyUtils.Text.NEW_LINE);
        } else if (type == Type.ASSERTION_PARAMETER_NODE) {
            if (nodeData == null) {
                buffer.append(innerIndent).append("no parameter data set");
            }
            else {
                nodeData.toString(indentLevel + 1, buffer);
            }
            buffer.append(PolicyUtils.Text.NEW_LINE);
        }

        if (children.size() > 0) {
            for (ModelNode child : children) {
                child.toString(indentLevel + 1, buffer).append(PolicyUtils.Text.NEW_LINE);
            }
        } else {
            buffer.append(innerIndent).append("no child nodes").append(PolicyUtils.Text.NEW_LINE);
        }

        buffer.append(indent).append('}');
        return buffer;
    }

    @Override
    protected ModelNode clone() throws CloneNotSupportedException {
        final ModelNode clone = (ModelNode) super.clone();

        if (this.nodeData != null) {
            clone.nodeData = this.nodeData.clone();
        }

        // no need to clone PolicyReferenceData, since those are immutable

        if (this.referencedModel != null) {
            clone.referencedModel = this.referencedModel.clone();
        }


        clone.children = new LinkedList<ModelNode>();
        clone.unmodifiableViewOnContent = Collections.unmodifiableCollection(clone.children);

        for (ModelNode thisChild : this.children) {
            clone.addChild(thisChild.clone());
        }

        return clone;
    }

    PolicyReferenceData getReferenceData() {
        return referenceData;
    }
}