[ONOS-3905, ONOS-3901, ONOS-3900] choice, grouping and augment data model support.

Change-Id: Iaee5175e4e06249f5b56192f4744e9297289194c
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangCase.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangCase.java
new file mode 100644
index 0000000..b3a17bd
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangCase.java
@@ -0,0 +1,333 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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 org.onosproject.yangutils.datamodel;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.ParsableDataType;
+
+/*-
+ * Reference RFC 6020.
+ *
+ * The "case" statement is used to define branches of the choice. It takes as an
+ * argument an identifier, followed by a block of sub-statements that holds
+ * detailed case information.
+ *
+ * The identifier is used to identify the case node in the schema tree. A case
+ * node does not exist in the data tree.
+ *
+ * Within a "case" statement, the "anyxml", "choice", "container", "leaf",
+ * "list", "leaf-list", and "uses" statements can be used to define child nodes
+ * to the case node. The identifiers of all these child nodes MUST be unique
+ * within all cases in a choice. For example, the following is illegal:
+ *
+ * choice interface-type {     // This example is illegal YANG
+ *        case a {
+ *            leaf ethernet { ... }
+ *        }
+ *        case b {
+ *            container ethernet { ...}
+ *        }
+ *    }
+ *
+ *  As a shorthand, the "case" statement can be omitted if the branch
+ *  contains a single "anyxml", "container", "leaf", "list", or
+ *  "leaf-list" statement.  In this case, the identifier of the case node
+ *  is the same as the identifier in the branch statement.  The following
+ *  example:
+ *
+ *    choice interface-type {
+ *        container ethernet { ... }
+ *    }
+ *
+ *  is equivalent to:
+ *
+ *    choice interface-type {
+ *        case ethernet {
+ *            container ethernet { ... }
+ *        }
+ *    }
+ *
+ *  The case identifier MUST be unique within a choice.
+ *
+ *  The case's sub-statements
+ *
+ *                +--------------+---------+-------------+------------------+
+ *                | substatement | section | cardinality |data model mapping|
+ *                +--------------+---------+-------------+------------------+
+ *                | anyxml       | 7.10    | 0..n        |-not supported    |
+ *                | choice       | 7.9     | 0..n        |-child nodes      |
+ *                | container    | 7.5     | 0..n        |-child nodes      |
+ *                | description  | 7.19.3  | 0..1        |-string           |
+ *                | if-feature   | 7.18.2  | 0..n        |-TODO             |
+ *                | leaf         | 7.6     | 0..n        |-YangLeaf         |
+ *                | leaf-list    | 7.7     | 0..n        |-YangLeafList     |
+ *                | list         | 7.8     | 0..n        |-child nodes      |
+ *                | reference    | 7.19.4  | 0..1        |-string           |
+ *                | status       | 7.19.2  | 0..1        |-YangStatus       |
+ *                | uses         | 7.12    | 0..n        |-child node       |
+ *                | when         | 7.19.5  | 0..1        |-TODO             |
+ *                +--------------+---------+-------------+------------------+
+ */
+/**
+ * Data model node to maintain information defined in YANG case.
+ */
+public class YangCase extends YangNode
+        implements YangLeavesHolder, YangCommonInfo, Parsable {
+
+    /**
+     * Case name.
+     */
+    private String name;
+
+    // TODO: default field identification for the case
+
+    /**
+     * Description of container.
+     */
+    private String description;
+
+    /**
+     * List of leaves.
+     */
+    @SuppressWarnings("rawtypes")
+    private List<YangLeaf> listOfLeaf;
+
+    /**
+     * List of leaf lists.
+     */
+    @SuppressWarnings("rawtypes")
+    private List<YangLeafList> listOfLeafList;
+
+    /**
+     * Reference of the module.
+     */
+    private String reference;
+
+    /**
+     * Status of the node.
+     */
+    private YangStatusType status;
+
+    /**
+     * Create a choice node.
+     */
+    public YangCase() {
+        super(YangNodeType.CASE_NODE);
+    }
+
+    /* (non-Javadoc)
+     * @see org.onosproject.yangutils.datamodel.YangNode#getName()
+     */
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    /* (non-Javadoc)
+     * @see org.onosproject.yangutils.datamodel.YangNode#setName(java.lang.String)
+     */
+    @Override
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    /**
+     * Get the description.
+     *
+     * @return the description.
+     */
+    public String getDescription() {
+        return description;
+    }
+
+    /**
+     * Set the description.
+     *
+     * @param description set the description.
+     */
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    /**
+     * Get the list of leaves.
+     *
+     * @return the list of leaves.
+     */
+    @SuppressWarnings("rawtypes")
+    public List<YangLeaf> getListOfLeaf() {
+        return listOfLeaf;
+    }
+
+    /**
+     * Set the list of leaves.
+     *
+     * @param leafsList the list of leaf to set.
+     */
+    @SuppressWarnings("rawtypes")
+    private void setListOfLeaf(List<YangLeaf> leafsList) {
+        listOfLeaf = leafsList;
+    }
+
+    /**
+     * Add a leaf.
+     *
+     * @param leaf the leaf to be added.
+     */
+    @SuppressWarnings("rawtypes")
+    public void addLeaf(YangLeaf<?> leaf) {
+        if (getListOfLeaf() == null) {
+            setListOfLeaf(new LinkedList<YangLeaf>());
+        }
+
+        getListOfLeaf().add(leaf);
+    }
+
+    /**
+     * Get the list of leaf-list.
+     *
+     * @return the list of leaf-list.
+     */
+    @SuppressWarnings("rawtypes")
+    public List<YangLeafList> getListOfLeafList() {
+        return listOfLeafList;
+    }
+
+    /**
+     * Set the list of leaf-list.
+     *
+     * @param listOfLeafList the list of leaf-list to set.
+     */
+    @SuppressWarnings("rawtypes")
+    private void setListOfLeafList(List<YangLeafList> listOfLeafList) {
+        this.listOfLeafList = listOfLeafList;
+    }
+
+    /**
+     * Add a leaf-list.
+     *
+     * @param leafList the leaf-list to be added.
+     */
+    @SuppressWarnings("rawtypes")
+    public void addLeafList(YangLeafList<?> leafList) {
+        if (getListOfLeafList() == null) {
+            setListOfLeafList(new LinkedList<YangLeafList>());
+        }
+
+        getListOfLeafList().add(leafList);
+    }
+
+    /**
+     * Get the textual reference.
+     *
+     * @return the reference.
+     */
+    public String getReference() {
+        return reference;
+    }
+
+    /**
+     * Set the textual reference.
+     *
+     * @param reference the reference to set.
+     */
+    public void setReference(String reference) {
+        this.reference = reference;
+    }
+
+    /**
+     * Get the status.
+     *
+     * @return the status.
+     */
+    public YangStatusType getStatus() {
+        return status;
+    }
+
+    /**
+     * Set the status.
+     *
+     * @param status the status to set.
+     */
+    public void setStatus(YangStatusType status) {
+        this.status = status;
+    }
+
+    /**
+     * Returns the type of the data.
+     *
+     * @return returns CASE_DATA
+     */
+    public ParsableDataType getParsableDataType() {
+        return ParsableDataType.CASE_DATA;
+    }
+
+    /**
+     * Validate the data on entering the corresponding parse tree node.
+     *
+     * @throws DataModelException a violation of data model rules.
+     */
+    public void validateDataOnEntry() throws DataModelException {
+        // TODO auto-generated method stub, to be implemented by parser
+    }
+
+    /**
+     * Validate the data on exiting the corresponding parse tree node.
+     *
+     * @throws DataModelException a violation of data model rules.
+     */
+    public void validateDataOnExit() throws DataModelException {
+        // TODO auto-generated method stub, to be implemented by parser
+    }
+
+    /* (non-Javadoc)
+     * @see org.onosproject.yangutils.datamodel.YangNode#getPackage()
+     */
+    @Override
+    public String getPackage() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    /* (non-Javadoc)
+     * @see org.onosproject.yangutils.datamodel.YangNode#setPackage(java.lang.String)
+     */
+    @Override
+    public void setPackage(String pkg) {
+        // TODO Auto-generated method stub
+
+    }
+
+    /* (non-Javadoc)
+     * @see org.onosproject.yangutils.translator.CodeGenerator#generateJavaCodeEntry()
+     */
+    public void generateJavaCodeEntry() {
+        // TODO Auto-generated method stub
+
+    }
+
+    /* (non-Javadoc)
+     * @see org.onosproject.yangutils.translator.CodeGenerator#generateJavaCodeExit()
+     */
+    public void generateJavaCodeExit() {
+        // TODO Auto-generated method stub
+
+    }
+}