[ONOS-4350] Inter Jar dependency implementation and code restructuring.

Change-Id: Iacac75e4187aed93ce1754c170a9c19707e5b8c3
diff --git a/utils/yangutils/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumerationListener.java b/utils/yangutils/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumerationListener.java
new file mode 100644
index 0000000..2db40f3
--- /dev/null
+++ b/utils/yangutils/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumerationListener.java
@@ -0,0 +1,225 @@
+/*
+ * Copyright 2016-present 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.parser.impl.listeners;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ * type-body-stmts     = numerical-restrictions /
+ *                       decimal64-specification /
+ *                      string-restrictions /
+ *                       enum-specification /
+ *                       leafref-specification /
+ *                       identityref-specification /
+ *                       instance-identifier-specification /
+ *                       bits-specification /
+ *                       union-specification
+ *
+ * enum-specification  = 1*(enum-stmt stmtsep)
+ *
+ * ANTLR grammar rule
+ *
+ * typeBodyStatements : numericalRestrictions | stringRestrictions | enumSpecification
+ *                 | leafrefSpecification | identityrefSpecification | instanceIdentifierSpecification
+ *                 | bitsSpecification | unionSpecification;
+ *
+ * enumSpecification : enumStatement+;
+ */
+
+import org.onosproject.yangutils.datamodel.YangEnumeration;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.YangTypeDef;
+import org.onosproject.yangutils.datamodel.YangUnion;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.datamodel.utils.Parsable;
+import org.onosproject.yangutils.datamodel.utils.YangConstructType;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
+import static org.onosproject.yangutils.datamodel.utils.GeneratedLanguage.JAVA_GENERATION;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.ENUMERATION_DATA;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.TYPE_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.translator.tojava.YangDataModelFactory.getYangEnumerationNode;
+
+/**
+ * Represents listener based call back function corresponding to the
+ * "enumeration" rule defined in ANTLR grammar file for corresponding ABNF rule
+ * in RFC 6020.
+ */
+public final class EnumerationListener {
+
+    /**
+     * Suffix to be used while creating enumeration class.
+     */
+    private static final String ENUMERATION_CLASS_SUFFIX = "_enum";
+
+    /**
+     * Creates a new enumeration listener.
+     */
+    private EnumerationListener() {
+    }
+
+    /**
+     * It is called when parser enters grammar rule (enumeration), it perform
+     * validations and updates the data model tree.
+     *
+     * @param listener listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processEnumerationEntry(TreeWalkListener listener,
+            GeneratedYangParser.EnumSpecificationContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, ENUMERATION_DATA, "", ENTRY);
+
+        if (listener.getParsedDataStack().peek() instanceof YangType) {
+            YangEnumeration enumerationNode = getYangEnumerationNode(JAVA_GENERATION);
+            Parsable typeData = listener.getParsedDataStack().pop();
+
+            // Check for stack to be non empty.
+            checkStackIsNotEmpty(listener, MISSING_HOLDER, ENUMERATION_DATA, "", ENTRY);
+
+            Parsable tmpData = listener.getParsedDataStack().peek();
+
+            switch (tmpData.getYangConstructType()) {
+                case LEAF_DATA:
+                    // Set the name of enumeration same as leaf.
+                    enumerationNode.setName(((YangLeaf) tmpData).getName() + ENUMERATION_CLASS_SUFFIX);
+                    // Pop the stack entry to obtain the parent YANG node.
+                    Parsable leaf = listener.getParsedDataStack().pop();
+                    // Add the enumeration node to the parent holder of leaf.
+                    addChildToParentNode(listener, enumerationNode);
+                    // Push the popped entry back to the stack.
+                    listener.getParsedDataStack().push(leaf);
+                    break;
+                case LEAF_LIST_DATA:
+                    // Set the name of enumeration same as leaf list.
+                    enumerationNode.setName(((YangLeafList) tmpData).getName() + ENUMERATION_CLASS_SUFFIX);
+                    // Pop the stack entry to obtain the parent YANG node.
+                    Parsable leafList = listener.getParsedDataStack().pop();
+                    // Add the enumeration node to the parent holder of leaf.
+                    addChildToParentNode(listener, enumerationNode);
+                    // Push the popped entry back to the stack.
+                    listener.getParsedDataStack().push(leafList);
+                    break;
+                case UNION_DATA:
+                    YangUnion yangUnion = (YangUnion) tmpData;
+                    /*
+                     * In case parent of enumeration is a union, name of the
+                     * enumeration is parent union name suffixed with running
+                     * integer number, this is done because under union there
+                     * could be multiple child union types.
+                     */
+                    enumerationNode.setName(yangUnion.getName() + ENUMERATION_CLASS_SUFFIX
+                            + yangUnion.getChildUnionNumber());
+                    // Increment the running number.
+                    yangUnion.setChildUnionNumber(yangUnion.getChildUnionNumber() + 1);
+                    // Add union as a child to parent union.
+                    addChildToParentNode(listener, enumerationNode);
+                    break;
+                case TYPEDEF_DATA:
+                    YangTypeDef typeDef = (YangTypeDef) tmpData;
+                    // Set the name of enumeration same as typedef name.
+                    enumerationNode.setName(typeDef.getName() + ENUMERATION_CLASS_SUFFIX);
+                    // Add enumeration as a child to parent type def.
+                    addChildToParentNode(listener, enumerationNode);
+                    break;
+                // TODO deviate.
+                default:
+                    throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, TYPE_DATA,
+                            ((YangType<?>) typeData).getDataTypeName(), ENTRY));
+            }
+            listener.getParsedDataStack().push(typeData);
+            listener.getParsedDataStack().push(enumerationNode);
+        } else {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, ENUMERATION_DATA, "", ENTRY));
+        }
+    }
+
+    /**
+     * It is called when parser exits from grammar rule (enumeration), it
+     * perform validations and update the data model tree.
+     *
+     * @param listener Listener's object
+     * @param ctx context object of the grammar rule
+     */
+    public static void processEnumerationExit(TreeWalkListener listener,
+            GeneratedYangParser.EnumSpecificationContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, ENUMERATION_DATA, "", EXIT);
+
+        Parsable tmpEnumerationNode = listener.getParsedDataStack().peek();
+        if (tmpEnumerationNode instanceof YangEnumeration) {
+            YangEnumeration enumerationNode = (YangEnumeration) tmpEnumerationNode;
+            listener.getParsedDataStack().pop();
+
+            // Check for stack to be non empty.
+            checkStackIsNotEmpty(listener, MISSING_HOLDER, ENUMERATION_DATA, "", EXIT);
+
+            Parsable tmpNode = listener.getParsedDataStack().peek();
+            switch (tmpNode.getYangConstructType()) {
+                case TYPE_DATA: {
+                    YangType<YangEnumeration> typeNode = (YangType<YangEnumeration>) tmpNode;
+                    typeNode.setDataTypeExtendedInfo(enumerationNode);
+                    break;
+                }
+                default:
+                    throw new ParserException(
+                            constructListenerErrorMessage(INVALID_HOLDER, ENUMERATION_DATA, "", EXIT));
+            }
+        } else {
+            throw new ParserException(
+                    constructListenerErrorMessage(MISSING_CURRENT_HOLDER, ENUMERATION_DATA, "", EXIT));
+        }
+    }
+
+    /**
+     * Adds the enumeration node to the parent holder.
+     *
+     * @param listener listener's object
+     * @param enumerationNode enumeration node which needs to be added to parent
+     */
+    private static void addChildToParentNode(TreeWalkListener listener, YangEnumeration enumerationNode) {
+        if (!(listener.getParsedDataStack().peek() instanceof YangNode)) {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, ENUMERATION_DATA,
+                    "", ENTRY));
+        } else {
+            YangNode curNode = (YangNode) listener.getParsedDataStack().peek();
+            try {
+                curNode.addChild(enumerationNode);
+            } catch (DataModelException e) {
+                throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA,
+                        YangConstructType.ENUMERATION_DATA, "", ENTRY, e.getMessage()));
+            }
+        }
+    }
+}