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

Change-Id: Iacac75e4187aed93ce1754c170a9c19707e5b8c3
diff --git a/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java b/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java
new file mode 100644
index 0000000..2240c16
--- /dev/null
+++ b/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java
@@ -0,0 +1,223 @@
+/*
+ * 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;
+
+import org.onosproject.yangutils.datamodel.YangAugment;
+import org.onosproject.yangutils.datamodel.YangCase;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangGrouping;
+import org.onosproject.yangutils.datamodel.YangInput;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeIdentifier;
+import org.onosproject.yangutils.datamodel.YangNotification;
+import org.onosproject.yangutils.datamodel.YangOutput;
+import org.onosproject.yangutils.datamodel.YangSubModule;
+import org.onosproject.yangutils.datamodel.YangUses;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.datamodel.utils.Parsable;
+import org.onosproject.yangutils.linker.impl.YangResolutionInfoImpl;
+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.DataModelUtils.addResolutionInfo;
+import static org.onosproject.yangutils.datamodel.utils.GeneratedLanguage.JAVA_GENERATION;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.DESCRIPTION_DATA;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.REFERENCE_DATA;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.STATUS_DATA;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.USES_DATA;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.WHEN_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerCollisionDetector.detectCollidingChildUtil;
+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_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidNodeIdentifier;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityMaxOne;
+import static org.onosproject.yangutils.translator.tojava.YangDataModelFactory.getYangUsesNode;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ * data-def-stmt       = container-stmt /
+ *                      leaf-stmt /
+ *                      leaf-list-stmt /
+ *                      list-stmt /
+ *                      choice-stmt /
+ *                      anyxml-stmt /
+ *                      uses-stmt
+ *
+ * uses-stmt           = uses-keyword sep identifier-ref-arg-str optsep
+ *                       (";" /
+ *                        "{" stmtsep
+ *                            ;; these stmts can appear in any order
+ *                            [when-stmt stmtsep]
+ *                            *(if-feature-stmt stmtsep)
+ *                            [status-stmt stmtsep]
+ *                            [description-stmt stmtsep]
+ *                            [reference-stmt stmtsep]
+ *                            *(refine-stmt stmtsep)
+ *                            *(uses-augment-stmt stmtsep)
+ *                        "}")
+ *
+ * ANTLR grammar rule
+ * dataDefStatement : containerStatement
+ *                 | leafStatement
+ *                 | leafListStatement
+ *                 | listStatement
+ *                 | choiceStatement
+ *                 | usesStatement;
+ *
+ * usesStatement : USES_KEYWORD string (STMTEND | LEFT_CURLY_BRACE (whenStatement | ifFeatureStatement
+ *                 | statusStatement | descriptionStatement | referenceStatement | refineStatement
+ *                 | usesAugmentStatement)* RIGHT_CURLY_BRACE);
+ */
+
+/**
+ * Represents listener based call back function corresponding to the "uses"
+ * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class UsesListener {
+
+    /**
+     * Creates a new uses listener.
+     */
+    private UsesListener() {
+    }
+
+    /**
+     * It is called when parser enters grammar rule (uses), 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 processUsesEntry(TreeWalkListener listener, GeneratedYangParser.UsesStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, USES_DATA, ctx.string().getText(), ENTRY);
+
+        // Validate sub statement cardinality.
+        validateSubStatementsCardinality(ctx);
+
+        // Check for identifier collision
+        int line = ctx.getStart().getLine();
+        int charPositionInLine = ctx.getStart().getCharPositionInLine();
+
+        detectCollidingChildUtil(listener, line, charPositionInLine, ctx.string().getText(), USES_DATA);
+        Parsable curData = listener.getParsedDataStack().peek();
+
+        if (curData instanceof YangModule || curData instanceof YangSubModule
+                || curData instanceof YangContainer || curData instanceof YangList
+                || curData instanceof YangUses || curData instanceof YangAugment
+                || curData instanceof YangCase || curData instanceof YangGrouping
+                || curData instanceof YangInput || curData instanceof YangOutput
+                || curData instanceof YangNotification) {
+
+            YangUses usesNode = getYangUsesNode(JAVA_GENERATION);
+            YangNodeIdentifier nodeIdentifier = getValidNodeIdentifier(ctx.string().getText(), USES_DATA, ctx);
+            usesNode.setNodeIdentifier(nodeIdentifier);
+            YangNode curNode = (YangNode) curData;
+
+            try {
+                curNode.addChild(usesNode);
+            } catch (DataModelException e) {
+                throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA,
+                        USES_DATA, ctx.string().getText(), ENTRY, e.getMessage()));
+            }
+            listener.getParsedDataStack().push(usesNode);
+        } else {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER,
+                    USES_DATA, ctx.string().getText(), ENTRY));
+        }
+    }
+
+    /**
+     * It is called when parser exits from grammar rule (uses), 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 processUsesExit(TreeWalkListener listener,
+                                       GeneratedYangParser.UsesStatementContext ctx) {
+
+        // Check for stack to be non empty.
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, USES_DATA, ctx.string().getText(), EXIT);
+
+        Parsable parsableUses = listener.getParsedDataStack().pop();
+        if (!(parsableUses instanceof YangUses)) {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, USES_DATA,
+                    ctx.string().getText(), EXIT));
+        }
+        YangUses uses = (YangUses) parsableUses;
+        int errorLine = ctx.getStart().getLine();
+        int errorPosition = ctx.getStart().getCharPositionInLine();
+
+        // Parent YANG node of uses to be added in resolution information.
+        Parsable parentNode = listener.getParsedDataStack().peek();
+
+        // Verify parent node of leaf
+        if (!(parentNode instanceof YangNode)) {
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, USES_DATA,
+                    ctx.string().getText(), EXIT));
+        }
+
+        // Add resolution information to the list
+        YangResolutionInfoImpl resolutionInfo = new YangResolutionInfoImpl<YangUses>(uses,
+                (YangNode) parentNode, errorLine,
+                errorPosition);
+        addToResolutionList(resolutionInfo, ctx);
+    }
+
+    // TODO linker to handle collision scenarios like leaf obtained by uses, conflicts with some existing leaf.
+
+    /**
+     * Validates the cardinality of case sub-statements as per grammar.
+     *
+     * @param ctx context object of the grammar rule
+     */
+    private static void validateSubStatementsCardinality(GeneratedYangParser.UsesStatementContext ctx) {
+        validateCardinalityMaxOne(ctx.whenStatement(), WHEN_DATA, USES_DATA, ctx.string().getText());
+        validateCardinalityMaxOne(ctx.statusStatement(), STATUS_DATA, USES_DATA, ctx.string().getText());
+        validateCardinalityMaxOne(ctx.descriptionStatement(), DESCRIPTION_DATA, USES_DATA, ctx.string().getText());
+        validateCardinalityMaxOne(ctx.referenceStatement(), REFERENCE_DATA, USES_DATA, ctx.string().getText());
+    }
+
+    /**
+     * Add to resolution list.
+     *
+     * @param resolutionInfo resolution information.
+     * @param ctx            context object of the grammar rule
+     */
+    private static void addToResolutionList(YangResolutionInfoImpl<YangUses> resolutionInfo,
+                                            GeneratedYangParser.UsesStatementContext ctx) {
+
+        try {
+            addResolutionInfo(resolutionInfo);
+        } catch (DataModelException e) {
+            throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA,
+                    USES_DATA, ctx.string().getText(), EXIT, e.getMessage()));
+        }
+    }
+}