[ONOS-3906],[ONOS-3910] Implementation of YANG module and leaf/leaf-list translator.

Change-Id: If1a8a991ffafa14b51211f97c435176ee1bf856f
diff --git a/src/main/java/org/onosproject/yangutils/translator/tojava/CachedJavaFileHandle.java b/src/main/java/org/onosproject/yangutils/translator/tojava/CachedJavaFileHandle.java
new file mode 100644
index 0000000..86656e9
--- /dev/null
+++ b/src/main/java/org/onosproject/yangutils/translator/tojava/CachedJavaFileHandle.java
@@ -0,0 +1,652 @@
+/*
+ * 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.translator.tojava;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.translator.CachedFileHandle;
+import org.onosproject.yangutils.translator.GeneratedFileType;
+import org.onosproject.yangutils.translator.tojava.utils.JavaCodeSnippetGen;
+import org.onosproject.yangutils.translator.tojava.utils.JavaIdentifierSyntax;
+import org.onosproject.yangutils.translator.tojava.utils.MethodsGenerator;
+import org.onosproject.yangutils.utils.UtilConstants;
+import org.onosproject.yangutils.utils.io.impl.FileSystemUtil;
+import org.onosproject.yangutils.utils.io.impl.JavaDocGen;
+import org.onosproject.yangutils.utils.io.impl.SerializedDataStore;
+import org.onosproject.yangutils.utils.io.impl.JavaDocGen.JavaDocType;
+import org.onosproject.yangutils.utils.io.impl.CopyrightHeader;
+
+import static org.slf4j.LoggerFactory.getLogger;
+import org.slf4j.Logger;
+
+/**
+ * Maintain the information about the java file to be generated.
+ */
+public class CachedJavaFileHandle implements CachedFileHandle {
+
+    private static final Logger log = getLogger(CachedJavaFileHandle.class);
+
+    private static final int MAX_CACHABLE_ATTR = 64;
+    private static final String JAVA_FILE_EXTENSION = ".java";
+    private static final String TEMP_FILE_EXTENSION = ".tmp";
+
+    /**
+     * The type(s) of java source file(s) to be generated when the cached file
+     * handle is closed.
+     */
+    private GeneratedFileType genFileTypes;
+
+    /**
+     * The type(s) of java method to be generated when the cached file handle is
+     * closed.
+     */
+    private GeneratedMethodTypes genMethodTypes;
+
+    /**
+     * Java package in which the class/interface needs to be generated.
+     */
+    private String pkg;
+
+    /**
+     * Name of the object in YANG file.
+     */
+    private String yangName;
+
+    /**
+     * Sorted set of import info, to be used to maintain the set of classes to
+     * be imported in the generated class.
+     */
+    private SortedSet<ImportInfo> importSet;
+
+    /**
+     * Cached list of attribute info.
+     */
+    private List<AttributeInfo> attributeList;
+
+    /**
+     * Prevent invoking default constructor.
+     */
+    private CachedJavaFileHandle() {
+        setCachedAttributeList(new LinkedList<AttributeInfo>());
+    }
+
+    /**
+     * Create a cached file handle which takes care of adding attributes to the
+     * generated java file.
+     *
+     * @param pcg package in which class/interface need to be generated.
+     * @param yangName name of the attribute in YANG file.
+     * @param types the types of files that needs to be generated.
+     * @throws IOException file IO exception.
+     */
+    public CachedJavaFileHandle(String pcg, String yangName, GeneratedFileType types) throws IOException {
+        if ((new File(pcg).exists())) {
+            setGeneratedFileTypes(types);
+            setPackage(pcg);
+            setYangName(yangName);
+        } else {
+            FileSystemUtil.createPackage(pcg, yangName);
+            setGeneratedFileTypes(types);
+            setPackage(pcg);
+            setYangName(yangName);
+        }
+    }
+
+    /**
+     * Get the types of files being generated corresponding to the YANG
+     * definition.
+     *
+     * @return the types of files being generated corresponding to the YANG
+     *         definition.
+     */
+    public GeneratedFileType getGeneratedFileTypes() {
+        return genFileTypes;
+    }
+
+    /**
+     * Set the types of files being generated corresponding to the YANG
+     * definition.
+     *
+     * @param fileTypes the types of files being generated corresponding to the
+     *            YANG definition.
+     */
+    public void setGeneratedFileTypes(GeneratedFileType fileTypes) {
+        genFileTypes = fileTypes;
+    }
+
+    /**
+     * Get the corresponding name defined in YANG.
+     *
+     * @return the corresponding name defined in YANG.
+     */
+    public String getYangName() {
+        return yangName;
+    }
+
+    /**
+     * Set the corresponding name defined in YANG.
+     *
+     * @param yangName the corresponding name defined in YANG.
+     */
+    public void setYangName(String yangName) {
+        this.yangName = yangName;
+    }
+
+    /**
+     * Get the java package.
+     *
+     * @return the java package.
+     */
+    public String getPackage() {
+        return pkg;
+    }
+
+    /**
+     * Set the java package.
+     *
+     * @param pcg the package to set
+     */
+    public void setPackage(String pcg) {
+        pkg = pcg;
+    }
+
+    /**
+     * Get the set containing the imported class/interface info.
+     *
+     * @return the set containing the imported class/interface info.
+     */
+    public SortedSet<ImportInfo> getImportSet() {
+        return importSet;
+    }
+
+    /**
+     * Assign the set containing the imported class/interface info.
+     *
+     * @param importSet the set containing the imported class/interface info.
+     */
+    private void setImportSet(SortedSet<ImportInfo> importSet) {
+        this.importSet = importSet;
+    }
+
+    /**
+     * Add an imported class/interface info is it is not already part of the
+     * set. If already part of the set, return false, else add to set and return
+     * true.
+     *
+     * @param importInfo class/interface info being imported.
+     * @return status of new addition of class/interface to the import set
+     */
+    public boolean addImportInfo(ImportInfo importInfo) {
+        /*
+         * implement the import info adding. The return value will be used to
+         * check if the qualified name will be used or class/interface name will
+         * be used in the generated class.
+         */
+        if (getImportSet() == null) {
+            setImportSet(new TreeSet<ImportInfo>());
+        }
+        return getImportSet().add(importInfo);
+    }
+
+    /**
+     * Get the list of cached attribute list.
+     *
+     * @return the set containing the imported class/interface info.
+     */
+    public List<AttributeInfo> getCachedAttributeList() {
+        return attributeList;
+    }
+
+    /**
+     * Set the cached attribute list.
+     *
+     * @param attrList attribute list.
+     */
+    private void setCachedAttributeList(List<AttributeInfo> attrList) {
+        attributeList = attrList;
+    }
+
+    /**
+     * Flush the cached attribute list to the serialized file.
+     */
+    private void flushCacheAttrToSerFile() {
+
+        for (AttributeInfo attr : getCachedAttributeList()) {
+            parseAttributeInfo(attr);
+        }
+
+        /*
+         * clear the contents from the cached attribute list.
+         */
+        getCachedAttributeList().clear();
+    }
+
+    /**
+     * Add a new attribute to the file(s).
+     *
+     * @param attrType data type of the added attribute.
+     * @param name name of the attribute.
+     * @param isListAttr if the current added attribute needs to be maintained
+     *            in a list.
+     */
+    @Override
+    public void addAttributeInfo(YangType<?> attrType, String name, boolean isListAttr) {
+
+        AttributeInfo newAttr = new AttributeInfo();
+        attrType.setDataTypeName(attrType.getDataTypeName().replace("\"", ""));
+        if (attrType.getDataTypeName().equals("string")) {
+            attrType.setDataTypeName(
+                    attrType.getDataTypeName().substring(0, 1).toUpperCase() + attrType.getDataTypeName().substring(1));
+        }
+        newAttr.setAttributeType(attrType);
+        newAttr.setAttributeName(name);
+        newAttr.setListAttr(isListAttr);
+
+        /*
+         * TODO: get the prefix and name of data type from attrType and
+         * initialize in importInfo.
+         */
+
+        /**
+         * TODO: Handle QualifiedFlag for imports.
+         */
+
+        if (getCachedAttributeList() != null) {
+            if (getCachedAttributeList().size() == MAX_CACHABLE_ATTR) {
+                flushCacheAttrToSerFile();
+            }
+            getCachedAttributeList().add(newAttr);
+        } else {
+            List<AttributeInfo> newAttributeInfo = new LinkedList<>();
+            newAttributeInfo.add(newAttr);
+            setCachedAttributeList(newAttributeInfo);
+        }
+        name = JavaIdentifierSyntax.getCamelCase(name);
+    }
+
+    /**
+     * Flushes the cached contents to the target file, frees used resources.
+     */
+    @Override
+    public void close() throws IOException {
+
+        String className = getYangName();
+        className = (className.substring(0, 1).toUpperCase() + className.substring(1));
+        String packagePath = getPackage();
+        String filePath = UtilConstants.YANG_GEN_DIR + packagePath.replace(".", "/");
+        GeneratedFileType fileType = getGeneratedFileTypes();
+
+        /**
+         * Create interface file.
+         */
+        String interfaceFileName = className + JAVA_FILE_EXTENSION;
+        File interfaceFile = new File(filePath + File.separator + interfaceFileName);
+
+        /**
+         * Create temp builder interface file.
+         */
+        String builderInterfaceFileName = interfaceFileName + TEMP_FILE_EXTENSION;
+        File builderInterfaceFile = new File(filePath + File.separator + builderInterfaceFileName);
+
+        /**
+         * Create builder class file.
+         */
+        String builderFileName = className + UtilConstants.BUILDER + JAVA_FILE_EXTENSION;
+        File builderFile = new File(filePath + File.separator + builderFileName);
+        MethodsGenerator.setBuilderClassName(className + UtilConstants.BUILDER);
+
+        /**
+         * Create temp impl class file.
+         */
+
+        String implFileName = className + UtilConstants.IMPL + TEMP_FILE_EXTENSION;
+        File implTempFile = new File(filePath + File.separator + implFileName);
+
+        if (fileType.equals(GeneratedFileType.INTERFACE) || fileType.equals(GeneratedFileType.ALL)) {
+
+            try {
+                interfaceFile.createNewFile();
+                appendContents(interfaceFile, className, GeneratedFileType.INTERFACE);
+            } catch (IOException e) {
+                throw new IOException("Failed to create interface file.");
+            }
+        }
+
+        if (fileType.equals(GeneratedFileType.BUILDER_CLASS) || fileType.equals(GeneratedFileType.ALL)) {
+
+            try {
+                builderFile.createNewFile();
+                appendContents(builderFile, className, GeneratedFileType.BUILDER_CLASS);
+            } catch (IOException e) {
+                throw new IOException("Failed to create builder class file.");
+            }
+        }
+
+        if (fileType.equals(GeneratedFileType.IMPL) || fileType.equals(GeneratedFileType.ALL)) {
+
+            try {
+                implTempFile.createNewFile();
+                appendContents(implTempFile, className, GeneratedFileType.IMPL);
+            } catch (IOException e) {
+                throw new IOException("Failed to create impl class file.");
+            }
+        }
+
+        if (fileType.equals(GeneratedFileType.BUILDER_INTERFACE) || fileType.equals(GeneratedFileType.ALL)) {
+
+            try {
+                builderInterfaceFile.createNewFile();
+                appendContents(builderInterfaceFile, className, GeneratedFileType.BUILDER_INTERFACE);
+            } catch (IOException e) {
+                throw new IOException("Failed to create builder interface class file.");
+            }
+        }
+        /*
+         * TODO: add the file header using
+         * JavaCodeSnippetGen.getFileHeaderComment
+         */
+        /*
+         * TODO: get the import list using getImportText and add to the
+         * generated java file using JavaCodeSnippetGen.getImportText
+         */
+
+        List<String> attributes = new LinkedList<>();
+        List<String> interfaceMethods = new LinkedList<>();
+        List<String> builderInterfaceMethods = new LinkedList<>();
+        List<String> builderClassMethods = new LinkedList<>();
+        List<String> implClassMethods = new LinkedList<>();
+        //TODO: Handle imports for the attributes.
+        try {
+            attributes = SerializedDataStore.getSerializeData(SerializedDataStore.SerializedDataStoreType.ATTRIBUTE);
+
+            interfaceMethods = SerializedDataStore
+                    .getSerializeData(SerializedDataStore.SerializedDataStoreType.INTERFACE_METHODS);
+
+            builderInterfaceMethods = SerializedDataStore
+                    .getSerializeData(SerializedDataStore.SerializedDataStoreType.BUILDER_INTERFACE_METHODS);
+
+            builderClassMethods = SerializedDataStore
+                    .getSerializeData(SerializedDataStore.SerializedDataStoreType.BUILDER_METHODS);
+
+            implClassMethods = SerializedDataStore
+                    .getSerializeData(SerializedDataStore.SerializedDataStoreType.IMPL_METHODS);
+
+            //TODO:imports = SerializedDataStore.getSerializeData(SerializedDataStore.SerializedDataStoreType.IMPORT);
+        } catch (ClassNotFoundException | IOException e) {
+            log.info("There is no attribute info of " + className + " YANG file in the serialized files.");
+        }
+
+        if (getCachedAttributeList() != null) {
+            MethodsGenerator.setAttrInfo(getCachedAttributeList());
+            for (AttributeInfo attr : getCachedAttributeList()) {
+                attributes.add(getAttributeString(attr));
+
+                interfaceMethods.add(MethodsGenerator.getMethodString(attr, GeneratedFileType.INTERFACE));
+
+                builderClassMethods.add(MethodsGenerator.getMethodString(attr, GeneratedFileType.BUILDER_CLASS));
+
+                builderInterfaceMethods
+                .add(MethodsGenerator.getMethodString(attr, GeneratedFileType.BUILDER_INTERFACE));
+
+                implClassMethods.add(MethodsGenerator.getMethodString(attr, GeneratedFileType.IMPL));
+            }
+        }
+
+        builderInterfaceMethods.add(MethodsGenerator.parseBuilderInterfaceBuildMethodString(className));
+        builderClassMethods.add(UtilConstants.FOUR_SPACE_INDENTATION + UtilConstants.JAVA_DOC_FIRST_LINE
+                + MethodsGenerator.getDefaultConstructorString(GeneratedFileType.BUILDER_CLASS, className));
+        builderClassMethods.add(MethodsGenerator.getBuildString(className));
+
+        implClassMethods.add(UtilConstants.JAVA_DOC_FIRST_LINE
+                + MethodsGenerator.getDefaultConstructorString(GeneratedFileType.IMPL, className));
+        implClassMethods.add(MethodsGenerator.getConstructorString(className));
+
+        /**
+         * Add attributes to the file.
+         */
+        for (String attribute : attributes) {
+            insert(builderFile, UtilConstants.NEW_LINE + UtilConstants.FOUR_SPACE_INDENTATION + attribute);
+            insert(implTempFile, UtilConstants.NEW_LINE + UtilConstants.FOUR_SPACE_INDENTATION + attribute);
+        }
+
+        insert(builderFile, UtilConstants.NEW_LINE);
+        insert(implTempFile, UtilConstants.NEW_LINE);
+
+        /**
+         * Add getter methods to interface file.
+         */
+        for (String method : interfaceMethods) {
+            appendMethod(interfaceFile, method + UtilConstants.NEW_LINE);
+        }
+
+        /**
+         * Add getters and setters in builder interface.
+         */
+        for (String method : builderInterfaceMethods) {
+            appendMethod(builderInterfaceFile, UtilConstants.FOUR_SPACE_INDENTATION + method + UtilConstants.NEW_LINE);
+        }
+
+        insert(builderInterfaceFile, UtilConstants.CLOSE_CURLY_BRACKET + UtilConstants.NEW_LINE);
+        /**
+         * Add methods in builder class.
+         */
+        for (String method : builderClassMethods) {
+            appendMethod(builderFile, method + UtilConstants.NEW_LINE);
+        }
+
+        /**
+         * Add methods in impl class.
+         */
+        for (String method : implClassMethods) {
+            appendMethod(implTempFile, UtilConstants.FOUR_SPACE_INDENTATION + method + UtilConstants.NEW_LINE);
+        }
+
+        insert(implTempFile, UtilConstants.CLOSE_CURLY_BRACKET + UtilConstants.NEW_LINE);
+
+        /**
+         * Append builder interface file to interface file and close it.
+         */
+        appendFileContents(builderInterfaceFile, interfaceFile);
+        insert(interfaceFile, closeFile(GeneratedFileType.INTERFACE, interfaceFileName));
+
+        /**
+         * Append impl class to builder class and close it.
+         */
+        appendFileContents(implTempFile, builderFile);
+        insert(builderFile, closeFile(GeneratedFileType.BUILDER_CLASS, builderFileName));
+
+        /**
+         * Remove temp files.
+         */
+        clean(implTempFile);
+        clean(builderInterfaceFile);
+    }
+
+    /**
+     * Appends the temp files to main files.
+     *
+     * @param appendFile temp file
+     * @param srcFile main file
+     */
+    private static void appendFileContents(File appendFile, File srcFile) throws IOException {
+        try {
+            FileSystemUtil.appendFileContents(appendFile, srcFile);
+        } catch (IOException e) {
+            throw new IOException("Failed to append " + appendFile + " in " + srcFile);
+        }
+    }
+
+    /**
+     * Append methods to the generated files.
+     *
+     * @param file file in which method needs to be appended.
+     * @param method method which needs to be appended.
+     */
+    private static void appendMethod(File file, String method) throws IOException {
+        insert(file, method);
+    }
+
+    /**
+     * Closes the current generated file.
+     *
+     * @param fileType generate file type
+     * @param yangName file name
+     * @return end of class definition string.
+     */
+    private static String closeFile(GeneratedFileType fileType, String yangName) {
+        return JavaCodeSnippetGen.getJavaClassDefClose(fileType, yangName);
+    }
+
+    /**
+     * Parses attribute info and fetch specific data and creates serialized
+     * files of it.
+     *
+     * @param attr attribute info.
+     */
+    private void parseAttributeInfo(AttributeInfo attr) {
+
+        String attrString = "";
+        String methodString = "";
+        String getterString = "";
+
+        try {
+            /*
+             * Serialize attributes.
+             */
+            attrString = getAttributeString(attr);
+            attrString = attrString.replace("\"", "");
+            SerializedDataStore.setSerializeData(attrString, SerializedDataStore.SerializedDataStoreType.ATTRIBUTE);
+
+            if (getGeneratedFileTypes().equals(GeneratedFileType.ALL)) {
+
+                methodString = MethodsGenerator.getMethodString(attr, GeneratedFileType.INTERFACE);
+                SerializedDataStore.setSerializeData(methodString,
+                        SerializedDataStore.SerializedDataStoreType.INTERFACE_METHODS);
+
+                methodString = MethodsGenerator.getMethodString(attr, GeneratedFileType.BUILDER_CLASS);
+                SerializedDataStore.setSerializeData(methodString,
+                        SerializedDataStore.SerializedDataStoreType.BUILDER_METHODS);
+
+                methodString = MethodsGenerator.getMethodString(attr, GeneratedFileType.BUILDER_INTERFACE);
+                SerializedDataStore.setSerializeData(methodString,
+                        SerializedDataStore.SerializedDataStoreType.BUILDER_INTERFACE_METHODS);
+
+                methodString = MethodsGenerator.getMethodString(attr, GeneratedFileType.IMPL);
+                SerializedDataStore.setSerializeData(methodString,
+                        SerializedDataStore.SerializedDataStoreType.IMPL_METHODS);
+
+            } else if (getGeneratedFileTypes().equals(GeneratedFileType.INTERFACE)) {
+
+                getterString = MethodsGenerator.getGetterString(attr);
+                SerializedDataStore.setSerializeData(methodString,
+                        SerializedDataStore.SerializedDataStoreType.INTERFACE_METHODS);
+            }
+        } catch (IOException e) {
+            log.info("Failed to get data for " + attr.getAttributeName() + " from serialized files.");
+        }
+    }
+
+    /**
+     * Returns attribute string.
+     *
+     * @param attr attribute info
+     * @return attribute string
+     */
+    private String getAttributeString(AttributeInfo attr) {
+        return JavaCodeSnippetGen.getJavaAttributeInfo(getGeneratedFileTypes(), attr.getAttributeName(),
+                attr.getAttributeType());
+    }
+
+    /**
+     * Appends all the contents into a generated java file.
+     *
+     * @param file generated file
+     * @param fileName generated file name
+     * @param type generated file type
+     */
+    private void appendContents(File file, String fileName, GeneratedFileType type) throws IOException {
+
+        if (type.equals(GeneratedFileType.IMPL)) {
+
+            write(file, fileName, type, JavaDocType.IMPL_CLASS);
+        } else if (type.equals(GeneratedFileType.BUILDER_INTERFACE)) {
+
+            write(file, fileName, type, JavaDocType.BUILDER_INTERFACE);
+        } else {
+
+            // TODO: handle imports for attributes.
+
+            if (type.equals(GeneratedFileType.INTERFACE)) {
+                insert(file, CopyrightHeader.getCopyrightHeader());
+                insert(file, "package" + UtilConstants.SPACE + getPackage() + UtilConstants.SEMI_COLAN
+                        + UtilConstants.NEW_LINE);
+                write(file, fileName, type, JavaDocType.INTERFACE);
+            } else if (type.equals(GeneratedFileType.BUILDER_CLASS)) {
+                insert(file, CopyrightHeader.getCopyrightHeader());
+                insert(file, "package" + UtilConstants.SPACE + getPackage() + UtilConstants.SEMI_COLAN
+                        + UtilConstants.NEW_LINE);
+                write(file, fileName, type, JavaDocType.BUILDER_CLASS);
+            }
+        }
+    }
+
+    /**
+     * Write data to the specific generated file.
+     *
+     * @param file generated file
+     * @param fileName file name
+     * @param genType generated file type
+     * @param javaDocType java doc type
+     */
+    private static void write(File file, String fileName, GeneratedFileType genType, JavaDocGen.JavaDocType javaDocType)
+            throws IOException {
+
+        insert(file, JavaDocGen.getJavaDoc(javaDocType, fileName));
+        insert(file, JavaCodeSnippetGen.getJavaClassDefStart(genType, fileName));
+    }
+
+    /**
+     * Insert in the generated file.
+     *
+     * @param file file in which need to be inserted.
+     * @param data data which need to be inserted.
+     */
+    private static void insert(File file, String data) throws IOException {
+        try {
+            FileSystemUtil.insertStringInFile(file, data);
+        } catch (IOException e) {
+            throw new IOException("Failed to insert in " + file + "file");
+        }
+    }
+
+    /**
+     * Removes temp files.
+     *
+     * @param file file to be removed.
+     */
+    private static void clean(File file) {
+        if (file.exists()) {
+            file.delete();
+        }
+    }
+}