/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.yangtools.sal.binding.yang.types;

import static org.opendaylight.yangtools.binding.generator.util.BindingGeneratorUtil.*;
import static org.opendaylight.yangtools.yang.model.util.SchemaContextUtil.*;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringEscapeUtils;
import org.opendaylight.yangtools.binding.generator.util.BindingGeneratorUtil;
import org.opendaylight.yangtools.binding.generator.util.TypeConstants;
import org.opendaylight.yangtools.binding.generator.util.Types;
import org.opendaylight.yangtools.binding.generator.util.generated.type.builder.EnumerationBuilderImpl;
import org.opendaylight.yangtools.binding.generator.util.generated.type.builder.GeneratedPropertyBuilderImpl;
import org.opendaylight.yangtools.binding.generator.util.generated.type.builder.GeneratedTOBuilderImpl;
import org.opendaylight.yangtools.sal.binding.generator.spi.TypeProvider;
import org.opendaylight.yangtools.sal.binding.model.api.ConcreteType;
import org.opendaylight.yangtools.sal.binding.model.api.Enumeration;
import org.opendaylight.yangtools.sal.binding.model.api.GeneratedTransferObject;
import org.opendaylight.yangtools.sal.binding.model.api.Restrictions;
import org.opendaylight.yangtools.sal.binding.model.api.Type;
import org.opendaylight.yangtools.sal.binding.model.api.type.builder.EnumBuilder;
import org.opendaylight.yangtools.sal.binding.model.api.type.builder.GeneratedPropertyBuilder;
import org.opendaylight.yangtools.sal.binding.model.api.type.builder.GeneratedTOBuilder;
import org.opendaylight.yangtools.sal.binding.model.api.type.builder.GeneratedTypeBuilderBase;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
import org.opendaylight.yangtools.yang.model.api.IdentitySchemaNode;
import org.opendaylight.yangtools.yang.model.api.LeafListSchemaNode;
import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
import org.opendaylight.yangtools.yang.model.api.Module;
import org.opendaylight.yangtools.yang.model.api.RevisionAwareXPath;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang.model.api.SchemaNode;
import org.opendaylight.yangtools.yang.model.api.SchemaPath;
import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
import org.opendaylight.yangtools.yang.model.api.YangNode;
import org.opendaylight.yangtools.yang.model.api.type.BinaryTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.BitsTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.BitsTypeDefinition.Bit;
import org.opendaylight.yangtools.yang.model.api.type.BooleanTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.DecimalTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.EmptyTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.EnumTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.IdentityrefTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.InstanceIdentifierTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.LeafrefTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.PatternConstraint;
import org.opendaylight.yangtools.yang.model.api.type.StringTypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.UnionTypeDefinition;
import org.opendaylight.yangtools.yang.model.util.DataNodeIterator;
import org.opendaylight.yangtools.yang.model.util.ExtendedType;
import org.opendaylight.yangtools.yang.model.util.Int16;
import org.opendaylight.yangtools.yang.model.util.Int32;
import org.opendaylight.yangtools.yang.model.util.Int64;
import org.opendaylight.yangtools.yang.model.util.Int8;
import org.opendaylight.yangtools.yang.model.util.StringType;
import org.opendaylight.yangtools.yang.model.util.Uint16;
import org.opendaylight.yangtools.yang.model.util.Uint32;
import org.opendaylight.yangtools.yang.model.util.Uint64;
import org.opendaylight.yangtools.yang.model.util.Uint8;
import org.opendaylight.yangtools.yang.model.util.UnionType;
import org.opendaylight.yangtools.yang.parser.util.ModuleDependencySort;

import com.google.common.base.Preconditions;
import com.google.common.io.BaseEncoding;

public final class TypeProviderImpl implements TypeProvider {
    /**
     * Contains the schema data red from YANG files.
     */
    private final SchemaContext schemaContext;

    /**
     * The outter map maps module names to the map of the types for the module.
     * The inner map maps the name of the concrete type to the JAVA
     * <code>Type</code> (usually it is generated TO).
     */
    private Map<String, Map<String, Type>> genTypeDefsContextMap;

    /**
     * The map which maps schema paths to JAVA <code>Type</code>.
     */
    private final Map<SchemaPath, Type> referencedTypes;

    /**
     * Creates new instance of class <code>TypeProviderImpl</code>.
     *
     * @param schemaContext
     *            contains the schema data red from YANG files
     * @throws IllegalArgumentException
     *             if <code>schemaContext</code> equal null.
     */
    public TypeProviderImpl(final SchemaContext schemaContext) {
        Preconditions.checkArgument(schemaContext != null, "Schema Context cannot be null!");

        this.schemaContext = schemaContext;
        this.genTypeDefsContextMap = new HashMap<>();
        this.referencedTypes = new HashMap<>();
        resolveTypeDefsFromContext();
    }

    /**
     * Puts <code>refType</code> to map with key <code>refTypePath</code>
     *
     * @param refTypePath
     *            schema path used as the map key
     * @param refType
     *            type which represents the map value
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>refTypePath</code> equal null</li>
     *             <li>if <code>refType</code> equal null</li>
     *             </ul>
     *
     */
    public void putReferencedType(final SchemaPath refTypePath, final Type refType) {
        Preconditions.checkArgument(refTypePath != null,
                "Path reference of Enumeration Type Definition cannot be NULL!");
        Preconditions.checkArgument(refType != null, "Reference to Enumeration Type cannot be NULL!");
        referencedTypes.put(refTypePath, refType);
    }

    /**
     *
     * Converts basic YANG type <code>type</code> to JAVA <code>Type</code>.
     *
     * @param type
     *            string with YANG name of type
     * @return JAVA <code>Type</code> for YANG type <code>type</code>
     * @see TypeProvider#javaTypeForYangType(String)
     */
    @Override
    public Type javaTypeForYangType(String type) {
        return BaseYangTypes.BASE_YANG_TYPES_PROVIDER.javaTypeForYangType(type);
    }

    @Override
    public Type javaTypeForSchemaDefinitionType(final TypeDefinition<?> typeDefinition, final SchemaNode parentNode) {
        return javaTypeForSchemaDefinitionType(typeDefinition, parentNode, null);
    }

    /**
     * Converts schema definition type <code>typeDefinition</code> to JAVA
     * <code>Type</code>
     *
     * @param typeDefinition
     *            type definition which is converted to JAVA type
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>typeDefinition</code> equal null</li>
     *             <li>if Q name of <code>typeDefinition</code> equal null</li>
     *             <li>if name of <code>typeDefinition</code> equal null</li>
     *             </ul>
     */
    @Override
    public Type javaTypeForSchemaDefinitionType(final TypeDefinition<?> typeDefinition, final SchemaNode parentNode, Restrictions r) {
        Type returnType = null;
        Preconditions.checkArgument(typeDefinition != null, "Type Definition cannot be NULL!");
        if (typeDefinition.getQName() == null) {
            throw new IllegalArgumentException(
                    "Type Definition cannot have non specified QName (QName cannot be NULL!)");
        }
        Preconditions.checkArgument(typeDefinition.getQName().getLocalName() != null,
                "Type Definitions Local Name cannot be NULL!");

        if (typeDefinition instanceof ExtendedType) {
            returnType = javaTypeForExtendedType(typeDefinition);
        } else {
            returnType = javaTypeForLeafrefOrIdentityRef(typeDefinition, parentNode);
            if (returnType == null) {
                returnType = BaseYangTypes.BASE_YANG_TYPES_PROVIDER.javaTypeForSchemaDefinitionType(typeDefinition,
                        parentNode, r);
            }
        }
        // TODO: add throw exception when we will be able to resolve ALL yang
        // types!
        // if (returnType == null) {
        // throw new IllegalArgumentException("Type Provider can't resolve " +
        // "type for specified Type Definition " + typedefName);
        // }
        return returnType;
    }

    /**
     * Returns JAVA <code>Type</code> for instances of the type
     * <code>LeafrefTypeDefinition</code> or
     * <code>IdentityrefTypeDefinition</code>.
     *
     * @param typeDefinition
     *            type definition which is converted to JAVA <code>Type</code>
     * @return JAVA <code>Type</code> instance for <code>typeDefinition</code>
     */
    private Type javaTypeForLeafrefOrIdentityRef(TypeDefinition<?> typeDefinition, SchemaNode parentNode) {
        if (typeDefinition instanceof LeafrefTypeDefinition) {
            final LeafrefTypeDefinition leafref = (LeafrefTypeDefinition) typeDefinition;
            return provideTypeForLeafref(leafref, parentNode);
        } else if (typeDefinition instanceof IdentityrefTypeDefinition) {
            final IdentityrefTypeDefinition idref = (IdentityrefTypeDefinition) typeDefinition;
            return provideTypeForIdentityref(idref);
        } else {
            return null;
        }
    }

    /**
     * Returns JAVA <code>Type</code> for instances of the type
     * <code>ExtendedType</code>.
     *
     * @param typeDefinition
     *            type definition which is converted to JAVA <code>Type</code>
     * @return JAVA <code>Type</code> instance for <code>typeDefinition</code>
     */
    private Type javaTypeForExtendedType(TypeDefinition<?> typeDefinition) {
        final String typedefName = typeDefinition.getQName().getLocalName();
        final TypeDefinition<?> baseTypeDef = baseTypeDefForExtendedType(typeDefinition);
        Type returnType = null;
        returnType = javaTypeForLeafrefOrIdentityRef(baseTypeDef, typeDefinition);
        if (returnType == null) {
            if (baseTypeDef instanceof EnumTypeDefinition) {
                final EnumTypeDefinition enumTypeDef = (EnumTypeDefinition) baseTypeDef;
                returnType = provideTypeForEnum(enumTypeDef, typedefName, typeDefinition);
            } else {
                final Module module = findParentModule(schemaContext, typeDefinition);
                Restrictions r = BindingGeneratorUtil.getRestrictions(typeDefinition);
                if (module != null) {
                    final Map<String, Type> genTOs = genTypeDefsContextMap.get(module.getName());
                    if (genTOs != null) {
                        returnType = genTOs.get(typedefName);
                    }
                    if (returnType == null) {
                        returnType = BaseYangTypes.BASE_YANG_TYPES_PROVIDER.javaTypeForSchemaDefinitionType(
                                baseTypeDef, typeDefinition, r);
                    }
                }
            }
        }
        return returnType;
        // TODO: add throw exception when we will be able to resolve ALL yang
        // types!
        // if (returnType == null) {
        // throw new IllegalArgumentException("Type Provider can't resolve " +
        // "type for specified Type Definition " + typedefName);
        // }
    }

    /**
     * Seeks for identity reference <code>idref</code> the JAVA
     * <code>type</code>.<br />
     * <br />
     *
     * <i>Example:<br />
     * If identy which is referenced via <code>idref</code> has name <b>Idn</b>
     * then returning type is <b>{@code Class<? extends Idn>}</b></i>
     *
     * @param idref
     *            identityref type definition for which JAVA <code>Type</code>
     *            is sought
     * @return JAVA <code>Type</code> of the identity which is refrenced through
     *         <code>idref</code>
     */
    private Type provideTypeForIdentityref(IdentityrefTypeDefinition idref) {
        QName baseIdQName = idref.getIdentity().getQName();
        Module module = schemaContext.findModuleByNamespaceAndRevision(baseIdQName.getNamespace(),
                baseIdQName.getRevision());
        IdentitySchemaNode identity = null;
        for (IdentitySchemaNode id : module.getIdentities()) {
            if (id.getQName().equals(baseIdQName)) {
                identity = id;
            }
        }
        Preconditions.checkArgument(identity != null, "Target identity '" + baseIdQName + "' do not exists");

        final String basePackageName = moduleNamespaceToPackageName(module);
        final String packageName = packageNameForGeneratedType(basePackageName, identity.getPath());
        final String genTypeName = parseToClassName(identity.getQName().getLocalName());

        Type baseType = Types.typeForClass(Class.class);
        Type paramType = Types.wildcardTypeFor(packageName, genTypeName);
        return Types.parameterizedTypeFor(baseType, paramType);
    }

    /**
     * Converts <code>typeDefinition</code> to concrete JAVA <code>Type</code>.
     *
     * @param typeDefinition
     *            type definition which should be converted to JAVA
     *            <code>Type</code>
     * @return JAVA <code>Type</code> which represents
     *         <code>typeDefinition</code>
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>typeDefinition</code> equal null</li>
     *             <li>if Q name of <code>typeDefinition</code></li>
     *             <li>if name of <code>typeDefinition</code></li>
     *             </ul>
     */
    public Type generatedTypeForExtendedDefinitionType(final TypeDefinition<?> typeDefinition,
            final SchemaNode parentNode) {
        Type returnType = null;
        Preconditions.checkArgument(typeDefinition != null, "Type Definition cannot be NULL!");
        if (typeDefinition.getQName() == null) {
            throw new IllegalArgumentException(
                    "Type Definition cannot have non specified QName (QName cannot be NULL!)");
        }
        Preconditions.checkArgument(typeDefinition.getQName().getLocalName() != null,
                "Type Definitions Local Name cannot be NULL!");

        final String typedefName = typeDefinition.getQName().getLocalName();
        if (typeDefinition instanceof ExtendedType) {
            final TypeDefinition<?> baseTypeDef = baseTypeDefForExtendedType(typeDefinition);

            if (!(baseTypeDef instanceof LeafrefTypeDefinition) && !(baseTypeDef instanceof IdentityrefTypeDefinition)) {
                final Module module = findParentModule(schemaContext, parentNode);

                if (module != null) {
                    final Map<String, Type> genTOs = genTypeDefsContextMap.get(module.getName());
                    if (genTOs != null) {
                        returnType = genTOs.get(typedefName);
                    }
                }
            }
        }
        return returnType;
    }

    /**
     * Gets base type definition for <code>extendTypeDef</code>. The method is
     * recursivelly called until non <code>ExtendedType</code> type is found.
     *
     * @param extendTypeDef
     *            type definition for which is the base type definition sought
     * @return type definition which is base type for <code>extendTypeDef</code>
     * @throws IllegalArgumentException
     *             if <code>extendTypeDef</code> equal null
     */
    private TypeDefinition<?> baseTypeDefForExtendedType(final TypeDefinition<?> extendTypeDef) {
        Preconditions.checkArgument(extendTypeDef != null, "Type Definiition reference cannot be NULL!");
        final TypeDefinition<?> baseTypeDef = extendTypeDef.getBaseType();
        if (baseTypeDef instanceof ExtendedType) {
            return baseTypeDefForExtendedType(baseTypeDef);
        } else {
            return baseTypeDef;
        }

    }

    /**
     * Converts <code>leafrefType</code> to JAVA <code>Type</code>.
     *
     * The path of <code>leafrefType</code> is followed to find referenced node
     * and its <code>Type</code> is returned.
     *
     * @param leafrefType
     *            leafref type definition for which is the type sought
     * @return JAVA <code>Type</code> of data schema node which is referenced in
     *         <code>leafrefType</code>
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>leafrefType</code> equal null</li>
     *             <li>if path statement of <code>leafrefType</code> equal null</li>
     *             </ul>
     *
     */
    public Type provideTypeForLeafref(final LeafrefTypeDefinition leafrefType, final SchemaNode parentNode) {
        Type returnType = null;
        Preconditions.checkArgument(leafrefType != null, "Leafref Type Definition reference cannot be NULL!");

        Preconditions.checkArgument(leafrefType.getPathStatement() != null,
                "The Path Statement for Leafref Type Definition cannot be NULL!");

        final RevisionAwareXPath xpath = leafrefType.getPathStatement();
        final String strXPath = xpath.toString();

        if (strXPath != null) {
            if (strXPath.contains("[")) {
                returnType = Types.typeForClass(Object.class);
            } else {
                final Module module = findParentModule(schemaContext, parentNode);
                if (module != null) {
                    final SchemaNode dataNode;
                    if (xpath.isAbsolute()) {
                        dataNode = findDataSchemaNode(schemaContext, module, xpath);
                    } else {
                        dataNode = findDataSchemaNodeForRelativeXPath(schemaContext, module, parentNode, xpath);
                    }

                    if (leafContainsEnumDefinition(dataNode)) {
                        returnType = referencedTypes.get(dataNode.getPath());
                    } else if (leafListContainsEnumDefinition(dataNode)) {
                        returnType = Types.listTypeFor(referencedTypes.get(dataNode.getPath()));
                    } else {
                        returnType = resolveTypeFromDataSchemaNode(dataNode);
                    }
                }
            }
        }
        return returnType;
    }

    /**
     * Checks if <code>dataNode</code> is <code>LeafSchemaNode</code> and if it
     * so then checks if it is of type <code>EnumTypeDefinition</code>.
     *
     * @param dataNode
     *            data schema node for which is checked if it is leaf and if it
     *            is of enum type
     * @return boolean value
     *         <ul>
     *         <li>true - if <code>dataNode</code> is leaf of type enumeration</li>
     *         <li>false - other cases</li>
     *         </ul>
     */
    private boolean leafContainsEnumDefinition(final SchemaNode dataNode) {
        if (dataNode instanceof LeafSchemaNode) {
            final LeafSchemaNode leaf = (LeafSchemaNode) dataNode;
            if (leaf.getType() instanceof EnumTypeDefinition) {
                return true;
            }
        }
        return false;
    }

    /**
     * Checks if <code>dataNode</code> is <code>LeafListSchemaNode</code> and if
     * it so then checks if it is of type <code>EnumTypeDefinition</code>.
     *
     * @param dataNode
     *            data schema node for which is checked if it is leaflist and if
     *            it is of enum type
     * @return boolean value
     *         <ul>
     *         <li>true - if <code>dataNode</code> is leaflist of type
     *         enumeration</li>
     *         <li>false - other cases</li>
     *         </ul>
     */
    private boolean leafListContainsEnumDefinition(final SchemaNode dataNode) {
        if (dataNode instanceof LeafListSchemaNode) {
            final LeafListSchemaNode leafList = (LeafListSchemaNode) dataNode;
            if (leafList.getType() instanceof EnumTypeDefinition) {
                return true;
            }
        }
        return false;
    }

    /**
     * Converts <code>enumTypeDef</code> to
     * {@link org.opendaylight.yangtools.sal.binding.model.api.Enumeration
     * enumeration}.
     *
     * @param enumTypeDef
     *            enumeration type definition which is converted to enumeration
     * @param enumName
     *            string with name which is used as the enumeration name
     * @return enumeration type which is built with data (name, enum values)
     *         from <code>enumTypeDef</code>
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>enumTypeDef</code> equals null</li>
     *             <li>if enum values of <code>enumTypeDef</code> equal null</li>
     *             <li>if Q name of <code>enumTypeDef</code> equal null</li>
     *             <li>if name of <code>enumTypeDef</code> equal null</li>
     *             </ul>
     */
    private Enumeration provideTypeForEnum(final EnumTypeDefinition enumTypeDef, final String enumName,
            final SchemaNode parentNode) {
        Preconditions.checkArgument(enumTypeDef != null, "EnumTypeDefinition reference cannot be NULL!");
        Preconditions.checkArgument(enumTypeDef.getValues() != null,
                "EnumTypeDefinition MUST contain at least ONE value definition!");
        Preconditions.checkArgument(enumTypeDef.getQName() != null, "EnumTypeDefinition MUST contain NON-NULL QName!");
        Preconditions.checkArgument(enumTypeDef.getQName().getLocalName() != null,
                "Local Name in EnumTypeDefinition QName cannot be NULL!");

        final String enumerationName = parseToClassName(enumName);

        Module module = findParentModule(schemaContext, parentNode);
        final String basePackageName = moduleNamespaceToPackageName(module);

        final EnumBuilder enumBuilder = new EnumerationBuilderImpl(basePackageName, enumerationName);
        enumBuilder.updateEnumPairsFromEnumTypeDef(enumTypeDef);
        return enumBuilder.toInstance(null);
    }

    /**
     * Adds enumeration to <code>typeBuilder</code>. The enumeration data are
     * taken from <code>enumTypeDef</code>.
     *
     * @param enumTypeDef
     *            enumeration type definition is source of enumeration data for
     *            <code>typeBuilder</code>
     * @param enumName
     *            string with the name of enumeration
     * @param typeBuilder
     *            generated type builder to which is enumeration added
     * @return enumeration type which contains enumeration data form
     *         <code>enumTypeDef</code>
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>enumTypeDef</code> equals null</li>
     *             <li>if enum values of <code>enumTypeDef</code> equal null</li>
     *             <li>if Q name of <code>enumTypeDef</code> equal null</li>
     *             <li>if name of <code>enumTypeDef</code> equal null</li>
     *             <li>if name of <code>typeBuilder</code> equal null</li>
     *             </ul>
     *
     */
    private Enumeration addInnerEnumerationToTypeBuilder(final EnumTypeDefinition enumTypeDef, final String enumName,
            final GeneratedTypeBuilderBase<?> typeBuilder) {
        Preconditions.checkArgument(enumTypeDef != null, "EnumTypeDefinition reference cannot be NULL!");
        Preconditions.checkArgument(enumTypeDef.getValues() != null,
                "EnumTypeDefinition MUST contain at least ONE value definition!");
        Preconditions.checkArgument(enumTypeDef.getQName() != null, "EnumTypeDefinition MUST contain NON-NULL QName!");
        Preconditions.checkArgument(enumTypeDef.getQName().getLocalName() != null,
                "Local Name in EnumTypeDefinition QName cannot be NULL!");
        Preconditions.checkArgument(typeBuilder != null, "Generated Type Builder reference cannot be NULL!");

        final String enumerationName = parseToClassName(enumName);

        final EnumBuilder enumBuilder = typeBuilder.addEnumeration(enumerationName);
        enumBuilder.updateEnumPairsFromEnumTypeDef(enumTypeDef);
        return enumBuilder.toInstance(enumBuilder);
    }

    /**
     * Converts <code>dataNode</code> to JAVA <code>Type</code>.
     *
     * @param dataNode
     *            contains information about YANG type
     * @return JAVA <code>Type</code> representation of <code>dataNode</code>
     */
    private Type resolveTypeFromDataSchemaNode(final SchemaNode dataNode) {
        Type returnType = null;
        if (dataNode != null) {
            if (dataNode instanceof LeafSchemaNode) {
                final LeafSchemaNode leaf = (LeafSchemaNode) dataNode;
                returnType = javaTypeForSchemaDefinitionType(leaf.getType(), leaf);
            } else if (dataNode instanceof LeafListSchemaNode) {
                final LeafListSchemaNode leafList = (LeafListSchemaNode) dataNode;
                returnType = javaTypeForSchemaDefinitionType(leafList.getType(), leafList);
            }
        }
        return returnType;
    }

    /**
     * Passes through all modules and through all its type definitions and
     * convert it to generated types.
     *
     * The modules are firstly sorted by mutual dependencies. The modules are
     * sequentially passed. All type definitions of a module are at the
     * beginning sorted so that type definition with less amount of references
     * to other type definition are processed first.<br />
     * For each module is created mapping record in the map
     * {@link TypeProviderImpl#genTypeDefsContextMap genTypeDefsContextMap}
     * which map current module name to the map which maps type names to
     * returned types (generated types).
     *
     */
    private void resolveTypeDefsFromContext() {
        final Set<Module> modules = schemaContext.getModules();
        Preconditions.checkArgument(modules != null, "Sef of Modules cannot be NULL!");
        final Module[] modulesArray = new Module[modules.size()];
        int i = 0;
        for (Module modul : modules) {
            modulesArray[i++] = modul;
        }
        final List<Module> modulesSortedByDependency = ModuleDependencySort.sort(modulesArray);

        for (final Module module : modulesSortedByDependency) {
            if (module == null) {
                continue;
            }
            final String moduleName = module.getName();
            final String basePackageName = moduleNamespaceToPackageName(module);

            final DataNodeIterator it = new DataNodeIterator(module);
            final List<TypeDefinition<?>> typeDefinitions = it.allTypedefs();
            final List<TypeDefinition<?>> listTypeDefinitions = sortTypeDefinitionAccordingDepth(typeDefinitions);

            final Map<String, Type> typeMap = new HashMap<>();
            genTypeDefsContextMap.put(moduleName, typeMap);

            if ((listTypeDefinitions != null) && (basePackageName != null)) {
                for (final TypeDefinition<?> typedef : listTypeDefinitions) {
                    typedefToGeneratedType(basePackageName, moduleName, typedef);
                }
            }
        }
    }

    /**
     *
     * @param basePackageName
     *            string with name of package to which the module belongs
     * @param moduleName
     *            string with the name of the module for to which the
     *            <code>typedef</code> belongs
     * @param typedef
     *            type definition of the node for which should be creted JAVA
     *            <code>Type</code> (usually generated TO)
     * @return JAVA <code>Type</code> representation of <code>typedef</code> or
     *         <code>null</code> value if <code>basePackageName</code> or
     *         <code>modulName</code> or <code>typedef</code> or Q name of
     *         <code>typedef</code> equals <code>null</code>
     */
    private Type typedefToGeneratedType(final String basePackageName, final String moduleName,
            final TypeDefinition<?> typedef) {
        if ((basePackageName != null) && (moduleName != null) && (typedef != null) && (typedef.getQName() != null)) {

            final String typedefName = typedef.getQName().getLocalName();
            final TypeDefinition<?> innerTypeDefinition = typedef.getBaseType();
            if (!(innerTypeDefinition instanceof LeafrefTypeDefinition)
                    && !(innerTypeDefinition instanceof IdentityrefTypeDefinition)) {
                Type returnType = null;
                if (innerTypeDefinition instanceof ExtendedType) {
                    ExtendedType innerExtendedType = (ExtendedType) innerTypeDefinition;
                    returnType = provideGeneratedTOFromExtendedType(typedef, innerExtendedType, basePackageName);
                } else if (innerTypeDefinition instanceof UnionTypeDefinition) {
                    final GeneratedTOBuilder genTOBuilder = provideGeneratedTOBuilderForUnionTypeDef(basePackageName,
                            (UnionTypeDefinition) innerTypeDefinition, typedefName, typedef);
                    genTOBuilder.setIsUnion(true);
                    addUnitsToGenTO(genTOBuilder, typedef.getUnits());
                    returnType = genTOBuilder.toInstance();
                } else if (innerTypeDefinition instanceof EnumTypeDefinition) {
                    final EnumTypeDefinition enumTypeDef = (EnumTypeDefinition) innerTypeDefinition;
                    // TODO units for typedef enum
                    returnType = provideTypeForEnum(enumTypeDef, typedefName, typedef);
                } else if (innerTypeDefinition instanceof BitsTypeDefinition) {
                    final BitsTypeDefinition bitsTypeDefinition = (BitsTypeDefinition) innerTypeDefinition;
                    final GeneratedTOBuilder genTOBuilder = provideGeneratedTOBuilderForBitsTypeDefinition(
                            basePackageName, bitsTypeDefinition, typedefName);
                    addUnitsToGenTO(genTOBuilder, typedef.getUnits());
                    returnType = genTOBuilder.toInstance();
                } else {
                    final Type javaType = BaseYangTypes.BASE_YANG_TYPES_PROVIDER.javaTypeForSchemaDefinitionType(
                            innerTypeDefinition, typedef);
                    returnType = wrapJavaTypeIntoTO(basePackageName, typedef, javaType);
                }
                if (returnType != null) {
                    final Map<String, Type> typeMap = genTypeDefsContextMap.get(moduleName);
                    if (typeMap != null) {
                        typeMap.put(typedefName, returnType);
                    }
                    return returnType;
                }
            }
        }
        return null;
    }

    /**
     * Wraps base YANG type to generated TO.
     *
     * @param basePackageName
     *            string with name of package to which the module belongs
     * @param typedef
     *            type definition which is converted to the TO
     * @param javaType
     *            JAVA <code>Type</code> to which is <code>typedef</code> mapped
     * @return generated transfer object which represent<code>javaType</code>
     */
    private GeneratedTransferObject wrapJavaTypeIntoTO(final String basePackageName, final TypeDefinition<?> typedef,
            final Type javaType) {
        Preconditions.checkNotNull(javaType, "javaType cannot be null");
        final String propertyName = "value";

        final GeneratedTOBuilder genTOBuilder = typedefToTransferObject(basePackageName, typedef);
        genTOBuilder.setRestrictions(BindingGeneratorUtil.getRestrictions(typedef));
        final GeneratedPropertyBuilder genPropBuilder = genTOBuilder.addProperty(propertyName);
        genPropBuilder.setReturnType(javaType);
        genTOBuilder.addEqualsIdentity(genPropBuilder);
        genTOBuilder.addHashIdentity(genPropBuilder);
        genTOBuilder.addToStringProperty(genPropBuilder);
        if (javaType instanceof ConcreteType && "String".equals(javaType.getName()) && typedef instanceof ExtendedType) {
            final List<String> regExps = resolveRegExpressionsFromTypedef((ExtendedType) typedef);
            addStringRegExAsConstant(genTOBuilder, regExps);
        }
        addUnitsToGenTO(genTOBuilder, typedef.getUnits());
        return genTOBuilder.toInstance();
    }

    /**
     * Converts output list of generated TO builders to one TO builder (first
     * from list) which contains the remaining builders as its enclosing TO.
     *
     * @param basePackageName
     *            string with name of package to which the module belongs
     * @param typedef
     *            type definition which should be of type
     *            <code>UnionTypeDefinition</code>
     * @param typeDefName
     *            string with name for generated TO
     * @return generated TO builder with the list of enclosed generated TO
     *         builders
     */
    public GeneratedTOBuilder provideGeneratedTOBuilderForUnionTypeDef(final String basePackageName,
            final UnionTypeDefinition typedef, String typeDefName, SchemaNode parentNode) {
        final List<GeneratedTOBuilder> genTOBuilders = provideGeneratedTOBuildersForUnionTypeDef(basePackageName,
                typedef, typeDefName, parentNode);
        GeneratedTOBuilder resultTOBuilder = null;
        if (!genTOBuilders.isEmpty()) {
            resultTOBuilder = genTOBuilders.get(0);
            genTOBuilders.remove(0);
            for (GeneratedTOBuilder genTOBuilder : genTOBuilders) {
                resultTOBuilder.addEnclosingTransferObject(genTOBuilder);
            }
        }
        return resultTOBuilder;
    }

    /**
     * Converts <code>typedef</code> to generated TO with
     * <code>typeDefName</code>. Every union type from <code>typedef</code> is
     * added to generated TO builder as property.
     *
     * @param basePackageName
     *            string with name of package to which the module belongs
     * @param typedef
     *            type definition which should be of type
     *            <code>UnionTypeDefinition</code>
     * @param typeDefName
     *            string with name for generated TO
     * @return generated TO builder which represents <code>typedef</code>
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>basePackageName</code> equals null</li>
     *             <li>if <code>typedef</code> equals null</li>
     *             <li>if Q name of <code>typedef</code> equals null</li>
     *             </ul>
     */
    public List<GeneratedTOBuilder> provideGeneratedTOBuildersForUnionTypeDef(final String basePackageName,
            final UnionTypeDefinition typedef, final String typeDefName, final SchemaNode parentNode) {
        Preconditions.checkArgument(basePackageName != null, "Base Package Name cannot be NULL!");
        Preconditions.checkArgument(typedef != null, "Type Definition cannot be NULL!");
        Preconditions.checkArgument(typedef.getQName() != null,
                "Type Definition cannot have non specified QName (QName cannot be NULL!)");

        final List<GeneratedTOBuilder> generatedTOBuilders = new ArrayList<>();

        if (typedef != null) {
            final List<TypeDefinition<?>> unionTypes = typedef.getTypes();

            final GeneratedTOBuilder unionGenTOBuilder;
            if (typeDefName != null && !typeDefName.isEmpty()) {
                final String typeName = parseToClassName(typeDefName);
                unionGenTOBuilder = new GeneratedTOBuilderImpl(basePackageName, typeName);
            } else {
                unionGenTOBuilder = typedefToTransferObject(basePackageName, typedef);
            }
            generatedTOBuilders.add(unionGenTOBuilder);
            unionGenTOBuilder.setIsUnion(true);
            final List<String> regularExpressions = new ArrayList<String>();
            for (final TypeDefinition<?> unionType : unionTypes) {
                final String unionTypeName = unionType.getQName().getLocalName();
                if (unionType instanceof UnionType) {
                    generatedTOBuilders.addAll(resolveUnionSubtypeAsUnion(unionGenTOBuilder, (UnionType) unionType,
                            basePackageName, parentNode));
                } else if (unionType instanceof ExtendedType) {
                    resolveExtendedSubtypeAsUnion(unionGenTOBuilder, (ExtendedType) unionType, unionTypeName,
                            regularExpressions, parentNode);
                } else if (unionType instanceof EnumTypeDefinition) {
                    final Enumeration enumeration = addInnerEnumerationToTypeBuilder((EnumTypeDefinition) unionType,
                            unionTypeName, unionGenTOBuilder);
                    updateUnionTypeAsProperty(unionGenTOBuilder, enumeration, unionTypeName);
                } else {
                    final Type javaType = BaseYangTypes.BASE_YANG_TYPES_PROVIDER.javaTypeForSchemaDefinitionType(
                            unionType, parentNode);
                    updateUnionTypeAsProperty(unionGenTOBuilder, javaType, unionTypeName);
                }
            }
            if (!regularExpressions.isEmpty()) {
                addStringRegExAsConstant(unionGenTOBuilder, regularExpressions);
            }

            storeGenTO(typedef, unionGenTOBuilder, parentNode);
        }
        return generatedTOBuilders;
    }

    /**
     * Wraps code which handle case when union subtype is also of the type
     * <code>UnionType</code>.
     *
     * In this case the new generated TO is created for union subtype (recursive
     * call of method
     * {@link #provideGeneratedTOBuildersForUnionTypeDef(String, TypeDefinition, String)
     * provideGeneratedTOBuilderForUnionTypeDef} and in parent TO builder
     * <code>parentUnionGenTOBuilder</code> is created property which type is
     * equal to new generated TO.
     *
     * @param parentUnionGenTOBuilder
     *            generated TO builder to which is the property with the child
     *            union subtype added
     * @param basePackageName
     *            string with the name of the module package
     * @param unionSubtype
     *            type definition which represents union subtype
     * @return list of generated TO builders. The number of the builders can be
     *         bigger one due to recursive call of
     *         <code>provideGeneratedTOBuildersForUnionTypeDef</code> method.
     */
    private List<GeneratedTOBuilder> resolveUnionSubtypeAsUnion(final GeneratedTOBuilder parentUnionGenTOBuilder,
            final UnionTypeDefinition unionSubtype, final String basePackageName, final SchemaNode parentNode) {
        final String newTOBuilderName = provideAvailableNameForGenTOBuilder(parentUnionGenTOBuilder.getName());
        final List<GeneratedTOBuilder> subUnionGenTOBUilders = provideGeneratedTOBuildersForUnionTypeDef(
                basePackageName, unionSubtype, newTOBuilderName, parentNode);

        final GeneratedPropertyBuilder propertyBuilder;
        propertyBuilder = parentUnionGenTOBuilder.addProperty(BindingGeneratorUtil
                .parseToValidParamName(newTOBuilderName));
        propertyBuilder.setReturnType(subUnionGenTOBUilders.get(0));
        parentUnionGenTOBuilder.addEqualsIdentity(propertyBuilder);
        parentUnionGenTOBuilder.addToStringProperty(propertyBuilder);

        return subUnionGenTOBUilders;
    }

    /**
     * Wraps code which handle case when union subtype is of the type
     * <code>ExtendedType</code>.
     *
     * If TO for this type already exists it is used for the creation of the
     * property in <code>parentUnionGenTOBuilder</code>. In other case the base
     * type is used for the property creation.
     *
     * @param parentUnionGenTOBuilder
     *            generated TO builder in which new property is created
     * @param unionSubtype
     *            type definition of the <code>ExtendedType</code> type which
     *            represents union subtype
     * @param unionTypeName
     *            string with the name for <code>unionSubtype</code>
     * @param regularExpressions
     *            list of strings with the regular expressions
     */
    private void resolveExtendedSubtypeAsUnion(final GeneratedTOBuilder parentUnionGenTOBuilder,
            final ExtendedType unionSubtype, final String unionTypeName, final List<String> regularExpressions,
            final SchemaNode parentNode) {
        final Type genTO = findGenTO(unionTypeName, parentNode);
        if (genTO != null) {
            updateUnionTypeAsProperty(parentUnionGenTOBuilder, genTO, genTO.getName());
        } else {
            final TypeDefinition<?> baseType = baseTypeDefForExtendedType(unionSubtype);
            if (unionTypeName.equals(baseType.getQName().getLocalName())) {
                final Type javaType = BaseYangTypes.BASE_YANG_TYPES_PROVIDER.javaTypeForSchemaDefinitionType(baseType,
                        parentNode);
                if (javaType != null) {
                    updateUnionTypeAsProperty(parentUnionGenTOBuilder, javaType, unionTypeName);
                }
            }
            if (baseType instanceof StringType) {
                regularExpressions.addAll(resolveRegExpressionsFromTypedef(unionSubtype));
            }
        }
    }

    /**
     * Searches for generated TO for <code>searchedTypeDef</code> type
     * definition in {@link #genTypeDefsContextMap genTypeDefsContextMap}
     *
     * @param searchedTypeName
     *            string with name of <code>searchedTypeDef</code>
     * @return generated TO for <code>searchedTypeDef</code> or
     *         <code>null</code> it it doesn't exist
     */
    private Type findGenTO(final String searchedTypeName, final SchemaNode parentNode) {
        final Module typeModule = findParentModule(schemaContext, parentNode);
        if (typeModule != null && typeModule.getName() != null) {
            final Map<String, Type> genTOs = genTypeDefsContextMap.get(typeModule.getName());
            if (genTOs != null) {
                return genTOs.get(searchedTypeName);
            }
        }
        return null;
    }

    /**
     * Stores generated TO created from <code>genTOBuilder</code> for
     * <code>newTypeDef</code> to {@link #genTypeDefsContextMap
     * genTypeDefsContextMap} if the module for <code>newTypeDef</code> exists
     *
     * @param newTypeDef
     *            type definition for which is <code>genTOBuilder</code> created
     * @param genTOBuilder
     *            generated TO builder which is converted to generated TO and
     *            stored
     */
    private void storeGenTO(TypeDefinition<?> newTypeDef, GeneratedTOBuilder genTOBuilder, SchemaNode parentNode) {
        if (!(newTypeDef instanceof UnionType)) {
            Map<String, Type> genTOsMap = null;
            final Module parentModule = findParentModule(schemaContext, parentNode);
            if (parentModule != null && parentModule.getName() != null) {
                genTOsMap = genTypeDefsContextMap.get(parentModule.getName());
                genTOsMap.put(newTypeDef.getQName().getLocalName(), genTOBuilder.toInstance());
            }
        }
    }

    /**
     * Adds a new property with the name <code>propertyName</code> and with type
     * <code>type</code> to <code>unonGenTransObject</code>.
     *
     * @param unionGenTransObject
     *            generated TO to which should be property added
     * @param type
     *            JAVA <code>type</code> of the property which should be added
     *            to <code>unionGentransObject</code>
     * @param propertyName
     *            string with name of property which should be added to
     *            <code>unionGentransObject</code>
     */
    private void updateUnionTypeAsProperty(final GeneratedTOBuilder unionGenTransObject, final Type type,
            final String propertyName) {
        if (unionGenTransObject != null && type != null && !unionGenTransObject.containsProperty(propertyName)) {
            final GeneratedPropertyBuilder propBuilder = unionGenTransObject
                    .addProperty(parseToValidParamName(propertyName));
            propBuilder.setReturnType(type);

            unionGenTransObject.addEqualsIdentity(propBuilder);
            unionGenTransObject.addHashIdentity(propBuilder);
            unionGenTransObject.addToStringProperty(propBuilder);
        }
    }

    /**
     * Converts <code>typedef</code> to the generated TO builder.
     *
     * @param basePackageName
     *            string with name of package to which the module belongs
     * @param typedef
     *            type definition from which is the generated TO builder created
     * @return generated TO builder which contains data from
     *         <code>typedef</code> and <code>basePackageName</code>
     */
    private GeneratedTOBuilder typedefToTransferObject(final String basePackageName, final TypeDefinition<?> typedef) {

        final String packageName = packageNameForGeneratedType(basePackageName, typedef.getPath());
        final String typeDefTOName = typedef.getQName().getLocalName();

        if ((packageName != null) && (typedef != null) && (typeDefTOName != null)) {
            final String genTOName = parseToClassName(typeDefTOName);
            final GeneratedTOBuilder newType = new GeneratedTOBuilderImpl(packageName, genTOName);
            newType.addComment(typedef.getDescription());
            return newType;
        }
        return null;
    }

    /**
     * Converts <code>typeDef</code> which should be of the type
     * <code>BitsTypeDefinition</code> to <code>GeneratedTOBuilder</code>.
     *
     * All the bits of the typeDef are added to returning generated TO as
     * properties.
     *
     * @param basePackageName
     *            string with name of package to which the module belongs
     * @param typeDef
     *            type definition from which is the generated TO builder created
     * @param typeDefName
     *            string with the name for generated TO builder
     * @return generated TO builder which represents <code>typeDef</code>
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>typeDef</code> equals null</li>
     *             <li>if <code>basePackageName</code> equals null</li>
     *             </ul>
     */
    public GeneratedTOBuilder provideGeneratedTOBuilderForBitsTypeDefinition(final String basePackageName,
            final TypeDefinition<?> typeDef, String typeDefName) {

        Preconditions.checkArgument(typeDef != null, "typeDef cannot be NULL!");
        Preconditions.checkArgument(basePackageName != null, "Base Package Name cannot be NULL!");

        if (typeDef instanceof BitsTypeDefinition) {
            BitsTypeDefinition bitsTypeDefinition = (BitsTypeDefinition) typeDef;

            final String typeName = parseToClassName(typeDefName);
            final GeneratedTOBuilder genTOBuilder = new GeneratedTOBuilderImpl(basePackageName, typeName);

            final List<Bit> bitList = bitsTypeDefinition.getBits();
            GeneratedPropertyBuilder genPropertyBuilder;
            for (final Bit bit : bitList) {
                String name = bit.getName();
                genPropertyBuilder = genTOBuilder.addProperty(parseToValidParamName(name));
                genPropertyBuilder.setReadOnly(true);
                genPropertyBuilder.setReturnType(BaseYangTypes.BOOLEAN_TYPE);

                genTOBuilder.addEqualsIdentity(genPropertyBuilder);
                genTOBuilder.addHashIdentity(genPropertyBuilder);
                genTOBuilder.addToStringProperty(genPropertyBuilder);
            }

            return genTOBuilder;
        }
        return null;
    }

    /**
     * Converts the pattern constraints from <code>typedef</code> to the list of
     * the strings which represents these constraints.
     *
     * @param typedef
     *            extended type in which are the pattern constraints sought
     * @return list of strings which represents the constraint patterns
     * @throws IllegalArgumentException
     *             if <code>typedef</code> equals null
     *
     */
    private List<String> resolveRegExpressionsFromTypedef(ExtendedType typedef) {
        final List<String> regExps = new ArrayList<String>();
        Preconditions.checkArgument(typedef != null, "typedef can't be null");
        final TypeDefinition<?> strTypeDef = baseTypeDefForExtendedType(typedef);
        if (strTypeDef instanceof StringType) {
            final List<PatternConstraint> patternConstraints = typedef.getPatternConstraints();
            if (!patternConstraints.isEmpty()) {
                String regEx;
                String modifiedRegEx;
                for (PatternConstraint patternConstraint : patternConstraints) {
                    regEx = patternConstraint.getRegularExpression();
                    modifiedRegEx = StringEscapeUtils.escapeJava(regEx);
                    regExps.add(modifiedRegEx);
                }
            }
        }
        return regExps;
    }

    /**
     *
     * Adds to the <code>genTOBuilder</code> the constant which contains regular
     * expressions from the <code>regularExpressions</code>
     *
     * @param genTOBuilder
     *            generated TO builder to which are
     *            <code>regular expressions</code> added
     * @param regularExpressions
     *            list of string which represent regular expressions
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>genTOBuilder</code> equals null</li>
     *             <li>if <code>regularExpressions</code> equals null</li>
     *             </ul>
     */
    private void addStringRegExAsConstant(GeneratedTOBuilder genTOBuilder, List<String> regularExpressions) {
        if (genTOBuilder == null) {
            throw new IllegalArgumentException("Generated transfer object builder can't be null");
        }
        if (regularExpressions == null) {
            throw new IllegalArgumentException("List of regular expressions can't be null");
        }
        if (!regularExpressions.isEmpty()) {
            genTOBuilder.addConstant(Types.listTypeFor(BaseYangTypes.STRING_TYPE), TypeConstants.PATTERN_CONSTANT_NAME,
                    regularExpressions);
        }
    }

    /**
     * Creates generated TO with data about inner extended type
     * <code>innerExtendedType</code>, about the package name
     * <code>typedefName</code> and about the generated TO name
     * <code>typedefName</code>.
     *
     * It is supposed that <code>innerExtendedType</code> is already present in
     * {@link TypeProviderImpl#genTypeDefsContextMap genTypeDefsContextMap} to
     * be possible set it as extended type for the returning generated TO.
     *
     * @param innerExtendedType
     *            extended type which is part of some other extended type
     * @param basePackageName
     *            string with the package name of the module
     * @param typedefName
     *            string with the name for the generated TO
     * @return generated TO which extends generated TO for
     *         <code>innerExtendedType</code>
     * @throws IllegalArgumentException
     *             <ul>
     *             <li>if <code>extendedType</code> equals null</li>
     *             <li>if <code>basePackageName</code> equals null</li>
     *             <li>if <code>typedefName</code> equals null</li>
     *             </ul>
     */
    private GeneratedTransferObject provideGeneratedTOFromExtendedType(final TypeDefinition<?> typedef, final ExtendedType innerExtendedType,
            final String basePackageName) {
        Preconditions.checkArgument(innerExtendedType != null, "Extended type cannot be NULL!");
        Preconditions.checkArgument(basePackageName != null, "String with base package name cannot be NULL!");

        final String typedefName = typedef.getQName().getLocalName();
        final String classTypedefName = parseToClassName(typedefName);
        final String innerTypeDef = innerExtendedType.getQName().getLocalName();
        final GeneratedTOBuilder genTOBuilder = new GeneratedTOBuilderImpl(basePackageName, classTypedefName);
        Restrictions r = BindingGeneratorUtil.getRestrictions(typedef);
        genTOBuilder.setRestrictions(r);

        if (baseTypeDefForExtendedType(innerExtendedType) instanceof UnionTypeDefinition) {
            genTOBuilder.setIsUnion(true);
        }

        Map<String, Type> typeMap = null;
        final Module parentModule = findParentModule(schemaContext, innerExtendedType);
        if (parentModule != null) {
            typeMap = genTypeDefsContextMap.get(parentModule.getName());
        }

        if (typeMap != null) {
            Type type = typeMap.get(innerTypeDef);
            if (type instanceof GeneratedTransferObject) {
                genTOBuilder.setExtendsType((GeneratedTransferObject) type);
            }
        }
        addUnitsToGenTO(genTOBuilder, typedef.getUnits());

        return genTOBuilder.toInstance();
    }

    /**
     * Finds out for each type definition how many immersion (depth) is
     * necessary to get to the base type. Every type definition is inserted to
     * the map which key is depth and value is list of type definitions with
     * equal depth. In next step are lists from this map concatenated to one
     * list in ascending order according to their depth. All type definitions
     * are in the list behind all type definitions on which depends.
     *
     * @param unsortedTypeDefinitions
     *            list of type definitions which should be sorted by depth
     * @return list of type definitions sorted according their each other
     *         dependencies (type definitions which are depend on other type
     *         definitions are in list behind them).
     */
    private List<TypeDefinition<?>> sortTypeDefinitionAccordingDepth(
            final Collection<TypeDefinition<?>> unsortedTypeDefinitions) {
        List<TypeDefinition<?>> sortedTypeDefinition = new ArrayList<>();

        Map<Integer, List<TypeDefinition<?>>> typeDefinitionsDepths = new TreeMap<>();
        for (TypeDefinition<?> unsortedTypeDefinition : unsortedTypeDefinitions) {
            final int depth = getTypeDefinitionDepth(unsortedTypeDefinition);
            List<TypeDefinition<?>> typeDefinitionsConcreteDepth = typeDefinitionsDepths.get(depth);
            if (typeDefinitionsConcreteDepth == null) {
                typeDefinitionsConcreteDepth = new ArrayList<TypeDefinition<?>>();
                typeDefinitionsDepths.put(depth, typeDefinitionsConcreteDepth);
            }
            typeDefinitionsConcreteDepth.add(unsortedTypeDefinition);
        }
        // keys are in ascending order
        Set<Integer> depths = typeDefinitionsDepths.keySet();
        for (Integer depth : depths) {
            sortedTypeDefinition.addAll(typeDefinitionsDepths.get(depth));
        }

        return sortedTypeDefinition;
    }

    /**
     * Returns how many immersion is necessary to get from the type definition
     * to the base type.
     *
     * @param typeDefinition
     *            type definition for which is depth sought.
     * @return number of immersions which are necessary to get from the type
     *         definition to the base type
     */
    private int getTypeDefinitionDepth(final TypeDefinition<?> typeDefinition) {
        if (typeDefinition == null) {
            return 1;
        }
        int depth = 1;
        TypeDefinition<?> baseType = typeDefinition.getBaseType();

        if (baseType instanceof ExtendedType) {
            depth = depth + getTypeDefinitionDepth(typeDefinition.getBaseType());
        } else if (baseType instanceof UnionType) {
            List<TypeDefinition<?>> childTypeDefinitions = ((UnionType) baseType).getTypes();
            int maxChildDepth = 0;
            int childDepth = 1;
            for (TypeDefinition<?> childTypeDefinition : childTypeDefinitions) {
                childDepth = childDepth + getTypeDefinitionDepth(childTypeDefinition);
                if (childDepth > maxChildDepth) {
                    maxChildDepth = childDepth;
                }
            }
            return maxChildDepth;
        }
        return depth;
    }

    /**
     * Returns string which contains the same value as <code>name</code> but
     * integer suffix is incremented by one. If <code>name</code> contains no
     * number suffix then number 1 is added.
     *
     * @param name
     *            string with name of augmented node
     * @return string with the number suffix incremented by one (or 1 is added)
     */
    private String provideAvailableNameForGenTOBuilder(String name) {
        Pattern searchedPattern = Pattern.compile("[0-9]+\\z");
        Matcher mtch = searchedPattern.matcher(name);
        if (mtch.find()) {
            final int newSuffix = Integer.valueOf(name.substring(mtch.start())) + 1;
            return name.substring(0, mtch.start()) + newSuffix;
        } else {
            return name + 1;
        }
    }

    private void addUnitsToGenTO(GeneratedTOBuilder to, String units) {
        if (units != null && !units.isEmpty()) {
            to.addConstant(Types.STRING, "_UNITS", "\"" + units + "\"");
            GeneratedPropertyBuilder prop = new GeneratedPropertyBuilderImpl("UNITS");
            prop.setReturnType(Types.STRING);
            to.addToStringProperty(prop);
        }
    }

    @Override
    public String getTypeDefaultConstruction(LeafSchemaNode node) {
        return getTypeDefaultConstruction(node, node.getDefault());
    }

    public String getTypeDefaultConstruction(LeafSchemaNode node, String defaultValue) {
        TypeDefinition<?> type = node.getType();
        Preconditions.checkNotNull(type, "Cannot provide default construction for null type of " + node);
        Preconditions.checkNotNull(defaultValue, "Cannot provide default construction for null default statement of "
                + node);

        Module module = getParentModule(node);
        String basePackageName = BindingGeneratorUtil.moduleNamespaceToPackageName(module);
        String packageName = packageNameForGeneratedType(basePackageName, node.getPath());
        String className = packageName + "." + parseToClassName(node.getQName().getLocalName());

        StringBuilder sb = new StringBuilder();
        TypeDefinition<?> base = baseTypeDefForExtendedType(type);
        final boolean isBaseNull = base == null;

        if (isBaseNull) {
            base = type;
        }

        String result = null;
        if (base instanceof BinaryTypeDefinition) {
            result = binaryToDef(defaultValue);
        } else if (base instanceof BitsTypeDefinition) {
            String parentName;
            YangNode parent = node.getParent();
            if (parent instanceof Module) {
                parentName = parseToClassName(((Module)parent).getName()) + "Data";
                className = basePackageName + "." + parentName + "." + parseToClassName(node.getQName().getLocalName());
            } else {
                parentName = parseToClassName(((SchemaNode)parent).getQName().getLocalName());
                className = packageName + "." + parentName + "." + parseToClassName(node.getQName().getLocalName());
            }
            result = bitsToDef((BitsTypeDefinition) base, className, defaultValue, isBaseNull);
        } else if (base instanceof BooleanTypeDefinition) {
            result = typeToDef(Boolean.class, defaultValue);
        } else if (base instanceof DecimalTypeDefinition) {
            result = typeToDef(BigDecimal.class, defaultValue);
        } else if (base instanceof EmptyTypeDefinition) {
            result = typeToDef(Boolean.class, defaultValue);
        } else if (base instanceof EnumTypeDefinition) {
            char[] defValArray = defaultValue.toCharArray();
            char first = Character.toUpperCase(defaultValue.charAt(0));
            defValArray[0] = first;
            String newDefVal = new String(defValArray);
            if (type instanceof ExtendedType) {
                className = packageName + "." + parseToClassName(node.getType().getQName().getLocalName());
            }
            result = className + "." + newDefVal;
        } else if (base instanceof IdentityrefTypeDefinition) {
            throw new UnsupportedOperationException("Cannot get default construction for identityref type");
        } else if (base instanceof InstanceIdentifierTypeDefinition) {
            throw new UnsupportedOperationException("Cannot get default construction for instance-identifier type");
        } else if (base instanceof Int8) {
            result = typeToDef(Byte.class, defaultValue);
        } else if (base instanceof Int16) {
            result = typeToDef(Short.class, defaultValue);
        } else if (base instanceof Int32) {
            result = typeToDef(Integer.class, defaultValue);
        } else if (base instanceof Int64) {
            result = typeToDef(Long.class, defaultValue);
        } else if (base instanceof LeafrefTypeDefinition) {
            result = leafrefToDef(node, (LeafrefTypeDefinition)base);
        } else if (base instanceof StringTypeDefinition) {
            result = "\"" + defaultValue + "\"";
        } else if (base instanceof Uint8) {
            result = typeToDef(Short.class, defaultValue);
        } else if (base instanceof Uint16) {
            result = typeToDef(Integer.class, defaultValue);
        } else if (base instanceof Uint32) {
            result = typeToDef(Long.class, defaultValue);
        } else if (base instanceof Uint64) {
            result = typeToDef(BigInteger.class, defaultValue);
        } else if (base instanceof UnionTypeDefinition) {
            throw new UnsupportedOperationException("Cannot get default construction for union type");
        } else {
            result = "";
        }
        sb.append(result);

        if (result != null && !result.isEmpty() && type instanceof ExtendedType && !(base instanceof LeafrefTypeDefinition)) {
            className = packageName + "." + parseToClassName(node.getType().getQName().getLocalName());
            sb.insert(0, "new " + className + "(");
            sb.insert(sb.length(), ")");
        }

        return sb.toString();
    }


    private String typeToDef(Class<?> clazz, String defaultValue) {
        return "new " + clazz.getName() + "(\"" + defaultValue + "\")";
    }

    private String binaryToDef(String defaultValue) {
        StringBuilder sb = new StringBuilder();
        BaseEncoding en = BaseEncoding.base64();
        byte[] encoded = en.decode(defaultValue);
        sb.append("new byte[] {");
        for (int i = 0; i < encoded.length; i++) {
            sb.append(encoded[i]);
            if (i != encoded.length - 1) {
                sb.append(", ");
            }
        }
        sb.append("}");
        return sb.toString();
    }

    private String bitsToDef(BitsTypeDefinition type, String className, String defaultValue, boolean isBase) {
        List<Bit> bits = new ArrayList<>(type.getBits());
        Collections.sort(bits, new Comparator<Bit>() {
            @Override
            public int compare(Bit o1, Bit o2) {
                return o1.getName().compareTo(o2.getName());
            }
        });
        StringBuilder sb = new StringBuilder();
        sb.append(isBase ? "new " + className + "(" : "");
        for (int i = 0; i < bits.size(); i++) {
            if (bits.get(i).getName().equals(defaultValue)) {
                sb.append(true);
            } else {
                sb.append(false);
            }
            if (i != bits.size() - 1) {
                sb.append(", ");
            }
        }
        sb.append(isBase ? ")" : "");
        return sb.toString();
    }

    private Module getParentModule(YangNode node) {
        if (node instanceof Module) {
            return (Module) node;
        }

        YangNode parent = null;
        if (node instanceof DataSchemaNode) {
            parent = ((DataSchemaNode) node).getParent();
        } else if (node instanceof DataNodeContainer) {
            parent = ((DataNodeContainer) node).getParent();
        } else {
            parent = null;
        }

        while (parent != null && !(parent instanceof Module)) {
            if (parent instanceof DataSchemaNode) {
                parent = ((DataSchemaNode) parent).getParent();
            } else if (parent instanceof DataNodeContainer) {
                parent = ((DataNodeContainer) parent).getParent();
            } else {
                parent = null;
            }
        }
        return (Module) parent;
    }

    private String leafrefToDef(LeafSchemaNode parentNode, LeafrefTypeDefinition leafrefType) {
        Preconditions.checkArgument(leafrefType != null, "Leafref Type Definition reference cannot be NULL!");
        Preconditions.checkArgument(leafrefType.getPathStatement() != null, "The Path Statement for Leafref Type Definition cannot be NULL!");

        final RevisionAwareXPath xpath = leafrefType.getPathStatement();
        final String strXPath = xpath.toString();

        if (strXPath != null) {
            if (strXPath.contains("[")) {
                return "new java.lang.Object()";
            } else {
                final Module module = findParentModule(schemaContext, parentNode);
                if (module != null) {
                    final SchemaNode dataNode;
                    if (xpath.isAbsolute()) {
                        dataNode = findDataSchemaNode(schemaContext, module, xpath);
                    } else {
                        dataNode = findDataSchemaNodeForRelativeXPath(schemaContext, module, parentNode, xpath);
                    }
                    return getTypeDefaultConstruction((LeafSchemaNode)dataNode, parentNode.getDefault());
                }
            }
        }

        return null;
    }

}