Added YANG typedef support in the YANG parser
[controller.git] / opendaylight / sal / yang-prototype / code-generator / yang-model-parser-impl / src / main / java / org / opendaylight / controller / yang / model / parser / impl / YangModelParserImpl.java
index d86b49d78bccc6c219a475ea2d9ad89ac491bd7b..d7c6711affb740de272f754e76e331561782f8ba 100644 (file)
@@ -26,7 +26,22 @@ import org.antlr.v4.runtime.tree.ParseTree;
 import org.antlr.v4.runtime.tree.ParseTreeWalker;
 import org.opendaylight.controller.antlrv4.code.gen.YangLexer;
 import org.opendaylight.controller.antlrv4.code.gen.YangParser;
+import org.opendaylight.controller.model.api.type.BinaryTypeDefinition;
+import org.opendaylight.controller.model.api.type.BitsTypeDefinition;
+import org.opendaylight.controller.model.api.type.BitsTypeDefinition.Bit;
+import org.opendaylight.controller.model.api.type.DecimalTypeDefinition;
+import org.opendaylight.controller.model.api.type.InstanceIdentifierTypeDefinition;
+import org.opendaylight.controller.model.api.type.IntegerTypeDefinition;
+import org.opendaylight.controller.model.api.type.LengthConstraint;
+import org.opendaylight.controller.model.api.type.PatternConstraint;
+import org.opendaylight.controller.model.api.type.RangeConstraint;
+import org.opendaylight.controller.model.api.type.StringTypeDefinition;
+import org.opendaylight.controller.model.util.BaseConstraints;
+import org.opendaylight.controller.model.util.BinaryType;
+import org.opendaylight.controller.model.util.BitsType;
+import org.opendaylight.controller.model.util.StringType;
 import org.opendaylight.controller.model.util.UnknownType;
+import org.opendaylight.controller.model.util.YangTypesConverter;
 import org.opendaylight.controller.yang.common.QName;
 import org.opendaylight.controller.yang.model.api.AugmentationSchema;
 import org.opendaylight.controller.yang.model.api.DataSchemaNode;
@@ -37,6 +52,7 @@ import org.opendaylight.controller.yang.model.api.NotificationDefinition;
 import org.opendaylight.controller.yang.model.api.RpcDefinition;
 import org.opendaylight.controller.yang.model.api.SchemaContext;
 import org.opendaylight.controller.yang.model.api.SchemaPath;
+import org.opendaylight.controller.yang.model.api.TypeDefinition;
 import org.opendaylight.controller.yang.model.parser.api.YangModelParser;
 import org.opendaylight.controller.yang.model.parser.builder.api.AugmentationSchemaBuilder;
 import org.opendaylight.controller.yang.model.parser.builder.api.AugmentationTargetBuilder;
@@ -72,22 +88,85 @@ public class YangModelParserImpl implements YangModelParser {
         return new SchemaContextImpl(modules);
     }
 
+    private Map<String, TreeMap<Date, ModuleBuilder>> loadFiles(
+            String... yangFiles) {
+        final Map<String, TreeMap<Date, ModuleBuilder>> modules = new HashMap<String, TreeMap<Date, ModuleBuilder>>();
+
+        final YangModelParserListenerImpl yangModelParser = new YangModelParserListenerImpl();
+        final ParseTreeWalker walker = new ParseTreeWalker();
+
+        List<ParseTree> trees = parseFiles(yangFiles);
+
+        ModuleBuilder[] builders = new ModuleBuilder[trees.size()];
+
+        for (int i = 0; i < trees.size(); i++) {
+            walker.walk(yangModelParser, trees.get(i));
+            builders[i] = yangModelParser.getModuleBuilder();
+        }
+
+        for (ModuleBuilder builder : builders) {
+            final String builderName = builder.getName();
+            Date builderRevision = builder.getRevision();
+            if (builderRevision == null) {
+                builderRevision = createEpochTime();
+            }
+
+            TreeMap<Date, ModuleBuilder> builderByRevision = modules
+                    .get(builderName);
+            if (builderByRevision == null) {
+                builderByRevision = new TreeMap<Date, ModuleBuilder>();
+            }
+            builderByRevision.put(builderRevision, builder);
+
+            modules.put(builderName, builderByRevision);
+        }
+        return modules;
+    }
+
+    private List<ParseTree> parseFiles(String... yangFileNames) {
+        List<ParseTree> trees = new ArrayList<ParseTree>();
+        for (String fileName : yangFileNames) {
+            trees.add(parseFile(fileName));
+        }
+        return trees;
+    }
+
+    private ParseTree parseFile(String yangFileName) {
+        ParseTree result = null;
+        try {
+            final File yangFile = new File(yangFileName);
+            final FileInputStream inStream = new FileInputStream(yangFile);
+            final ANTLRInputStream input = new ANTLRInputStream(inStream);
+            final YangLexer lexer = new YangLexer(input);
+            final CommonTokenStream tokens = new CommonTokenStream(lexer);
+            final YangParser parser = new YangParser(tokens);
+            result = parser.yang();
+        } catch (IOException e) {
+            logger.warn("Exception while reading yang file: " + yangFileName, e);
+        }
+        return result;
+    }
+
     private Set<Module> build(Map<String, TreeMap<Date, ModuleBuilder>> modules) {
         // first validate
-        for (Map.Entry<String, TreeMap<Date, ModuleBuilder>> entry : modules.entrySet()) {
-            for (Map.Entry<Date, ModuleBuilder> childEntry : entry.getValue().entrySet()) {
+        for (Map.Entry<String, TreeMap<Date, ModuleBuilder>> entry : modules
+                .entrySet()) {
+            for (Map.Entry<Date, ModuleBuilder> childEntry : entry.getValue()
+                    .entrySet()) {
                 ModuleBuilder moduleBuilder = childEntry.getValue();
                 validateBuilder(modules, moduleBuilder);
             }
         }
-
         // then build
         final Set<Module> result = new HashSet<Module>();
-        for (Map.Entry<String, TreeMap<Date, ModuleBuilder>> entry : modules.entrySet()) {
+        for (Map.Entry<String, TreeMap<Date, ModuleBuilder>> entry : modules
+                .entrySet()) {
             final Map<Date, Module> modulesByRevision = new HashMap<Date, Module>();
-            for (Map.Entry<Date, ModuleBuilder> childEntry : entry.getValue().entrySet()) {
+            for (Map.Entry<Date, ModuleBuilder> childEntry : entry.getValue()
+                    .entrySet()) {
                 ModuleBuilder moduleBuilder = childEntry.getValue();
-                modulesByRevision.put(childEntry.getKey(),moduleBuilder.build());
+                modulesByRevision.put(childEntry.getKey(),
+                        moduleBuilder.build());
                 result.add(moduleBuilder.build());
             }
         }
@@ -95,47 +174,175 @@ public class YangModelParserImpl implements YangModelParser {
         return result;
     }
 
-    private void validateBuilder(Map<String, TreeMap<Date, ModuleBuilder>> modules, ModuleBuilder builder) {
+    private void validateBuilder(
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            ModuleBuilder builder) {
         resolveTypedefs(modules, builder);
         resolveAugments(modules, builder);
     }
 
-    private void resolveTypedefs(Map<String, TreeMap<Date, ModuleBuilder>> modules, ModuleBuilder builder) {
-        Map<List<String>, TypeAwareBuilder> dirtyNodes = builder.getDirtyNodes();
+    /**
+     * Search for dirty nodes (node which contains UnknownType) and resolve
+     * unknown types.
+     *
+     * @param modules
+     *            all available modules
+     * @param builder
+     *            current module
+     */
+    private void resolveTypedefs(
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            ModuleBuilder builder) {
+        Map<List<String>, TypeAwareBuilder> dirtyNodes = builder
+                .getDirtyNodes();
         if (dirtyNodes.size() == 0) {
             return;
         } else {
-            for (Map.Entry<List<String>, TypeAwareBuilder> entry : dirtyNodes.entrySet()) {
-                TypeAwareBuilder tab = entry.getValue();
-                TypeDefinitionBuilder tdb = findTypeDefinitionBuilder(modules,entry.getValue(), builder);
-                tab.setType(tdb.build());
+            for (Map.Entry<List<String>, TypeAwareBuilder> entry : dirtyNodes
+                    .entrySet()) {
+                TypeAwareBuilder typeToResolve = entry.getValue();
+                Map<TypeDefinitionBuilder, TypeConstraints> foundedTypeDefinitionBuilder = findTypeDefinitionBuilderWithConstraints(
+                        modules, entry.getValue(), builder);
+                TypeDefinitionBuilder targetType = foundedTypeDefinitionBuilder
+                        .entrySet().iterator().next().getKey();
+                TypeConstraints constraints = foundedTypeDefinitionBuilder
+                        .entrySet().iterator().next().getValue();
+
+                UnknownType ut = (UnknownType) typeToResolve.getType();
+
+                // RANGE
+                List<RangeConstraint> ranges = ut.getRangeStatements();
+                resolveRanges(ranges, typeToResolve, targetType, modules,
+                        builder);
+
+                // LENGTH
+                List<LengthConstraint> lengths = ut.getLengthStatements();
+                resolveLengths(lengths, typeToResolve, targetType, modules,
+                        builder);
+
+                // PATTERN
+                List<PatternConstraint> patterns = ut.getPatterns();
+
+                // Fraction Digits
+                Integer fractionDigits = ut.getFractionDigits();
+
+                TypeDefinition<?> type = targetType.getBaseType();
+                String typeName = type.getQName().getLocalName();
+
+                // MERGE CONSTRAINTS (enumeration and leafref omitted because
+                // they have no restrictions)
+                if (type instanceof DecimalTypeDefinition) {
+                    List<RangeConstraint> fullRanges = new ArrayList<RangeConstraint>();
+                    fullRanges.addAll(constraints.getRanges());
+                    fullRanges.addAll(ranges);
+                    Integer fd = fractionDigits == null ? constraints
+                            .getFractionDigits() : fractionDigits;
+                    type = YangTypesConverter.javaTypeForBaseYangDecimal64Type(
+                            fullRanges, fd);
+                } else if (type instanceof IntegerTypeDefinition) {
+                    List<RangeConstraint> fullRanges = new ArrayList<RangeConstraint>();
+                    fullRanges.addAll(constraints.getRanges());
+                    fullRanges.addAll(ranges);
+                    if (typeName.startsWith("int")) {
+                        type = YangTypesConverter
+                                .javaTypeForBaseYangSignedIntegerType(typeName,
+                                        fullRanges);
+                    } else {
+                        type = YangTypesConverter
+                                .javaTypeForBaseYangUnsignedIntegerType(
+                                        typeName, fullRanges);
+                    }
+                } else if (type instanceof StringTypeDefinition) {
+                    List<LengthConstraint> fullLengths = new ArrayList<LengthConstraint>();
+                    fullLengths.addAll(constraints.getLengths());
+                    fullLengths.addAll(lengths);
+                    List<PatternConstraint> fullPatterns = new ArrayList<PatternConstraint>();
+                    fullPatterns.addAll(constraints.getPatterns());
+                    fullPatterns.addAll(patterns);
+                    type = new StringType(fullLengths, fullPatterns);
+                } else if (type instanceof BitsTypeDefinition) {
+                    // TODO: add 'length' restriction to BitsType
+                    BitsTypeDefinition bitsType = (BitsTypeDefinition) type;
+                    List<Bit> bits = bitsType.getBits();
+                    type = new BitsType(bits);
+                } else if (type instanceof BinaryTypeDefinition) {
+                    type = new BinaryType(null, lengths, null);
+                } else if (typeName.equals("instance-identifier")) {
+                    // TODO: instance-identifier
+                    /*
+                     * boolean requireInstance = isRequireInstance(typeBody);
+                     * type = new InstanceIdentifier(null, requireInstance);
+                     */
+                }
+                typeToResolve.setType(type);
             }
         }
     }
 
-    private TypeDefinitionBuilder findTypeDefinitionBuilder(Map<String, TreeMap<Date, ModuleBuilder>> modules, TypeAwareBuilder typeBuilder, ModuleBuilder builder) {
+    private TypeDefinitionBuilder findTypeDefinitionBuilder(
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            TypeAwareBuilder typeBuilder, ModuleBuilder builder) {
+        Map<TypeDefinitionBuilder, TypeConstraints> result = findTypeDefinitionBuilderWithConstraints(
+                modules, typeBuilder, builder);
+        return result.entrySet().iterator().next().getKey();
+    }
+
+    private Map<TypeDefinitionBuilder, TypeConstraints> findTypeDefinitionBuilderWithConstraints(
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            TypeAwareBuilder typeBuilder, ModuleBuilder builder) {
+        return findTypeDefinitionBuilderWithConstraints(new TypeConstraints(),
+                modules, typeBuilder, builder);
+    }
+
+    /**
+     * Traverse through all referenced types chain until base YANG type is
+     * founded.
+     *
+     * @param constraints
+     *            current type constraints
+     * @param modules
+     *            all available modules
+     * @param typeBuilder
+     *            type builder which contains type
+     * @param builder
+     *            current module
+     * @return map, where key is type referenced and value is its constraints
+     */
+    private Map<TypeDefinitionBuilder, TypeConstraints> findTypeDefinitionBuilderWithConstraints(
+            TypeConstraints constraints,
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            TypeAwareBuilder typeBuilder, ModuleBuilder builder) {
+        Map<TypeDefinitionBuilder, TypeConstraints> result = new HashMap<TypeDefinitionBuilder, TypeConstraints>();
+
         UnknownType type = (UnknownType) typeBuilder.getType();
         QName typeQName = type.getQName();
         String typeName = type.getQName().getLocalName();
         String prefix = typeQName.getPrefix();
 
+        // search for module which contains referenced typedef
         ModuleBuilder dependentModuleBuilder;
         if (prefix.equals(builder.getPrefix())) {
             dependentModuleBuilder = builder;
         } else {
-            ModuleImport dependentModuleImport = getDependentModuleImport(builder, prefix);
+            ModuleImport dependentModuleImport = getModuleImport(builder,
+                    prefix);
             String dependentModuleName = dependentModuleImport.getModuleName();
             Date dependentModuleRevision = dependentModuleImport.getRevision();
-            TreeMap<Date, ModuleBuilder> moduleBuildersByRevision = modules.get(dependentModuleName);
-            if(dependentModuleRevision == null) {
-                dependentModuleBuilder = moduleBuildersByRevision.lastEntry().getValue();
+            TreeMap<Date, ModuleBuilder> moduleBuildersByRevision = modules
+                    .get(dependentModuleName);
+            if (dependentModuleRevision == null) {
+                dependentModuleBuilder = moduleBuildersByRevision.lastEntry()
+                        .getValue();
             } else {
-                dependentModuleBuilder = moduleBuildersByRevision.get(dependentModuleRevision);
+                dependentModuleBuilder = moduleBuildersByRevision
+                        .get(dependentModuleRevision);
             }
         }
 
-        final Set<TypeDefinitionBuilder> typedefs = dependentModuleBuilder.getModuleTypedefs();
-
+        // pull all typedef statements from dependent module...
+        final Set<TypeDefinitionBuilder> typedefs = dependentModuleBuilder
+                .getModuleTypedefs();
+        // and search for referenced typedef
         TypeDefinitionBuilder lookedUpBuilder = null;
         for (TypeDefinitionBuilder tdb : typedefs) {
             QName qname = tdb.getQName();
@@ -145,15 +352,65 @@ public class YangModelParserImpl implements YangModelParser {
             }
         }
 
-        if (lookedUpBuilder.getBaseType() instanceof UnknownType) {
-            return findTypeDefinitionBuilder(modules, (TypeAwareBuilder) lookedUpBuilder, dependentModuleBuilder);
+        // if referenced type is UnknownType again, search recursively with
+        // current constraints
+        TypeDefinition<?> referencedType = lookedUpBuilder.getBaseType();
+        if (referencedType instanceof UnknownType) {
+            UnknownType unknown = (UnknownType) lookedUpBuilder.getBaseType();
+
+            final List<RangeConstraint> ranges = unknown.getRangeStatements();
+            constraints.addRanges(ranges);
+            final List<LengthConstraint> lengths = unknown
+                    .getLengthStatements();
+            constraints.addLengths(lengths);
+            final List<PatternConstraint> patterns = unknown.getPatterns();
+            constraints.addPatterns(patterns);
+            return findTypeDefinitionBuilderWithConstraints(constraints,
+                    modules, (TypeAwareBuilder) lookedUpBuilder,
+                    dependentModuleBuilder);
         } else {
-            return lookedUpBuilder;
+            // pull restriction from this base type and add them to
+            // 'constraints'
+            if (referencedType instanceof DecimalTypeDefinition) {
+                constraints.addRanges(((DecimalTypeDefinition) referencedType)
+                        .getRangeStatements());
+                constraints
+                        .setFractionDigits(((DecimalTypeDefinition) referencedType)
+                                .getFractionDigits());
+            } else if (referencedType instanceof IntegerTypeDefinition) {
+                constraints.addRanges(((IntegerTypeDefinition) referencedType)
+                        .getRangeStatements());
+            } else if (referencedType instanceof StringTypeDefinition) {
+                constraints.addPatterns(((StringTypeDefinition) referencedType)
+                        .getPatterns());
+            } else if (referencedType instanceof BitsTypeDefinition) {
+                // TODO: add 'length' restriction to BitsType
+            } else if (referencedType instanceof BinaryTypeDefinition) {
+                // TODO
+            } else if (referencedType instanceof InstanceIdentifierTypeDefinition) {
+                // TODO: instance-identifier
+            }
+
+            result.put(lookedUpBuilder, constraints);
+            // return lookedUpBuilder;
+            return result;
         }
     }
 
-    private void resolveAugments(Map<String, TreeMap<Date, ModuleBuilder>> modules, ModuleBuilder builder) {
-        Set<AugmentationSchemaBuilder> augmentBuilders = builder.getAddedAugments();
+    /**
+     * Go through all augmentation definitions and resolve them. This means find
+     * referenced node and add child nodes to it.
+     *
+     * @param modules
+     *            all available modules
+     * @param builder
+     *            current module
+     */
+    private void resolveAugments(
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            ModuleBuilder builder) {
+        Set<AugmentationSchemaBuilder> augmentBuilders = builder
+                .getAddedAugments();
 
         Set<AugmentationSchema> augments = new HashSet<AugmentationSchema>();
         for (AugmentationSchemaBuilder augmentBuilder : augmentBuilders) {
@@ -164,21 +421,26 @@ public class YangModelParserImpl implements YangModelParser {
                 prefix = pathPart.getPrefix();
                 augmentTargetPath.add(pathPart.getLocalName());
             }
-            ModuleImport dependentModuleImport = getDependentModuleImport(builder, prefix);
+            ModuleImport dependentModuleImport = getModuleImport(builder,
+                    prefix);
             String dependentModuleName = dependentModuleImport.getModuleName();
             augmentTargetPath.add(0, dependentModuleName);
 
             Date dependentModuleRevision = dependentModuleImport.getRevision();
 
-            TreeMap<Date, ModuleBuilder> moduleBuildersByRevision = modules.get(dependentModuleName);
+            TreeMap<Date, ModuleBuilder> moduleBuildersByRevision = modules
+                    .get(dependentModuleName);
             ModuleBuilder dependentModule;
-            if(dependentModuleRevision == null) {
-                dependentModule = moduleBuildersByRevision.lastEntry().getValue();
+            if (dependentModuleRevision == null) {
+                dependentModule = moduleBuildersByRevision.lastEntry()
+                        .getValue();
             } else {
-                dependentModule = moduleBuildersByRevision.get(dependentModuleRevision);
+                dependentModule = moduleBuildersByRevision
+                        .get(dependentModuleRevision);
             }
 
-            AugmentationTargetBuilder augmentTarget = (AugmentationTargetBuilder) dependentModule.getNode(augmentTargetPath);
+            AugmentationTargetBuilder augmentTarget = (AugmentationTargetBuilder) dependentModule
+                    .getNode(augmentTargetPath);
             AugmentationSchema result = augmentBuilder.build();
             augmentTarget.addAugmentation(result);
             fillAugmentTarget(augmentBuilder, (ChildNodeBuilder) augmentTarget);
@@ -187,6 +449,12 @@ public class YangModelParserImpl implements YangModelParser {
         builder.setAugmentations(augments);
     }
 
+    /**
+     * Add all augment's child nodes to given target.
+     *
+     * @param augment
+     * @param target
+     */
     private void fillAugmentTarget(AugmentationSchemaBuilder augment,
             ChildNodeBuilder target) {
         for (DataSchemaNodeBuilder builder : augment.getChildNodes()) {
@@ -195,72 +463,143 @@ public class YangModelParserImpl implements YangModelParser {
         }
     }
 
-    private Map<String, TreeMap<Date, ModuleBuilder>> loadFiles(String... yangFiles) {
-        final Map<String, TreeMap<Date, ModuleBuilder>> modules = new HashMap<String, TreeMap<Date, ModuleBuilder>>();
-
-        final YangModelParserListenerImpl yangModelParser = new YangModelParserListenerImpl();
-        final ParseTreeWalker walker = new ParseTreeWalker();
-
-        List<ParseTree> trees = parseFiles(yangFiles);
-
-        ModuleBuilder[] builders = new ModuleBuilder[trees.size()];
-
-        for (int i = 0; i < trees.size(); i++) {
-            walker.walk(yangModelParser, trees.get(i));
-            builders[i] = yangModelParser.getModuleBuilder();
-        }
-
-        for (ModuleBuilder builder : builders) {
-            final String builderName = builder.getName();
-            Date builderRevision = builder.getRevision();
-            if(builderRevision == null) {
-                builderRevision = createEpochTime();
-            }
-
-            TreeMap<Date, ModuleBuilder> builderByRevision = modules.get(builderName);
-            if (builderByRevision == null) {
-                builderByRevision = new TreeMap<Date, ModuleBuilder>();
+    /**
+     * Get module import referenced by given prefix.
+     *
+     * @param builder
+     *            module to search
+     * @param prefix
+     *            prefix associated with import
+     * @return ModuleImport based on given prefix
+     */
+    private ModuleImport getModuleImport(ModuleBuilder builder, String prefix) {
+        ModuleImport moduleImport = null;
+        for (ModuleImport mi : builder.getModuleImports()) {
+            if (mi.getPrefix().equals(prefix)) {
+                moduleImport = mi;
+                break;
             }
-            builderByRevision.put(builderRevision, builder);
-
-            modules.put(builderName, builderByRevision);
         }
-        return modules;
+        return moduleImport;
     }
 
-    private List<ParseTree> parseFiles(String... yangFileNames) {
-        List<ParseTree> trees = new ArrayList<ParseTree>();
-        for (String fileName : yangFileNames) {
-            trees.add(parseFile(fileName));
+    /**
+     * Helper method for resolving special 'min' or 'max' values in range
+     * constraint
+     *
+     * @param ranges
+     *            ranges to resolve
+     * @param typeToResolve
+     *            type to resolve
+     * @param targetType
+     *            target type
+     * @param modules
+     *            all available modules
+     * @param builder
+     *            current module
+     */
+    private void resolveRanges(List<RangeConstraint> ranges,
+            TypeAwareBuilder typeToResolve, TypeDefinitionBuilder targetType,
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            ModuleBuilder builder) {
+        if (ranges != null && ranges.size() > 0) {
+            Long min = (Long) ranges.get(0).getMin();
+            Long max = (Long) ranges.get(ranges.size() - 1).getMax();
+            // if range contains one of the special values 'min' or 'max'
+            if (min.equals(Long.MIN_VALUE) || max.equals(Long.MAX_VALUE)) {
+                Long[] values = parseRangeConstraint(typeToResolve, targetType,
+                        modules, builder);
+                if (min.equals(Long.MIN_VALUE)) {
+                    min = values[0];
+                    RangeConstraint oldFirst = ranges.get(0);
+                    RangeConstraint newFirst = BaseConstraints.rangeConstraint(
+                            min, oldFirst.getMax(), oldFirst.getDescription(),
+                            oldFirst.getReference());
+                    ranges.set(0, newFirst);
+                }
+                if (max.equals(Long.MAX_VALUE)) {
+                    max = values[1];
+                    RangeConstraint oldLast = ranges.get(ranges.size() - 1);
+                    RangeConstraint newLast = BaseConstraints.rangeConstraint(
+                            oldLast.getMin(), max, oldLast.getDescription(),
+                            oldLast.getReference());
+                    ranges.set(ranges.size() - 1, newLast);
+                }
+            }
         }
-        return trees;
     }
 
-    private ParseTree parseFile(String yangFileName) {
-        ParseTree result = null;
-        try {
-            final File yangFile = new File(yangFileName);
-            final FileInputStream inStream = new FileInputStream(yangFile);
-            final ANTLRInputStream input = new ANTLRInputStream(inStream);
-            final YangLexer lexer = new YangLexer(input);
-            final CommonTokenStream tokens = new CommonTokenStream(lexer);
-            final YangParser parser = new YangParser(tokens);
-            result = parser.yang();
-        } catch (IOException e) {
-            logger.warn("Exception while reading yang file: " + yangFileName, e);
+    /**
+     * Helper method for resolving special 'min' or 'max' values in length
+     * constraint
+     *
+     * @param ranges
+     *            ranges to resolve
+     * @param typeToResolve
+     *            type to resolve
+     * @param targetType
+     *            target type
+     * @param modules
+     *            all available modules
+     * @param builder
+     *            current module
+     */
+    private void resolveLengths(List<LengthConstraint> lengths,
+            TypeAwareBuilder typeToResolve, TypeDefinitionBuilder targetType,
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            ModuleBuilder builder) {
+        if (lengths != null && lengths.size() > 0) {
+            Long min = lengths.get(0).getMin();
+            Long max = lengths.get(lengths.size() - 1).getMax();
+            // if length contains one of the special values 'min' or 'max'
+            if (min.equals(Long.MIN_VALUE) || max.equals(Long.MAX_VALUE)) {
+                Long[] values = parseRangeConstraint(typeToResolve, targetType,
+                        modules, builder);
+                if (min.equals(Long.MIN_VALUE)) {
+                    min = values[0];
+                    LengthConstraint oldFirst = lengths.get(0);
+                    LengthConstraint newFirst = BaseConstraints
+                            .lengthConstraint(min, oldFirst.getMax(),
+                                    oldFirst.getDescription(),
+                                    oldFirst.getReference());
+                    lengths.set(0, newFirst);
+                }
+                if (max.equals(Long.MAX_VALUE)) {
+                    max = values[1];
+                    LengthConstraint oldLast = lengths.get(lengths.size() - 1);
+                    LengthConstraint newLast = BaseConstraints
+                            .lengthConstraint(oldLast.getMin(), max,
+                                    oldLast.getDescription(),
+                                    oldLast.getReference());
+                    lengths.set(lengths.size() - 1, newLast);
+                }
+            }
         }
-        return result;
     }
 
-    private ModuleImport getDependentModuleImport(ModuleBuilder builder, String prefix) {
-        ModuleImport moduleImport = null;
-        for (ModuleImport mi : builder.getModuleImports()) {
-            if (mi.getPrefix().equals(prefix)) {
-                moduleImport = mi;
-                break;
-            }
+    private Long[] parseRangeConstraint(TypeAwareBuilder typeToResolve,
+            TypeDefinitionBuilder targetType,
+            Map<String, TreeMap<Date, ModuleBuilder>> modules,
+            ModuleBuilder builder) {
+        TypeDefinition<?> targetBaseType = targetType.getBaseType();
+
+        if (targetBaseType instanceof IntegerTypeDefinition) {
+            IntegerTypeDefinition itd = (IntegerTypeDefinition) targetBaseType;
+            List<RangeConstraint> ranges = itd.getRangeStatements();
+            Long min = (Long) ranges.get(0).getMin();
+            Long max = (Long) ranges.get(ranges.size() - 1).getMax();
+            return new Long[] { min, max };
+        } else if (targetBaseType instanceof DecimalTypeDefinition) {
+            DecimalTypeDefinition dtd = (DecimalTypeDefinition) targetBaseType;
+            List<RangeConstraint> ranges = dtd.getRangeStatements();
+            Long min = (Long) ranges.get(0).getMin();
+            Long max = (Long) ranges.get(ranges.size() - 1).getMax();
+            return new Long[] { min, max };
+        } else {
+            return parseRangeConstraint(typeToResolve,
+                    findTypeDefinitionBuilder(modules, typeToResolve, builder),
+                    modules, builder);
         }
-        return moduleImport;
     }
 
     private Date createEpochTime() {
@@ -318,4 +657,45 @@ public class YangModelParserImpl implements YangModelParser {
         }
     }
 
+    private static class TypeConstraints {
+        private final List<RangeConstraint> ranges = new ArrayList<RangeConstraint>();
+        private final List<LengthConstraint> lengths = new ArrayList<LengthConstraint>();
+        private final List<PatternConstraint> patterns = new ArrayList<PatternConstraint>();
+        private Integer fractionDigits;
+
+        public List<RangeConstraint> getRanges() {
+            return ranges;
+        }
+
+        public void addRanges(List<RangeConstraint> ranges) {
+            this.ranges.addAll(0, ranges);
+        }
+
+        public List<LengthConstraint> getLengths() {
+            return lengths;
+        }
+
+        public void addLengths(List<LengthConstraint> lengths) {
+            this.lengths.addAll(0, lengths);
+        }
+
+        public List<PatternConstraint> getPatterns() {
+            return patterns;
+        }
+
+        public void addPatterns(List<PatternConstraint> patterns) {
+            this.patterns.addAll(0, patterns);
+        }
+
+        public Integer getFractionDigits() {
+            return fractionDigits;
+        }
+
+        public void setFractionDigits(Integer fractionDigits) {
+            if (fractionDigits != null) {
+                this.fractionDigits = fractionDigits;
+            }
+        }
+    }
+
 }