/**
    * Copyright (c) 2008-2011, http://www.snakeyaml.org
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.yaml.snakeyaml;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.Reader;
  import java.io.StringReader;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.regex.Pattern;
  
  import org.yaml.snakeyaml.DumperOptions.FlowStyle;
  import org.yaml.snakeyaml.composer.Composer;
  import org.yaml.snakeyaml.constructor.BaseConstructor;
  import org.yaml.snakeyaml.constructor.Constructor;
  import org.yaml.snakeyaml.emitter.Emitable;
  import org.yaml.snakeyaml.emitter.Emitter;
  import org.yaml.snakeyaml.error.YAMLException;
  import org.yaml.snakeyaml.events.Event;
  import org.yaml.snakeyaml.introspector.BeanAccess;
  import org.yaml.snakeyaml.nodes.Node;
  import org.yaml.snakeyaml.nodes.Tag;
  import org.yaml.snakeyaml.parser.Parser;
  import org.yaml.snakeyaml.parser.ParserImpl;
  import org.yaml.snakeyaml.reader.StreamReader;
  import org.yaml.snakeyaml.reader.UnicodeReader;
  import org.yaml.snakeyaml.representer.Representer;
  import org.yaml.snakeyaml.resolver.Resolver;
  import org.yaml.snakeyaml.serializer.Serializer;
  
  /**
   * Public YAML interface. Each Thread must have its own instance.
   */
  public class Yaml {
      protected final Resolver resolver;
      private String name;
      protected BaseConstructor constructor;
      protected Representer representer;
      protected DumperOptions dumperOptions;
      protected LoaderOptions loaderOptions;
  
      /**
       * Create Yaml instance. It is safe to create a few instances and use them
       * in different Threads.
       */
      public Yaml() {
          this(new Constructor(), new LoaderOptions(), new Representer(), new DumperOptions(),
                  new Resolver());
      }
  
      public Yaml(LoaderOptions loaderOptions) {
          this(new Constructor(), loaderOptions, new Representer(), new DumperOptions(),
                  new Resolver());
      }
  
      /**
       * Create Yaml instance.
       * 
       * @param dumperOptions
       *            DumperOptions to configure outgoing objects
       */
      public Yaml(DumperOptions dumperOptions) {
          this(new Constructor(), new Representer(), dumperOptions);
      }
  
      /**
       * Create Yaml instance. It is safe to create a few instances and use them
       * in different Threads.
       * 
       * @param representer
       *            Representer to emit outgoing objects
       */
      public Yaml(Representer representer) {
          this(new Constructor(), representer);
      }
  
      /**
       * Create Yaml instance. It is safe to create a few instances and use them
       * in different Threads.
       * 
       * @param constructor
      *            BaseConstructor to construct incoming documents
      */
     public Yaml(BaseConstructor constructor) {
         this(constructor, new Representer());
     }
 
     /**
      * Create Yaml instance. It is safe to create a few instances and use them
      * in different Threads.
      * 
      * @param constructor
      *            BaseConstructor to construct incoming documents
      * @param representer
      *            Representer to emit outgoing objects
      */
     public Yaml(BaseConstructor constructor, Representer representer) {
         this(constructor, representer, new DumperOptions());
     }
 
     /**
      * Create Yaml instance. It is safe to create a few instances and use them
      * in different Threads.
      * 
      * @param representer
      *            Representer to emit outgoing objects
      * @param dumperOptions
      *            DumperOptions to configure outgoing objects
      */
     public Yaml(Representer representer, DumperOptions dumperOptions) {
         this(new Constructor(), representer, dumperOptions, new Resolver());
     }
 
     /**
      * Create Yaml instance. It is safe to create a few instances and use them
      * in different Threads.
      * 
      * @param constructor
      *            BaseConstructor to construct incoming documents
      * @param representer
      *            Representer to emit outgoing objects
      * @param dumperOptions
      *            DumperOptions to configure outgoing objects
      */
     public Yaml(BaseConstructor constructor, Representer representer, DumperOptions dumperOptions) {
         this(constructor, representer, dumperOptions, new Resolver());
     }
 
     /**
      * Create Yaml instance. It is safe to create a few instances and use them
      * in different Threads.
      * 
      * @param constructor
      *            BaseConstructor to construct incoming documents
      * @param representer
      *            Representer to emit outgoing objects
      * @param dumperOptions
      *            DumperOptions to configure outgoing objects
      * @param resolver
      *            Resolver to detect implicit type
      */
     public Yaml(BaseConstructor constructor, Representer representer, DumperOptions dumperOptions,
             Resolver resolver) {
         this(constructor, new LoaderOptions(), representer, dumperOptions, resolver);
     }
 
     /**
      * Create Yaml instance. It is safe to create a few instances and use them
      * in different Threads.
      * 
      * @param constructor
      *            BaseConstructor to construct incoming documents
      * @param loaderOptions
      *            LoaderOptions to control construction process
      * @param representer
      *            Representer to emit outgoing objects
      * @param dumperOptions
      *            DumperOptions to configure outgoing objects
      * @param resolver
      *            Resolver to detect implicit type
      */
     public Yaml(BaseConstructor constructor, LoaderOptions loaderOptions, Representer representer,
             DumperOptions dumperOptions, Resolver resolver) {
         if (!constructor.isExplicitPropertyUtils()) {
             constructor.setPropertyUtils(representer.getPropertyUtils());
         } else if (!representer.isExplicitPropertyUtils()) {
             representer.setPropertyUtils(constructor.getPropertyUtils());
         }
         this.constructor = constructor;
         this.loaderOptions = loaderOptions;
         representer.setDefaultFlowStyle(dumperOptions.getDefaultFlowStyle());
         representer.setDefaultScalarStyle(dumperOptions.getDefaultScalarStyle());
         representer.getPropertyUtils().setAllowReadOnlyProperties(
                 dumperOptions.isAllowReadOnlyProperties());
         this.representer = representer;
         this.dumperOptions = dumperOptions;
         this.resolver = resolver;
         this.name = "Yaml:" + System.identityHashCode(this);
     }
 
     /**
      * Serialize a Java object into a YAML String.
      * 
      * @param data
      *            Java object to be Serialized to YAML
      * @return YAML String
      */
     public String dump(Object data) {
         List<Object> list = new ArrayList<Object>(1);
         list.add(data);
         return dumpAll(list.iterator());
     }
 
     /**
      * Produce the corresponding representation tree for a given Object.
      * 
      * @see http://yaml.org/spec/1.1/#id859333
      * @param data
      *            instance to build the representation tree for
      * @return representation tree
      */
     public Node represent(Object data) {
         return representer.represent(data);
     }
 
     /**
      * Serialize a sequence of Java objects into a YAML String.
      * 
      * @param data
      *            Iterator with Objects
      * @return YAML String with all the objects in proper sequence
      */
     public String dumpAll(Iterator<? extends Object> data) {
         StringWriter buffer = new StringWriter();
         dumpAll(data, buffer);
         return buffer.toString();
     }
 
     /**
      * Serialize a Java object into a YAML stream.
      * 
      * @param data
      *            Java object to be serialized to YAML
      * @param output
      *            stream to write to
      */
     public void dump(Object data, Writer output) {
         List<Object> list = new ArrayList<Object>(1);
         list.add(data);
         dumpAll(list.iterator(), output);
     }
 
     /**
      * Serialize a sequence of Java objects into a YAML stream.
      * 
      * @param data
      *            Iterator with Objects
      * @param output
      *            stream to write to
      */
     @SuppressWarnings("deprecation")
     public void dumpAll(Iterator<? extends Object> data, Writer output) {
         dumpAll(data, output, dumperOptions.getExplicitRoot());
     }
 
     private void dumpAll(Iterator<? extends Object> data, Writer output, Tag rootTag) {
         Serializer serializer = new Serializer(new Emitter(output, dumperOptions), resolver,
                 dumperOptions, rootTag);
         try {
             serializer.open();
             while (data.hasNext()) {
                 Node node = representer.represent(data.next());
                 serializer.serialize(node);
             }
             serializer.close();
         } catch (java.io.IOException e) {
             throw new YAMLException(e);
         }
     }
 
     /**
      * <p>
      * Serialize a Java object into a YAML string. Override the default root tag
      * with <code>rootTag</code>.
      * </p>
      * 
      * <p>
      * This method is similar to <code>Yaml.dump(data)</code> except that the
      * root tag for the whole document is replaced with the given tag. This has
      * two main uses.
      * </p>
      * 
      * <p>
      * First, if the root tag is replaced with a standard YAML tag, such as
      * <code>Tag.MAP</code>, then the object will be dumped as a map. The root
      * tag will appear as <code>!!map</code>, or blank (implicit !!map).
      * </p>
      * 
      * <p>
      * Second, if the root tag is replaced by a different custom tag, then the
      * document appears to be a different type when loaded. For example, if an
      * instance of MyClass is dumped with the tag !!YourClass, then it will be
      * handled as an instance of YourClass when loaded.
      * </p>
      * 
      * @param data
      *            Java object to be serialized to YAML
      * @param rootTag
      *            the tag for the whole YAML document. The tag should be Tag.MAP
      *            for a JavaBean to make the tag disappear (to use implicit tag
      *            !!map). If <code>null</code> is provided then the standard tag
      *            with the full class name is used.
      * @param flowStyle
      *            flow style for the whole document. See Chapter 10. Collection
      *            Styles http://yaml.org/spec/1.1/#id930798. If
      *            <code>null</code> is provided then the flow style from
      *            DumperOptions is used.
      * 
      * @return YAML String
      */
     public String dumpAs(Object data, Tag rootTag, FlowStyle flowStyle) {
         FlowStyle oldStyle = representer.getDefaultFlowStyle();
         if (flowStyle != null) {
             representer.setDefaultFlowStyle(flowStyle);
         }
         List<Object> list = new ArrayList<Object>(1);
         list.add(data);
         StringWriter buffer = new StringWriter();
         dumpAll(list.iterator(), buffer, rootTag);
         representer.setDefaultFlowStyle(oldStyle);
         return buffer.toString();
     }
 
     /**
      * <p>
      * Serialize a Java object into a YAML string. Override the default root tag
      * with <code>Tag.MAP</code>.
      * </p>
      * <p>
      * This method is similar to <code>Yaml.dump(data)</code> except that the
      * root tag for the whole document is replaced with <code>Tag.MAP</code> tag
      * (implicit !!map).
      * </p>
      * <p>
      * Block Mapping is used as the collection style. See 10.2.2. Block Mappings
      * (http://yaml.org/spec/1.1/#id934537)
      * </p>
      * 
      * @param data
      *            Java object to be serialized to YAML
      * @return YAML String
      */
     public String dumpAsMap(Object data) {
         return dumpAs(data, Tag.MAP, FlowStyle.BLOCK);
     }
 
     /**
      * Serialize the representation tree into Events.
      * 
      * @see http://yaml.org/spec/1.1/#id859333
      * @param data
      *            representation tree
      * @return Event list
      */
     public List<Event> serialize(Node data) {
         SilentEmitter emitter = new SilentEmitter();
         @SuppressWarnings("deprecation")
         Serializer serializer = new Serializer(emitter, resolver, dumperOptions,
                 dumperOptions.getExplicitRoot());
         try {
             serializer.open();
             serializer.serialize(data);
             serializer.close();
         } catch (java.io.IOException e) {
             throw new YAMLException(e);
         }
         return emitter.getEvents();
     }
 
     private class SilentEmitter implements Emitable {
         private List<Event> events = new ArrayList<Event>(100);
 
         public List<Event> getEvents() {
             return events;
         }
 
         public void emit(Event event) throws IOException {
             events.add(event);
         }
     }
 
     /**
      * Parse the only YAML document in a String and produce the corresponding
      * Java object. (Because the encoding in known BOM is not respected.)
      * 
      * @param yaml
      *            YAML data to load from (BOM must not be present)
      * @return parsed object
      */
     public Object load(String yaml) {
         return loadFromReader(new StreamReader(yaml), Object.class);
     }
 
     /**
      * Parse the only YAML document in a stream and produce the corresponding
      * Java object.
      * 
      * @param io
      *            data to load from (BOM is respected and removed)
      * @return parsed object
      */
     public Object load(InputStream io) {
         return loadFromReader(new StreamReader(new UnicodeReader(io)), Object.class);
     }
 
     /**
      * Parse the only YAML document in a stream and produce the corresponding
      * Java object.
      * 
      * @param io
      *            data to load from (BOM must not be present)
      * @return parsed object
      */
     public Object load(Reader io) {
         return loadFromReader(new StreamReader(io), Object.class);
     }
 
     /**
      * Parse the only YAML document in a stream and produce the corresponding
      * Java object.
      * 
      * @param <T>
      *            Class is defined by the second argument
      * @param io
      *            data to load from (BOM must not be present)
      * @param type
      *            Class of the object to be created
      * @return parsed object
      */
     @SuppressWarnings("unchecked")
     public <T> T loadAs(Reader io, Class<T> type) {
         return (T) loadFromReader(new StreamReader(io), type);
     }
 
     /**
      * Parse the only YAML document in a String and produce the corresponding
      * Java object. (Because the encoding in known BOM is not respected.)
      * 
      * @param <T>
      *            Class is defined by the second argument
      * @param yaml
      *            YAML data to load from (BOM must not be present)
      * @param type
      *            Class of the object to be created
      * @return parsed object
      */
     @SuppressWarnings("unchecked")
     public <T> T loadAs(String yaml, Class<T> type) {
         return (T) loadFromReader(new StreamReader(yaml), type);
     }
 
     /**
      * Parse the only YAML document in a stream and produce the corresponding
      * Java object.
      * 
      * @param <T>
      *            Class is defined by the second argument
      * @param input
      *            data to load from (BOM is respected and removed)
      * @param type
      *            Class of the object to be created
      * @return parsed object
      */
     @SuppressWarnings("unchecked")
     public <T> T loadAs(InputStream input, Class<T> type) {
         return (T) loadFromReader(new StreamReader(new UnicodeReader(input)), type);
     }
 
     private Object loadFromReader(StreamReader sreader, Class<?> type) {
         Composer composer = new Composer(new ParserImpl(sreader), resolver);
         constructor.setComposer(composer);
         return constructor.getSingleData(type);
     }
 
     /**
      * Parse all YAML documents in a String and produce corresponding Java
      * objects. The documents are parsed only when the iterator is invoked.
      * 
      * @param yaml
      *            YAML data to load from (BOM must not be present)
      * @return an iterator over the parsed Java objects in this String in proper
      *         sequence
      */
     public Iterable<Object> loadAll(Reader yaml) {
         Composer composer = new Composer(new ParserImpl(new StreamReader(yaml)), resolver);
         constructor.setComposer(composer);
         Iterator<Object> result = new Iterator<Object>() {
             public boolean hasNext() {
                 return constructor.checkData();
             }
 
             public Object next() {
                 return constructor.getData();
             }
 
             public void remove() {
                 throw new UnsupportedOperationException();
             }
         };
         return new YamlIterable(result);
     }
 
     private class YamlIterable implements Iterable<Object> {
         private Iterator<Object> iterator;
 
         public YamlIterable(Iterator<Object> iterator) {
             this.iterator = iterator;
         }
 
         public Iterator<Object> iterator() {
             return iterator;
         }
 
     }
 
     /**
      * Parse all YAML documents in a String and produce corresponding Java
      * objects. (Because the encoding in known BOM is not respected.) The
      * documents are parsed only when the iterator is invoked.
      * 
      * @param yaml
      *            YAML data to load from (BOM must not be present)
      * @return an iterator over the parsed Java objects in this String in proper
      *         sequence
      */
     public Iterable<Object> loadAll(String yaml) {
         return loadAll(new StringReader(yaml));
     }
 
     /**
      * Parse all YAML documents in a stream and produce corresponding Java
      * objects. The documents are parsed only when the iterator is invoked.
      * 
      * @param yaml
      *            YAML data to load from (BOM is respected and ignored)
      * @return an iterator over the parsed Java objects in this stream in proper
      *         sequence
      */
     public Iterable<Object> loadAll(InputStream yaml) {
         return loadAll(new UnicodeReader(yaml));
     }
 
     /**
      * Parse the first YAML document in a stream and produce the corresponding
      * representation tree. (This is the opposite of the represent() method)
      * 
      * @see http://yaml.org/spec/1.1/#id859333
      * @param yaml
      *            YAML document
      * @return parsed root Node for the specified YAML document
      */
     public Node compose(Reader yaml) {
         Composer composer = new Composer(new ParserImpl(new StreamReader(yaml)), resolver);
         constructor.setComposer(composer);
         return composer.getSingleNode();
     }
 
     /**
      * Parse all YAML documents in a stream and produce corresponding
      * representation trees.
      * 
      * @see http://yaml.org/spec/1.1/#id859333
      * @param yaml
      *            stream of YAML documents
      * @return parsed root Nodes for all the specified YAML documents
      */
     public Iterable<Node> composeAll(Reader yaml) {
         final Composer composer = new Composer(new ParserImpl(new StreamReader(yaml)), resolver);
         constructor.setComposer(composer);
         Iterator<Node> result = new Iterator<Node>() {
             public boolean hasNext() {
                 return composer.checkNode();
             }
 
             public Node next() {
                 return composer.getNode();
             }
 
             public void remove() {
                 throw new UnsupportedOperationException();
             }
         };
         return new NodeIterable(result);
     }
 
     private class NodeIterable implements Iterable<Node> {
         private Iterator<Node> iterator;
 
         public NodeIterable(Iterator<Node> iterator) {
             this.iterator = iterator;
         }
 
         public Iterator<Node> iterator() {
             return iterator;
         }
     }
 
     /**
      * Add an implicit scalar detector. If an implicit scalar value matches the
      * given regexp, the corresponding tag is assigned to the scalar.
      * 
      * @deprecated use Tag instead of String
      * @param tag
      *            tag to assign to the node
      * @param regexp
      *            regular expression to match against
      * @param first
      *            a sequence of possible initial characters or null (which means
      *            any).
      * 
      */
     public void addImplicitResolver(String tag, Pattern regexp, String first) {
         addImplicitResolver(new Tag(tag), regexp, first);
     }
 
     /**
      * Add an implicit scalar detector. If an implicit scalar value matches the
      * given regexp, the corresponding tag is assigned to the scalar.
      * 
      * @param tag
      *            tag to assign to the node
      * @param regexp
      *            regular expression to match against
      * @param first
      *            a sequence of possible initial characters or null (which means
      *            any).
      */
     public void addImplicitResolver(Tag tag, Pattern regexp, String first) {
         resolver.addImplicitResolver(tag, regexp, first);
     }
 
     @Override
     public String toString() {
         return name;
     }
 
     /**
      * Get a meaningful name. It simplifies debugging in a multi-threaded
      * environment. If nothing is set explicitly the address of the instance is
      * returned.
      * 
      * @return human readable name
      */
     public String getName() {
         return name;
     }
 
     /**
      * Set a meaningful name to be shown in toString()
      * 
      * @param name
      *            human readable name
      */
     public void setName(String name) {
         this.name = name;
     }
 
     /**
      * Parse a YAML stream and produce parsing events.
      * 
      * @see http://yaml.org/spec/1.1/#id859333
      * @param yaml
      *            YAML document(s)
      * @return parsed events
      */
     public Iterable<Event> parse(Reader yaml) {
         final Parser parser = new ParserImpl(new StreamReader(yaml));
         Iterator<Event> result = new Iterator<Event>() {
             public boolean hasNext() {
                 return parser.peekEvent() != null;
             }
 
             public Event next() {
                 return parser.getEvent();
             }
 
             public void remove() {
                 throw new UnsupportedOperationException();
             }
         };
         return new EventIterable(result);
     }
 
     private class EventIterable implements Iterable<Event> {
         private Iterator<Event> iterator;
 
         public EventIterable(Iterator<Event> iterator) {
             this.iterator = iterator;
         }
 
         public Iterator<Event> iterator() {
             return iterator;
         }
     }
 
     public void setBeanAccess(BeanAccess beanAccess) {
         constructor.getPropertyUtils().setBeanAccess(beanAccess);
         representer.getPropertyUtils().setBeanAccess(beanAccess);
     }
 
     // deprecated
     /**
      * @deprecated use with Constructor instead of Loader
      */
     public Yaml(Loader loader) {
         this(loader, new Dumper(new DumperOptions()));
     }
 
     /**
      * @deprecated use with Constructor instead of Loader
      */
     public Yaml(Loader loader, Dumper dumper) {
         this(loader, dumper, new Resolver());
     }
 
     /**
      * @deprecated use with Constructor instead of Loader
      */
     public Yaml(Loader loader, Dumper dumper, Resolver resolver) {
         this(loader.constructor, dumper.representer, dumper.options, resolver);
     }
 
     /**
      * Create Yaml instance. It is safe to create a few instances and use them
      * in different Threads.
      * 
      * @param dumper
      *            Dumper to emit outgoing objects
      */
     @SuppressWarnings("deprecation")
     public Yaml(Dumper dumper) {
         this(new Constructor(), dumper.representer, dumper.options);
     }
 }