// ***************************************************************************************************************************
// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
// * to you 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.apache.juneau.xml;

import static javax.xml.stream.XMLStreamConstants.*;
import static org.apache.juneau.internal.StringUtils.*;
import static org.apache.juneau.xml.annotation.XmlFormat.*;

import java.io.IOException;
import java.lang.reflect.*;
import java.util.*;

import javax.xml.stream.*;
import javax.xml.stream.util.*;

import org.apache.juneau.*;
import org.apache.juneau.collections.*;
import org.apache.juneau.parser.*;
import org.apache.juneau.transform.*;
import org.apache.juneau.xml.annotation.*;

/**
 * Session object that lives for the duration of a single use of {@link XmlParser}.
 *
 * <p>
 * This class is NOT thread safe.
 * It is typically discarded after one-time use although it can be reused against multiple inputs.
 */
@SuppressWarnings({ "unchecked", "rawtypes" })
public class XmlParserSession extends ReaderParserSession {

   private static final int UNKNOWN=0, OBJECT=1, ARRAY=2, STRING=3, NUMBER=4, BOOLEAN=5, NULL=6;

   private final XmlParser ctx;
   private final StringBuilder rsb = new StringBuilder();  // Reusable string builder used in this class.

   /**
    * Create a new session using properties specified in the context.
    *
    * @param ctx
    *    The context creating this session object.
    *    The context contains all the configuration settings for this object.
    * @param args
    *    Runtime session arguments.
    */
   protected XmlParserSession(XmlParser ctx, ParserSessionArgs args) {
      super(ctx, args);
      this.ctx = ctx;
   }

   /**
    * Wrap the specified reader in a STAX reader based on settings in this context.
    *
    * @param pipe The parser input.
    * @return The new STAX reader.
    * @throws IOException Thrown by underlying stream.
    * @throws XMLStreamException Unexpected XML processing error.
    */
   protected final XmlReader getXmlReader(ParserPipe pipe) throws IOException, XMLStreamException {
      return new XmlReader(pipe, isValidating(), getReporter(), getResolver(), getEventAllocator());
   }

   /**
    * Decodes and trims the specified string.
    *
    * <p>
    * Any <js>'_x####_'</js> sequences in the string will be decoded.
    *
    * @param s The string to be decoded.
    * @return The decoded string.
    */
   protected final String decodeString(String s) {
      if (s == null)
         return null;
      rsb.setLength(0);
      s = XmlUtils.decode(s, rsb);
      if (isTrimStrings())
         s = s.trim();
      return s;
   }

   /*
    * Returns the name of the current XML element.
    * Any <js>'_x####_'</js> sequences in the string will be decoded.
    */
   private String getElementName(XmlReader r) {
      return decodeString(r.getLocalName());
   }

   /*
    * Returns the _name attribute value.
    * Any <js>'_x####_'</js> sequences in the string will be decoded.
    */
   private String getNameProperty(XmlReader r) {
      return decodeString(r.getAttributeValue(null, getNamePropertyName()));
   }

   /*
    * Returns the name of the specified attribute on the current XML element.
    * Any <js>'_x####_'</js> sequences in the string will be decoded.
    */
   private String getAttributeName(XmlReader r, int i) {
      return decodeString(r.getAttributeLocalName(i));
   }

   /*
    * Returns the value of the specified attribute on the current XML element.
    * Any <js>'_x####_'</js> sequences in the string will be decoded.
    */
   private String getAttributeValue(XmlReader r, int i) {
      return decodeString(r.getAttributeValue(i));
   }

   /**
    * Returns the text content of the current XML element.
    *
    * <p>
    * Any <js>'_x####_'</js> sequences in the string will be decoded.
    *
    * <p>
    * Leading and trailing whitespace (unencoded) will be trimmed from the result.
    *
    * @param r The reader to read the element text from.
    * @return The decoded text.  <jk>null</jk> if the text consists of the sequence <js>'_x0000_'</js>.
    * @throws XMLStreamException Thrown by underlying reader.
    * @throws IOException Thrown by underlying stream.
    * @throws ParseException Malformed input encountered.
    */
   protected String getElementText(XmlReader r) throws XMLStreamException, IOException, ParseException {
      return decodeString(r.getElementText().trim());
   }

   /*
    * Returns the content of the current CHARACTERS node.
    * Any <js>'_x####_'</js> sequences in the string will be decoded.
    * Leading and trailing whitespace (unencoded) will be trimmed from the result.
    */
   private String getText(XmlReader r, boolean trim) {
      String s = r.getText();
      if (trim)
         s = s.trim();
      if (s.isEmpty())
         return null;
      return decodeString(s);
   }

   /*
    * Shortcut for calling <code>getText(r, <jk>true</jk>);</code>.
    */
   private String getText(XmlReader r) {
      return getText(r, true);
   }

   /*
    * Takes the element being read from the XML stream reader and reconstructs it as XML.
    * Used when reconstructing bean properties of type {@link XmlFormat#XMLTEXT}.
    */
   private String getElementAsString(XmlReader r) {
      int t = r.getEventType();
      if (t > 2)
         throw new BasicRuntimeException("Invalid event type on stream reader for elementToString() method: ''{0}''", XmlUtils.toReadableEvent(r));
      rsb.setLength(0);
      rsb.append("<").append(t == 1 ? "" : "/").append(r.getLocalName());
      if (t == 1)
         for (int i = 0; i < r.getAttributeCount(); i++)
            rsb.append(' ').append(r.getAttributeName(i)).append('=').append('\'').append(r.getAttributeValue(i)).append('\'');
      rsb.append('>');
      return rsb.toString();
   }

   /**
    * Parses the current element as text.
    *
    * @param r The input reader.
    * @return The parsed text.
    * @throws XMLStreamException Thrown by underlying reader.
    * @throws IOException Thrown by underlying stream.
    * @throws ParseException Malformed input encountered.
    */
   protected String parseText(XmlReader r) throws IOException, XMLStreamException, ParseException {
      // Note that this is different than {@link #getText(XmlReader)} since it assumes that we're pointing to a
      // whitespace element.

      StringBuilder sb2 = getStringBuilder();

      int depth = 0;
      while (true) {
         int et = r.getEventType();
         if (et == START_ELEMENT) {
            sb2.append(getElementAsString(r));
            depth++;
         } else if (et == CHARACTERS) {
            sb2.append(getText(r));
         } else if (et == END_ELEMENT) {
            sb2.append(getElementAsString(r));
            depth--;
            if (depth <= 0)
               break;
         }
         et = r.next();
      }
      String s = sb2.toString();
      returnStringBuilder(sb2);
      return s;
   }

   /**
    * Returns <jk>true</jk> if the current element is a whitespace element.
    *
    * <p>
    * For the XML parser, this always returns <jk>false</jk>.
    * However, the HTML parser defines various whitespace elements such as <js>"br"</js> and <js>"sp"</js>.
    *
    * @param r The XML stream reader to read the current event from.
    * @return <jk>true</jk> if the current element is a whitespace element.
    */
   protected boolean isWhitespaceElement(XmlReader r) {
      return false;
   }

   /**
    * Parses the current whitespace element.
    *
    * <p>
    * For the XML parser, this always returns <jk>null</jk> since there is no concept of a whitespace element.
    * However, the HTML parser defines various whitespace elements such as <js>"br"</js> and <js>"sp"</js>.
    *
    * @param r The XML stream reader to read the current event from.
    * @return The whitespace character or characters.
    * @throws XMLStreamException Thrown by underlying reader.
    * @throws IOException Thrown by underlying stream.
    * @throws ParseException Malformed input encountered.
    */
   protected String parseWhitespaceElement(XmlReader r) throws IOException, XMLStreamException, ParseException {
      return null;
   }

   @Override /* ParserSession */
   protected <T> T doParse(ParserPipe pipe, ClassMeta<T> type) throws IOException, ParseException, ExecutableException {
      try {
         return parseAnything(type, null, getXmlReader(pipe), getOuter(), true, null);
      } catch (XMLStreamException e) {
         throw new ParseException(e);
      }
   }

   @Override /* ReaderParserSession */
   protected <K,V> Map<K,V> doParseIntoMap(ParserPipe pipe, Map<K,V> m, Type keyType, Type valueType) throws Exception {
      ClassMeta cm = getClassMeta(m.getClass(), keyType, valueType);
      return parseIntoMap(pipe, m, cm.getKeyType(), cm.getValueType());
   }

   @Override /* ReaderParserSession */
   protected <E> Collection<E> doParseIntoCollection(ParserPipe pipe, Collection<E> c, Type elementType) throws Exception {
      ClassMeta cm = getClassMeta(c.getClass(), elementType);
      return parseIntoCollection(pipe, c, cm.getElementType());
   }

   /**
    * Workhorse method.
    *
    * @param <T> The expected type of object.
    * @param eType The expected type of object.
    * @param currAttr The current bean property name.
    * @param r The reader.
    * @param outer The outer object.
    * @param isRoot If <jk>true</jk>, then we're serializing a root element in the document.
    * @param pMeta The bean property metadata.
    * @return The parsed object.
    * @throws IOException Thrown by underlying stream.
    * @throws ParseException Malformed input encountered.
    * @throws ExecutableException Exception occurred on invoked constructor/method/field.
    * @throws XMLStreamException Malformed XML encountered.
    */
   protected <T> T parseAnything(ClassMeta<T> eType, String currAttr, XmlReader r,
         Object outer, boolean isRoot, BeanPropertyMeta pMeta) throws IOException, ParseException, ExecutableException, XMLStreamException {

      if (eType == null)
         eType = (ClassMeta<T>)object();
      PojoSwap<T,Object> swap = (PojoSwap<T,Object>)eType.getSwap(this);
      BuilderSwap<T,Object> builder = (BuilderSwap<T,Object>)eType.getBuilderSwap(this);
      ClassMeta<?> sType = null;
      if (builder != null)
         sType = builder.getBuilderClassMeta(this);
      else if (swap != null)
         sType = swap.getSwapClassMeta(this);
      else
         sType = eType;

      if (sType.isOptional())
         return (T)Optional.ofNullable(parseAnything(eType.getElementType(), currAttr, r, outer, isRoot, pMeta));

      setCurrentClass(sType);

      String wrapperAttr = (isRoot && isPreserveRootElement()) ? r.getName().getLocalPart() : null;
      String typeAttr = r.getAttributeValue(null, getBeanTypePropertyName(eType));
      boolean isNil = "true".equals(r.getAttributeValue(null, "nil"));
      int jsonType = getJsonType(typeAttr);
      String elementName = getElementName(r);
      if (jsonType == 0) {
         if (elementName == null || elementName.equals(currAttr))
            jsonType = UNKNOWN;
         else {
            typeAttr = elementName;
            jsonType = getJsonType(elementName);
         }
      }

      ClassMeta tcm = getClassMeta(typeAttr, pMeta, eType);
      if (tcm == null && elementName != null && ! elementName.equals(currAttr))
         tcm = getClassMeta(elementName, pMeta, eType);
      if (tcm != null)
         sType = eType = tcm;

      Object o = null;

      if (jsonType == NULL) {
         r.nextTag();   // Discard end tag
         return null;
      }

      if (sType.isObject()) {
         if (jsonType == OBJECT) {
            OMap m = new OMap(this);
            parseIntoMap(r, m, string(), object(), pMeta);
            if (wrapperAttr != null)
               m = new OMap(this).a(wrapperAttr, m);
            o = cast(m, pMeta, eType);
         } else if (jsonType == ARRAY)
            o = parseIntoCollection(r, new OList(this), null, pMeta);
         else if (jsonType == STRING) {
            o = getElementText(r);
            if (sType.isChar())
               o = parseCharacter(o);
         }
         else if (jsonType == NUMBER)
            o = parseNumber(getElementText(r), null);
         else if (jsonType == BOOLEAN)
            o = Boolean.parseBoolean(getElementText(r));
         else if (jsonType == UNKNOWN)
            o = getUnknown(r);
      } else if (sType.isBoolean()) {
         o = Boolean.parseBoolean(getElementText(r));
      } else if (sType.isCharSequence()) {
         o = getElementText(r);
      } else if (sType.isChar()) {
         o = parseCharacter(getElementText(r));
      } else if (sType.isMap()) {
         Map m = (sType.canCreateNewInstance(outer) ? (Map)sType.newInstance(outer) : new OMap(this));
         o = parseIntoMap(r, m, sType.getKeyType(), sType.getValueType(), pMeta);
         if (wrapperAttr != null)
            o = new OMap(this).a(wrapperAttr, m);
      } else if (sType.isCollection()) {
         Collection l = (sType.canCreateNewInstance(outer) ? (Collection)sType.newInstance(outer) : new OList(this));
         o = parseIntoCollection(r, l, sType, pMeta);
      } else if (sType.isNumber()) {
         o = parseNumber(getElementText(r), (Class<? extends Number>)sType.getInnerClass());
      } else if (builder != null || sType.canCreateNewBean(outer)) {
         if (getXmlClassMeta(sType).getFormat() == COLLAPSED) {
            String fieldName = r.getLocalName();
            BeanMap<?> m = builder != null ? toBeanMap(builder.create(this, eType)) : newBeanMap(outer, sType.getInnerClass());
            BeanPropertyMeta bpm = getXmlBeanMeta(m.getMeta()).getPropertyMeta(fieldName);
            ClassMeta<?> cm = m.getMeta().getClassMeta();
            Object value = parseAnything(cm, currAttr, r, m.getBean(false), false, null);
            setName(cm, value, currAttr);
            bpm.set(m, currAttr, value);
            o = builder != null ? builder.build(this, m.getBean(), eType) : m.getBean();
         } else {
            BeanMap m = builder != null ? toBeanMap(builder.create(this, eType)) : newBeanMap(outer, sType.getInnerClass());
            m = parseIntoBean(r, m, isNil);
            o = builder != null ? builder.build(this, m.getBean(), eType) : m.getBean();
         }
      } else if (sType.isArray() || sType.isArgs()) {
         ArrayList l = (ArrayList)parseIntoCollection(r, new ArrayList(), sType, pMeta);
         o = toArray(sType, l);
      } else if (sType.canCreateNewInstanceFromString(outer)) {
         o = sType.newInstanceFromString(outer, getElementText(r));
      } else if (sType.getProxyInvocationHandler() != null) {
         OMap m = new OMap(this);
         parseIntoMap(r, m, string(), object(), pMeta);
         if (wrapperAttr != null)
            m = new OMap(this).a(wrapperAttr, m);
         o = newBeanMap(outer, sType.getInnerClass()).load(m).getBean();
      } else {
         throw new ParseException(this,
            "Class ''{0}'' could not be instantiated.  Reason: ''{1}'', property: ''{2}''",
            sType.getInnerClass().getName(), sType.getNotABeanReason(), pMeta == null ? null : pMeta.getName());
      }

      if (swap != null && o != null)
         o = unswap(swap, o, eType);

      if (outer != null)
         setParent(eType, o, outer);

      return (T)o;
   }

   private <K,V> Map<K,V> parseIntoMap(XmlReader r, Map<K,V> m, ClassMeta<K> keyType,
         ClassMeta<V> valueType, BeanPropertyMeta pMeta) throws IOException, ParseException, ExecutableException, XMLStreamException {
      int depth = 0;
      for (int i = 0; i < r.getAttributeCount(); i++) {
         String a = r.getAttributeLocalName(i);
         // TODO - Need better handling of namespaces here.
         if (! isSpecialAttr(a)) {
            K key = trim(convertAttrToType(m, a, keyType));
            V value = trim(convertAttrToType(m, r.getAttributeValue(i), valueType));
            setName(valueType, value, key);
            m.put(key, value);
         }
      }
      do {
         int event = r.nextTag();
         String currAttr;
         if (event == START_ELEMENT) {
            depth++;
            currAttr = getNameProperty(r);
            if (currAttr == null)
               currAttr = getElementName(r);
            K key = convertAttrToType(m, currAttr, keyType);
            V value = parseAnything(valueType, currAttr, r, m, false, pMeta);
            setName(valueType, value, currAttr);
            if (valueType.isObject() && m.containsKey(key)) {
               Object o = m.get(key);
               if (o instanceof List)
                  ((List)o).add(value);
               else
                  m.put(key, (V)new OList(o, value).setBeanSession(this));
            } else {
               m.put(key, value);
            }
         } else if (event == END_ELEMENT) {
            depth--;
            return m;
         }
      } while (depth > 0);
      return m;
   }

   private <E> Collection<E> parseIntoCollection(XmlReader r, Collection<E> l,
         ClassMeta<?> type, BeanPropertyMeta pMeta) throws IOException, ParseException, ExecutableException, XMLStreamException {
      int depth = 0;
      int argIndex = 0;
      do {
         int event = r.nextTag();
         if (event == START_ELEMENT) {
            depth++;
            ClassMeta<?> elementType = type == null ? object() : type.isArgs() ? type.getArg(argIndex++) : type.getElementType();
            E value = (E)parseAnything(elementType, null, r, l, false, pMeta);
            l.add(value);
         } else if (event == END_ELEMENT) {
            depth--;
            return l;
         }
      } while (depth > 0);
      return l;
   }

   private static int getJsonType(String s) {
      if (s == null)
         return UNKNOWN;
      char c = s.charAt(0);
      switch(c) {
         case 'o': return (s.equals("object") ? OBJECT : UNKNOWN);
         case 'a': return (s.equals("array") ? ARRAY : UNKNOWN);
         case 's': return (s.equals("string") ? STRING : UNKNOWN);
         case 'b': return (s.equals("boolean") ? BOOLEAN : UNKNOWN);
         case 'n': {
            c = s.charAt(2);
            switch(c) {
               case 'm': return (s.equals("number") ? NUMBER : UNKNOWN);
               case 'l': return (s.equals("null") ? NULL : UNKNOWN);
            }
            //return NUMBER;
         }
      }
      return UNKNOWN;
   }

   private <T> BeanMap<T> parseIntoBean(XmlReader r, BeanMap<T> m, boolean isNil) throws IOException, ParseException, ExecutableException, XMLStreamException {
      BeanMeta<?> bMeta = m.getMeta();
      XmlBeanMeta xmlMeta = getXmlBeanMeta(bMeta);

      for (int i = 0; i < r.getAttributeCount(); i++) {
         String key = getAttributeName(r, i);
         if (! ("nil".equals(key) || isSpecialAttr(key))) {
            String val = r.getAttributeValue(i);
            String ns = r.getAttributeNamespace(i);
            BeanPropertyMeta bpm = xmlMeta.getPropertyMeta(key);
            if (bpm == null) {
               if (xmlMeta.getAttrsProperty() != null) {
                  xmlMeta.getAttrsProperty().add(m, key, key, val);
               } else if (ns == null) {
                  onUnknownProperty(key, m, val);
               }
            } else {
               try {
                  bpm.set(m, key, val);
               } catch (BeanRuntimeException e) {
                  onBeanSetterException(bpm, e);
                  throw e;
               }
            }
         }
      }

      BeanPropertyMeta cp = xmlMeta.getContentProperty();
      XmlFormat cpf = xmlMeta.getContentFormat();
      boolean trim = cp == null || ! cpf.isOneOf(MIXED_PWS, TEXT_PWS);
      ClassMeta<?> cpcm = (cp == null ? object() : cp.getClassMeta());
      StringBuilder sb = null;
      BeanRegistry breg = cp == null ? null : cp.getBeanRegistry();
      LinkedList<Object> l = null;

      int depth = 0;
      do {
         int event = r.next();
         String currAttr;
         // We only care about text in MIXED mode.
         // Ignore if in ELEMENTS mode.
         if (event == CHARACTERS) {
            if (cp != null && cpf.isOneOf(MIXED, MIXED_PWS)) {
               if (cpcm.isCollectionOrArray()) {
                  if (l == null)
                     l = new LinkedList<>();
                  l.add(getText(r, false));
               } else {
                  cp.set(m, null, getText(r, trim));
               }
            } else if (cpf != ELEMENTS) {
               String s = getText(r, trim);
               if (s != null) {
                  if (sb == null)
                     sb = getStringBuilder();
                  sb.append(s);
               }
            } else {
               // Do nothing...we're in ELEMENTS mode.
            }
         } else if (event == START_ELEMENT) {
            if (cp != null && cpf.isOneOf(TEXT, TEXT_PWS)) {
               String s = parseText(r);
               if (s != null) {
                  if (sb == null)
                     sb = getStringBuilder();
                  sb.append(s);
               }
               depth--;
            } else if (cpf == XMLTEXT) {
               if (sb == null)
                  sb = getStringBuilder();
               sb.append(getElementAsString(r));
               depth++;
            } else if (cp != null && cpf.isOneOf(MIXED, MIXED_PWS)) {
               if (isWhitespaceElement(r) && (breg == null || ! breg.hasName(r.getLocalName()))) {
                  if (cpcm.isCollectionOrArray()) {
                     if (l == null)
                        l = new LinkedList<>();
                     l.add(parseWhitespaceElement(r));
                  } else {
                     cp.set(m, null, parseWhitespaceElement(r));
                  }
               } else {
                  if (cpcm.isCollectionOrArray()) {
                     if (l == null)
                        l = new LinkedList<>();
                     l.add(parseAnything(cpcm.getElementType(), cp.getName(), r, m.getBean(false), false, cp));
                  } else {
                     cp.set(m, null, parseAnything(cpcm, cp.getName(), r, m.getBean(false), false, cp));
                  }
               }
            } else if (cp != null && cpf == ELEMENTS) {
               cp.add(m, null, parseAnything(cpcm.getElementType(), cp.getName(), r, m.getBean(false), false, cp));
            } else {
               currAttr = getNameProperty(r);
               if (currAttr == null)
                  currAttr = getElementName(r);
               BeanPropertyMeta pMeta = xmlMeta.getPropertyMeta(currAttr);
               if (pMeta == null) {
                  Object value = parseAnything(object(), currAttr, r, m.getBean(false), false, null);
                  onUnknownProperty(currAttr, m, value);
               } else {
                  setCurrentProperty(pMeta);
                  XmlFormat xf = getXmlBeanPropertyMeta(pMeta).getXmlFormat();
                  if (xf == COLLAPSED) {
                     ClassMeta<?> et = pMeta.getClassMeta().getElementType();
                     Object value = parseAnything(et, currAttr, r, m.getBean(false), false, pMeta);
                     setName(et, value, currAttr);
                     pMeta.add(m, currAttr, value);
                  } else if (xf == ATTR)  {
                     pMeta.set(m, currAttr, getAttributeValue(r, 0));
                     r.nextTag();
                  } else {
                     ClassMeta<?> cm = pMeta.getClassMeta();
                     Object value = parseAnything(cm, currAttr, r, m.getBean(false), false, pMeta);
                     setName(cm, value, currAttr);
                     pMeta.set(m, currAttr, value);
                  }
                  setCurrentProperty(null);
               }
            }
         } else if (event == END_ELEMENT) {
            if (depth > 0) {
               if (cpf == XMLTEXT) {
                  if (sb == null)
                     sb = getStringBuilder();
                  sb.append(getElementAsString(r));
               }
               else
                  throw new ParseException("End element found where one was not expected.  {0}", XmlUtils.toReadableEvent(r));
            }
            depth--;
         } else if (event == COMMENT) {
            // Ignore comments.
         } else {
            throw new ParseException("Unexpected event type: {0}", XmlUtils.toReadableEvent(r));
         }
      } while (depth >= 0);

      if (cp != null && ! isNil) {
         if (sb != null)
            cp.set(m, null, sb.toString());
         else if (l != null)
            cp.set(m, null, XmlUtils.collapseTextNodes(l));
         else if (cpcm.isCollectionOrArray()) {
            Object o = cp.get(m, null);
            if (o == null)
               cp.set(m, cp.getName(), new ArrayList<>());
         }
      }

      returnStringBuilder(sb);
      return m;
   }

   private boolean isSpecialAttr(String key) {
      return key.equals(getBeanTypePropertyName(null)) || key.equals(getNamePropertyName());
   }

   private Object getUnknown(XmlReader r) throws IOException, ParseException, ExecutableException, XMLStreamException {
      if (r.getEventType() != START_ELEMENT) {
         throw new ParseException(this, "Parser must be on START_ELEMENT to read next text.");
      }
      OMap m = null;

      // If this element has attributes, then it's always an OMap.
      if (r.getAttributeCount() > 0) {
         m = new OMap(this);
         for (int i = 0; i < r.getAttributeCount(); i++) {
            String key = getAttributeName(r, i);
            String val = r.getAttributeValue(i);
            if (! isSpecialAttr(key))
               m.put(key, val);
         }
      }
      int eventType = r.next();
      StringBuilder sb = getStringBuilder();
      while (eventType != END_ELEMENT) {
         if (eventType == CHARACTERS || eventType == CDATA || eventType == SPACE || eventType == ENTITY_REFERENCE) {
            sb.append(r.getText());
         } else if (eventType == PROCESSING_INSTRUCTION || eventType == COMMENT) {
            // skipping
         } else if (eventType == END_DOCUMENT) {
            throw new ParseException(this, "Unexpected end of document when reading element text content");
         } else if (eventType == START_ELEMENT) {
            // Oops...this has an element in it.
            // Parse it as a map.
            if (m == null)
               m = new OMap(this);
            int depth = 0;
            do {
               int event = (eventType == -1 ? r.nextTag() : eventType);
               String currAttr;
               if (event == START_ELEMENT) {
                  depth++;
                  currAttr = getNameProperty(r);
                  if (currAttr == null)
                     currAttr = getElementName(r);
                  String key = convertAttrToType(null, currAttr, string());
                  Object value = parseAnything(object(), currAttr, r, null, false, null);
                  if (m.containsKey(key)) {
                     Object o = m.get(key);
                     if (o instanceof OList)
                        ((OList)o).add(value);
                     else
                        m.put(key, new OList(o, value).setBeanSession(this));
                  } else {
                     m.put(key, value);
                  }

               } else if (event == END_ELEMENT) {
                  depth--;
                  break;
               }
               eventType = -1;
            } while (depth > 0);
            break;
         } else {
            throw new ParseException(this, "Unexpected event type ''{0}''", eventType);
         }
         eventType = r.next();
      }
      String s = sb.toString().trim();
      returnStringBuilder(sb);
      s = decodeString(s);
      if (m != null) {
         if (! s.isEmpty())
            m.put("contents", s);
         return m;
      }
      return s;
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Properties
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Configuration property:  XML event allocator.
    *
    * @see XmlParser#XML_eventAllocator
    * @return
    *    The {@link XMLEventAllocator} associated with this parser, or <jk>null</jk> if there isn't one.
    */
   protected final XMLEventAllocator getEventAllocator() {
      return ctx.getEventAllocator();
   }

   /**
    * Configuration property:  Preserve root element during generalized parsing.
    *
    * @see XmlParser#XML_preserveRootElement
    * @return
    *    <jk>true</jk> if when parsing into a generic {@link OMap}, the map will contain a single entry whose key
    *    is the root element name.
    */
   protected final boolean isPreserveRootElement() {
      return ctx.isPreserveRootElement();
   }

   /**
    * Configuration property:  XML reporter.
    *
    * @see XmlParser#XML_reporter
    * @return
    *    The {@link XMLReporter} associated with this parser, or <jk>null</jk> if there isn't one.
    */
   protected final XMLReporter getReporter() {
      return ctx.getReporter();
   }

   /**
    * Configuration property:  XML resolver.
    *
    * @see XmlParser#XML_resolver
    * @return
    *    The {@link XMLResolver} associated with this parser, or <jk>null</jk> if there isn't one.
    */
   protected final XMLResolver getResolver() {
      return ctx.getResolver();
   }

   /**
    * Configuration property:  Enable validation.
    *
    * @see XmlParser#XML_validating
    * @return
    *    <jk>true</jk> if XML document will be validated.
    */
   protected final boolean isValidating() {
      return ctx.isValidating();
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Extended metadata
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Returns the language-specific metadata on the specified class.
    *
    * @param cm The class to return the metadata on.
    * @return The metadata.
    */
   protected XmlClassMeta getXmlClassMeta(ClassMeta<?> cm) {
      return ctx.getXmlClassMeta(cm);
   }

   /**
    * Returns the language-specific metadata on the specified bean.
    *
    * @param bm The bean to return the metadata on.
    * @return The metadata.
    */
   protected XmlBeanMeta getXmlBeanMeta(BeanMeta<?> bm) {
      return ctx.getXmlBeanMeta(bm);
   }

   /**
    * Returns the language-specific metadata on the specified bean property.
    *
    * @param bpm The bean property to return the metadata on.
    * @return The metadata.
    */
   protected XmlBeanPropertyMeta getXmlBeanPropertyMeta(BeanPropertyMeta bpm) {
      return ctx.getXmlBeanPropertyMeta(bpm);
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Other methods
   //-----------------------------------------------------------------------------------------------------------------

   @Override /* Session */
   public OMap toMap() {
      return super.toMap()
         .a("XmlParserSession", new DefaultFilteringOMap()
         );
   }
}