/*
 * 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 org.apache.juneau.commons.utils.CollectionUtils.*;
import static org.apache.juneau.commons.utils.ThrowableUtils.*;
import static org.apache.juneau.commons.utils.Utils.*;

import org.apache.juneau.*;
import org.apache.juneau.commons.collections.*;
import org.apache.juneau.commons.reflect.*;
import org.apache.juneau.xml.annotation.*;

/**
 * Metadata on bean properties specific to the XML serializers and parsers pulled from the {@link Xml @Xml} annotation
 * on the bean property.
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/XmlBasics">XML Basics</a>
 * </ul>
 */
public class XmlBeanPropertyMeta extends ExtendedBeanPropertyMeta {

   /**
    * Default instance.
    */
   public static final XmlBeanPropertyMeta DEFAULT = new XmlBeanPropertyMeta();

   private Namespace namespace;
   private XmlFormat xmlFormat = XmlFormat.DEFAULT;
   private String childName;
   private final XmlMetaProvider xmlMetaProvider;

   /**
    * Constructor.
    *
    * @param bpm The metadata of the bean property of this additional metadata.
    * @param mp XML metadata provider (for finding information about other artifacts).
    */
   public XmlBeanPropertyMeta(BeanPropertyMeta bpm, XmlMetaProvider mp) {
      super(bpm);
      this.xmlMetaProvider = mp;

      bpm.getAnnotations(Xml.class).forEach(x -> findXmlInfo(x.inner(), bpm.getClassMeta().getBeanContext().getAnnotationProvider()));

      if (namespace == null)
         namespace = mp.getXmlClassMeta(bpm.getBeanMeta().getClassMeta()).getNamespace();
   }

   private XmlBeanPropertyMeta() {
      super(null);
      this.xmlMetaProvider = null;
   }

   /**
    * Returns the child element of this property from the {@link Xml#childName} annotation on this bean property.
    *
    * @return The child element, or <jk>null</jk> if annotation not specified.
    */
   public String getChildName() { return childName; }

   /**
    * Returns the XML namespace associated with this bean property.
    *
    * <p>
    * Namespace is determined in the following order of {@link Xml#prefix() @Xml(prefix)} annotation:
    * <ol>
    *    <li>Bean property field.
    *    <li>Bean getter.
    *    <li>Bean setter.
    *    <li>Bean class.
    *    <li>Bean package.
    *    <li>Bean superclasses.
    *    <li>Bean superclass packages.
    *    <li>Bean interfaces.
    *    <li>Bean interface packages.
    * </ol>
    *
    * @return The namespace associated with this bean property, or <jk>null</jk> if no namespace is associated with it.
    */
   public Namespace getNamespace() { return namespace; }

   /**
    * Returns the XML format of this property from the {@link Xml#format} annotation on this bean property.
    *
    * @return The XML format, or {@link XmlFormat#DEFAULT} if annotation not specified.
    */
   public XmlFormat getXmlFormat() { return xmlFormat; }

   private void findXmlInfo(Xml xml, AnnotationProvider mp) {
      if (xml == null)
         return;
      var bpm = getBeanPropertyMeta();
      var cmProperty = bpm.getClassMeta();
      var cmBean = bpm.getBeanMeta().getClassMeta();
      var name = bpm.getName();

      var ap = bpm.getClassMeta().getBeanContext().getAnnotationProvider();
      var xmls = new MultiList<>(
         rstream(ap.find(Xml.class, bpm.getBeanMeta().getClassMeta())).map(AnnotationInfo::inner).toList(),
         reverse(bpm.getAnnotations(Xml.class).map(AnnotationInfo::inner).toList())
      );
      var schemas = new MultiList<>(
         rstream(ap.find(XmlSchema.class, bpm.getBeanMeta().getClassMeta())).map(AnnotationInfo::inner).toList(),
         reverse(bpm.getAnnotations(XmlSchema.class).map(AnnotationInfo::inner).toList())
      );
      namespace = XmlUtils.findNamespace(xmls, schemas);

      if (xmlFormat == XmlFormat.DEFAULT)
         xmlFormat = xml.format();

      boolean isCollection = cmProperty.isCollectionOrArray();

      String cen = xml.childName();
      if ((! cen.isEmpty()) && (! isCollection))
         throw bex(cmProperty.inner(), "Annotation error on property ''{0}''.  @Xml.childName can only be specified on collections and arrays.", name);

      if (xmlFormat == XmlFormat.COLLAPSED) {
         if (isCollection) {
            if (cen.isEmpty() && nn(xmlMetaProvider))
               cen = xmlMetaProvider.getXmlClassMeta(cmProperty).getChildName();
            if (cen == null || cen.isEmpty())
               cen = cmProperty.getElementType().getBeanDictionaryName();
            if (cen == null || cen.isEmpty())
               cen = name;
         } else {
            throw bex(cmBean.inner(), "Annotation error on property ''{0}''.  @Xml.format=COLLAPSED can only be specified on collections and arrays.", name);
         }
         if (cen.isEmpty() && isCollection)
            cen = cmProperty.getBeanDictionaryName();
      }

      if (! cen.isEmpty())
         childName = cen;
   }
}