/*

  * Copyright 2004-2008 the Seasar Foundation and the Others.

  *

  * 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.seasar.uruma.rcp.configuration.writer;

 import java.io.IOException;

 import java.io.Writer;

 import java.lang.reflect.Field;

 import java.util.List;

 import org.seasar.framework.beans.BeanDesc;

 import org.seasar.framework.beans.PropertyDesc;

 import org.seasar.framework.beans.factory.BeanDescFactory;

 import org.seasar.framework.exception.IORuntimeException;

 import org.seasar.framework.util.FieldUtil;

 import org.seasar.framework.util.StringUtil;

 import org.seasar.uruma.annotation.ConfigurationAttribute;

 import org.seasar.uruma.core.UrumaConstants;

 import org.seasar.uruma.rcp.configuration.ConfigurationElement;

 import org.seasar.uruma.rcp.configuration.ConfigurationWriter;

 import org.seasar.uruma.rcp.configuration.elements.AbstractConfigurationElementContainer;

 import org.seasar.uruma.util.AnnotationUtil;

 /**

  * 汎用的な {@link ConfigurationWriter} です。<br />

  * 

  * @author y-komori

  */

 public class GenericConfigurationWriter implements ConfigurationWriter,

         UrumaConstants {

     private Class<? extends ConfigurationElement> supportType;

     private String elementName;

     private boolean startTagOnly;

     private static final String ELEMENT_NAME = "ELEMENT_NAME";

     /**

      * {@link GenericConfigurationWriter} を構築します。<br />

      * 

      * @param supportType

      *            対応する {@link ConfigurationElement} の型

      */

     public GenericConfigurationWriter(

             final Class<? extends ConfigurationElement> supportType) {

         this.supportType = supportType;

         this.startTagOnly = AbstractConfigurationElementContainer.class

                 .isAssignableFrom(supportType) ? false : true;

         BeanDesc desc = BeanDescFactory.getBeanDesc(supportType);

         Field field = desc.getField(ELEMENT_NAME);

         this.elementName = FieldUtil.getString(field);

     }

     /**

      * {@link GenericConfigurationWriter} を構築します。<br />

      * 

      * @param supportType

      *            対応する {@link ConfigurationElement} の型

      * @param elementName

      *            要素名

      * @param startTagOnly

      *            <code>true</code> の場合、開始タグのみを出力する

      */

     public GenericConfigurationWriter(

             final Class<? extends ConfigurationElement> supportType,

             final String elementName, final boolean startTagOnly) {

         this.supportType = supportType;

         this.elementName = elementName;

         this.startTagOnly = startTagOnly;

     }

     /*

      * @see org.seasar.uruma.rcp.configuration.ConfigurationWriter#getSupportType()

      */

     public Class<? extends ConfigurationElement> getSupportType() {

         return this.supportType;

     }

     /*

      * @see org.seasar.uruma.rcp.configuration.ConfigurationWriter#writeStartTag(org.seasar.uruma.rcp.configuration.ConfigurationElement,

      *      java.io.Writer)

      */

     public void writeStartTag(final ConfigurationElement element,

             final Writer writer) {

         writeStartTag(element, writer, 0);

     }

     /*

      * @see org.seasar.uruma.rcp.configuration.ConfigurationWriter#writeStartTag(org.seasar.uruma.rcp.configuration.ConfigurationElement,

      *      java.io.Writer, int)

      */

     public void writeStartTag(final ConfigurationElement element,

             final Writer writer, final int level) {

         try {

             writer.write(createIndent(level));

             writer.write("<");

             writer.write(elementName);

             writer.write(WHITE_SPACE);

             List<PropertyDesc> pdLists = AnnotationUtil

                     .getAnnotatedPropertyDescs(supportType,

                             ConfigurationAttribute.class);

             for (PropertyDesc pd : pdLists) {

                 Field field = pd.getField();

                 ConfigurationAttribute anno = field

                         .getAnnotation(ConfigurationAttribute.class);

                 String name = anno.name();

                 if (StringUtil.isEmpty(name)) {

                     name = field.getName();

                 }

                 Object value = pd.getValue(element);

                 if (value != null) {

                     writer.write(name);

                     writer.write("=\"");

                     escapeChars(value.toString(), writer);

                     writer.write("\" ");

                 } else if (anno.required()) {

                     writer.write(name);

                     writer.write("=\"\" ");

                 }

             }

             if (startTagOnly) {

                 writer.write("/>\n");

             } else {

                 writer.write(">\n");

             }

         } catch (IOException ex) {

             throw new IORuntimeException(ex);

         }

     }

     /*

      * @see org.seasar.uruma.rcp.configuration.ConfigurationWriter#writeEndTag(org.seasar.uruma.rcp.configuration.ConfigurationElement,

      *      java.io.Writer)

      */

     public void writeEndTag(final ConfigurationElement element,

             final Writer writer) {

         writeEndTag(element, writer, 0);

     }

     /*

      * @see org.seasar.uruma.rcp.configuration.ConfigurationWriter#writeEndTag(org.seasar.uruma.rcp.configuration.ConfigurationElement,

      *      java.io.Writer, int)

      */

     public void writeEndTag(final ConfigurationElement element,

             final Writer writer, final int level) {

         if (!startTagOnly) {

             try {

                 writer.write(createIndent(level));

                 writer.write("</" + elementName + ">\n");

             } catch (IOException ex) {

                 throw new IORuntimeException(ex);

             }

         }

     }

     protected void escapeChars(final String str, final Writer writer)

             throws IOException {

         for (int i = 0; i < str.length(); i++) {

             int chr = str.charAt(i);

             switch (chr) {

             case '&':

                 writer.write("&");

                 break;

             case '<':

                 writer.write("<");

                 break;

             case '>':

                 writer.write(">");

                 break;

             case '"':

                 writer.write(""");

                 break;

             default:

                 writer.write(chr);

             }

         }

     }

     protected String createIndent(final int level) {

         if (level > 0) {

             StringBuilder builder = new StringBuilder(level);

             for (int i = 0; i < level; i++) {

                 builder.append(WHITE_SPACE);

             }

             return builder.toString();

         } else {

             return NULL_STRING;

         }

     }

 }