/*

  * 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.component.factory.desc;

 import java.io.InputStream;

 import java.net.URL;

 import java.util.ArrayList;

 import java.util.List;

 import javax.xml.XMLConstants;

 import javax.xml.parsers.SAXParser;

 import javax.xml.parsers.SAXParserFactory;

 import javax.xml.transform.stream.StreamSource;

 import javax.xml.validation.Schema;

 import javax.xml.validation.SchemaFactory;

 import org.seasar.framework.container.factory.ClassPathResourceResolver;

 import org.seasar.framework.exception.ResourceNotFoundRuntimeException;

 import org.seasar.framework.exception.SAXRuntimeException;

 import org.seasar.framework.util.InputStreamUtil;

 import org.seasar.framework.util.OgnlUtil;

 import org.seasar.framework.util.SAXParserFactoryUtil;

 import org.seasar.framework.xml.SaxHandler;

 import org.seasar.framework.xml.SaxHandlerParser;

 import org.seasar.uruma.component.factory.desc.handler.UcdTagHandlerRule;

 import org.seasar.uruma.core.UrumaConstants;

 import org.seasar.uruma.util.AssertionUtil;

 import org.seasar.uruma.util.resource.ResourceHandler;

 import org.seasar.uruma.util.resource.ResourceTraverser;

 import org.seasar.uruma.util.resource.ResourceTraverserFactory;

 import org.seasar.uruma.util.resource.impl.ExtResourceFilter;

 import org.xml.sax.SAXException;

 /**

  * @author y-komori

  */

 public class ComponentRegistry implements ResourceHandler {

     protected ClassPathResourceResolver resolver = new ClassPathResourceResolver();

     private List<UrumaComponentDesc> descs = new ArrayList<UrumaComponentDesc>();

     /**

      * 

      */

     public void registComponents() {

         registComponents(Thread.currentThread().getContextClassLoader());

     }

     /**

      * @param loader

      */

     public void registComponents(final ClassLoader loader) {

         URL root = loader.getResource("");

         URL origin = loader.getResource("components");

         ResourceTraverser traverser = ResourceTraverserFactory

                 .getResourceTraverser(origin);

         ExtResourceFilter filter = new ExtResourceFilter("ucd");

         traverser.traverse(root, origin, this, filter);

     }

     /*

      * @see

      * org.seasar.uruma.util.resource.ResourceHandler#handle(java.lang.String,

      * java.lang.String, java.io.InputStream)

      */

     public void handle(final String rootPath, final String path,

             final InputStream is) {

         System.err.println(path + " から読み込みます");

         UrumaComponentDesc desc = load(path);

         registComponent(desc);

         System.err.println(desc);

     }

     /**

      * コンポーネント・ディスクリプタを登録します。<br />

      * 

      * @param desc

      *            {@link UrumaComponentDesc} オブジェクト

      */

     public void registComponent(final UrumaComponentDesc desc) {

         AssertionUtil.assertNotNull("desc", desc);

         descs.add(desc);

     }

     /**

      * 指定されたパスから Uruma コンポーネントディスクリプタを読み込みます。<br />

      * 

      * @param path

      *            コンポーネントディスクリプタファイルのパス

      * @return {@link UrumaComponentDesc} オブジェクト

      */

     public UrumaComponentDesc load(final String path) {

         final SaxHandlerParser parser = createSaxHandlerParser(path);

         final InputStream is = getInputStream(path);

         try {

             UrumaComponentDesc desc = (UrumaComponentDesc) parser.parse(is,

                     path);

             return desc;

         } finally {

             InputStreamUtil.close(is);

         }

     }

     protected SaxHandlerParser createSaxHandlerParser(final String path) {

         System.setProperty("javax.xml.parsers.SAXParserFactory",

                 "com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl");

         final SAXParserFactory factory = SAXParserFactoryUtil.newInstance();

         factory.setNamespaceAware(true);

         final SchemaFactory schemaFactory = SchemaFactory

                 .newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

         InputStream is = getInputStream(UrumaConstants.COMPONENT_DESC_SCHEMA_PATH);

         try {

             final Schema schema = schemaFactory.newSchema(new StreamSource(is));

             factory.setSchema(schema);

         } catch (SAXException ex) {

             throw new SAXRuntimeException(ex);

         } finally {

             InputStreamUtil.close(is);

         }

         final SAXParser saxParser = SAXParserFactoryUtil.newSAXParser(factory);

         final SaxHandler handler = createSaxHandler();

         return new SaxHandlerParser(handler, saxParser);

     }

     protected InputStream getInputStream(final String path) {

         final InputStream is = resolver.getInputStream(path);

         if (is == null) {

             throw new ResourceNotFoundRuntimeException(path);

         }

         return is;

     }

     protected SaxHandler createSaxHandler() {

         SaxHandler handler = new SaxHandler(new UcdTagHandlerRule());

         return handler;

     }

     protected void setupComponents() {

     }

     protected Object[] evaluateArgs(final List<String> argExprs) {

         int size = argExprs.size();

         Object[] args = new Object[size];

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

             Object exp = OgnlUtil.parseExpression(argExprs.get(i));

             args[i] = OgnlUtil.getValue(exp, null);

         }

         return args;

     }

 }