/**
 * 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.cxf.databinding.stax;

import java.util.Collection;
import java.util.logging.Logger;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.validation.Schema;

import org.w3c.dom.Node;

import org.apache.cxf.common.logging.LogUtils;
import org.apache.cxf.common.xmlschema.SchemaCollection;
import org.apache.cxf.databinding.AbstractInterceptorProvidingDataBinding;
import org.apache.cxf.databinding.DataReader;
import org.apache.cxf.databinding.DataWriter;
import org.apache.cxf.interceptor.Fault;
import org.apache.cxf.interceptor.StaxInEndingInterceptor;
import org.apache.cxf.message.Attachment;
import org.apache.cxf.message.Message;
import org.apache.cxf.phase.AbstractPhaseInterceptor;
import org.apache.cxf.phase.Phase;
import org.apache.cxf.service.Service;
import org.apache.cxf.service.ServiceModelVisitor;
import org.apache.cxf.service.model.MessagePartInfo;
import org.apache.cxf.service.model.ServiceInfo;
import org.apache.cxf.staxutils.StaxUtils;
import org.apache.ws.commons.schema.constants.Constants;

/**
 * A simple databinding implementation which reads and writes Source objects.
 * This will not work with the standard databinding interceptors.
 */
public class StaxDataBinding extends AbstractInterceptorProvidingDataBinding {

    private XMLStreamDataReader xsrReader;
    private XMLStreamDataWriter xswWriter;

    public StaxDataBinding() {
        super();
        this.xsrReader = new XMLStreamDataReader();
        this.xswWriter = new XMLStreamDataWriter();
        inInterceptors.add(new StaxInEndingInterceptor(Phase.POST_INVOKE));
        inFaultInterceptors.add(new StaxInEndingInterceptor(Phase.POST_INVOKE));

        inInterceptors.add(RemoveStaxInEndingInterceptor.INSTANCE);
        inFaultInterceptors.add(RemoveStaxInEndingInterceptor.INSTANCE);
    }
    
    static class RemoveStaxInEndingInterceptor extends AbstractPhaseInterceptor<Message> {
        static final RemoveStaxInEndingInterceptor INSTANCE = new RemoveStaxInEndingInterceptor();
        
        RemoveStaxInEndingInterceptor() {
            super(Phase.PRE_INVOKE);
            addBefore(StaxInEndingInterceptor.class.getName());
        }

        public void handleMessage(Message message) throws Fault {
            message.getInterceptorChain().remove(StaxInEndingInterceptor.INSTANCE);
        }
    }
    

    public void initialize(Service service) {
        for (ServiceInfo serviceInfo : service.getServiceInfos()) {
            SchemaCollection schemaCollection = serviceInfo.getXmlSchemaCollection();
            if (schemaCollection.getXmlSchemas().length > 1) {
                // Schemas are already populated.
                continue;
            }
            new ServiceModelVisitor(serviceInfo) {
                public void begin(MessagePartInfo part) {
                    if (part.getTypeQName() != null || part.getElementQName() != null) {
                        return;
                    }
                    part.setTypeQName(Constants.XSD_ANYTYPE);
                }
            } .walk();
        }
    }

    @SuppressWarnings("unchecked")
    public <T> DataReader<T> createReader(Class<T> cls) {
        if (cls == XMLStreamReader.class) {
            return (DataReader<T>) xsrReader;
        } else {
            throw new UnsupportedOperationException("The type " + cls.getName() + " is not supported.");
        }
    }

    public Class<?>[] getSupportedReaderFormats() {
        return new Class[] {XMLStreamReader.class};
    }

    @SuppressWarnings("unchecked")
    public <T> DataWriter<T> createWriter(Class<T> cls) {
        if (cls == XMLStreamWriter.class) {
            return (DataWriter<T>) xswWriter;
        } else {
            throw new UnsupportedOperationException("The type " + cls.getName() + " is not supported.");
        }
    }

    public Class<?>[] getSupportedWriterFormats() {
        return new Class[] {XMLStreamWriter.class, Node.class};
    }

    public static class XMLStreamDataReader implements DataReader<XMLStreamReader> {

        public Object read(MessagePartInfo part, XMLStreamReader input) {
            return read(null, input, part.getTypeClass());
        }

        public Object read(QName name, XMLStreamReader input, Class<?> type) {
            return input;
        }

        public Object read(XMLStreamReader reader) {
            return reader;
        }
        
        public void setSchema(Schema s) {
        }

        public void setAttachments(Collection<Attachment> attachments) {
        }

        public void setProperty(String prop, Object value) {   
        }
    }

    public static class XMLStreamDataWriter implements DataWriter<XMLStreamWriter> {
        private static final Logger LOG = LogUtils.getL7dLogger(XMLStreamDataWriter.class);

        public void write(Object obj, MessagePartInfo part, XMLStreamWriter output) {
            write(obj, output);
        }

        public void write(Object obj, XMLStreamWriter writer) {
            try {
                if (obj instanceof XMLStreamReader) {
                    XMLStreamReader xmlStreamReader = (XMLStreamReader) obj;
                    StaxUtils.copy(xmlStreamReader, writer);
                    xmlStreamReader.close();
                } else if (obj instanceof XMLStreamWriterCallback) {
                    ((XMLStreamWriterCallback) obj).write(writer);
                } else {
                    throw new UnsupportedOperationException("Data types of " 
                                                            + obj.getClass() + " are not supported.");
                }
            } catch (XMLStreamException e) {
                throw new Fault("COULD_NOT_READ_XML_STREAM", LOG, e);
            }
        }

        public void setSchema(Schema s) {
        }

        public void setAttachments(Collection<Attachment> attachments) {
        }

        public void setProperty(String key, Object value) {
        }
        
    }
}
