/*
 * 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.cocoon.components.pipeline.impl;

import org.apache.avalon.framework.component.ComponentException;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.caching.CachedResponse;
import org.apache.cocoon.caching.CachingOutputStream;
import org.apache.cocoon.caching.ComponentCacheKey;
import org.apache.cocoon.components.sax.XMLDeserializer;
import org.apache.cocoon.components.sax.XMLSerializer;
import org.apache.cocoon.components.sax.XMLTeePipe;
import org.apache.cocoon.environment.Environment;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.xml.XMLConsumer;
import org.apache.cocoon.xml.XMLProducer;

import java.io.OutputStream;
import java.io.Serializable;
import java.util.Iterator;

/**
 * The CachingProcessingPipeline
 *
 * @since 2.1
 * @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
 * @version $Id$
 */
public class CachingProcessingPipeline extends AbstractCachingProcessingPipeline {

    /**
     * Cache longest cacheable key
     */
    protected void cacheResults(Environment environment, OutputStream os)
    throws Exception {
        if (this.toCacheKey != null) {
            // See if there is an expires object for this resource.
            Long expiresObj = (Long) environment.getObjectModel().get(ObjectModelHelper.EXPIRES_OBJECT);

            CachedResponse response;
            if (this.cacheCompleteResponse) {
                response = new CachedResponse(this.toCacheSourceValidities,
                                              ((CachingOutputStream) os).getContent(),
                                              expiresObj);
                response.setContentType(environment.getContentType());
            } else {
                response = new CachedResponse(this.toCacheSourceValidities,
                                              (byte[]) this.xmlSerializer.getSAXFragment(),
                                              expiresObj);
            }

            this.cache.store(this.toCacheKey, response);
        }
    }

    /**
     * Create a new cache key
     */
    protected ComponentCacheKey newComponentCacheKey(int type, String role,Serializable key) {
        return new ComponentCacheKey(type, role, key);
    }


    /**
     * Connect the pipeline.
     */
    protected void connectCachingPipeline(Environment   environment)
    throws ProcessingException {
        try {
            XMLSerializer localXMLSerializer = null;
            if (!this.cacheCompleteResponse) {
                this.xmlSerializer = (XMLSerializer) this.manager.lookup(XMLSerializer.ROLE);
                localXMLSerializer = this.xmlSerializer;
            }

            if (this.cachedResponse == null) {
                XMLProducer prev = super.generator;
                XMLConsumer next;

                int cacheableTransformerCount = this.firstNotCacheableTransformerIndex;
                Iterator itt = this.transformers.iterator();
                while (itt.hasNext()) {
                    next = (XMLConsumer) itt.next();
                    if (localXMLSerializer != null) {
                        if (cacheableTransformerCount == 0) {
                            next = new XMLTeePipe(next, localXMLSerializer);
                            localXMLSerializer = null;
                        } else {
                            cacheableTransformerCount--;
                        }
                    }
                    connect(environment, prev, next);
                    prev = (XMLProducer) next;
                }

                next = super.lastConsumer;
                if (localXMLSerializer != null) {
                    next = new XMLTeePipe(next, localXMLSerializer);
                    localXMLSerializer = null;
                }
                connect(environment, prev, next);

            } else {
                this.xmlDeserializer = (XMLDeserializer) this.manager.lookup(XMLDeserializer.ROLE);

                // connect the pipeline:
                XMLProducer prev = xmlDeserializer;
                XMLConsumer next;

                int cacheableTransformerCount = 0;
                Iterator itt = this.transformers.iterator();
                while (itt.hasNext()) {
                    next = (XMLConsumer) itt.next();
                    if (cacheableTransformerCount >= this.firstProcessedTransformerIndex) {
                        if (localXMLSerializer != null
                                && cacheableTransformerCount == this.firstNotCacheableTransformerIndex) {
                            next = new XMLTeePipe(next, localXMLSerializer);
                            localXMLSerializer = null;
                        }
                        connect(environment, prev, next);
                        prev = (XMLProducer) next;
                    }
                    cacheableTransformerCount++;
                }

                next = super.lastConsumer;
                if (localXMLSerializer != null) {
                    next = new XMLTeePipe(next, localXMLSerializer);
                    localXMLSerializer = null;
                }
                connect(environment, prev, next);
            }

        } catch (ComponentException e) {
            throw new ProcessingException("Could not connect pipeline.", e);
        }
    }
}