/*
 * 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.treeprocessor.sitemap;

import java.util.ArrayList;
import java.util.List;

import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.components.pipeline.ProcessingPipeline;
import org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNodeBuilder;
import org.apache.cocoon.components.treeprocessor.ProcessingNode;
import org.apache.cocoon.components.treeprocessor.ProcessingNodeBuilder;

/**
 * Builds a <map:pipeline>
 *
 * @author <a href="mailto:sylvain@apache.org">Sylvain Wallez</a>
 * @author <a href="mailto:gianugo@apache.org">Gianugo Rabellino</a>
 * @version $Id$
 */
public class PipelineNodeBuilder extends AbstractParentProcessingNodeBuilder
                                 implements ThreadSafe {

    /** This builder can have parameters -- return <code>true</code> */
    protected boolean hasParameters() {
        return true;
    }

    public ProcessingNode buildNode(Configuration config)
    throws Exception {
        String type = this.treeBuilder.getTypeForStatement(config, ProcessingPipeline.ROLE + "Selector");
        PipelineNode node = new PipelineNode(type);

        this.treeBuilder.setupNode(node, config);
        node.setInternalOnly(config.getAttributeAsBoolean("internal-only", false));

        // Main (with no "type" attribute) error handler: new in Cocoon 2.1, must have a generator
        ProcessingNode mainHandler = null;

        // 404 & 500 error handlers as in Cocoon 2.0.x, have an implicit generator
        ProcessingNode error404Handler = null;
        ProcessingNode error500Handler = null;

        Configuration[] childConfigs = config.getChildren();
        List children = new ArrayList();
        for (int i = 0; i < childConfigs.length; i++) {
            Configuration childConfig = childConfigs[i];
            if (isChild(childConfig)) {

                ProcessingNodeBuilder builder = this.treeBuilder.createNodeBuilder(childConfig);
                if (builder instanceof HandleErrorsNodeBuilder) {
                    // Error handler : check type
                    HandleErrorsNode handler = (HandleErrorsNode)builder.buildNode(childConfig);
                    int status = handler.getStatusCode();

                    switch(status) {
                        case -1: // main handler (needs generator)
                            if (mainHandler != null) {
                                throw new ConfigurationException("Duplicate <handle-errors> at " + handler.getLocation());
                            } else if (error500Handler != null || error404Handler != null) {
                                throw new ConfigurationException("Cannot mix <handle-errors> with and without 'type' attribute at " +
                                                                 handler.getLocation());
                            } else {
                                mainHandler = handler;
                            }
                            break;

                        case 404:
                            if (error404Handler != null) {
                                throw new ConfigurationException("Duplicate <handle-errors type='404' at " + handler.getLocation());
                            } else if(mainHandler != null) {
                                throw new ConfigurationException("Cannot mix <handle-errors> with and without 'type' attribute at " +
                                                                 handler.getLocation());
                            } else {
                                error404Handler = handler;
                            }
                            break;

                        case 500:
                            if (error500Handler != null) {
                                throw new ConfigurationException("Duplicate <handle-errors type='500' at " + handler.getLocation());
                            } else if (mainHandler != null) {
                                throw new ConfigurationException("Cannot mix <handle-errors> with and without 'type' attribute at " +
                                                                 handler.getLocation());
                            } else {
                                error500Handler = handler;
                            }
                            break;

                        default:
                            throw new ConfigurationException("Unknown handle-errors type (" + type + ") at " + handler.getLocation());
                    }
                } else {
                    // Regular builder
                    children.add(builder.buildNode(childConfig));
                }
            }
        }

        node.setChildren(toNodeArray(children));
        node.set404Handler(error404Handler);
        // Set either main or error500 handler as only one can exist
        node.set500Handler(error500Handler == null ? mainHandler : error500Handler);

        return node;
    }
}