/*
 * 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.camel.component.jetty9;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Map;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.Part;

import org.apache.camel.Attachment;
import org.apache.camel.Exchange;
import org.apache.camel.RuntimeCamelException;
import org.apache.camel.http.common.DefaultHttpBinding;
import org.apache.camel.http.common.HttpHelper;
import org.apache.camel.http.common.HttpMessage;
import org.apache.camel.support.DefaultAttachment;
import org.eclipse.jetty.util.MultiPartInputStreamParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * To handle attachments with Jetty 9.
 * <p/>
 * This implementation is needed to deal with attachments when using Jetty 9.
 */
final class AttachmentHttpBinding extends DefaultHttpBinding {
    private static final Logger LOG = LoggerFactory.getLogger(AttachmentHttpBinding.class);

    AttachmentHttpBinding() {
    }

    @Override
    protected void populateAttachments(HttpServletRequest request, HttpMessage message) {
        Object object = request.getAttribute("org.eclipse.jetty.servlet.MultiPartFile.multiPartInputStream");
        if (object instanceof MultiPartInputStreamParser) {
            MultiPartInputStreamParser parser = (MultiPartInputStreamParser)object;
            Collection<Part> parts;
            try {
                parts = parser.getParts();
                for (Part part : parts) {
                    DataSource ds = new PartDataSource(part);
                    Attachment attachment = new DefaultAttachment(ds);
                    for (String headerName : part.getHeaderNames()) {
                        for (String headerValue : part.getHeaders(headerName)) {
                            attachment.addHeader(headerName, headerValue);
                        }
                    }
                    message.addAttachmentObject(part.getName(), attachment);
                }
            } catch (Exception e) {
                throw new RuntimeCamelException("Cannot populate attachments", e);
            }
        }
    }

    protected void populateRequestParameters(HttpServletRequest request, HttpMessage message) throws Exception {
        //we populate the http request parameters without checking the request method
        Map<String, Object> headers = message.getHeaders();
        //remove Content-Encoding from request
        if (request instanceof org.eclipse.jetty.server.Request) {
            org.eclipse.jetty.server.Request jettyRequest = (org.eclipse.jetty.server.Request)request;
            jettyRequest.getHttpFields().remove(Exchange.CONTENT_ENCODING);
        }
        
        Enumeration<?> names = request.getParameterNames();
        while (names.hasMoreElements()) {
            String name = (String)names.nextElement();
            if (message.getAttachment(name) != null) {
                DataHandler dh = message.getAttachment(name);
                Object value = dh;
                if (dh.getContentType() == null || dh.getContentType().startsWith("text/plain")) {
                    value = request.getParameter(name);
                }
                if (getHeaderFilterStrategy() != null
                    && !getHeaderFilterStrategy().applyFilterToExternalHeaders(name, value, message.getExchange())) {
                    HttpHelper.appendHeader(headers, name, value);
                }
                continue;
            }

            // there may be multiple values for the same name
            String[] values = request.getParameterValues(name);
            LOG.trace("HTTP parameter {} = {}", name, values);

            if (values != null) {
                for (String value : values) {
                    if (getHeaderFilterStrategy() != null
                        && !getHeaderFilterStrategy().applyFilterToExternalHeaders(name, value, message.getExchange())) {
                        HttpHelper.appendHeader(headers, name, value);
                    }
                }
            }
        }
    }
    
    final class PartDataSource implements DataSource {
        private final Part part;

        PartDataSource(Part part) {
            this.part = part;
        }

        @Override
        public OutputStream getOutputStream() throws IOException {
            return null;
        }

        @Override
        public String getName() {
            return part.getName();
        }

        @Override
        public InputStream getInputStream() throws IOException {
            return part.getInputStream();
        }

        @Override
        public String getContentType() {
            return part.getContentType();
        }
    }
}