/*
 * $Id$
 *
 * 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.struts2.dispatcher.multipart;

import http.utils.multipartrequest.ServletMultipartRequest;

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.StrutsConstants;

import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;


/**
 * Multipart form data request adapter for Jason Pell's multipart utils package.
 *
 */
public class PellMultiPartRequest implements MultiPartRequest {

    private static final Logger LOG = LoggerFactory.getLogger(PellMultiPartRequest.class);
    private ServletMultipartRequest multi;

    private String defaultEncoding;
    private boolean maxSizeProvided;
    private int maxSize;
    
    @Inject(StrutsConstants.STRUTS_I18N_ENCODING)
    public void setDefaultEncoding(String enc) {
        this.defaultEncoding = enc;
    }
    
    @Inject(StrutsConstants.STRUTS_MULTIPART_MAXSIZE)
    public void setMaxSize(String maxSize) {
    	this.maxSizeProvided = true;
        this.maxSize = Integer.parseInt(maxSize);
    }
    
    /**
     * Creates a new request wrapper to handle multi-part data using methods adapted from Jason Pell's
     * multipart classes (see class description).
     *
     * @param saveDir        the directory to save off the file
     * @param servletRequest the request containing the multipart
     */
    public void parse(HttpServletRequest servletRequest, String saveDir) throws IOException {
        //this needs to be synchronised, as we should not change the encoding at the same time as
        //calling the constructor.  See javadoc for MultipartRequest.setEncoding().
        synchronized (this) {
            setEncoding();
            if (maxSizeProvided){
            	multi = new ServletMultipartRequest(servletRequest, saveDir, maxSize);
            }else{
            	multi = new ServletMultipartRequest(servletRequest, saveDir);
            }
        }
    }
    
    public Enumeration getFileParameterNames() {
        return multi.getFileParameterNames();
    }

    public String[] getContentType(String fieldName) {
        return new String[]{multi.getContentType(fieldName)};
    }

    public File[] getFile(String fieldName) {
        return new File[]{multi.getFile(fieldName)};
    }

    public String[] getFileNames(String fieldName) {

        // TODO - not sure about this - is this the filename of the actual file or
        // TODO - the uploaded filename as provided by the browser?
        // TODO - Not sure what version of Pell this class uses as it doesn't seem to be the latest
        return new String[]{multi.getFile(fieldName).getName()};
    }

    public String[] getFilesystemName(String fieldName) {
        return new String[]{multi.getFileSystemName(fieldName)};
    }

    public String getParameter(String name) {
        return multi.getURLParameter(name);
    }

    public Enumeration getParameterNames() {
        return multi.getParameterNames();
    }

    public String[] getParameterValues(String name) {
        Enumeration enumeration = multi.getURLParameters(name);

        if (!enumeration.hasMoreElements()) {
            return null;
        }

        List values = new ArrayList();

        while (enumeration.hasMoreElements()) {
            values.add(enumeration.nextElement());
        }

        return (String[]) values.toArray(new String[values.size()]);
    }

    public List getErrors() {
        return Collections.EMPTY_LIST;
    }

    /**
     * Sets the encoding for the uploaded params.  This needs to be set if you are using character sets other than
     * ASCII.
     * <p/>
     * The encoding is looked up from the configuration setting 'struts.i18n.encoding'.  This is usually set in
     * default.properties & struts.properties.
     */
    private void setEncoding() {
        String encoding = null;

        try {
            encoding = defaultEncoding;

            if (encoding != null) {
                //NB: This should never be called at the same time as the constructor for
                //ServletMultiPartRequest, as it can cause problems.
                //See javadoc for MultipartRequest.setEncoding()
                http.utils.multipartrequest.MultipartRequest.setEncoding(encoding);
            } else {
                http.utils.multipartrequest.MultipartRequest.setEncoding("UTF-8");
            }
        } catch (IllegalArgumentException e) {
            LOG.info("Could not get encoding property 'struts.i18n.encoding' for file upload.  Using system default");
        } catch (UnsupportedEncodingException e) {
            LOG.error("Encoding " + encoding + " is not a valid encoding.  Please check your struts.properties file.");
        }
    }
}
