// ========================================================================
// $Id: MultiPartRequest.java,v 1.16 2005/12/02 20:13:52 gregwilkins Exp $
// Copyright 1996-2004 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// Licensed 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.mortbay.servlet;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.Hashtable;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.logging.Log;
import org.mortbay.log.LogFactory;
import org.mortbay.http.HttpFields;
import org.mortbay.util.LineInput;
import org.mortbay.util.MultiMap;
import org.mortbay.util.StringUtil;

/* ------------------------------------------------------------ */
/** Multipart Form Data request.
 * <p>
 * This class decodes the multipart/form-data stream sent by
 * a HTML form that uses a file input item.
 *
 * <p><h4>Usage</h4>
 * Each part of the form data is named from the HTML form and
 * is available either via getString(name) or getInputStream(name).
 * Furthermore the MIME parameters and filename can be requested for
 * each part.
 * <pre>
 * </pre>
 *
 * @version $Id: MultiPartRequest.java,v 1.16 2005/12/02 20:13:52 gregwilkins Exp $
 * @author  Greg Wilkins
 * @author  Jim Crossley
 */
public class MultiPartRequest
{
    private static Log log = LogFactory.getLog(MultiPartRequest.class);

    /* ------------------------------------------------------------ */
    HttpServletRequest _request;
    LineInput _in;
    String _boundary;
    String _encoding;
    byte[] _byteBoundary;
    MultiMap _partMap = new MultiMap(10);
    int _char=-2;
    boolean _lastPart=false;
    
    /* ------------------------------------------------------------ */
    /** Constructor. 
     * @param request The request containing a multipart/form-data
     * request
     * @exception IOException IOException
     */
    public MultiPartRequest(HttpServletRequest request)
        throws IOException
    {
        _request=request;
        String content_type = request.getHeader(HttpFields.__ContentType);
        if (!content_type.startsWith("multipart/form-data"))
            throw new IOException("Not multipart/form-data request");

        if(log.isDebugEnabled())log.debug("Multipart content type = "+content_type);
        _encoding = request.getCharacterEncoding();
        if (_encoding != null)
            _in = new LineInput(request.getInputStream(), 2048, _encoding);
        else
            _in = new LineInput(request.getInputStream());
        
        // Extract boundary string
        _boundary="--"+
            value(content_type.substring(content_type.indexOf("boundary=")));
        
        if(log.isDebugEnabled())log.debug("Boundary="+_boundary);
        _byteBoundary= (_boundary+"--").getBytes(StringUtil.__ISO_8859_1);
        
        loadAllParts();
    }
    
    /* ------------------------------------------------------------ */
    /** Get the part names.
     * @return an array of part names
     */
    public String[] getPartNames()
    {
        Set s = _partMap.keySet();
        return (String[]) s.toArray(new String[s.size()]);
    }
    
    /* ------------------------------------------------------------ */
    /** Check if a named part is present 
     * @param name The part
     * @return true if it was included 
     */
    public boolean contains(String name)
    {
        Part part = (Part)_partMap.get(name);
        return (part!=null);
    }
    
    /* ------------------------------------------------------------ */
    /** Get the data of a part as a string.
     * @param name The part name 
     * @return The part data
     */
    public String getString(String name)
    {
        List part = _partMap.getValues(name);
        if (part==null)
            return null;
        if (_encoding != null)
        {
            try 
            {
                return new String(((Part)part.get(0))._data, _encoding);
            } 
            catch (UnsupportedEncodingException uee) 
            {
                if (log.isDebugEnabled())log.debug("Invalid character set: " + uee);
                return null;
            }
        }
        else
            return new String(((Part)part.get(0))._data);
    }
    
    /* ------------------------------------------------------------ */
    /** 
     * @param name The part name 
     * @return The parts data
     */
    public String[] getStrings(String name)
    {
        List parts = _partMap.getValues(name);
        if (parts==null)
            return null;
        String[] strings = new String[parts.size()];
        
        if (_encoding == null) 
        {
            for (int i=0; i<strings.length; i++) 
                strings[i] = new String(((Part)parts.get(i))._data);
        } 
        else 
        {
            try 
            {
                for (int i=0; i<strings.length; i++)
                    strings[i] = new String(((Part)parts.get(i))._data, _encoding);
            }
            catch (UnsupportedEncodingException uee) 
            {
                if (log.isDebugEnabled())log.debug("Invalid character set: " + uee);
                return null;
            }
        }
       
        return strings;
    }
    
    /* ------------------------------------------------------------ */
    /** Get the data of a part as a stream.
     * @param name The part name 
     * @return Stream providing the part data
     */
    public InputStream getInputStream(String name)
    {
        List part = (List)_partMap.getValues(name);
        if (part==null)
            return null;
        return new ByteArrayInputStream(((Part)part.get(0))._data);
    }

    /* ------------------------------------------------------------ */
    public InputStream[] getInputStreams(String name) 
    {
        List parts = (List)_partMap.getValues(name);
        if (parts==null)
            return null;
        InputStream[] streams = new InputStream[parts.size()];
        for (int i=0; i<streams.length; i++) {
            streams[i] = new ByteArrayInputStream(((Part)parts.get(i))._data);
        }
        return streams;
    }

    /* ------------------------------------------------------------ */
    /** Get the MIME parameters associated with a part.
     * @param name The part name 
     * @return Hashtable of parameters
     */
    public Hashtable getParams(String name)
    {
        List part = (List)_partMap.getValues(name);
        if (part==null)
            return null;
        return ((Part)part.get(0))._headers;
    }

    /* ------------------------------------------------------------ */
    public Hashtable[] getMultipleParams(String name) 
    {
        List parts = (List)_partMap.getValues(name);
        if (parts==null)
            return null;
        Hashtable[] params = new Hashtable[parts.size()];
        for (int i=0; i<params.length; i++) {
            params[i] = ((Part)parts.get(i))._headers;
        }
        return params;
    }

    /* ------------------------------------------------------------ */
    /** Get any file name associated with a part.
     * @param name The part name 
     * @return The filename
     */
    public String getFilename(String name)
    {
        List part = (List)_partMap.getValues(name);
        if (part==null)
            return null;
        return ((Part)part.get(0))._filename;
    }

    /* ------------------------------------------------------------ */
    public String[] getFilenames(String name) 
    {
        List parts = (List)_partMap.getValues(name);
        if (parts==null)
            return null;
        String[] filenames = new String[parts.size()];
        for (int i=0; i<filenames.length; i++) {
            filenames[i] = ((Part)parts.get(i))._filename;
        }
        return filenames;
    }

    /* ------------------------------------------------------------ */
    private void loadAllParts()
        throws IOException
    {
        // Get first boundary
        String line = _in.readLine();
        if (!line.equals(_boundary))
        {
            log.warn(line);
            throw new IOException("Missing initial multi part boundary");
        }
        
        // Read each part
        while (!_lastPart)
        {
            // Read Part headers
            Part part = new Part();
            
            String content_disposition=null;
            while ((line=_in.readLine())!=null)
            {
                // If blank line, end of part headers
                if (line.length()==0)
                    break;

                if(log.isDebugEnabled())log.debug("LINE="+line);
                
                // place part header key and value in map
                int c = line.indexOf(':',0);
                if (c>0)
                {
                    String key = line.substring(0,c).trim().toLowerCase();
                    String value = line.substring(c+1,line.length()).trim();
                    String ev = (String) part._headers.get(key);
                    part._headers.put(key,(ev!=null)?(ev+';'+value):value);
                    if(log.isDebugEnabled())log.debug(key+": "+value);
                    if (key.equals("content-disposition"))
                        content_disposition=value;
                }
            }

            // Extract content-disposition
            boolean form_data=false;
            if (content_disposition==null)
            {
                throw new IOException("Missing content-disposition");
            }
            
            StringTokenizer tok =
                new StringTokenizer(content_disposition,";");
            while (tok.hasMoreTokens())
            {
                String t = tok.nextToken().trim();
                String tl = t.toLowerCase();
                if (t.startsWith("form-data"))
                    form_data=true;
                else if (tl.startsWith("name="))
                    part._name=value(t);
                else if (tl.startsWith("filename="))
                    part._filename=value(t);
            }

            // Check disposition
            if (!form_data)
            {
                log.warn("Non form-data part in multipart/form-data");
                continue;
            }
            if (part._name==null || part._name.length()==0)
            {
                log.warn("Part with no name in multipart/form-data");
                continue;
            }
            if(log.isDebugEnabled())log.debug("name="+part._name);
            if(log.isDebugEnabled())log.debug("filename="+part._filename);
            _partMap.add(part._name,part);
            part._data=readBytes();
        }       
    }

    /* ------------------------------------------------------------ */
    private byte[] readBytes()
        throws IOException
    {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        int c;
        boolean cr=false;
        boolean lf=false;
        
        // loop for all lines`
        while (true)
        {
            int b=0;
            while ((c=(_char!=-2)?_char:_in.read())!=-1)
            {
                _char=-2;

                // look for CR and/or LF
                if (c==13 || c==10)
                {
                    if (c==13) _char=_in.read();
                    break;
                }

                // look for boundary
                if (b>=0 && b<_byteBoundary.length && c==_byteBoundary[b])
                    b++;
                else
                {
                    // this is not a boundary
                    if (cr) baos.write(13);
                    if (lf) baos.write(10);
                    cr=lf=false;
                    
                    if (b>0)
                        baos.write(_byteBoundary,0,b);
                    b=-1;
                  
                    baos.write(c);
                }
            }

            // check partial boundary
            if ((b>0 && b<_byteBoundary.length-2) ||
                (b==_byteBoundary.length-1))
            {
                if (cr) baos.write(13);
                if (lf) baos.write(10);
                cr=lf=false;
                baos.write(_byteBoundary,0,b);
                b=-1;
            }
            
            // boundary match
            if (b>0 || c==-1)
            {
                if (b==_byteBoundary.length)
                    _lastPart=true;
                if (_char==10) _char=-2;
                break;
            }
            
            // handle CR LF
            if (cr) baos.write(13);
            if (lf) baos.write(10);
            cr=(c==13);
            lf=(c==10 || _char==10);
            if (_char==10) _char=-2;  
        }
        if(log.isTraceEnabled())log.trace(baos.toString());
        return baos.toByteArray();
    }
    
    
    /* ------------------------------------------------------------ */
    private String value(String nameEqualsValue)
    {   
        String value =
            nameEqualsValue.substring(nameEqualsValue.indexOf('=')+1).trim();
        
        int i=value.indexOf(';');
        if (i>0)
            value=value.substring(0,i);
        if (value.startsWith("\""))
        {
            value=value.substring(1,value.indexOf('"',1));
        }
        
        else
        {
            i=value.indexOf(' ');
            if (i>0)
                value=value.substring(0,i);
        }
        return value;
    }
    
    /* ------------------------------------------------------------ */
    private class Part
    {
        String _name=null;
        String _filename=null;
        Hashtable _headers= new Hashtable(10);
        byte[] _data=null;
    }    
};
