//
//  ========================================================================
//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.Base64;

import javax.servlet.ServletException;
import javax.servlet.http.Part;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;



/**
 * MultiPartInputStream
 *
 * Handle a MultiPart Mime input stream, breaking it up on the boundary into files and strings.
 */
public class MultiPartInputStream
{
	private static final Logger LOG = LoggerFactory.getLogger(MultiPartInputStream.class);

	protected InputStream _in;
	protected String _contentType;
	protected MultiMap<String> _parts;
	
	
	
	public final class MultiPart implements Part
	{
		protected String _name;
		protected String _filename;
		protected File _file;
		protected OutputStream _out;
		protected ByteArrayOutputStream2 _bout;
		protected String _contentType;
		protected MultiMap<String> _headers;
		protected long _size = 0;

		public MultiPart (String name, String filename) 
		throws IOException
		{
			_name = name;
			_filename = filename;
		}

		protected void setContentType (String contentType)
		{
			_contentType = contentType;
		}
		
		
		protected void open() 
		throws IOException
		{
			//We will either be writing to a file, if it has a filename on the content-disposition
			//and otherwise a byte-array-input-stream, OR if we exceed the getFileSizeThreshold, we
			//will need to change to write to a file.           
			if (_filename != null && _filename.trim().length() > 0)
			{
				createFile();            
			}
			else
			{
				//Write to a buffer in memory until we discover we've exceed the 
				//MultipartConfig fileSizeThreshold
				_out = _bout= new ByteArrayOutputStream2();
			}
		}
		
		protected void close() 
		throws IOException
		{
			_out.close();
		}
		
	  
		protected void write (int b)
		throws IOException
		{      
			_out.write(b);   
			_size ++;
		}
		
		protected void write (byte[] bytes, int offset, int length) 
		throws IOException
		{ 
			_out.write(bytes, offset, length);
			_size += length;
		}
		
		protected void createFile ()
		throws IOException
		{
			_file = File.createTempFile("MultiPart", null);
			_file.deleteOnExit();
			FileOutputStream fos = new FileOutputStream(_file);
			BufferedOutputStream bos = new BufferedOutputStream(fos);
			
			if (_size > 0 && _out != null)
			{
				//already written some bytes, so need to copy them into the file
				_out.flush();
				_bout.writeTo(bos);
				_out.close();
				_bout = null;
			}
			_out = bos;
		}
		

		
		protected void setHeaders(MultiMap<String> headers)
		{
			_headers = headers;
		}
		
		/** 
		 * @see javax.servlet.http.Part#getContentType()
		 */
		public String getContentType()
		{
			return _contentType;
		}

		/** 
		 * @see javax.servlet.http.Part#getHeader(java.lang.String)
		 */
		public String getHeader(String name)
		{
			if (name == null)
				return null;
			return (String)_headers.getValue(name.toLowerCase(Locale.ENGLISH), 0);
		}

		/** 
		 * @see javax.servlet.http.Part#getHeaderNames()
		 */
		public Collection<String> getHeaderNames()
		{
			return _headers.keySet();
		}

		/** 
		 * @see javax.servlet.http.Part#getHeaders(java.lang.String)
		 */
		public Collection<String> getHeaders(String name)
		{
		   return _headers.getValues(name);
		}

		/** 
		 * @see javax.servlet.http.Part#getInputStream()
		 */
		public InputStream getInputStream() throws IOException
		{
		   if (_file != null)
		   {
			   //written to a file, whether temporary or not
			   return new BufferedInputStream (new FileInputStream(_file));
		   }
		   else
		   {
			   //part content is in memory
			   return new ByteArrayInputStream(_bout.getBuf(),0,_bout.size());
		   }
		}

		public byte[] getBytes()
		{
			if (_bout!=null)
				return _bout.toByteArray();
			return null;
		}
		
		/** 
		 * @see javax.servlet.http.Part#getName()
		 */
		public String getName()
		{
		   return _name;
		}

		/** 
		 * @see javax.servlet.http.Part#getSize()
		 */
		public long getSize()
		{
			return _size;         
		}

		/** 
		 * @see javax.servlet.http.Part#write(java.lang.String)
		 */
		public void write(String fileName) throws IOException
		{
			throw new UnsupportedOperationException();
		}
		
		/** 
		 * Remove the file, whether or not Part.write() was called on it
		 * (ie no longer temporary)
		 * @see javax.servlet.http.Part#delete()
		 */
		public void delete() throws IOException
		{
			if (_file != null && _file.exists())
				_file.delete();     
		}
		
		/**
		 * Only remove tmp files.
		 * 
		 * @throws IOException
		 */
		public void cleanUp() throws IOException
		{
			if (_file != null && _file.exists())
				_file.delete();
		}
		
		
		/**
		 * Get the file, if any, the data has been written to.
		 * @return
		 */
		public File getFile ()
		{
			return _file;
		}  
		
		
		/**
		 * Get the filename from the content-disposition.
		 * @return null or the filename
		 */
		public String getContentDispositionFilename ()
		{
			return _filename;
		}
	}
	
	
	
	
	/**
	 * @param in Request input stream 
	 * @param contentType Content-Type header
	 * @param config MultipartConfigElement 
	 * @param contextTmpDir javax.servlet.context.tempdir
	 */
	public MultiPartInputStream (InputStream in, String contentType)
	{
		_in = new ReadLineInputStream(in);
	   _contentType = contentType;
	}

	/**
	 * Get the already parsed parts.
	 * 
	 * @return
	 */
	public Collection<Part> getParsedParts()
	{
		if (_parts == null)
			return Collections.emptyList();

		Collection<Object> values = _parts.values();
		List<Part> parts = new ArrayList<Part>();
		for (Object o: values)
		{
			List<Part> asList = LazyList.getList(o, false);
			parts.addAll(asList);
		}
		return parts;
	}
	
	/**
	 * Delete any tmp storage for parts, and clear out the parts list.
	 * 
	 * @throws MultiException
	 */
	public void deleteParts ()
	throws MultiException
	{
		Collection<Part> parts = getParsedParts();
		MultiException err = new MultiException();
		for (Part p:parts)
		{
			try
			{
				((MultiPartInputStream.MultiPart)p).cleanUp();
			} 
			catch(Exception e)
			{     
				err.add(e); 
			}
		}
		_parts.clear();
		
		err.ifExceptionThrowMulti();
	}

   
	/**
	 * Parse, if necessary, the multipart data and return the list of Parts.
	 * 
	 * @return
	 * @throws IOException
	 * @throws ServletException
	 */
	public Collection<Part> getParts()
	throws IOException, ServletException
	{
		parse();
		Collection<Object> values = _parts.values();
		List<Part> parts = new ArrayList<Part>();
		for (Object o: values)
		{
			List<Part> asList = LazyList.getList(o, false);
			parts.addAll(asList);
		}
		return parts;
	}
	
	
	/**
	 * Get the named Part.
	 * 
	 * @param name
	 * @return
	 * @throws IOException
	 * @throws ServletException
	 */
	public Part getPart(String name)
	throws IOException, ServletException
	{
		parse();
		return (Part)_parts.getValue(name, 0);
	}
	
	
	/**
	 * Parse, if necessary, the multipart stream.
	 * 
	 * @throws IOException
	 * @throws ServletException
	 */
	protected void parse ()
	throws IOException, ServletException
	{
		//have we already parsed the input?
		if (_parts != null)
			return;
		
		//initialize
		long total = 0; //keep running total of size of bytes read from input and throw an exception if exceeds MultipartConfigElement._maxRequestSize              
		_parts = new MultiMap<String>();

		//if its not a multipart request, don't parse it
		if (_contentType == null || !_contentType.startsWith("multipart/form-data"))
			return;

		String contentTypeBoundary = "";
		int bstart = _contentType.indexOf("boundary=");
		if (bstart >= 0)
		{
			int bend = _contentType.indexOf(";", bstart);
			bend = (bend < 0? _contentType.length(): bend);
			contentTypeBoundary = QuotedStringTokenizer.unquote(value(_contentType.substring(bstart,bend), true).trim());
		}
		
		String boundary="--"+contentTypeBoundary;
		byte[] byteBoundary=(boundary+"--").getBytes(StringUtil.__ISO_8859_1);

		// Get first boundary
		String line = null;
		try
		{
			line=((ReadLineInputStream)_in).readLine();  
		}
		catch (IOException e)
		{
			LOG.warn("Badly formatted multipart request");
			throw e;
		}

		if (line == null)
			throw new IOException("Missing content for multipart request");

		boolean badFormatLogged = false;
		line=line.trim();
		while (line != null && !line.equals(boundary))
		{
			if (!badFormatLogged)
			{
				LOG.warn("Badly formatted multipart request");
				badFormatLogged = true;
			}
			line=((ReadLineInputStream)_in).readLine();
			line=(line==null?line:line.trim());
		}

		if (line == null)
			throw new IOException("Missing initial multi part boundary");

		// Read each part
		boolean lastPart=false;

		outer:while(!lastPart)
		{
			String contentDisposition=null;
			String contentType=null;
			String contentTransferEncoding=null;
			
			MultiMap<String> headers = new MultiMap<String>();
			while(true)
			{
				line=((ReadLineInputStream)_in).readLine();
				
				//No more input
				if(line==null)
					break outer;

				// If blank line, end of part headers
				if("".equals(line))
					break;
				
				total += line.length();

				//get content-disposition and content-type
				int c=line.indexOf(':',0);
				if(c>0)
				{
					String key=line.substring(0,c).trim().toLowerCase(Locale.ENGLISH);
					String value=line.substring(c+1,line.length()).trim();
					headers.put(key, value);
					if (key.equalsIgnoreCase("content-disposition"))
						contentDisposition=value;
					if (key.equalsIgnoreCase("content-type"))
						contentType = value;
					if(key.equals("content-transfer-encoding"))
						contentTransferEncoding=value;

				}
			}

			// Extract content-disposition
			boolean form_data=false;
			if(contentDisposition==null)
			{
				throw new IOException("Missing content-disposition");
			}

			QuotedStringTokenizer tok=new QuotedStringTokenizer(contentDisposition,";", false, true);
			String name=null;
			String filename=null;
			while(tok.hasMoreTokens())
			{
				String t=tok.nextToken().trim();
				String tl=t.toLowerCase(Locale.ENGLISH);
				if(t.startsWith("form-data"))
					form_data=true;
				else if(tl.startsWith("name="))
					name=value(t, true);
				else if(tl.startsWith("filename="))
					filename=filenameValue(t);
			}

			// Check disposition
			if(!form_data)
			{
				continue;
			}
			//It is valid for reset and submit buttons to have an empty name.
			//If no name is supplied, the browser skips sending the info for that field.
			//However, if you supply the empty string as the name, the browser sends the
			//field, with name as the empty string. So, only continue this loop if we
			//have not yet seen a name field.
			if(name==null)
			{
				continue;
			}

			//Have a new Part
			MultiPart part = new MultiPart(name, filename);
			part.setHeaders(headers);
			part.setContentType(contentType);
			_parts.add(name, part);
			part.open();
			
			InputStream partInput = null;
			if ("base64".equalsIgnoreCase(contentTransferEncoding))
			{
				partInput = Base64.getDecoder().wrap(_in);
			}
			else if ("quoted-printable".equalsIgnoreCase(contentTransferEncoding))
			{
				partInput = new FilterInputStream(_in)
				{
					@Override
					public int read() throws IOException
					{
						int c = in.read();
						if (c >= 0 && c == '=')
						{
							int hi = in.read();
							int lo = in.read();
							if (hi < 0 || lo < 0)
							{
								throw new IOException("Unexpected end to quoted-printable byte");
							}
							char[] chars = new char[] { (char)hi, (char)lo };
							c = Integer.parseInt(new String(chars),16);
						}
						return c;
					}
				};
			}
			else
				partInput = _in;
			
			try
			{ 
				int state=-2;
				int c;
				boolean cr=false;
				boolean lf=false;

				// loop for all lines
				while(true)
				{
					int b=0;
					while((c=(state!=-2)?state:partInput.read())!=-1)
					{
						total ++;
						
						state=-2;
						
						// look for CR and/or LF
						if(c==13||c==10)
						{
							if(c==13)
							{
								partInput.mark(1);
								int tmp=partInput.read();
								if (tmp!=10)
									partInput.reset();
								else
									state=tmp;
							}
							break;
						}
						
						// Look for boundary
						if(b>=0&&b<byteBoundary.length&&c==byteBoundary[b])
						{
							b++;
						}
						else
						{
							// Got a character not part of the boundary, so we don't have the boundary marker.
							// Write out as many chars as we matched, then the char we're looking at.
							if(cr)
								part.write(13);
					
							if(lf)
								part.write(10); 
							
							cr=lf=false;
							if(b>0)
								part.write(byteBoundary,0,b);
							  
							b=-1;
							part.write(c);
						}
					}
					
					// Check for incomplete boundary match, writing out the chars we matched along the way
					if((b>0&&b<byteBoundary.length-2)||(b==byteBoundary.length-1))
					{
						if(cr)
							part.write(13);

						if(lf)
							part.write(10);

						cr=lf=false;
						part.write(byteBoundary,0,b);
						b=-1;
					}
					
					// Boundary match. If we've run out of input or we matched the entire final boundary marker, then this is the last part.
					if(b>0||c==-1)
					{
					   
						if(b==byteBoundary.length)
							lastPart=true;
						if(state==10)
							state=-2;
						break;
					}
					
					// handle CR LF
					if(cr)
						part.write(13); 

					if(lf)
						part.write(10);

					cr=(c==13);
					lf=(c==10||state==10);
					if(state==10)
						state=-2;
				}
			}
			finally
			{
				part.close();
			}
		}
		if (!lastPart)
			throw new IOException("Incomplete parts");
	}
	

	/* ------------------------------------------------------------ */
	private String value(String nameEqualsValue, boolean splitAfterSpace)
	{
		/*
		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 if (splitAfterSpace)
		{
			i=value.indexOf(' ');
			if(i>0)
				value=value.substring(0,i);
		}
		return value;
		*/
		 int idx = nameEqualsValue.indexOf('=');
		 String value = nameEqualsValue.substring(idx+1).trim();
		 return QuotedStringTokenizer.unquoteOnly(value);
	}
	
	
	/* ------------------------------------------------------------ */
	private String filenameValue(String nameEqualsValue)
	{
		int idx = nameEqualsValue.indexOf('=');
		String value = nameEqualsValue.substring(idx+1).trim();   

		if (value.matches(".??[a-z,A-Z]\\:\\\\[^\\\\].*"))
		{
			//incorrectly escaped IE filenames that have the whole path
			//we just strip any leading & trailing quotes and leave it as is
			char first=value.charAt(0);
			if (first=='"' || first=='\'')
				value=value.substring(1);
			char last=value.charAt(value.length()-1);
			if (last=='"' || last=='\'')
				value = value.substring(0,value.length()-1);

			return value;
		}
		else
			//unquote the string, but allow any backslashes that don't
			//form a valid escape sequence to remain as many browsers
			//even on *nix systems will not escape a filename containing
			//backslashes
			return QuotedStringTokenizer.unquoteOnly(value, true);
	}
}