/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (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.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): ruslan
 */

#include "nsHTTPChunkConv.h"
#include "nsIAllocator.h"
#include "plstr.h"
#include "prlog.h"
#include "nsIChannel.h"
#include "nsCOMPtr.h"
#include "nsIStringStream.h"
#include "nsIStreamListener.h"
#include "nsIStringStream.h"

#include <ctype.h>

// nsISupports implementation
NS_IMPL_ISUPPORTS2 (nsHTTPChunkConv, nsIStreamConverter, nsIStreamListener);

// nsFTPDirListingConv methods
nsHTTPChunkConv::nsHTTPChunkConv()
{
    NS_INIT_ISUPPORTS ();
    mListener    = nsnull;
	mChunkBuffer = NULL;
	mState = CHUNK_STATE_INIT;
}

nsHTTPChunkConv::~nsHTTPChunkConv ()
{
    NS_IF_RELEASE(mListener);

	if (mChunkBuffer != NULL)
		nsAllocator::Free (mChunkBuffer);
}

NS_IMETHODIMP
nsHTTPChunkConv::AsyncConvertData (
							const PRUnichar *aFromType, 
							const PRUnichar *aToType, 
							nsIStreamListener *aListener, 
							nsISupports *aCtxt)
{
	nsString2 from (aFromType);
	nsString2 to   ( aToType );

	char * fromStr = from.ToNewCString ();
	char *   toStr =   to.ToNewCString ();

	if (!PL_strncasecmp (fromStr, HTTP_CHUNK_TYPE, strlen (HTTP_CHUNK_TYPE  ) )
		&&
		!PL_strncasecmp (toStr, HTTP_UNCHUNK_TYPE, strlen (HTTP_UNCHUNK_TYPE)))
		mMode = DO_UNCHUNKING;
	else
		mMode = DO_CHUNKING;

	nsAllocator::Free (fromStr);
	nsAllocator::Free (  toStr);

    // hook ourself up with the receiving listener. 
    mListener = aListener;
    NS_ADDREF (mListener);
	
    return NS_OK; 
} 

NS_IMETHODIMP
nsHTTPChunkConv::OnStartRequest (nsIChannel *aChannel, nsISupports *aContext)
{
    return mListener -> OnStartRequest (aChannel, aContext);
} 

NS_IMETHODIMP
nsHTTPChunkConv::OnStopRequest  (nsIChannel *aChannel, nsISupports *aContext, nsresult status, const PRUnichar *errorMsg)
{
    return mListener -> OnStopRequest  (aChannel, aContext, status, errorMsg);
} 

NS_IMETHODIMP
nsHTTPChunkConv::OnDataAvailable ( 
							  nsIChannel *aChannel, 
							  nsISupports *aContext, 
							  nsIInputStream *iStr, 
							  PRUint32 aSourceOffset, 
							  PRUint32 aCount)
{
    nsresult rv = NS_ERROR_FAILURE;
	PRUint32 rl;
	PRUint32 streamLen;
	char c;

    rv = iStr -> Available (&streamLen);
    if (NS_FAILED (rv))
		return rv;

	if (streamLen == 0)
		return NS_OK;

	if (mMode == DO_CHUNKING)
	{
		mChunkBuffer = (char * )nsAllocator::Alloc (streamLen + 20);
		mChunkBufferPos = sprintf (mChunkBuffer, "%x%c%c", streamLen, '\r', '\n');

		rv = iStr -> Read (&mChunkBuffer[mChunkBufferPos], streamLen, &rl);
		if (NS_FAILED (rv))
			return rv;

		mChunkBufferPos += streamLen;
		mChunkBuffer[mChunkBufferPos++] = '\r';
		mChunkBuffer[mChunkBufferPos++] = '\n';
		mChunkBuffer[mChunkBufferPos  ] = 0;

		mChunkBufferLength = mChunkBufferPos;

	    nsIInputStream * convertedStream = nsnull; 
		nsCString convertedString (mChunkBuffer);
		nsISupports	* convertedStreamSup = nsnull;

		rv = NS_NewStringInputStream (&convertedStreamSup, convertedString);
		if (NS_FAILED (rv)) 
			return rv;

		rv = convertedStreamSup -> QueryInterface (NS_GET_IID (nsIInputStream), (void**)&convertedStream);
		NS_RELEASE (convertedStreamSup);
 
		if (NS_FAILED (rv)) 
			return rv;

		rv = mListener -> OnDataAvailable (aChannel, aContext, convertedStream, aSourceOffset, mChunkBufferLength);
		
		if (NS_FAILED (rv))
			return rv;
	}
	else
	{
		// DO_UNCHUNKING

		while (streamLen > 0 || mState == CHUNK_STATE_FINAL)
		{
			switch (mState)
			{
				case CHUNK_STATE_INIT:
					
					if (mChunkBuffer != NULL)
					{
						nsAllocator::Free (mChunkBuffer);
						mChunkBuffer = NULL;
					}

					mChunkBufferPos = mChunkBufferLength = 0;
					mLenBufCnt = 0;

					mState = CHUNK_STATE_LENGTH;
					break;

				case CHUNK_STATE_FINAL:
					// send data upstream

					{
						nsIInputStream * convertedStream = nsnull; 
						nsCString convertedString (mChunkBuffer);
						nsISupports	* convertedStreamSup = nsnull;

						rv = NS_NewStringInputStream (&convertedStreamSup, convertedString);
						if (NS_FAILED (rv)) 
							return rv;

						rv = convertedStreamSup -> QueryInterface (NS_GET_IID(nsIInputStream), (void**)&convertedStream);
						NS_RELEASE (convertedStreamSup);
 
						if (NS_FAILED (rv)) 
							return rv;

						rv = mListener -> OnDataAvailable (aChannel, aContext, convertedStream, aSourceOffset, mChunkBufferLength);

						if (NS_FAILED (rv))
							return rv;

						mState = CHUNK_STATE_INIT;
				    
						if (mChunkBuffer != NULL)
						{
							nsAllocator::Free (mChunkBuffer);
							mChunkBuffer = NULL;
						}
					}

					break;

				case CHUNK_STATE_CR:
				case CHUNK_STATE_CR_FINAL:

					rv = iStr -> Read (&c, 1, &rl);
					if (NS_FAILED (rv))
						return rv;

					if (c != '\r')
						return NS_ERROR_FAILURE;
				
					streamLen--;
					mState = mState == CHUNK_STATE_CR ? CHUNK_STATE_LF : CHUNK_STATE_LF_FINAL;
					break;

				case CHUNK_STATE_LF:
				case CHUNK_STATE_LF_FINAL:
					rv = iStr -> Read (&c, 1, &rl);
					if (NS_FAILED (rv))
						return rv;

					if (c != '\n')
						return NS_ERROR_FAILURE;

					streamLen--;
					if (mState == CHUNK_STATE_LF)
					{
						mChunkBuffer = (char * )nsAllocator::Alloc (mChunkBufferLength + 1);
						mState = CHUNK_STATE_DATA;
					}
					else
						mState = CHUNK_STATE_FINAL;
					break;

				case CHUNK_STATE_LENGTH:
				
					if (mLenBufCnt >= sizeof (mLenBuf) - 1)
						return NS_ERROR_FAILURE;

					rv = iStr -> Read (&c, 1, &rl);
					if (NS_FAILED (rv))
						return rv;

					streamLen--;
				
					if (isxdigit (c))
						mLenBuf[mLenBufCnt++] = c;
					else
					{
						mLenBuf[mLenBufCnt] = 0;
						sscanf (mLenBuf, "%x", &mChunkBufferLength);

						if (c != '\r')
							return NS_ERROR_FAILURE;
				
						mState = CHUNK_STATE_LF;
					}
					break;
			
				case CHUNK_STATE_DATA:
					if (mChunkBufferLength - mChunkBufferPos <= streamLen)
					{
						// entire chunk
						rv = iStr -> Read (&mChunkBuffer[mChunkBufferPos], mChunkBufferLength - mChunkBufferPos, &rl);
						if (NS_FAILED (rv))
							return rv;

						mChunkBufferPos += rl;
						mChunkBuffer[mChunkBufferPos++] = 0;
						streamLen -= rl;

						mState = CHUNK_STATE_CR_FINAL;
					}
					else
					{
						rv = iStr -> Read (&mChunkBuffer[mChunkBufferPos], streamLen, &rl);						
						if (NS_FAILED (rv))
							return rv;

						mChunkBufferPos += rl;
						streamLen -= rl;
					}
					break;
			} /* switch */
		} /* while */
	} /* DO_UNCHUNKING */

	return NS_OK;
} /* OnDataAvailable */


// XXX/ruslan: need to implement this too

NS_IMETHODIMP
nsHTTPChunkConv::Convert (
						  nsIInputStream *aFromStream, 
						  const PRUnichar *aFromType, 
						  const PRUnichar *aToType, 
						  nsISupports *aCtxt, 
						  nsIInputStream **_retval)
{ 
    return NS_ERROR_NOT_IMPLEMENTED;
} 

nsresult
NS_NewHTTPChunkConv (nsHTTPChunkConv ** aHTTPChunkConv)
{
    NS_PRECONDITION(aHTTPChunkConv != nsnull, "null ptr");

    if (! aHTTPChunkConv)
        return NS_ERROR_NULL_POINTER;

    *aHTTPChunkConv = new nsHTTPChunkConv ();

    if (! *aHTTPChunkConv)
        return NS_ERROR_OUT_OF_MEMORY;

    NS_ADDREF(*aHTTPChunkConv);
    return NS_OK;
}