/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla 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/MPL/
 *
 * 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 the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Pierre Phaneuf <pp@ludusdesign.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */
#include "nscore.h"
#include "nsCyrillicProb.h"
#include <stdio.h>

#include "nsCOMPtr.h"
#include "nsISupports.h"
#include "nsICharsetDetector.h"
#include "nsCharDetDll.h"
#include "nsCyrillicDetector.h"

//----------------------------------------------------------------------
// Interface nsISupports [implementation]
NS_IMPL_ISUPPORTS1(nsCyrXPCOMDetector, nsICharsetDetector)
NS_IMPL_ISUPPORTS1(nsCyrXPCOMStringDetector, nsIStringCharsetDetector)

void nsCyrillicDetector::HandleData(const char* aBuf, PRUint32 aLen)
{
   PRUint8 cls;
   const char* b;
   PRUint32 i;
   if(mDone) 
      return;
   for(i=0, b=aBuf;i<aLen;i++,b++)
   {
     for(PRUintn j=0;j<mItems;j++)
     {
        if( 0x80 & *b)
           cls = mCyrillicClass[j][(*b) & 0x7F];
        else 
           cls = 0;
        NS_ASSERTION( cls <= 32 , "illegal character class");
        mProb[j] += gCyrillicProb[mLastCls[j]][cls];
        mLastCls[j] = cls;
     } 
   }
   // We now only based on the first block we receive
   DataEnd();
}

//---------------------------------------------------------------------
#define THRESHOLD_RATIO 1.5f
void nsCyrillicDetector::DataEnd()
{
   PRUint32 max=0;
   PRUint8  maxIdx=0;
   PRUint8 j;
   if(mDone) 
      return;
   for(j=0;j<mItems;j++) {
      if(mProb[j] > max)
      {
           max = mProb[j];
           maxIdx= j;
      }
   }

   if( 0 == max ) // if we didn't get any 8 bits data 
     return;

#ifdef DEBUG
   for(j=0;j<mItems;j++) 
      printf("Charset %s->\t%d\n", mCharsets[j], mProb[j]);
#endif
   this->Report(mCharsets[maxIdx]);
   mDone = PR_TRUE;
}

//---------------------------------------------------------------------
nsCyrXPCOMDetector:: nsCyrXPCOMDetector(PRUint8 aItems, 
                      const PRUint8 ** aCyrillicClass, 
                      const char **aCharsets)
	     : nsCyrillicDetector(aItems, aCyrillicClass, aCharsets)
{
    mObserver = nsnull;
}

//---------------------------------------------------------------------
nsCyrXPCOMDetector::~nsCyrXPCOMDetector() 
{
}

//---------------------------------------------------------------------
NS_IMETHODIMP nsCyrXPCOMDetector::Init(
  nsICharsetDetectionObserver* aObserver)
{
  NS_ASSERTION(mObserver == nsnull , "Init twice");
  if(nsnull == aObserver)
     return NS_ERROR_ILLEGAL_VALUE;

  mObserver = aObserver;
  return NS_OK;
}

//----------------------------------------------------------
NS_IMETHODIMP nsCyrXPCOMDetector::DoIt(
  const char* aBuf, PRUint32 aLen, PRBool* oDontFeedMe)
{
  NS_ASSERTION(mObserver != nsnull , "have not init yet");

  if((nsnull == aBuf) || (nsnull == oDontFeedMe))
     return NS_ERROR_ILLEGAL_VALUE;

  this->HandleData(aBuf, aLen);
  *oDontFeedMe = PR_FALSE;
  return NS_OK;
}

//----------------------------------------------------------
NS_IMETHODIMP nsCyrXPCOMDetector::Done()
{
  NS_ASSERTION(mObserver != nsnull , "have not init yet");
  this->DataEnd();
  return NS_OK;
}

//----------------------------------------------------------
void nsCyrXPCOMDetector::Report(const char* aCharset)
{
  NS_ASSERTION(mObserver != nsnull , "have not init yet");
  mObserver->Notify(aCharset, eBestAnswer);
}

//---------------------------------------------------------------------
nsCyrXPCOMStringDetector:: nsCyrXPCOMStringDetector(PRUint8 aItems, 
                      const PRUint8 ** aCyrillicClass, 
                      const char **aCharsets)
	     : nsCyrillicDetector(aItems, aCyrillicClass, aCharsets)
{
}

//---------------------------------------------------------------------
nsCyrXPCOMStringDetector::~nsCyrXPCOMStringDetector() 
{
}

//---------------------------------------------------------------------
void nsCyrXPCOMStringDetector::Report(const char *aCharset) 
{
   mResult = aCharset;
}

//---------------------------------------------------------------------
NS_IMETHODIMP nsCyrXPCOMStringDetector::DoIt(const char* aBuf, PRUint32 aLen, 
                     const char** oCharset, nsDetectionConfident &oConf)
{
   mResult = nsnull;
   mDone = PR_FALSE;
   this->HandleData(aBuf, aLen); 
   this->DataEnd();
   *oCharset=mResult;
   oConf = eBestAnswer;
   return NS_OK;
}