/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * 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 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 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 NPL, 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 NPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#define NS_IMPL_IDS
#include "nsIPlatformCharset.h"
#undef NS_IMPL_IDS
#include "nsIServiceManager.h"
#include "nsIComponentManager.h"
#include "nsCollation.h"
#include "nsCollationCID.h"
#include "nsUnicharUtilCIID.h"
#include "prmem.h"
#include "nsReadableUtils.h"

////////////////////////////////////////////////////////////////////////////////

NS_DEFINE_CID(kCollationCID, NS_COLLATION_CID);

NS_IMPL_ISUPPORTS1(nsCollationFactory, nsICollationFactory);

nsresult nsCollationFactory::CreateCollation(nsILocale* locale, nsICollation** instancePtr)
{
  // Create a collation interface instance.
  //
  nsICollation *inst;
  nsresult res;
  
  res = CallCreateInstance(kCollationCID, &inst);
  if (NS_FAILED(res)) {
    return res;
  }

  inst->Initialize(locale);
  *instancePtr = inst;

  return res;
}

////////////////////////////////////////////////////////////////////////////////

nsCollation::nsCollation()
{
  MOZ_COUNT_CTOR(nsCollation);
  nsresult res;
  mCaseConversion = do_GetService(NS_UNICHARUTIL_CONTRACTID, &res);
  NS_ASSERTION(NS_SUCCEEDED(res), "CreateInstance failed for kCaseConversionIID");
}

nsCollation::~nsCollation()
{
  MOZ_COUNT_DTOR(nsCollation);
}

nsresult nsCollation::CompareString(nsICollation *inst, const nsCollationStrength strength, 
                                    const nsAString& string1, const nsAString& string2, PRInt32* result)
{
  PRUint32 aLength1, aLength2;
  PRUint8 *aKey1, *aKey2;
  nsresult res;

  res = inst->GetSortKeyLen(strength, string1, &aLength1);
  if (NS_FAILED(res))
    return res;
  res = inst->GetSortKeyLen(strength, string2, &aLength2);
  if (NS_FAILED(res)) {
    return res;
  }

  // if input string is small then use local buffer for keys
  if (aLength1 <= 128 && aLength2 <= 128) {
    PRUint8 aKeyBuf1[128], aKeyBuf2[128];
    res = inst->CreateRawSortKey(strength, string1, aKeyBuf1, &aLength1);
    if (NS_SUCCEEDED(res)) {
      res = inst->CreateRawSortKey(strength, string2, aKeyBuf2, &aLength2);
      if (NS_SUCCEEDED(res)) {
        *result = CompareRawSortKey(aKeyBuf1, aLength1, aKeyBuf2, aLength2);
      }
    }
    return res;
  }

  // Create a key for string1
  aKey1 = new PRUint8[aLength1];
  if (NULL == aKey1)
    return NS_ERROR_OUT_OF_MEMORY;
  res = inst->CreateRawSortKey(strength, string1, aKey1, &aLength1);
  if (NS_FAILED(res)) {
    delete [] aKey1;
    return res;
  }

  // Create a key for string2
  aKey2 = new PRUint8[aLength2];
  if (NULL == aKey2) {
    delete [] aKey1;
    return NS_ERROR_OUT_OF_MEMORY;
  }
  res = inst->CreateRawSortKey(strength, string2, aKey2, &aLength2);
  if (NS_FAILED(res)) {
    delete [] aKey1;
    delete [] aKey2;
    return res;
  }

  // Compare keys
  *result = CompareRawSortKey(aKey1, aLength1, aKey2, aLength2);

  // delete keys
  delete [] aKey1;
  delete [] aKey2;

  return res;
}

PRInt32 nsCollation::CompareRawSortKey(const PRUint8* key1, const PRUint32 len1, 
                                       const PRUint8* key2, const PRUint32 len2)
{
  PRUint32 len = (len1 < len2) ? len1 : len2;
  PRInt32 result;

  result = (PRUint32) memcmp(key1, key2, len);
  if (result == 0 && len1 != len2) {
    result = (len1 < len2) ? -1 : 1;
  }

  return result;
}

nsresult nsCollation::CreateASCIISortKey(nsICollation *inst, const nsCollationStrength strength, 
                                         const PRUnichar* stringIn, char* key, PRUint32 *outLen)
{
  NS_ENSURE_ARG_POINTER(stringIn);
  NS_ENSURE_ARG_POINTER(key);

  // ASCII key is twice as large as the original raw key.
  // In order to avoid overrun the raw data while encoding,
  // place the raw key at higher address in the buffer
  // then place encoded data from begining of the buffer.
  NS_ASSERTION(!(*outLen % 2), "the key length should be even");
  PRUint8 *rawKey = (PRUint8 *)key + (*outLen / 2);
  nsresult rv = inst->CreateRawSortKey(strength, nsDependentString(stringIn), rawKey, outLen);
  NS_ENSURE_SUCCESS(rv, rv);

  const char* hexChars = "0123456789ABCDEF";
  for (PRUint32 i = 0; i < *outLen; i++) {
    *key++ = hexChars[*rawKey >> 4];
    *key++ = hexChars[*rawKey & 0x0f];
    rawKey++;
  }

  return rv;
}

nsresult nsCollation::NormalizeString(const nsAString& stringIn, nsAString& stringOut)
{
  if (!mCaseConversion) {
    stringOut = stringIn;
  }
  else {
    PRInt32 aLength = stringIn.Length();

    if (aLength <= 64) {
      PRUnichar conversionBuffer[64];
      mCaseConversion->ToLower(PromiseFlatString(stringIn).get(), conversionBuffer, aLength);
      stringOut.Assign(conversionBuffer, aLength);
    }
    else {
      PRUnichar* conversionBuffer;
      conversionBuffer = new PRUnichar[aLength];
      if (!conversionBuffer) {
        return NS_ERROR_OUT_OF_MEMORY;
      }
      mCaseConversion->ToLower(PromiseFlatString(stringIn).get(), conversionBuffer, aLength);
      stringOut.Assign(conversionBuffer, aLength);
      delete [] conversionBuffer;
    }
  }
  return NS_OK;
}

nsresult nsCollation::UnicodeToChar(const nsAString& aSrc, char** dst, const nsAString& aCharset)
{
  NS_ENSURE_ARG_POINTER(dst);

  nsresult res = NS_OK;

  if (!mCharsetConverterManager)
    mCharsetConverterManager = do_GetService(NS_CHARSETCONVERTERMANAGER_CONTRACTID, &res);

  if (NS_SUCCEEDED(res)) {
    nsCOMPtr <nsIAtom>  charsetAtom;
    res = mCharsetConverterManager->GetCharsetAtom(PromiseFlatString(aCharset).get(), getter_AddRefs(charsetAtom));
    if (NS_SUCCEEDED(res)) {
      if (charsetAtom != mEncoderCharsetAtom) {
        mEncoderCharsetAtom = charsetAtom;
        res = mCharsetConverterManager->GetUnicodeEncoder(mEncoderCharsetAtom, getter_AddRefs(mEncoder));
      }
      if (NS_SUCCEEDED(res)) {
        const nsPromiseFlatString& src = PromiseFlatString(aSrc);
        const PRUnichar *unichars = src.get();
        PRInt32 unicharLength = src.Length();
        PRInt32 dstLength;
        res = mEncoder->GetMaxLength(unichars, unicharLength, &dstLength);
        if (NS_SUCCEEDED(res)) {
          PRInt32 bufLength = dstLength + 1 + 32; // extra 32 bytes for Finish() call
          *dst = (char *) PR_Malloc(bufLength);
          if (*dst) {
            **dst = '\0';
            res = mEncoder->Convert(unichars, &unicharLength, *dst, &dstLength);

            if (NS_SUCCEEDED(res) || (NS_ERROR_UENC_NOMAPPING == res)) {
              // Finishes the conversion. The converter has the possibility to write some 
              // extra data and flush its final state.
              PRInt32 finishLength = bufLength - dstLength; // remaining unused buffer length
              if (finishLength > 0) {
                res = mEncoder->Finish((*dst + dstLength), &finishLength);
                if (NS_SUCCEEDED(res)) {
                  (*dst)[dstLength + finishLength] = '\0';
                }
              }
            }
            if (NS_FAILED(res)) {
              PR_Free(*dst);
              *dst = nsnull;
            }
          }
          else {
            res = NS_ERROR_OUT_OF_MEMORY;
          }
        }
      }    
    }
  }

  return res;
}