/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is 
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 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *
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 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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#include "pratom.h"
#include "nsUUDll.h"
#include "nsCaseConversionImp2.h"
#include "casetable.h"


// For gUpperToTitle 
enum {
  kUpperIdx =0,
  kTitleIdx
};

// For gUpperToTitle
enum {
  kLowIdx =0,
  kSizeEveryIdx,
  kDiffIdx
};

#define IS_ASCII(u)       ( 0x0000 == ((u) & 0xFF80))
#define IS_ASCII_UPPER(u) ((0x0041 <= (u)) && ( (u) <= 0x005a))
#define IS_ASCII_LOWER(u) ((0x0061 <= (u)) && ( (u) <= 0x007a))
#define IS_ASCII_ALPHA(u) (IS_ASCII_UPPER(u) || IS_ASCII_LOWER(u))
#define IS_ASCII_SPACE(u) ( 0x0020 == (u) )

#define IS_NOCASE_CHAR(u)  (0==(1&(gCaseBlocks[(u)>>13]>>(0x001F&((u)>>8)))))
  
// Size of Tables


#define CASE_MAP_CACHE_SIZE 0x40
#define CASE_MAP_CACHE_MASK 0x3F

class nsCompressedMap {
public:
   nsCompressedMap(const PRUnichar *aTable, PRUint32 aSize);
   ~nsCompressedMap();
   PRUnichar Map(PRUnichar aChar);
protected:
   PRUnichar Lookup(PRUint32 l, PRUint32 m, PRUint32 r, PRUnichar aChar);

private: 
   const PRUnichar *mTable;
   PRUint32 mSize;
   PRUint32 *mCache;
   PRUint32 mLastBase;
};

nsCompressedMap::nsCompressedMap(const PRUnichar *aTable, PRUint32 aSize)
{
   MOZ_COUNT_CTOR(nsCompressedMap);
   mTable = aTable;
   mSize = aSize;
   mLastBase = 0;
   mCache = new PRUint32[CASE_MAP_CACHE_SIZE];
   for(int i = 0; i < CASE_MAP_CACHE_SIZE; i++)
      mCache[i] = 0;
}

nsCompressedMap::~nsCompressedMap()
{
   MOZ_COUNT_DTOR(nsCompressedMap);
   delete[] mCache;
}

PRUnichar nsCompressedMap::Map(PRUnichar aChar)
{
   // no need to worry thread since cached value are 
   // not object but primitive data type which could be 
   // accessed in atomic operation. We need to access
   // the whole 32 bit of cachedData at once in order to make it
   // thread safe. Never access bits from mCache dirrectly

   PRUint32 cachedData = mCache[aChar & CASE_MAP_CACHE_MASK];
   if(aChar == ((cachedData >> 16) & 0x0000FFFF))
     return (cachedData & 0x0000FFFF);

   // try the last index first
   // store into local variable so we can be thread safe
   PRUint32 base = mLastBase; 
   PRUnichar res = 0;
 
   if (( aChar <=  ((mTable[base+kSizeEveryIdx] >> 8) + 
                 mTable[base+kLowIdx])) &&
       ( mTable[base+kLowIdx]  <= aChar )) 
   {
      // Hit the last base
      if(((mTable[base+kSizeEveryIdx] & 0x00FF) > 0) && 
         (0 != ((aChar - mTable[base+kLowIdx]) % 
               (mTable[base+kSizeEveryIdx] & 0x00FF))))
      {
         res = aChar;
      } else {
         res = aChar + mTable[base+kDiffIdx];
      }
   } else {
      res = this->Lookup(0, (mSize/2), mSize-1, aChar);
   }

   mCache[aChar & CASE_MAP_CACHE_MASK] =
       (((aChar << 16) & 0xFFFF0000) | (0x0000FFFF & res));
   return res;
}

PRUnichar nsCompressedMap::Lookup(
   PRUint32 l, PRUint32 m, PRUint32 r, PRUnichar aChar)
{
  PRUint32 base = m*3;
  if ( aChar >  ((mTable[base+kSizeEveryIdx] >> 8) + 
                 mTable[base+kLowIdx])) 
  {
    if( l > m )
      return aChar;
    PRUint32 newm = (m+r+1)/2;
    if(newm == m)
	   newm++;
    return this->Lookup(m+1, newm , r, aChar);
    
  } else if ( mTable[base+kLowIdx]  > aChar ) {
    if( r < m )
      return aChar;
    PRUint32 newm = (l+m-1)/2;
    if(newm == m)
	   newm++;
	return this->Lookup(l, newm, m-1, aChar);

  } else  {
    if(((mTable[base+kSizeEveryIdx] & 0x00FF) > 0) && 
       (0 != ((aChar - mTable[base+kLowIdx]) % 
              (mTable[base+kSizeEveryIdx] & 0x00FF))))
    {
       return aChar;
    }
    mLastBase = base; // cache the base
    return aChar + mTable[base+kDiffIdx];
  }
}

nsrefcnt nsCaseConversionImp2::gInit      = 0;

NS_IMPL_ISUPPORTS1(nsCaseConversionImp2, nsICaseConversion)

static nsCompressedMap *gUpperMap = nsnull;
static nsCompressedMap *gLowerMap = nsnull;

nsresult nsCaseConversionImp2::ToUpper(
  PRUnichar aChar, PRUnichar* aReturn
)
{
  if( IS_ASCII(aChar)) // optimize for ASCII
  {
     if(IS_ASCII_LOWER(aChar))
        *aReturn = aChar - 0x0020;
     else
        *aReturn = aChar;
  } 
  else if( IS_NOCASE_CHAR(aChar)) // optimize for block which have no case
  {
    *aReturn = aChar;
  } 
  else 
  {
    *aReturn = gUpperMap->Map(aChar);
  }
  return NS_OK;
}

// a non-virtual version of ToLower
static PRUnichar FastToLower(
  PRUnichar aChar
)
{
  if( IS_ASCII(aChar)) // optimize for ASCII
  {
     if(IS_ASCII_UPPER(aChar))
        return aChar + 0x0020;
     else
        return aChar;
  } 
  else if( IS_NOCASE_CHAR(aChar)) // optimize for block which have no case
  {
    return aChar;
  } 
  else
  {
    return gLowerMap->Map(aChar);
  } 
  return NS_OK;
}

nsresult nsCaseConversionImp2::ToLower(
  PRUnichar aChar, PRUnichar* aReturn
)
{
  *aReturn = FastToLower(aChar);
  return NS_OK;
}
nsresult nsCaseConversionImp2::ToTitle(
  PRUnichar aChar, PRUnichar* aReturn
)
{
  if( IS_ASCII(aChar)) // optimize for ASCII
  {
    return this->ToUpper(aChar, aReturn);
  }
  else if( IS_NOCASE_CHAR(aChar)) // optimize for block which have no case
  {
    *aReturn = aChar;
  } 
  else
  {
    PRUnichar upper;
    upper = gUpperMap->Map(aChar);
    
    if( 0x01C0 == ( upper & 0xFFC0)) // 0x01Cx - 0x01Fx
    {
      for(PRUint32 i = 0 ; i < gUpperToTitleItems; i++) {
        if ( upper == gUpperToTitle[(i*2)+kUpperIdx]) {
           *aReturn = gUpperToTitle[(i*2)+kTitleIdx];
           return NS_OK;
        }
      }
    }
    *aReturn = upper;
  }
  return NS_OK;
}

nsresult nsCaseConversionImp2::ToUpper(
  const PRUnichar* anArray, PRUnichar* aReturn, PRUint32 aLen
)
{
  PRUint32 i;
  for(i=0;i<aLen;i++) 
  {
    PRUnichar aChar = anArray[i];
    if( IS_ASCII(aChar)) // optimize for ASCII
    {
       if(IS_ASCII_LOWER(aChar))
          aReturn[i] = aChar - 0x0020;
       else
          aReturn[i] = aChar;
    }
    else if( IS_NOCASE_CHAR(aChar)) // optimize for block which have no case
    {
          aReturn[i] = aChar;
    } 
    else 
    {
      aReturn[i] = gUpperMap->Map(aChar);
    }
  }
  return NS_OK;
}

nsresult nsCaseConversionImp2::ToLower(
  const PRUnichar* anArray, PRUnichar* aReturn, PRUint32 aLen
)
{
  PRUint32 i;
  for(i=0;i<aLen;i++) 
    aReturn[i] = FastToLower(anArray[i]);
  return NS_OK;
}



nsresult nsCaseConversionImp2::ToTitle(
  const PRUnichar* anArray, PRUnichar* aReturn, PRUint32 aLen,
  PRBool aStartInWordBoundary
)
{
  if(0 == aLen)
    return NS_OK;

  //
  // We need to replace this implementation to a real one
  // Currently, it only do the right thing for ASCII
  // Howerver, we need a word breaker to do the right job
  //
  // this->ToLower(anArray, aReturn, aLen); 
  // CSS define Capitalize as 
  //  Uppercases the first character of each word
  // 
  
  PRBool bLastIsSpace =  IS_ASCII_SPACE(anArray[0]);
  if(aStartInWordBoundary)
  {
     this->ToTitle(aReturn[0], &aReturn[0]);
  }

  PRUint32 i;
  for(i=1;i<aLen;i++)
  {
    if(bLastIsSpace)
    {
      this->ToTitle(aReturn[i], &aReturn[i]);
    }

    bLastIsSpace = IS_ASCII_SPACE(aReturn[i]);
  }
  return NS_OK;
}

// implementation moved from the old nsCRT routine
NS_IMETHODIMP
nsCaseConversionImp2::CaseInsensitiveCompare(const PRUnichar *aLeft,
                                             const PRUnichar *aRight,
                                             PRUint32 aCount, PRInt32* aResult)
{
  if (!aLeft || !aRight)
    return NS_ERROR_INVALID_POINTER;

  // assume equality. We bail early if no equality
  *aResult = 0;
  
  if (aCount) {
    do {
      PRUnichar c1 = *aLeft++;
      PRUnichar c2 = *aRight++;
      
      if (c1 != c2) {
        c1 = FastToLower(c1);
        c2 = FastToLower(c2);
        if (c1 != c2) {
          if (c1 < c2) {
            *aResult = -1;
            return NS_OK;
          }
          *aResult = 1;
          return NS_OK;
        }
      }
    } while (--aCount != 0);
  }
  return NS_OK;
}

nsCaseConversionImp2::nsCaseConversionImp2()
{
  if (gInit++ == 0) {
    gUpperMap = new nsCompressedMap(NS_REINTERPRET_CAST(const PRUnichar*, &gToUpper[0]), gToUpperItems);
    gLowerMap = new nsCompressedMap(NS_REINTERPRET_CAST(const PRUnichar*, &gToLower[0]), gToLowerItems);
  }
}

nsCaseConversionImp2::~nsCaseConversionImp2()
{
  if (--gInit == 0) {
    delete gUpperMap;
    gUpperMap = nsnull;
    delete gLowerMap;
    gLowerMap = nsnull;
  }
}

nsresult NS_NewCaseConversion(nsISupports** oResult)
{
  if(!oResult)
    return NS_ERROR_NULL_POINTER;
  *oResult = new nsCaseConversionImp2();
  if(*oResult)
    NS_ADDREF(*oResult);
  return (*oResult) ? NS_OK : NS_ERROR_OUT_OF_MEMORY; 
}