/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "DOMtoATK.h"

#include "nsUTF8Utils.h"

namespace mozilla {

namespace a11y {

namespace DOMtoATK {

void

AddBOMs(nsACString& aDest, const nsACString& aSource)

{

  uint32_t destlength = 0;

  // First compute how much room we will need.

  for (uint32_t srci = 0; srci < aSource.Length(); ) {

    int bytes = UTF8traits::bytes(aSource[srci]);

    if (bytes >= 4) {

      // Non-BMP character, will add a BOM after it.

      destlength += 3;

    }

    // Skip whole character encoding.

    srci += bytes;

    destlength += bytes;

  }

  uint32_t desti = 0; // Index within aDest.

  // Add BOMs after non-BMP characters.

  aDest.SetLength(destlength);

  for (uint32_t srci = 0; srci < aSource.Length(); ) {

    uint32_t bytes = UTF8traits::bytes(aSource[srci]);

    MOZ_ASSERT(bytes <= aSource.Length() - srci, "We should have the whole sequence");

    // Copy whole sequence.

    aDest.Replace(desti, bytes, Substring(aSource, srci, bytes));

    desti += bytes;

    srci += bytes;

    if (bytes >= 4) {

      // More than 4 bytes in UTF-8 encoding exactly means more than 16 encoded

      // bits.  This is thus a non-BMP character which needed a surrogate

      // pair to get encoded in UTF-16, add a BOM after it.

      // And add a BOM after it.

      aDest.Replace(desti, 3, "\xEF\xBB\xBF");

      desti += 3;

    }

  }

  MOZ_ASSERT(desti == destlength, "Incoherency between computed length"

                                  "and actually translated length");

}

void

ATKStringConverterHelper::AdjustOffsets(gint* aStartOffset, gint* aEndOffset,

                                        gint count)

{

  MOZ_ASSERT(!mAdjusted, "DOMtoATK::ATKStringConverterHelper::AdjustOffsets needs to be called only once");

  if (*aStartOffset > 0) {

    (*aStartOffset)--;

    mStartShifted = true;

  }

  if (*aEndOffset != -1 && *aEndOffset < count) {

    (*aEndOffset)++;

    mEndShifted = true;

  }

#ifdef DEBUG

  mAdjusted = true;

#endif

}

gchar*

ATKStringConverterHelper::FinishUTF16toUTF8(nsCString& aStr)

{

  int skip = 0;

  if (mStartShifted) {

    // AdjustOffsets added a leading character.

    MOZ_ASSERT(aStr.Length() > 0, "There should be a leading character");

    MOZ_ASSERT(static_cast<int>(aStr.Length()) >= UTF8traits::bytes(aStr.CharAt(0)),

               "The leading character should be complete");

    // drop first character

    skip = UTF8traits::bytes(aStr.CharAt(0));

  }

  if (mEndShifted) {

    // AdjustOffsets added a trailing character.

    MOZ_ASSERT(aStr.Length() > 0, "There should be a trailing character");

    int trail = -1;

    // Find beginning of last character.

    for (trail = aStr.Length() - 1; trail >= 0; trail--) {

      if (!UTF8traits::isInSeq(aStr.CharAt(trail))) {

        break;

      }

    }

    MOZ_ASSERT(trail >= 0,

               "There should be at least a whole trailing character");

    MOZ_ASSERT(trail + UTF8traits::bytes(aStr.CharAt(trail)) == static_cast<int>(aStr.Length()),

               "The trailing character should be complete");

    // Drop the last character.

    aStr.Truncate(trail);

  }

  // copy and return, libspi will free it

  return g_strdup(aStr.get() + skip);

}

gchar*

ATKStringConverterHelper::ConvertAdjusted(const nsAString& aStr)

{

  MOZ_ASSERT(mAdjusted, "DOMtoATK::ATKStringConverterHelper::AdjustOffsets needs to be called before ATKStringConverterHelper::ConvertAdjusted");

  NS_ConvertUTF16toUTF8 cautoStr(aStr);

  if (!cautoStr.get()) {

    return nullptr;

  }

  nsAutoCString cautoStrBOMs;

  AddBOMs(cautoStrBOMs, cautoStr);

  return FinishUTF16toUTF8(cautoStrBOMs);

}

gchar*

Convert(const nsAString& aStr)

{

  NS_ConvertUTF16toUTF8 cautoStr(aStr);

  if (!cautoStr.get()) {

    return nullptr;

  }

  nsAutoCString cautoStrBOMs;

  AddBOMs(cautoStrBOMs, cautoStr);

  return g_strdup(cautoStrBOMs.get());

}

void

ConvertTexttoAsterisks(nsAString& aString)

{

  for (uint32_t i = 0; i < aString.Length(); i++) {

    aString.ReplaceLiteral(i, 1, u"*");

  }

}

}

} // namespace a11y

} // namespace mozilla