// Copyright 2017 The Abseil Authors.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//      https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

// UTF8 utilities, implemented to reduce dependencies.

#include "absl/strings/internal/utf8.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

namespace strings_internal {

size_t EncodeUTF8Char(char *buffer, char32_t utf8_char) {

  if (utf8_char <= 0x7F) {

    *buffer = static_cast<char>(utf8_char);

    return 1;

  } else if (utf8_char <= 0x7FF) {

    buffer[1] = static_cast<char>(0x80 | (utf8_char & 0x3F));

    utf8_char >>= 6;

    buffer[0] = static_cast<char>(0xC0 | utf8_char);

    return 2;

  } else if (utf8_char <= 0xFFFF) {

    buffer[2] = static_cast<char>(0x80 | (utf8_char & 0x3F));

    utf8_char >>= 6;

    buffer[1] = static_cast<char>(0x80 | (utf8_char & 0x3F));

    utf8_char >>= 6;

    buffer[0] = static_cast<char>(0xE0 | utf8_char);

    return 3;

  } else {

    buffer[3] = static_cast<char>(0x80 | (utf8_char & 0x3F));

    utf8_char >>= 6;

    buffer[2] = static_cast<char>(0x80 | (utf8_char & 0x3F));

    utf8_char >>= 6;

    buffer[1] = static_cast<char>(0x80 | (utf8_char & 0x3F));

    utf8_char >>= 6;

    buffer[0] = static_cast<char>(0xF0 | utf8_char);

    return 4;

  }

}

}  // namespace strings_internal

ABSL_NAMESPACE_END

}  // namespace absl