/*
 * Copyright (C) 2011 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_TEXT_CODEC_UTF8_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_TEXT_CODEC_UTF8_H_

#include <unicode/utf8.h>
#include <memory>

#include "third_party/blink/renderer/platform/wtf/text/text_codec.h"

namespace blink {

class TextCodecUtf8 : public TextCodec {
 public:
  static void RegisterEncodingNames(EncodingNameRegistrar);
  static void RegisterCodecs(TextCodecRegistrar);
  // Returns true if the given `canonical_name` is supported.
  // This function ignores ASCII cases.
  static bool IsSupported(StringView canonical_name);

 protected:
  TextCodecUtf8() : partial_sequence_size_(0) {}

 private:
  static std::unique_ptr<TextCodec> Create(const TextEncoding&);

  String Decode(base::span<const uint8_t> data,
                FlushBehavior,
                bool stop_on_error,
                bool& saw_error) override;
  std::string Encode(base::span<const UChar>, UnencodableHandling) override;
  std::string Encode(base::span<const LChar>, UnencodableHandling) override;

  // See comment above TextCodec::EncodeInto for more information.
  // This implementation writes as many code points to |destination| as will
  // fit, while never writing partial code points. If EncodeIntoResult's
  // |bytes_written| member is less than |capacity|, the remaining
  // |capacity| - |bytes_written| bytes remain untouched.
  EncodeIntoResult EncodeInto(base::span<const UChar>,
                              base::span<uint8_t> destination) override;
  EncodeIntoResult EncodeInto(base::span<const LChar>,
                              base::span<uint8_t> destination) override;

  template <typename CharType>
  std::string EncodeCommon(base::span<const CharType> characters);
  template <typename CharType>
  EncodeIntoResult EncodeIntoCommon(base::span<const CharType> characters,
                                    base::span<uint8_t> destination);

  bool HandlePartialSequence(base::span<LChar>& destination,
                             base::span<const uint8_t>& source,
                             bool flush);
  bool HandlePartialSequence(base::span<UChar>& destination,
                             base::span<const uint8_t>& source,
                             bool flush,
                             bool stop_on_error,
                             bool& saw_error);
  void FillPartialSequenceBytes(size_t sequence_length,
                                base::span<const uint8_t>& source);
  bool NeedMoreData(size_t sequence_length, int character, bool flush) const;
  void SavePartialSequenceBytes(base::span<const uint8_t>& source);
  void ConsumePartialSequenceBytes(size_t num_bytes);

  std::array<uint8_t, U8_MAX_LENGTH> partial_sequence_;
  size_t partial_sequence_size_ = 0;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_TEXT_CODEC_UTF8_H_