#ifndef SIMDJSON_SRC_FALLBACK_CPP

#define SIMDJSON_SRC_FALLBACK_CPP

#ifndef SIMDJSON_CONDITIONAL_INCLUDE

#include <base.h>

#endif // SIMDJSON_CONDITIONAL_INCLUDE

#include <simdjson/fallback.h>

#include <simdjson/fallback/implementation.h>

#include <simdjson/fallback/begin.h>

#include <generic/stage1/find_next_document_index.h>

#include <generic/stage2/stringparsing.h>

#include <generic/stage2/logger.h>

#include <generic/stage2/json_iterator.h>

#include <generic/stage2/tape_writer.h>

#include <generic/stage2/tape_builder.h>

//

// Stage 1

//

namespace simdjson {

namespace fallback {

simdjson_warn_unused error_code implementation::create_dom_parser_implementation(

  size_t capacity,

  size_t max_depth,

  std::unique_ptr<internal::dom_parser_implementation>& dst

) const noexcept {

  dst.reset( new (std::nothrow) SIMDJSON_IMPLEMENTATION::dom_parser_implementation() );

  if (!dst) { return MEMALLOC; }

  if (auto err = dst->set_capacity(capacity))

    return err;

  if (auto err = dst->set_max_depth(max_depth))

    return err;

  return SUCCESS;

}

namespace {

namespace stage1 {

class structural_scanner {

public:

simdjson_inline structural_scanner(dom_parser_implementation &_parser, stage1_mode _partial)

  : buf{_parser.buf},

    next_structural_index{_parser.structural_indexes.get()},

    parser{_parser},

    len{static_cast<uint32_t>(_parser.len)},

    partial{_partial} {

}

simdjson_inline void add_structural() {

  *next_structural_index = idx;

  next_structural_index++;

}

simdjson_inline bool is_continuation(uint8_t c) {

  return (c & 0xc0) == 0x80;

}

simdjson_inline void validate_utf8_character() {

  // Continuation

  if (simdjson_unlikely((buf[idx] & 0x40) == 0)) {

    // extra continuation

    error = UTF8_ERROR;

    idx++;

    return;

  }

  // 2-byte

  if ((buf[idx] & 0x20) == 0) {

    // missing continuation

    if (simdjson_unlikely(idx+1 > len || !is_continuation(buf[idx+1]))) {

      if (idx+1 > len && is_streaming(partial)) { idx = len; return; }

      error = UTF8_ERROR;

      idx++;

      return;

    }

    // overlong: 1100000_ 10______

    if (buf[idx] <= 0xc1) { error = UTF8_ERROR; }

    idx += 2;

    return;

  }

  // 3-byte

  if ((buf[idx] & 0x10) == 0) {

    // missing continuation

    if (simdjson_unlikely(idx+2 > len || !is_continuation(buf[idx+1]) || !is_continuation(buf[idx+2]))) {

      if (idx+2 > len && is_streaming(partial)) { idx = len; return; }

      error = UTF8_ERROR;

      idx++;

      return;

    }

    // overlong: 11100000 100_____ ________

    if (buf[idx] == 0xe0 && buf[idx+1] <= 0x9f) { error = UTF8_ERROR; }

    // surrogates: U+D800-U+DFFF 11101101 101_____

    if (buf[idx] == 0xed && buf[idx+1] >= 0xa0) { error = UTF8_ERROR; }

    idx += 3;

    return;

  }

  // 4-byte

  // missing continuation

  if (simdjson_unlikely(idx+3 > len || !is_continuation(buf[idx+1]) || !is_continuation(buf[idx+2]) || !is_continuation(buf[idx+3]))) {

    if (idx+2 > len && is_streaming(partial)) { idx = len; return; }

    error = UTF8_ERROR;

    idx++;

    return;

  }

  // overlong: 11110000 1000____ ________ ________

  if (buf[idx] == 0xf0 && buf[idx+1] <= 0x8f) { error = UTF8_ERROR; }

  // too large: > U+10FFFF:

  // 11110100 (1001|101_)____

  // 1111(1___|011_|0101) 10______

  // also includes 5, 6, 7 and 8 byte characters:

  // 11111___

  if (buf[idx] == 0xf4 && buf[idx+1] >= 0x90) { error = UTF8_ERROR; }

  if (buf[idx] >= 0xf5) { error = UTF8_ERROR; }

  idx += 4;

}

// Returns true if the string is unclosed.

simdjson_inline bool validate_string() {

  idx++; // skip first quote

  while (idx < len && buf[idx] != '"') {

    if (buf[idx] == '\\') {

      idx += 2;

    } else if (simdjson_unlikely(buf[idx] & 0x80)) {

      validate_utf8_character();

    } else {

      if (buf[idx] < 0x20) { error = UNESCAPED_CHARS; }

      idx++;

    }

  }

  if (idx >= len) { return true; }

  return false;

}

simdjson_inline bool is_whitespace_or_operator(uint8_t c) {

  switch (c) {

    case '{': case '}': case '[': case ']': case ',': case ':':

    case ' ': case '\r': case '\n': case '\t':

      return true;

    default:

      return false;

  }

}

//

// Parse the entire input in STEP_SIZE-byte chunks.

//

simdjson_inline error_code scan() {

  bool unclosed_string = false;

  for (;idx<len;idx++) {

    switch (buf[idx]) {

      // String

      case '"':

        add_structural();

        unclosed_string |= validate_string();

        break;

      // Operator

      case '{': case '}': case '[': case ']': case ',': case ':':

        add_structural();

        break;

      // Whitespace

      case ' ': case '\r': case '\n': case '\t':

        break;

      // Primitive or invalid character (invalid characters will be checked in stage 2)

      default:

        // Anything else, add the structural and go until we find the next one

        add_structural();

        while (idx+1<len && !is_whitespace_or_operator(buf[idx+1])) {

          idx++;

        };

        break;

    }

  }

  // We pad beyond.

  // https://github.com/simdjson/simdjson/issues/906

  // See json_structural_indexer.h for an explanation.

  *next_structural_index = len; // assumed later in partial == stage1_mode::streaming_final

  next_structural_index[1] = len;

  next_structural_index[2] = 0;

  parser.n_structural_indexes = uint32_t(next_structural_index - parser.structural_indexes.get());

  if (simdjson_unlikely(parser.n_structural_indexes == 0)) { return EMPTY; }

  parser.next_structural_index = 0;

  if (partial == stage1_mode::streaming_partial) {

    if(unclosed_string) {

      parser.n_structural_indexes--;

      if (simdjson_unlikely(parser.n_structural_indexes == 0)) { return CAPACITY; }

    }

    // We truncate the input to the end of the last complete document (or zero).

    auto new_structural_indexes = find_next_document_index(parser);

    if (new_structural_indexes == 0 && parser.n_structural_indexes > 0) {

      if(parser.structural_indexes[0] == 0) {

        // If the buffer is partial and we started at index 0 but the document is

        // incomplete, it's too big to parse.

        return CAPACITY;

      } else {

        // It is possible that the document could be parsed, we just had a lot

        // of white space.

        parser.n_structural_indexes = 0;

        return EMPTY;

      }

    }

    parser.n_structural_indexes = new_structural_indexes;

  } else if(partial == stage1_mode::streaming_final) {

    if(unclosed_string) { parser.n_structural_indexes--; }

    // We truncate the input to the end of the last complete document (or zero).

    // Because partial == stage1_mode::streaming_final, it means that we may

    // silently ignore trailing garbage. Though it sounds bad, we do it

    // deliberately because many people who have streams of JSON documents

    // will truncate them for processing. E.g., imagine that you are uncompressing

    // the data from a size file or receiving it in chunks from the network. You

    // may not know where exactly the last document will be. Meanwhile the

    // document_stream instances allow people to know the JSON documents they are

    // parsing (see the iterator.source() method).

    parser.n_structural_indexes = find_next_document_index(parser);

    // We store the initial n_structural_indexes so that the client can see

    // whether we used truncation. If initial_n_structural_indexes == parser.n_structural_indexes,

    // then this will query parser.structural_indexes[parser.n_structural_indexes] which is len,

    // otherwise, it will copy some prior index.

    parser.structural_indexes[parser.n_structural_indexes + 1] = parser.structural_indexes[parser.n_structural_indexes];

    // This next line is critical, do not change it unless you understand what you are

    // doing.

    parser.structural_indexes[parser.n_structural_indexes] = uint32_t(len);

    if (parser.n_structural_indexes == 0) { return EMPTY; }

  } else if(unclosed_string) { error = UNCLOSED_STRING; }

  return error;

}

private:

  const uint8_t *buf;

  uint32_t *next_structural_index;

  dom_parser_implementation &parser;

  uint32_t len;

  uint32_t idx{0};

  error_code error{SUCCESS};

  stage1_mode partial;

}; // structural_scanner

} // namespace stage1

} // unnamed namespace

simdjson_warn_unused error_code dom_parser_implementation::stage1(const uint8_t *_buf, size_t _len, stage1_mode partial) noexcept {

  this->buf = _buf;

  this->len = _len;

  stage1::structural_scanner scanner(*this, partial);

  return scanner.scan();

}

// big table for the minifier

static uint8_t jump_table[256 * 3] = {

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0,

    1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0,

    1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1,

    1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

    0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,

};

simdjson_warn_unused error_code implementation::minify(const uint8_t *buf, size_t len, uint8_t *dst, size_t &dst_len) const noexcept {

  size_t i = 0, pos = 0;

  uint8_t quote = 0;

  uint8_t nonescape = 1;

  while (i < len) {

    unsigned char c = buf[i];

    uint8_t *meta = jump_table + 3 * c;

    quote = quote ^ (meta[0] & nonescape);

    dst[pos] = c;

    pos += meta[2] | quote;

    i += 1;

    nonescape = uint8_t(~nonescape) | (meta[1]);

  }

  dst_len = pos; // we intentionally do not work with a reference

  // for fear of aliasing

  return quote ? UNCLOSED_STRING : SUCCESS;

}

// credit: based on code from Google Fuchsia (Apache Licensed)

simdjson_warn_unused bool implementation::validate_utf8(const char *buf, size_t len) const noexcept {

  const uint8_t *data = reinterpret_cast<const uint8_t *>(buf);

  uint64_t pos = 0;

  uint32_t code_point = 0;

  while (pos < len) {

    // check of the next 8 bytes are ascii.

    uint64_t next_pos = pos + 16;

    if (next_pos <= len) { // if it is safe to read 8 more bytes, check that they are ascii

      uint64_t v1;

      memcpy(&v1, data + pos, sizeof(uint64_t));

      uint64_t v2;

      memcpy(&v2, data + pos + sizeof(uint64_t), sizeof(uint64_t));

      uint64_t v{v1 | v2};

      if ((v & 0x8080808080808080) == 0) {

        pos = next_pos;

        continue;

      }

    }

    unsigned char byte = data[pos];

    if (byte < 0x80) {

      pos++;

      continue;

    } else if ((byte & 0xe0) == 0xc0) {

      next_pos = pos + 2;

      if (next_pos > len) { return false; }

      if ((data[pos + 1] & 0xc0) != 0x80) { return false; }

      // range check

      code_point = (byte & 0x1f) << 6 | (data[pos + 1] & 0x3f);

      if (code_point < 0x80 || 0x7ff < code_point) { return false; }

    } else if ((byte & 0xf0) == 0xe0) {

      next_pos = pos + 3;

      if (next_pos > len) { return false; }

      if ((data[pos + 1] & 0xc0) != 0x80) { return false; }

      if ((data[pos + 2] & 0xc0) != 0x80) { return false; }

      // range check

      code_point = (byte & 0x0f) << 12 |

                   (data[pos + 1] & 0x3f) << 6 |

                   (data[pos + 2] & 0x3f);

      if (code_point < 0x800 || 0xffff < code_point ||

          (0xd7ff < code_point && code_point < 0xe000)) {

        return false;

      }

    } else if ((byte & 0xf8) == 0xf0) { // 0b11110000

      next_pos = pos + 4;

      if (next_pos > len) { return false; }

      if ((data[pos + 1] & 0xc0) != 0x80) { return false; }

      if ((data[pos + 2] & 0xc0) != 0x80) { return false; }

      if ((data[pos + 3] & 0xc0) != 0x80) { return false; }

      // range check

      code_point =

          (byte & 0x07) << 18 | (data[pos + 1] & 0x3f) << 12 |

          (data[pos + 2] & 0x3f) << 6 | (data[pos + 3] & 0x3f);

      if (code_point <= 0xffff || 0x10ffff < code_point) { return false; }

    } else {

      // we may have a continuation

      return false;

    }

    pos = next_pos;

  }

  return true;

}

} // namespace fallback

} // namespace simdjson

//

// Stage 2

//

namespace simdjson {

namespace fallback {

simdjson_warn_unused error_code dom_parser_implementation::stage2(dom::document &_doc) noexcept {

  return stage2::tape_builder::parse_document<false>(*this, _doc);

}

simdjson_warn_unused error_code dom_parser_implementation::stage2_next(dom::document &_doc) noexcept {

  return stage2::tape_builder::parse_document<true>(*this, _doc);

}

simdjson_warn_unused uint8_t *dom_parser_implementation::parse_string(const uint8_t *src, uint8_t *dst, bool replacement_char) const noexcept {

  return fallback::stringparsing::parse_string(src, dst, replacement_char);

}

simdjson_warn_unused uint8_t *dom_parser_implementation::parse_wobbly_string(const uint8_t *src, uint8_t *dst) const noexcept {

  return fallback::stringparsing::parse_wobbly_string(src, dst);

}

simdjson_warn_unused error_code dom_parser_implementation::parse(const uint8_t *_buf, size_t _len, dom::document &_doc) noexcept {

  auto error = stage1(_buf, _len, stage1_mode::regular);

  if (error) { return error; }

  return stage2(_doc);

}

} // namespace fallback

} // namespace simdjson

#include <simdjson/fallback/end.h>

#endif // SIMDJSON_SRC_FALLBACK_CPP