/* Copyright (c) 2014, 2025, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is designed to work with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have either included with
   the program or referenced in the documentation.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include <cstddef>

#include "mysql/gtid/uuid.h"

/*
const size_t Uuid::TEXT_LENGTH;
const size_t Uuid::BYTE_LENGTH;
const size_t Uuid::BIT_LENGTH;
*/
namespace mysql::gtid {

int Uuid::parse(const char *string, size_t len) {
  return parse(string, len, bytes.data());
}

int Uuid::parse(const char *in_string, size_t len,
                const unsigned char *out_str) {
  const unsigned char **p_out_str = out_str ? &out_str : nullptr;

  switch (len) {
    // UUID without dashes. ex 12345678123456781234567812345678
    case TEXT_LENGTH - 4:
      if (read_section((TEXT_LENGTH - 4) / 2, &in_string, p_out_str)) return 1;
      break;
    // UUID with braces ex {12345678-1234-5678-1234-567812345678}
    case TEXT_LENGTH + 2:
      if (*in_string != '{' || in_string[TEXT_LENGTH + 1] != '}') return 1;
      in_string++;
      [[fallthrough]];
    // standard UUID ex 12345678-1234-5678-1234-567812345678
    case TEXT_LENGTH:
      for (int i = 0; i < NUMBER_OF_SECTIONS - 1; i++) {
        if (read_section(bytes_per_section[i], &in_string, p_out_str)) return 1;
        if (*in_string == '-')
          in_string++;
        else
          return 1;
      }
      if (read_section(bytes_per_section[NUMBER_OF_SECTIONS - 1], &in_string,
                       p_out_str))
        return 1;
      break;
    default:
      return 1;
  }
  return 0;
}

bool Uuid::read_section(int section_len, const char **section_str,
                        const unsigned char **out_binary_str) {
  const auto **section_string =
      reinterpret_cast<const unsigned char **>(section_str);
  for (int j = 0; j < section_len; j++) {
    int const hi = hex_to_byte[**section_string];
    if (hi == -1) return true;
    (*section_string)++;
    int const lo = hex_to_byte[**section_string];
    if (lo == -1) return true;
    (*section_string)++;
    if (out_binary_str) {
      auto *u = const_cast<unsigned char *>(*out_binary_str);
      *u = ((hi << 4) + lo);
      (*out_binary_str)++;
    }
  }
  return false;
}

bool Uuid::is_valid(const char *s, size_t len) {
  return parse(s, len, nullptr) == 0;
}

size_t Uuid::to_string(const unsigned char *bytes_arg, char *buf) {
  static const char byte_to_hex[] = "0123456789abcdef";
  const unsigned char *u = bytes_arg;
  for (int i = 0; i < NUMBER_OF_SECTIONS; i++) {
    if (i > 0) {
      *buf = '-';
      buf++;
    }
    for (int j = 0; j < bytes_per_section[i]; j++) {
      int const byte = *u;
      *buf = byte_to_hex[byte >> 4];
      buf++;
      *buf = byte_to_hex[byte & 0xf];
      buf++;
      u++;
    }
  }
  *buf = '\0';
  return TEXT_LENGTH;
}

size_t Uuid::to_string(char *buf) const { return to_string(bytes.data(), buf); }
}  // namespace mysql::gtid
