/**
 * Copyright (c) 2021 OceanBase
 * OceanBase Database Proxy(ODP) is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef OB_BASE64_ENCODE_H_
#define OB_BASE64_ENCODE_H_

#include <cctype>
#include <stdint.h>

namespace oceanbase
{
namespace common
{
class ObBase64Encoder
{
private:
template<int N>
friend class InitBase64Values;
static char BASE64_CHARS[];
static int FROM_BASE64_TABLE[];

  static uint8_t BASE64_VALUES[256];

  static inline bool is_base64_char(char c)
  {
    return std::isalnum(c) || c == '+' || c == '/';
  }

  static inline bool my_base64_decoder_skip_spaces(char c)
  {
    if (FROM_BASE64_TABLE[(uint8_t) c] != -2) {
      return false;
    }
    return true;
  }
public:
  static int64_t needed_encoded_length(const int64_t buf_size)
  {
    return (buf_size / 3) * 4 + (buf_size % 3 == 0 ? 0 : 4);
  }

  static int64_t needed_decoded_length(const int64_t buf_size)
  {
    return (buf_size / 4) * 3;
  }

  static int encode(const uint8_t* input, const int64_t input_len,
                    char* output, const int64_t output_len, int64_t &pos);

  static int decode(const char* input, const int64_t input_len,
                    uint8_t* output, const int64_t output_len,
                    int64_t &pos, bool skip_spaces = false);
};
} // end namespace common
} // end namespace oceanbase
#endif // !OB_BASE64_ENCODE_H_