// Copyright 2020 Google LLC
//
// 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.

#include "internal/crypto_cros/nearby_base.h"

#include <cstddef>
#include <limits>
#include <string>

#ifdef NEARBY_CHROMIUM
#include "internal/platform/logging.h"
#elif defined(NEARBY_SWIFTPM)
#include "internal/platform/logging.h"
#else
#include "absl/log/check.h"  // nogncheck
#endif

#include "absl/types/span.h"

namespace nearbybase {

char* WriteInto(std::string* str, size_t length_with_null) {
  DCHECK_GE(length_with_null, 1u);
  str->reserve(length_with_null);
  str->resize(length_with_null - 1);
  return &((*str)[0]);
}

std::string HexEncode(const void* bytes, size_t size) {
  static const char kHexChars[] = "0123456789ABCDEF";

  // Each input byte creates two output hex characters.
  std::string ret(size * 2, '\0');

  for (size_t i = 0; i < size; ++i) {
    char b = reinterpret_cast<const char*>(bytes)[i];
    ret[(i * 2)] = kHexChars[(b >> 4) & 0xf];
    ret[(i * 2) + 1] = kHexChars[b & 0xf];
  }
  return ret;
}
}  // namespace nearbybase