//

// Copyright 2017 The Abseil Authors.

//

// 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

//

//      http://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.

//

#ifndef ABSL_STRINGS_STR_JOIN_H_

#define ABSL_STRINGS_STR_JOIN_H_

#include <string>

#include "third_party/absl/strings/string_view.h"

namespace absl {

namespace {

template <typename T>

inline size_t Itoa(T val, char *s) {

  char *org = s;

  if (val < 0) {

    *s++ = '-';

    val = -val;

  }

  char *t = s;

  T mod = 0;

  while (val) {

    mod = val % 10;

    *t++ = static_cast<char>(mod) + '0';

    val /= 10;

  }

  if (s == t) {

    *t++ = '0';

  }

  *t = '\0';

  std::reverse(s, t);

  return static_cast<size_t>(t - org);

}

}  // namespace

inline std::string StrJoin(const std::vector<std::string> &tokens,

                           absl::string_view delim) {

  std::string result;

  if (!tokens.empty()) {

    result.append(tokens[0]);

  }

  for (size_t i = 1; i < tokens.size(); ++i) {

    result.append(delim.data(), delim.size());

    result.append(tokens[i]);

  }

  return result;

}

inline std::string StrJoin(const std::vector<absl::string_view> &tokens,

                           absl::string_view delim) {

  std::string result;

  if (!tokens.empty()) {

    result.append(tokens[0].data(), tokens[0].size());

  }

  for (size_t i = 1; i < tokens.size(); ++i) {

    result.append(delim.data(), delim.size());

    result.append(tokens[i].data(), tokens[i].size());

  }

  return result;

}

inline std::string StrJoin(const std::vector<int> &tokens,

                           absl::string_view delim) {

  std::string result;

  char buf[32];

  if (!tokens.empty()) {

    const size_t len = Itoa(tokens[0], buf);

    result.append(buf, len);

  }

  for (size_t i = 1; i < tokens.size(); ++i) {

    result.append(delim.data(), delim.size());

    const size_t len = Itoa(tokens[i], buf);

    result.append(buf, len);

  }

  return result;

}

}  // namespace absl

#endif  // ABSL_STRINGS_STR_CAT_H_