// Copyright 2023 The Pigweed 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

//

//     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 "pw_string/format.h"

#include <cstdio>

namespace pw::string {

StatusWithSize Format(span<char> buffer, const char* format, ...) {

  va_list args;

  va_start(args, format);

  const StatusWithSize result = FormatVaList(buffer, format, args);

  va_end(args);

  return result;

}

StatusWithSize FormatVaList(span<char> buffer,

                            const char* format,

                            va_list args) {

  if (buffer.empty()) {

    return StatusWithSize::ResourceExhausted();

  }

  const int result = std::vsnprintf(buffer.data(), buffer.size(), format, args);

  // If an error occurred, the number of characters written is unknown.

  // Discard any output by terminating the buffer.

  if (result < 0) {

    buffer[0] = '\0';

    return StatusWithSize::InvalidArgument();

  }

  // If result >= buffer.size(), the output was truncated and null-terminated.

  if (static_cast<unsigned>(result) >= buffer.size()) {

    return StatusWithSize::ResourceExhausted(buffer.size() - 1);

  }

  return StatusWithSize(result);

}

Status Format(InlineString<>& string, const char* format, ...) {

  va_list args;

  va_start(args, format);

  const Status status = FormatVaList(string, format, args);

  va_end(args);

  return status;

}

Status FormatVaList(InlineString<>& string, const char* format, va_list args) {

  Status status;

  string.resize_and_overwrite([&](char* buffer, size_t capacity) {

    // The vsnprintf buffer size includes a byte for the null terminator.

    StatusWithSize result =

        FormatVaList(span(buffer + string.size(), capacity + 1 - string.size()),

                     format,

                     args);

    status = result.status();

    return string.size() + result.size();

  });

  return status;

}

Status FormatOverwrite(InlineString<>& string, const char* format, ...) {

  va_list args;

  va_start(args, format);

  const Status status = FormatOverwriteVaList(string, format, args);

  va_end(args);

  return status;

}

}  // namespace pw::string