// Copyright 2020 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "croslog/log_parser_syslog.h"

#include <memory>
#include <string>
#include <utility>

namespace {
// The length of time string like "2020-05-25T00:00:00.000000+00:00".
constexpr size_t kTimeStringLength = 32;
}  // namespace

namespace croslog {

LogParserSyslog::LogParserSyslog() = default;

MaybeLogEntry LogParserSyslog::Parse(std::string&& entire_line) {
  if (entire_line.empty()) {
    // Returns an invalid value if the line is invalid or empty.
    return base::nullopt;
  }

  if (entire_line.size() < kTimeStringLength) {
    LOG(WARNING) << "The line is too short: looks non-RFC5424 format?";
    return base::nullopt;
  }

  // Extract 32 chars from the beginning.
  std::string log_time = entire_line.substr(0, kTimeStringLength);

  base::Time time;
  bool result = base::Time::FromString(log_time.c_str(), &time);
  if (!result) {
    LOG(WARNING) << "The line has incorrect time format.";
    return base::nullopt;
  }

  return LogEntry{time, std::move(entire_line)};
}

}  // namespace croslog