/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * 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.
 */
#pragma once

#include <optional>

#include "json/json.h"

#include "cuttlefish/common/libs/fs/shared_fd.h"
#include "cuttlefish/host/commands/kernel_log_monitor/kernel_log_server.h"
#include "cuttlefish/result/result.h"

namespace cuttlefish::monitor {

struct ReadEventResult {
  Event event;
  Json::Value metadata;
};

// TODO(schuffelen): Remove `std::optional` if `socket_vsock_proxy` doesn't need
// this distinction.
/** Read a kernel log event from fd. A failed result indicates an error occurred
 * while reading the event, while an empty optional indicates EOF. */
Result<std::optional<ReadEventResult>> ReadEvent(SharedFD fd);

// Writes a kernel log event to the fd, in a format expected by ReadEvent.
bool WriteEvent(SharedFD fd, const Json::Value& event_message);

}  // namespace cuttlefish::monitor
