//
// Copyright (C) 2015 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.
//

#include "update_engine/daemon_chromeos.h"

#include <sysexits.h>

#include <base/bind.h>
#include <base/location.h>

#include "update_engine/real_system_state.h"

using brillo::Daemon;
using std::unique_ptr;

namespace chromeos_update_engine {

unique_ptr<DaemonBase> DaemonBase::CreateInstance() {
  return std::make_unique<DaemonChromeOS>();
}

int DaemonChromeOS::OnInit() {
  // Register the |subprocess_| singleton with this Daemon as the signal
  // handler.
  subprocess_.Init(this);

  int exit_code = Daemon::OnInit();
  if (exit_code != EX_OK)
    return exit_code;

  // Initialize update engine global state but continue if something fails.
  // TODO(deymo): Move the daemon_state_ initialization to a factory method
  // avoiding the explicit re-usage of the |bus| instance, shared between
  // D-Bus service and D-Bus client calls.
  RealSystemState* real_system_state = new RealSystemState();
  daemon_state_.reset(real_system_state);
  LOG_IF(ERROR, !real_system_state->Initialize())
      << "Failed to initialize system state.";

  // Create the DBus service.
  dbus_adaptor_.reset(new UpdateEngineAdaptor(real_system_state));
  daemon_state_->AddObserver(dbus_adaptor_.get());

  dbus_adaptor_->RegisterAsync(
      base::Bind(&DaemonChromeOS::OnDBusRegistered, base::Unretained(this)));
  LOG(INFO) << "Waiting for DBus object to be registered.";
  return EX_OK;
}

void DaemonChromeOS::OnDBusRegistered(bool succeeded) {
  if (!succeeded) {
    LOG(ERROR) << "Registering the UpdateEngineAdaptor";
    QuitWithExitCode(1);
    return;
  }

  // Take ownership of the service now that everything is initialized. We need
  // to this now and not before to avoid exposing a well known DBus service
  // path that doesn't have the service it is supposed to implement.
  if (!dbus_adaptor_->RequestOwnership()) {
    LOG(ERROR) << "Unable to take ownership of the DBus service, is there "
               << "other update_engine daemon running?";
    QuitWithExitCode(1);
    return;
  }
  daemon_state_->StartUpdater();
}

}  // namespace chromeos_update_engine