// Copyright (c) 2017 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#include "atom/browser/lib/power_observer_linux.h"

#include <unistd.h>
#include <uv.h>
#include <iostream>

#include "base/bind.h"
#include "device/bluetooth/dbus/dbus_thread_manager_linux.h"

namespace {

const char kLogindServiceName[] = "org.freedesktop.login1";
const char kLogindObjectPath[] = "/org/freedesktop/login1";
const char kLogindManagerInterface[] = "org.freedesktop.login1.Manager";

// Store shutdown lock as a global, since we only want to release it when the
// main process exits.
base::ScopedFD shutdown_lock;

std::string get_executable_basename() {
  char buf[4096];
  size_t buf_size = sizeof(buf);
  std::string rv("electron");
  if (!uv_exepath(buf, &buf_size)) {
    rv = strrchr(static_cast<const char*>(buf), '/') + 1;
  }
  return std::move(rv);
}

}  // namespace

namespace atom {

PowerObserverLinux::PowerObserverLinux()
    : lock_owner_name_(get_executable_basename()), weak_ptr_factory_(this) {
  auto dbus_thread_manager = bluez::DBusThreadManagerLinux::Get();
  if (dbus_thread_manager) {
    bus_ = dbus_thread_manager->GetSystemBus();
    if (bus_) {
      logind_ = bus_->GetObjectProxy(kLogindServiceName,
                                     dbus::ObjectPath(kLogindObjectPath));
      logind_->WaitForServiceToBeAvailable(
          base::Bind(&PowerObserverLinux::OnLoginServiceAvailable,
                     weak_ptr_factory_.GetWeakPtr()));
    } else {
      LOG(WARNING) << "Failed to get system bus connection";
    }
  } else {
    LOG(WARNING) << "DBusThreadManagerLinux instance isn't available";
  }
}

void PowerObserverLinux::OnLoginServiceAvailable(bool service_available) {
  if (!service_available) {
    LOG(WARNING) << kLogindServiceName << " not available";
    return;
  }
  // Connect to PrepareForShutdown/PrepareForSleep signals
  logind_->ConnectToSignal(kLogindManagerInterface, "PrepareForShutdown",
                           base::Bind(&PowerObserverLinux::OnPrepareForShutdown,
                                      weak_ptr_factory_.GetWeakPtr()),
                           base::Bind(&PowerObserverLinux::OnSignalConnected,
                                      weak_ptr_factory_.GetWeakPtr()));
  logind_->ConnectToSignal(kLogindManagerInterface, "PrepareForSleep",
                           base::Bind(&PowerObserverLinux::OnPrepareForSleep,
                                      weak_ptr_factory_.GetWeakPtr()),
                           base::Bind(&PowerObserverLinux::OnSignalConnected,
                                      weak_ptr_factory_.GetWeakPtr()));
  // Take sleep inhibit lock
  TakeSleepLock();
}

void PowerObserverLinux::TakeSleepLock() {
  dbus::MethodCall sleep_inhibit_call(kLogindManagerInterface, "Inhibit");
  dbus::MessageWriter inhibit_writer(&sleep_inhibit_call);
  inhibit_writer.AppendString("sleep");                               // what
  // Use the executable name as the lock owner, which will list rebrands of the
  // electron executable as separate entities.
  inhibit_writer.AppendString(lock_owner_name_);                      // who
  inhibit_writer.AppendString("Application cleanup before suspend");  // why
  inhibit_writer.AppendString("delay");                               // mode
  logind_->CallMethod(&sleep_inhibit_call,
                      dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
                      base::Bind(&PowerObserverLinux::OnInhibitResponse,
                                 weak_ptr_factory_.GetWeakPtr(), &sleep_lock_));
}

void PowerObserverLinux::BlockShutdown() {
  if (shutdown_lock.is_valid()) {
    LOG(WARNING) << "Trying to subscribe to shutdown multiple times";
    return;
  }
  dbus::MethodCall shutdown_inhibit_call(kLogindManagerInterface, "Inhibit");
  dbus::MessageWriter inhibit_writer(&shutdown_inhibit_call);
  inhibit_writer.AppendString("shutdown");                 // what
  inhibit_writer.AppendString(lock_owner_name_);           // who
  inhibit_writer.AppendString("Ensure a clean shutdown");  // why
  inhibit_writer.AppendString("delay");                    // mode
  logind_->CallMethod(
      &shutdown_inhibit_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
      base::Bind(&PowerObserverLinux::OnInhibitResponse,
                 weak_ptr_factory_.GetWeakPtr(), &shutdown_lock));
}

void PowerObserverLinux::UnblockShutdown() {
  if (!shutdown_lock.is_valid()) {
    LOG(WARNING)
        << "Trying to unsubscribe to shutdown without being subscribed";
    return;
  }
  shutdown_lock.reset();
}

void PowerObserverLinux::OnInhibitResponse(base::ScopedFD* scoped_fd,
                                           dbus::Response* response) {
  dbus::MessageReader reader(response);
  reader.PopFileDescriptor(scoped_fd);
}

void PowerObserverLinux::OnPrepareForSleep(dbus::Signal* signal) {
  dbus::MessageReader reader(signal);
  bool suspending;
  if (!reader.PopBool(&suspending)) {
    LOG(ERROR) << "Invalid signal: " << signal->ToString();
    return;
  }
  if (suspending) {
    OnSuspend();
    sleep_lock_.reset();
  } else {
    TakeSleepLock();
    OnResume();
  }
}

void PowerObserverLinux::OnPrepareForShutdown(dbus::Signal* signal) {
  dbus::MessageReader reader(signal);
  bool shutting_down;
  if (!reader.PopBool(&shutting_down)) {
    LOG(ERROR) << "Invalid signal: " << signal->ToString();
    return;
  }
  if (shutting_down) {
    if (!OnShutdown()) {
      // The user didn't try to prevent shutdown. Release the lock and allow the
      // shutdown to continue normally.
      shutdown_lock.reset();
    }
  }
}

void PowerObserverLinux::OnSignalConnected(const std::string& interface,
                                           const std::string& signal,
                                           bool success) {
  LOG_IF(WARNING, !success) << "Failed to connect to " << signal;
}

}  // namespace atom