// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/views/frame/dbus_appmenu_registrar.h"

#include "base/check_op.h"
#include "base/functional/bind.h"
#include "base/functional/callback_helpers.h"
#include "base/no_destructor.h"
#include "chrome/browser/ui/views/frame/dbus_appmenu.h"
#include "components/dbus/thread_linux/dbus_thread_linux.h"
#include "components/dbus/utils/call_method.h"
#include "dbus/bus.h"
#include "dbus/object_path.h"
#include "dbus/object_proxy.h"
#include "ui/platform_window/extensions/wayland_extension.h"
#include "ui/platform_window/extensions/x11_extension.h"

namespace {

const char kAppMenuRegistrarName[] = "com.canonical.AppMenu.Registrar";
const char kAppMenuRegistrarPath[] = "/com/canonical/AppMenu/Registrar";
const char kAppMenuRegistrarInterface[] = "com.canonical.AppMenu.Registrar";

}  // namespace

// static
DbusAppmenuRegistrar* DbusAppmenuRegistrar::GetInstance() {
  static base::NoDestructor<DbusAppmenuRegistrar> instance;
  return instance.get();
}

void DbusAppmenuRegistrar::OnMenuBarCreated(DbusAppmenu* menu) {
  // Make sure insertion succeeds, we should not already be tracking `menu`.
  CHECK(menus_.insert({menu, kUninitialized}).second);
  if (service_has_owner_) {
    InitializeMenu(menu);
  }
}

void DbusAppmenuRegistrar::OnMenuBarDestroyed(DbusAppmenu* menu) {
  DCHECK(menus_.contains(menu));
  if (menus_[menu] == kRegistered) {
    if (auto* toplevel_extension =
            ui::GetWaylandToplevelExtension(*menu->platform_window())) {
      toplevel_extension->UnsetAppmenu();
    } else if (ui::GetX11Extension(*menu->platform_window())) {
      dbus_utils::CallMethod<"u", "">(
          registrar_proxy_, kAppMenuRegistrarInterface, "UnregisterWindow",
          base::DoNothing(), menu->browser_frame_id());
    }
  }
  menus_.erase(menu);
}

DbusAppmenuRegistrar::DbusAppmenuRegistrar()
    : bus_(dbus_thread_linux::GetSharedSessionBus()) {
  registrar_proxy_ = bus_->GetObjectProxy(
      kAppMenuRegistrarName, dbus::ObjectPath(kAppMenuRegistrarPath));

  dbus::Bus::ServiceOwnerChangeCallback callback =
      base::BindRepeating(&DbusAppmenuRegistrar::OnNameOwnerChanged,
                          weak_ptr_factory_.GetWeakPtr());
  bus_->ListenForServiceOwnerChange(kAppMenuRegistrarName, callback);
  bus_->GetServiceOwner(kAppMenuRegistrarName, callback);
}

void DbusAppmenuRegistrar::InitializeMenu(DbusAppmenu* menu) {
  DCHECK(menus_.contains(menu));
  DCHECK_EQ(menus_[menu], kUninitialized);
  menus_[menu] = kInitializing;
  menu->Initialize(base::BindOnce(&DbusAppmenuRegistrar::OnMenuInitialized,
                                  weak_ptr_factory_.GetWeakPtr(), menu));
}

void DbusAppmenuRegistrar::RegisterMenu(DbusAppmenu* menu) {
  DCHECK(menus_.contains(menu));
  DCHECK(menus_[menu] == kInitializeSucceeded || menus_[menu] == kRegistered);
  menus_[menu] = kRegistered;

  if (auto* toplevel_extension =
          ui::GetWaylandToplevelExtension(*menu->platform_window())) {
    toplevel_extension->SetAppmenu(bus_->GetConnectionName(), menu->GetPath());
  } else if (ui::GetX11Extension(*menu->platform_window())) {
    dbus_utils::CallMethod<"uo", "">(
        registrar_proxy_, kAppMenuRegistrarInterface, "RegisterWindow",
        base::DoNothing(), menu->browser_frame_id(),
        dbus::ObjectPath(menu->GetPath()));
  }
}

void DbusAppmenuRegistrar::OnMenuInitialized(DbusAppmenu* menu, bool success) {
  DCHECK(menus_.contains(menu));
  DCHECK(menus_[menu] == kInitializing);
  menus_[menu] = success ? kInitializeSucceeded : kInitializeFailed;
  if (success && service_has_owner_) {
    RegisterMenu(menu);
  }
}

void DbusAppmenuRegistrar::OnNameOwnerChanged(
    const std::string& service_owner) {
  service_has_owner_ = !service_owner.empty();

  // If the name owner changed, we need to reregister all the live menus with
  // the system.
  for (const auto& pair : menus_) {
    DbusAppmenu* menu = pair.first;
    switch (pair.second) {
      case kUninitialized:
        if (service_has_owner_) {
          InitializeMenu(menu);
        }
        break;
      case kInitializing:
        // Wait for Initialize() to finish.
        break;
      case kInitializeFailed:
        // Don't try to recover.
        break;
      case kInitializeSucceeded:
        if (service_has_owner_) {
          RegisterMenu(menu);
        }
        break;
      case kRegistered:
        if (service_has_owner_) {
          RegisterMenu(menu);
        } else {
          menus_[menu] = kInitializeSucceeded;
        }
        break;
    }
  }
}