// Copyright 2018 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.

#ifndef DLCSERVICE_DLC_SERVICE_DBUS_ADAPTOR_H_
#define DLCSERVICE_DLC_SERVICE_DBUS_ADAPTOR_H_

#include <memory>
#include <string>
#include <vector>

#include <base/files/file_path.h>
#include <imageloader/dbus-proxies.h>
#include <update_engine/dbus-proxies.h>

#include "dlcservice/dbus_adaptors/org.chromium.DlcServiceInterface.h"

namespace dlcservice {

class BootSlot;

// DlcServiceDBusAdaptor is a D-Bus adaptor that manages life-cycles of DLCs
// (Downloadable Content) and provides an API for the rest of the system to
// install/uninstall DLCs.
class DlcServiceDBusAdaptor
    : public org::chromium::DlcServiceInterfaceInterface,
      public org::chromium::DlcServiceInterfaceAdaptor {
 public:
  class ShutdownDelegate {
   public:
    virtual ~ShutdownDelegate() = default;
    // Cancels the shutdown event scheduled.
    virtual void CancelShutdown() = 0;
    // Schedules the shutdown event.
    virtual void ScheduleShutdown() = 0;
  };

  class ScopedShutdown {
   public:
    explicit ScopedShutdown(ShutdownDelegate* shutdown_delegate)
        : shutdown_delegate_(shutdown_delegate) {
      shutdown_delegate_->CancelShutdown();
    }
    ~ScopedShutdown() { shutdown_delegate_->ScheduleShutdown(); }

   private:
    ShutdownDelegate* shutdown_delegate_;

    DISALLOW_COPY_AND_ASSIGN(ScopedShutdown);
  };

  DlcServiceDBusAdaptor(
      std::unique_ptr<org::chromium::ImageLoaderInterfaceProxyInterface>
          image_loader_proxy,
      std::unique_ptr<org::chromium::UpdateEngineInterfaceProxyInterface>
          update_engine_proxy,
      std::unique_ptr<BootSlot> boot_slot,
      const base::FilePath& manifest_dir,
      const base::FilePath& content_dir,
      ShutdownDelegate* shutdown_delegate);
  ~DlcServiceDBusAdaptor();

  // Loads installed DLC module images.
  void LoadDlcModuleImages();

  // org::chromium::DlServiceInterfaceInterface overrides:
  bool Install(brillo::ErrorPtr* err,
               const std::string& id_in,
               const std::string& omaha_url_in,
               std::string* dlc_root_out) override;
  bool Uninstall(brillo::ErrorPtr* err, const std::string& id_in) override;
  bool GetInstalled(brillo::ErrorPtr* err,
                    std::string* dlc_module_list_out) override;

 private:
  // Scans manifest_dir_ for a list of supported DLC modules and returns them.
  std::vector<std::string> ScanDlcModules();

  // Waits for Update Engine to be idle.
  bool WaitForUpdateEngineIdle();

  // Checks if Update Engine is in a state among |status_list|.
  bool CheckForUpdateEngineStatus(const std::vector<std::string>& status_list);

  std::unique_ptr<org::chromium::ImageLoaderInterfaceProxyInterface>
      image_loader_proxy_;
  std::unique_ptr<org::chromium::UpdateEngineInterfaceProxyInterface>
      update_engine_proxy_;
  std::unique_ptr<BootSlot> boot_slot_;

  base::FilePath manifest_dir_;
  base::FilePath content_dir_;

  ShutdownDelegate* shutdown_delegate_;

  DISALLOW_COPY_AND_ASSIGN(DlcServiceDBusAdaptor);
};

}  // namespace dlcservice

#endif  // DLCSERVICE_DLC_SERVICE_DBUS_ADAPTOR_H_