// Copyright 2019 The Chromium 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 COMPONENTS_DBUS_PROPERTIES_DBUS_PROPERTIES_H_
#define COMPONENTS_DBUS_PROPERTIES_DBUS_PROPERTIES_H_

#include "base/callback_forward.h"
#include "base/component_export.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/stl_util.h"
#include "components/dbus/properties/types.h"
#include "dbus/bus.h"
#include "dbus/exported_object.h"

// https://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-properties
class COMPONENT_EXPORT(DBUS) DbusProperties {
 public:
  using InitializedCallback = base::OnceCallback<void(bool success)>;

  // Registers method handlers for the properties interface.  The handlers will
  // not be removed until the bus is shut down.
  DbusProperties(dbus::ExportedObject* exported_object,
                 InitializedCallback callback);
  ~DbusProperties();

  void RegisterInterface(const std::string& interface);

  template <typename T>
  void SetProperty(const std::string& interface,
                   const std::string& name,
                   T&& value,
                   bool emit_signal = true,
                   bool send_change = true) {
    auto interface_it = properties_.find(interface);
    DCHECK(interface_it != properties_.end());
    auto property_it = interface_it->second.find(name);
    DbusVariant new_value = MakeDbusVariant(std::move(value));
    const bool send_signal =
        emit_signal && (property_it == interface_it->second.end() ||
                        property_it->second != new_value);
    (interface_it->second)[name] = std::move(new_value);
    if (send_signal)
      PropertyUpdated(interface, name, send_change);
  }

  DbusVariant* GetProperty(const std::string& interface,
                           const std::string& property_name);

  // If emitting a PropertiesChangedSignal is desired, this should be called
  // after an existing property is modified through any means other than
  // SetProperty().
  void PropertyUpdated(const std::string& interface,
                       const std::string& property_name,
                       bool send_change = true);

 private:
  void OnExported(const std::string& interface_name,
                  const std::string& method_name,
                  bool success);

  void OnGetAllProperties(dbus::MethodCall* method_call,
                          dbus::ExportedObject::ResponseSender response_sender);
  void OnGetProperty(dbus::MethodCall* method_call,
                     dbus::ExportedObject::ResponseSender response_sender);
  void OnSetProperty(dbus::MethodCall* method_call,
                     dbus::ExportedObject::ResponseSender response_sender);

  bool initialized_ = false;

  dbus::ExportedObject* exported_object_ = nullptr;

  base::RepeatingCallback<void(bool)> barrier_;

  // A map from interface name to a map of properties.  The properties map is
  // from property name to property value.
  std::map<std::string, std::map<std::string, DbusVariant>> properties_;

  base::WeakPtrFactory<DbusProperties> weak_factory_{this};

  DISALLOW_COPY_AND_ASSIGN(DbusProperties);
};

#endif  // COMPONENTS_DBUS_PROPERTIES_DBUS_PROPERTIES_H_