//
// Copyright (C) 2012 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.
//

#ifndef UPDATE_ENGINE_UPDATE_ATTEMPTER_NESTLABS_H_
#define UPDATE_ENGINE_UPDATE_ATTEMPTER_NESTLABS_H_

#include <time.h>

#include <memory>
#include <set>
#include <string>
#include <utility>
#include <vector>

#include <base/bind.h>
#include <base/time/time.h>
#include <gtest/gtest_prod.h>  // for FRIEND_TEST

#include "update_engine/certificate_checker.h"
#include "update_engine/client_library/include/update_engine/update_status.h"
#include "update_engine/common/action_processor.h"
#include "update_engine/common/cpu_limiter.h"
#include "update_engine/payload_properties_request_action.h"
#include "update_engine/payload_properties_handler_action.h"
#include "update_engine/payload_properties.h"
#include "update_engine/payload_consumer/download_action.h"
#include "update_engine/payload_consumer/postinstall_runner_action.h"
#include "update_engine/proxy_resolver.h"
#include "update_engine/service_observer_interface.h"
#include "update_engine/system_state.h"
#include "update_engine/update_manager/policy.h"
#include "update_engine/update_manager/update_manager.h"
#include "update_engine/weave_service_interface.h"

class MetricsLibraryInterface;

namespace policy {
class PolicyProvider;
}

namespace chromeos_update_engine {

class LibCrosProxy;
class UpdateEngineAdaptor;

class UpdateAttempter : public ActionProcessorDelegate,
                        public DownloadActionDelegate,
                        public CertificateChecker::Observer,
                        public WeaveServiceInterface::DelegateInterface, // TODO remove
                        public PostinstallRunnerAction::DelegateInterface {
 public:
  using UpdateStatus = update_engine::UpdateStatus;
  static const int kMaxDeltaUpdateFailures;

  UpdateAttempter(SystemState* system_state,
                  CertificateChecker* cert_checker,
                  LibCrosProxy* libcros_proxy);
  ~UpdateAttempter() override;

  // Further initialization to be done post construction.
  void Init();

  // Initiates scheduling of update checks.
  virtual void ScheduleUpdates();

  // Checks for update and, if a newer version is available, attempts to update
  // the system. Non-empty |in_app_version| or |in_update_url| prevents
  // automatic detection of the parameter.  |target_channel| denotes a
  // policy-mandated channel we are updating to, if not empty. If |obey_proxies|
  // is true, the update will likely respect Chrome's proxy setting. For
  // security reasons, we may still not honor them. |interactive| should be true
  // if this was called from the user (ie dbus).
  virtual void Update(const std::string& app_version,
                      const std::string& url,
                      const std::string& target_channel = "",
                      const std::string& target_version_prefix = "",
                      bool obey_proxies = false,
                      bool interactive = false);

  // ActionProcessorDelegate methods:
  void ProcessingDone(const ActionProcessor* processor,
                      ErrorCode code) override;
  void ProcessingStopped(const ActionProcessor* processor) override;
  void ActionCompleted(ActionProcessor* processor,
                       AbstractAction* action,
                       ErrorCode code) override;
  // WeaveServiceInterface::DelegateInterface overrides.
  bool OnCheckForUpdates(brillo::ErrorPtr* error) override { return false; };
  bool OnTrackChannel(const std::string& channel,
                      brillo::ErrorPtr* error) override { return false; };
  bool GetWeaveState(int64_t* last_checked_time,
                     double* progress,
                     UpdateStatus* update_status,
                     std::string* current_channel,
                     std::string* tracking_channel) override { return false;};

  // PostinstallRunnerAction::DelegateInterface
  void ProgressUpdate(double progress) override;

  // Resets the current state to UPDATE_STATUS_IDLE.
  // Used by update_engine_client for restarting a new update without
  // having to reboot once the previous update has reached
  // UPDATE_STATUS_UPDATED_NEED_REBOOT state. This is used only
  // for testing purposes.
  virtual bool ResetStatus();

  // Returns the current status in the out params. Returns true on success.
  virtual bool GetStatus(int64_t* last_checked_time,
                         double* progress,
                         std::string* current_operation,
                         std::string* new_version,
                         int64_t* new_size);

  // Runs chromeos-setgoodkernel, whose responsibility it is to mark the
  // currently booted partition has high priority/permanent/etc. The execution
  // is asynchronous. On completion, the action processor may be started
  // depending on the |start_action_processor_| field. Note that every update
  // attempt goes through this method.
  void UpdateBootFlags();

  // Called when the boot flags have been updated.
  void CompleteUpdateBootFlags(bool success);

  UpdateStatus status() const { return status_; }

  int http_response_code() const { return http_response_code_; }
  void set_http_response_code(int code) { http_response_code_ = code; }

  // This is the internal entry point for going through an
  // update. If the current status is idle invokes Update.
  // This is called by the DBus implementation.
  virtual void CheckForUpdate(const std::string& app_version,
                              const std::string& url,
                              bool is_interactive);
  // This is the internal entry point for going through a rollback. This will
  // attempt to run the postinstall on the non-active partition and set it as
  // the partition to boot from. If |powerwash| is True, perform a powerwash
  // as part of rollback. Returns True on success.
  bool Rollback(bool powerwash);

  // This is the internal entry point for checking if we can rollback.
  bool CanRollback() const;

  // This is the internal entry point for getting a rollback partition name,
  // if one exists. It returns the bootable rollback kernel device partition
  // name or empty string if none is available.
  BootControlInterface::Slot GetRollbackSlot() const;
  // Initiates a reboot if the current state is
  // UPDATED_NEED_REBOOT. Returns true on sucess, false otherwise.
  bool RebootIfNeeded();

  // DownloadActionDelegate methods:
  void BytesReceived(uint64_t bytes_progressed,
                     uint64_t bytes_received,
                     uint64_t total) override;
  // Returns that the update should be canceled when the download channel was
  // changed.
  // TODO (dmitryya) figire out why do we need it
  bool ShouldCancel(ErrorCode* cancel_reason) override { return false;};

  void DownloadComplete() override;

  // Broadcasts the current status to all observers.
  void BroadcastStatus();

  // Called at update_engine startup to do various house-keeping.
  void UpdateEngineStarted();

  // Reloads the device policy from libbrillo. Note: This method doesn't
  // cause a real-time policy fetch from the policy server. It just reloads the
  // latest value that libbrillo has cached. libbrillo fetches the policies
  // from the server asynchronously at its own frequency.
  virtual void RefreshDevicePolicy();

  // Stores in |out_boot_time| the boottime (CLOCK_BOOTTIME) recorded at the
  // time of the last successful update in the current boot. Returns false if
  // there wasn't a successful update in the current boot.
  virtual bool GetBootTimeAtUpdate(base::Time *out_boot_time);

  // Returns a version OS version that was being used before the last reboot,
  // and if that reboot happended to be into an update (current version).
  // This will return an empty string otherwise.
  std::string const& GetPrevVersion() const { return prev_version_; }

  // Sets a callback to be used when either a forced update request is received
  // (first argument set to true) or cleared by an update attempt (first
  // argument set to false). The callback further encodes whether the forced
  // check is an interactive one (second argument set to true). Takes ownership
  // of the callback object. A null value disables callback on these events.
  // Note that only one callback can be set, so effectively at most one client
  // can be notified.
  virtual void set_forced_update_pending_callback(
      base::Callback<void(bool, bool)>*  // NOLINT(readability/function)
      callback) {
    forced_update_pending_callback_.reset(callback);
  }

  // Add and remove a service observer.
  void AddObserver(ServiceObserverInterface* observer) {
    service_observers_.insert(observer);
  }
  void RemoveObserver(ServiceObserverInterface* observer) {
    service_observers_.erase(observer);
  }

  const std::set<ServiceObserverInterface*>& service_observers() {
    return service_observers_;
  }

  // Remove all the observers.
  void ClearObservers() { service_observers_.clear(); }


  // =================== TO REMOVE 
  // Broadcasts the current tracking channel to all observers.
  void BroadcastChannel() {};

  // Returns the poll interval dictated by Omaha, if provided; zero otherwise.
  virtual unsigned int server_dictated_poll_interval() const {
    return 0;
  }

  // Returns the number of consecutive failed update checks.
  virtual unsigned int consecutive_failed_update_checks() const {
    return 0;
  }

 private:
  // Update server URL for automated lab test.
  static const char* const kTestUpdateUrl;

  // Friend declarations for testing purposes.
  friend class UpdateAttempterUnderTest;
  friend class UpdateAttempterTest;
  FRIEND_TEST(UpdateAttempterTest, ActionCompletedDownloadTest);
  FRIEND_TEST(UpdateAttempterTest, ActionCompletedErrorTest);
  FRIEND_TEST(UpdateAttempterTest, MarkDeltaUpdateFailureTest);
  FRIEND_TEST(UpdateAttempterTest, UpdateTest);
  FRIEND_TEST(UpdateAttempterTest, ReportDailyMetrics);
  FRIEND_TEST(UpdateAttempterTest, BootTimeInUpdateMarkerFile);

private:
  bool CalculateUpdateParams(const std::string& version,
                             const std::string& url);

  // CertificateChecker::Observer method.
  // Report metrics about the certificate being checked.
  void CertificateChecked(ServerToCheck server_to_check,
                          CertificateCheckResult result) override;

  // Sets the status to the given status and notifies a status update over dbus.
  void SetStatusAndNotify(UpdateStatus status);

  // Sets up the download parameters after receiving the update check response.
  void SetupDownload();

  // Schedules an event loop callback to start the action processor. This is
  // scheduled asynchronously to unblock the event loop.
  void ScheduleProcessingStart();

  // If this was a delta update attempt that failed, count it so that a full
  // update can be tried when needed.
  void MarkDeltaUpdateFailure();

  ProxyResolver* GetProxyResolver() {
    return &direct_proxy_resolver_;
  }

  // Helper method of Update() and Rollback() to construct the sequence of
  // actions to be performed for the postinstall.
  // |previous_action| is the previous action to get
  // bonded with the install_plan that gets passed to postinstall.
  void BuildPostInstallActions(InstallPlanAction* previous_action);

  // Helper method of Update() to construct the sequence of actions to
  // be performed for an update check. Please refer to
  // Update() method for the meaning of the parameters.
  void BuildUpdateActions(bool interactive);

  // Writes to the processing completed marker. Does nothing if
  // |update_completed_marker_| is empty.
  void WriteUpdateCompletedMarker();

  // Reboots the system directly by calling /sbin/shutdown. Returns true on
  // success.
  bool RebootDirectly();

  // Callback for the async UpdateCheckAllowed policy request. If |status| is
  // |EvalStatus::kSucceeded|, either runs or suppresses periodic update checks,
  // based on the content of |params|. Otherwise, retries the policy request.
  void OnUpdateScheduled(
      chromeos_update_manager::EvalStatus status,
      const chromeos_update_manager::UpdateCheckParams& params);

  // Updates the time an update was last attempted to the current time.
  void UpdateLastCheckedTime();

  // Returns whether an update is currently running or scheduled.
  bool IsUpdateRunningOrScheduled();

  // Last status notification timestamp used for throttling. Use monotonic
  // TimeTicks to ensure that notifications are sent even if the system clock is
  // set back in the middle of an update.
  base::TimeTicks last_notify_time_;

  std::vector<std::shared_ptr<AbstractAction>> actions_;
  std::unique_ptr<ActionProcessor> processor_;

  // External state of the system outside the update_engine process
  // carved out separately to mock out easily in unit tests.
  SystemState* system_state_;

  // Pointer to the certificate checker instance to use.
  CertificateChecker* cert_checker_;

  // The list of services observing changes in the updater.
  std::set<ServiceObserverInterface*> service_observers_;

  // Pointer to the DownloadAction in the actions_ vector.
  std::shared_ptr<DownloadAction> download_action_;

  std::shared_ptr<PayloadPropertiesHandlerAction> payload_properties_handler_action_;
  std::shared_ptr<PayloadPropertiesRequestAction> payload_properties_request_action_;

  // Pointer to the preferences store interface. This is just a cached
  // copy of system_state->prefs() because it's used in many methods and
  // is convenient this way.
  PrefsInterface* prefs_ = nullptr;

  // HTTP server response code from the last HTTP request action.
  int http_response_code_ = 0;

  // CPU limiter during the update.
  CPULimiter cpu_limiter_;

  // For status:
  UpdateStatus status_{UpdateStatus::IDLE};
  double download_progress_ = 0.0;
  int64_t last_checked_time_ = 0;
  std::string prev_version_;
  std::string new_version_ = "0000000";
  int64_t new_payload_size_ = 0;

  // Our two proxy resolvers
  DirectProxyResolver direct_proxy_resolver_;

  // Originally, both of these flags are false. Once UpdateBootFlags is called,
  // |update_boot_flags_running_| is set to true. As soon as UpdateBootFlags
  // completes its asynchronous run, |update_boot_flags_running_| is reset to
  // false and |updated_boot_flags_| is set to true. From that point on there
  // will be no more changes to these flags.
  //
  // True if UpdateBootFlags has completed.
  bool updated_boot_flags_ = false;
  // True if UpdateBootFlags is running.
  bool update_boot_flags_running_ = false;

  // True if the action processor needs to be started by the boot flag updater.
  bool start_action_processor_ = false;

  // Used for fetching information about the device policy.
  std::unique_ptr<policy::PolicyProvider> policy_provider_;

  // Tracks whether we have scheduled update checks.
  bool waiting_for_scheduled_check_ = false;

  // A callback to use when a forced update request is either received (true) or
  // cleared by an update attempt (false). The second argument indicates whether
  // this is an interactive update, and its value is significant iff the first
  // argument is true.
  std::unique_ptr<base::Callback<void(bool, bool)>>
      forced_update_pending_callback_;

  std::string app_version_;
  std::string url_;

  PayloadProperties payload_properties_;

  DISALLOW_COPY_AND_ASSIGN(UpdateAttempter);
};

}  // namespace chromeos_update_engine

#endif  // UPDATE_ENGINE_UPDATE_ATTEMPTER_NESTLABS_H_