//
// Copyright (C) 2016 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.
//

#include "update_engine/update_attempter_android.h"

#include <algorithm>
#include <map>
#include <utility>

#include <base/bind.h>
#include <base/logging.h>
#include <base/strings/string_number_conversions.h>
#include <brillo/bind_lambda.h>
#include <brillo/message_loops/message_loop.h>
#include <brillo/strings/string_utils.h>

#include "update_engine/common/constants.h"
#include "update_engine/common/libcurl_http_fetcher.h"
#include "update_engine/common/multi_range_http_fetcher.h"
#include "update_engine/common/utils.h"
#include "update_engine/daemon_state_android.h"
#include "update_engine/payload_consumer/download_action.h"
#include "update_engine/payload_consumer/filesystem_verifier_action.h"
#include "update_engine/payload_consumer/postinstall_runner_action.h"
#include "update_engine/update_status_utils.h"

using base::Bind;
using base::TimeDelta;
using base::TimeTicks;
using std::shared_ptr;
using std::string;
using std::vector;

namespace chromeos_update_engine {

namespace {

const char* const kErrorDomain = "update_engine";
// TODO(deymo): Convert the different errors to a numeric value to report them
// back on the service error.
const char* const kGenericError = "generic_error";

// Log and set the error on the passed ErrorPtr.
bool LogAndSetError(brillo::ErrorPtr* error,
                    const tracked_objects::Location& location,
                    const string& reason) {
  brillo::Error::AddTo(error, location, kErrorDomain, kGenericError, reason);
  LOG(ERROR) << "Replying with failure: " << location.ToString() << ": "
             << reason;
  return false;
}

}  // namespace

UpdateAttempterAndroid::UpdateAttempterAndroid(
    DaemonStateAndroid* daemon_state,
    PrefsInterface* prefs,
    BootControlInterface* boot_control,
    HardwareInterface* hardware)
    : daemon_state_(daemon_state),
      prefs_(prefs),
      boot_control_(boot_control),
      hardware_(hardware),
      processor_(new ActionProcessor()) {
}

UpdateAttempterAndroid::~UpdateAttempterAndroid() {
  // Release ourselves as the ActionProcessor's delegate to prevent
  // re-scheduling the updates due to the processing stopped.
  processor_->set_delegate(nullptr);
}

void UpdateAttempterAndroid::Init() {
  // In case of update_engine restart without a reboot we need to restore the
  // reboot needed state.
  if (UpdateCompletedOnThisBoot())
    SetStatusAndNotify(UpdateStatus::UPDATED_NEED_REBOOT);
  else
    SetStatusAndNotify(UpdateStatus::IDLE);
}

bool UpdateAttempterAndroid::ApplyPayload(
    const string& payload_url,
    int64_t payload_offset,
    int64_t payload_size,
    const vector<string>& key_value_pair_headers,
    brillo::ErrorPtr* error) {
  if (status_ == UpdateStatus::UPDATED_NEED_REBOOT) {
    return LogAndSetError(
        error, FROM_HERE, "An update already applied, waiting for reboot");
  }
  if (ongoing_update_) {
    return LogAndSetError(
        error, FROM_HERE, "Already processing an update, cancel it first.");
  }
  DCHECK(status_ == UpdateStatus::IDLE);

  std::map<string, string> headers;
  for (const string& key_value_pair : key_value_pair_headers) {
    string key;
    string value;
    if (!brillo::string_utils::SplitAtFirst(
            key_value_pair, "=", &key, &value, false)) {
      return LogAndSetError(
          error, FROM_HERE, "Passed invalid header: " + key_value_pair);
    }
    if (!headers.emplace(key, value).second)
      return LogAndSetError(error, FROM_HERE, "Passed repeated key: " + key);
  }

  // Unique identifier for the payload. An empty string means that the payload
  // can't be resumed.
  string payload_id = (headers[kPayloadPropertyFileHash] +
                       headers[kPayloadPropertyMetadataHash]);

  // Setup the InstallPlan based on the request.
  install_plan_ = InstallPlan();

  install_plan_.download_url = payload_url;
  install_plan_.version = "";
  base_offset_ = payload_offset;
  install_plan_.payload_size = payload_size;
  if (!install_plan_.payload_size) {
    if (!base::StringToUint64(headers[kPayloadPropertyFileSize],
                              &install_plan_.payload_size)) {
      install_plan_.payload_size = 0;
    }
  }
  install_plan_.payload_hash = headers[kPayloadPropertyFileHash];
  if (!base::StringToUint64(headers[kPayloadPropertyMetadataSize],
                            &install_plan_.metadata_size)) {
    install_plan_.metadata_size = 0;
  }
  install_plan_.metadata_signature = "";
  // The |public_key_rsa| key would override the public key stored on disk.
  install_plan_.public_key_rsa = "";

  install_plan_.hash_checks_mandatory = hardware_->IsOfficialBuild();
  install_plan_.is_resume = !payload_id.empty() &&
                            DeltaPerformer::CanResumeUpdate(prefs_, payload_id);
  if (!install_plan_.is_resume) {
    if (!DeltaPerformer::ResetUpdateProgress(prefs_, false)) {
      LOG(WARNING) << "Unable to reset the update progress.";
    }
    if (!prefs_->SetString(kPrefsUpdateCheckResponseHash, payload_id)) {
      LOG(WARNING) << "Unable to save the update check response hash.";
    }
  }
  // The |payload_type| is not used anymore since minor_version 3.
  install_plan_.payload_type = InstallPayloadType::kUnknown;

  install_plan_.source_slot = boot_control_->GetCurrentSlot();
  install_plan_.target_slot = install_plan_.source_slot == 0 ? 1 : 0;
  install_plan_.powerwash_required = false;

  LOG(INFO) << "Using this install plan:";
  install_plan_.Dump();

  BuildUpdateActions();
  SetupDownload();
  cpu_limiter_.StartLimiter();
  SetStatusAndNotify(UpdateStatus::UPDATE_AVAILABLE);

  // Just in case we didn't update boot flags yet, make sure they're updated
  // before any update processing starts. This will start the update process.
  UpdateBootFlags();
  return true;
}

bool UpdateAttempterAndroid::SuspendUpdate(brillo::ErrorPtr* error) {
  // TODO(deymo): Implement suspend/resume.
  return LogAndSetError(error, FROM_HERE, "Suspend/resume not implemented");
}

bool UpdateAttempterAndroid::ResumeUpdate(brillo::ErrorPtr* error) {
  // TODO(deymo): Implement suspend/resume.
  return LogAndSetError(error, FROM_HERE, "Suspend/resume not implemented");
}

bool UpdateAttempterAndroid::CancelUpdate(brillo::ErrorPtr* error) {
  if (status_ == UpdateStatus::IDLE ||
      status_ == UpdateStatus::UPDATED_NEED_REBOOT) {
    return LogAndSetError(error, FROM_HERE, "No ongoing update to cancel.");
  }

  // TODO(deymo): Implement cancel.
  return LogAndSetError(error, FROM_HERE, "Cancel not implemented");
}

bool UpdateAttempterAndroid::ResetStatus(brillo::ErrorPtr* error) {
  LOG(INFO) << "Attempting to reset state from "
            << UpdateStatusToString(status_) << " to UpdateStatus::IDLE";

  switch (status_) {
    case UpdateStatus::IDLE:
      return true;

    case UpdateStatus::UPDATED_NEED_REBOOT:  {
      // Remove the reboot marker so that if the machine is rebooted
      // after resetting to idle state, it doesn't go back to
      // UpdateStatus::UPDATED_NEED_REBOOT state.
      bool ret_value = prefs_->Delete(kPrefsUpdateCompletedOnBootId);

      // Update the boot flags so the current slot has higher priority.
      if (!boot_control_->SetActiveBootSlot(boot_control_->GetCurrentSlot()))
        ret_value = false;

      if (!ret_value) {
        return LogAndSetError(
            error,
            FROM_HERE,
            "Failed to reset the status to ");
      }

      SetStatusAndNotify(UpdateStatus::IDLE);
      LOG(INFO) << "Reset status successful";
      return true;
    }

    default:
      return LogAndSetError(
          error,
          FROM_HERE,
          "Reset not allowed in this state. Cancel the ongoing update first");
  }
}

void UpdateAttempterAndroid::ProcessingDone(const ActionProcessor* processor,
                                            ErrorCode code) {
  LOG(INFO) << "Processing Done.";

  if (code == ErrorCode::kSuccess) {
    // Update succeeded.
    WriteUpdateCompletedMarker();
    prefs_->SetInt64(kPrefsDeltaUpdateFailures, 0);
    DeltaPerformer::ResetUpdateProgress(prefs_, false);

    LOG(INFO) << "Update successfully applied, waiting to reboot.";
  }

  TerminateUpdateAndNotify(code);
}

void UpdateAttempterAndroid::ProcessingStopped(
    const ActionProcessor* processor) {
  TerminateUpdateAndNotify(ErrorCode::kUserCanceled);
}

void UpdateAttempterAndroid::ActionCompleted(ActionProcessor* processor,
                                             AbstractAction* action,
                                             ErrorCode code) {
  // Reset download progress regardless of whether or not the download
  // action succeeded.
  const string type = action->Type();
  if (type == DownloadAction::StaticType()) {
    download_progress_ = 0.0;
  }
  if (code != ErrorCode::kSuccess) {
    // If an action failed, the ActionProcessor will cancel the whole thing.
    return;
  }
  if (type == DownloadAction::StaticType()) {
    SetStatusAndNotify(UpdateStatus::FINALIZING);
  }
}

void UpdateAttempterAndroid::BytesReceived(uint64_t bytes_progressed,
                                           uint64_t bytes_received,
                                           uint64_t total) {
  double progress = 0.;
  if (total)
    progress = static_cast<double>(bytes_received) / static_cast<double>(total);
  // Self throttle based on progress. Also send notifications if
  // progress is too slow.
  const double kDeltaPercent = 0.01;  // 1%
  if (status_ != UpdateStatus::DOWNLOADING || bytes_received == total ||
      progress - download_progress_ >= kDeltaPercent ||
      TimeTicks::Now() - last_notify_time_ >= TimeDelta::FromSeconds(10)) {
    download_progress_ = progress;
    SetStatusAndNotify(UpdateStatus::DOWNLOADING);
  }
}

bool UpdateAttempterAndroid::ShouldCancel(ErrorCode* cancel_reason) {
  // TODO(deymo): Notify the DownloadAction that it should cancel the update
  // download.
  return false;
}

void UpdateAttempterAndroid::DownloadComplete() {
  // Nothing needs to be done when the download completes.
}

void UpdateAttempterAndroid::UpdateBootFlags() {
  if (updated_boot_flags_) {
    LOG(INFO) << "Already updated boot flags. Skipping.";
    CompleteUpdateBootFlags(true);
    return;
  }
  // This is purely best effort.
  LOG(INFO) << "Marking booted slot as good.";
  if (!boot_control_->MarkBootSuccessfulAsync(
          Bind(&UpdateAttempterAndroid::CompleteUpdateBootFlags,
               base::Unretained(this)))) {
    LOG(ERROR) << "Failed to mark current boot as successful.";
    CompleteUpdateBootFlags(false);
  }
}

void UpdateAttempterAndroid::CompleteUpdateBootFlags(bool successful) {
  updated_boot_flags_ = true;
  ScheduleProcessingStart();
}

void UpdateAttempterAndroid::ScheduleProcessingStart() {
  LOG(INFO) << "Scheduling an action processor start.";
  brillo::MessageLoop::current()->PostTask(
      FROM_HERE, Bind([this] { this->processor_->StartProcessing(); }));
}

void UpdateAttempterAndroid::TerminateUpdateAndNotify(ErrorCode error_code) {
  if (status_ == UpdateStatus::IDLE) {
    LOG(ERROR) << "No ongoing update, but TerminatedUpdate() called.";
    return;
  }

  // Reset cpu shares back to normal.
  cpu_limiter_.StopLimiter();
  download_progress_ = 0.0;
  actions_.clear();
  UpdateStatus new_status =
      (error_code == ErrorCode::kSuccess ? UpdateStatus::UPDATED_NEED_REBOOT
                                         : UpdateStatus::IDLE);
  SetStatusAndNotify(new_status);
  ongoing_update_ = false;

  for (auto observer : daemon_state_->service_observers())
    observer->SendPayloadApplicationComplete(error_code);
}

void UpdateAttempterAndroid::SetStatusAndNotify(UpdateStatus status) {
  status_ = status;
  for (auto observer : daemon_state_->service_observers()) {
    observer->SendStatusUpdate(
        0, download_progress_, status_, "", install_plan_.payload_size);
  }
  last_notify_time_ = TimeTicks::Now();
}

void UpdateAttempterAndroid::BuildUpdateActions() {
  CHECK(!processor_->IsRunning());
  processor_->set_delegate(this);

  // Actions:
  shared_ptr<InstallPlanAction> install_plan_action(
      new InstallPlanAction(install_plan_));

  LibcurlHttpFetcher* download_fetcher =
      new LibcurlHttpFetcher(&proxy_resolver_, hardware_);
  download_fetcher->set_server_to_check(ServerToCheck::kDownload);
  shared_ptr<DownloadAction> download_action(new DownloadAction(
      prefs_,
      boot_control_,
      hardware_,
      nullptr,                                        // system_state, not used.
      new MultiRangeHttpFetcher(download_fetcher)));  // passes ownership
  shared_ptr<FilesystemVerifierAction> dst_filesystem_verifier_action(
      new FilesystemVerifierAction(boot_control_,
                                   VerifierMode::kVerifyTargetHash));

  shared_ptr<PostinstallRunnerAction> postinstall_runner_action(
      new PostinstallRunnerAction(boot_control_));

  download_action->set_delegate(this);
  download_action_ = download_action;

  actions_.push_back(shared_ptr<AbstractAction>(install_plan_action));
  actions_.push_back(shared_ptr<AbstractAction>(download_action));
  actions_.push_back(
      shared_ptr<AbstractAction>(dst_filesystem_verifier_action));
  actions_.push_back(shared_ptr<AbstractAction>(postinstall_runner_action));

  // Bond them together. We have to use the leaf-types when calling
  // BondActions().
  BondActions(install_plan_action.get(), download_action.get());
  BondActions(download_action.get(), dst_filesystem_verifier_action.get());
  BondActions(dst_filesystem_verifier_action.get(),
              postinstall_runner_action.get());

  // Enqueue the actions.
  for (const shared_ptr<AbstractAction>& action : actions_)
    processor_->EnqueueAction(action.get());
}

void UpdateAttempterAndroid::SetupDownload() {
  MultiRangeHttpFetcher* fetcher =
      static_cast<MultiRangeHttpFetcher*>(download_action_->http_fetcher());
  fetcher->ClearRanges();
  if (install_plan_.is_resume) {
    // Resuming an update so fetch the update manifest metadata first.
    int64_t manifest_metadata_size = 0;
    prefs_->GetInt64(kPrefsManifestMetadataSize, &manifest_metadata_size);
    fetcher->AddRange(base_offset_, manifest_metadata_size);
    // If there're remaining unprocessed data blobs, fetch them. Be careful not
    // to request data beyond the end of the payload to avoid 416 HTTP response
    // error codes.
    int64_t next_data_offset = 0;
    prefs_->GetInt64(kPrefsUpdateStateNextDataOffset, &next_data_offset);
    uint64_t resume_offset = manifest_metadata_size + next_data_offset;
    if (!install_plan_.payload_size) {
      fetcher->AddRange(base_offset_ + resume_offset);
    } else if (resume_offset < install_plan_.payload_size) {
      fetcher->AddRange(base_offset_ + resume_offset,
                        install_plan_.payload_size - resume_offset);
    }
  } else {
    if (install_plan_.payload_size) {
      fetcher->AddRange(base_offset_, install_plan_.payload_size);
    } else {
      // If no payload size is passed we assume we read until the end of the
      // stream.
      fetcher->AddRange(base_offset_);
    }
  }
}

bool UpdateAttempterAndroid::WriteUpdateCompletedMarker() {
  string boot_id;
  TEST_AND_RETURN_FALSE(utils::GetBootId(&boot_id));
  prefs_->SetString(kPrefsUpdateCompletedOnBootId, boot_id);
  return true;
}

bool UpdateAttempterAndroid::UpdateCompletedOnThisBoot() {
  // In case of an update_engine restart without a reboot, we stored the boot_id
  // when the update was completed by setting a pref, so we can check whether
  // the last update was on this boot or a previous one.
  string boot_id;
  TEST_AND_RETURN_FALSE(utils::GetBootId(&boot_id));

  string update_completed_on_boot_id;
  return (prefs_->Exists(kPrefsUpdateCompletedOnBootId) &&
          prefs_->GetString(kPrefsUpdateCompletedOnBootId,
                            &update_completed_on_boot_id) &&
          update_completed_on_boot_id == boot_id);
}

}  // namespace chromeos_update_engine