// Copyright 2018 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.

#include "components/unified_consent/url_keyed_data_collection_consent_helper.h"

#include "base/bind.h"
#include "components/prefs/pref_change_registrar.h"
#include "components/prefs/pref_service.h"
#include "components/sync/base/model_type.h"
#include "components/sync/driver/sync_service.h"
#include "components/sync/driver/sync_service_observer.h"
#include "components/sync/driver/sync_service_utils.h"
#include "components/unified_consent/pref_names.h"

namespace unified_consent {

namespace {

class PrefBasedUrlKeyedDataCollectionConsentHelper
    : public UrlKeyedDataCollectionConsentHelper {
 public:
  explicit PrefBasedUrlKeyedDataCollectionConsentHelper(
      PrefService* pref_service);
  ~PrefBasedUrlKeyedDataCollectionConsentHelper() override = default;

  // UrlKeyedDataCollectionConsentHelper:
  bool IsEnabled() override;

 private:
  void OnPrefChanged();
  PrefService* pref_service_;  // weak (must outlive this)
  PrefChangeRegistrar pref_change_registrar_;

  DISALLOW_COPY_AND_ASSIGN(PrefBasedUrlKeyedDataCollectionConsentHelper);
};

class SyncBasedUrlKeyedDataCollectionConsentHelper
    : public UrlKeyedDataCollectionConsentHelper,
      syncer::SyncServiceObserver {
 public:
  SyncBasedUrlKeyedDataCollectionConsentHelper(
      syncer::SyncService* sync_service,
      syncer::ModelType sync_data_type);
  ~SyncBasedUrlKeyedDataCollectionConsentHelper() override;

  // UrlKeyedDataCollectionConsentHelper:
  bool IsEnabled() override;

  // syncer::SyncServiceObserver:
  void OnStateChanged(syncer::SyncService* sync) override;
  void OnSyncShutdown(syncer::SyncService* sync) override;

 private:
  syncer::SyncService* sync_service_;
  syncer::ModelType sync_data_type_;
  syncer::UploadState sync_data_type_upload_state_;

  DISALLOW_COPY_AND_ASSIGN(SyncBasedUrlKeyedDataCollectionConsentHelper);
};

PrefBasedUrlKeyedDataCollectionConsentHelper::
    PrefBasedUrlKeyedDataCollectionConsentHelper(PrefService* pref_service)
    : pref_service_(pref_service) {
  pref_change_registrar_.Init(pref_service_);
  pref_change_registrar_.Add(
      prefs::kUrlKeyedAnonymizedDataCollectionEnabled,
      base::BindRepeating(
          &PrefBasedUrlKeyedDataCollectionConsentHelper::OnPrefChanged,
          base::Unretained(this)));
}

bool PrefBasedUrlKeyedDataCollectionConsentHelper::IsEnabled() {
  return pref_service_->GetBoolean(
      prefs::kUrlKeyedAnonymizedDataCollectionEnabled);
}

void PrefBasedUrlKeyedDataCollectionConsentHelper::OnPrefChanged() {
  FireOnStateChanged();
}

SyncBasedUrlKeyedDataCollectionConsentHelper::
    SyncBasedUrlKeyedDataCollectionConsentHelper(
        syncer::SyncService* sync_service,
        syncer::ModelType sync_data_type)
    : sync_service_(sync_service),
      sync_data_type_(sync_data_type),
      sync_data_type_upload_state_(
          syncer::GetUploadToGoogleState(sync_service_, sync_data_type_)) {
  DCHECK(sync_service_);
  sync_service_->AddObserver(this);
}

SyncBasedUrlKeyedDataCollectionConsentHelper::
    ~SyncBasedUrlKeyedDataCollectionConsentHelper() {
  if (sync_service_)
    sync_service_->RemoveObserver(this);
}

bool SyncBasedUrlKeyedDataCollectionConsentHelper::IsEnabled() {
  return sync_data_type_upload_state_ == syncer::UploadState::ACTIVE;
}

void SyncBasedUrlKeyedDataCollectionConsentHelper::OnStateChanged(
    syncer::SyncService* sync_service) {
  DCHECK_EQ(sync_service_, sync_service);
  bool enabled_before_state_updated = IsEnabled();
  sync_data_type_upload_state_ =
      syncer::GetUploadToGoogleState(sync_service_, sync_data_type_);

  if (enabled_before_state_updated != IsEnabled())
    FireOnStateChanged();
}

void SyncBasedUrlKeyedDataCollectionConsentHelper::OnSyncShutdown(
    syncer::SyncService* sync_service) {
  DCHECK_EQ(sync_service_, sync_service);
  sync_service_->RemoveObserver(this);
  sync_service_ = nullptr;
}

}  // namespace

UrlKeyedDataCollectionConsentHelper::UrlKeyedDataCollectionConsentHelper() =
    default;
UrlKeyedDataCollectionConsentHelper::~UrlKeyedDataCollectionConsentHelper() =
    default;

// static
std::unique_ptr<UrlKeyedDataCollectionConsentHelper>
UrlKeyedDataCollectionConsentHelper::NewAnonymizedDataCollectionConsentHelper(
    bool is_unified_consent_enabled,
    PrefService* pref_service,
    syncer::SyncService* sync_service) {
  if (is_unified_consent_enabled) {
    return std::make_unique<PrefBasedUrlKeyedDataCollectionConsentHelper>(
        pref_service);
  }

  return std::make_unique<SyncBasedUrlKeyedDataCollectionConsentHelper>(
      sync_service, syncer::ModelType::HISTORY_DELETE_DIRECTIVES);
}

// static
std::unique_ptr<UrlKeyedDataCollectionConsentHelper>
UrlKeyedDataCollectionConsentHelper::NewPersonalizedDataCollectionConsentHelper(
    bool is_unified_consent_enabled,
    syncer::SyncService* sync_service) {
  syncer::ModelType sync_type =
      is_unified_consent_enabled ? syncer::ModelType::USER_EVENTS
                                 : syncer::ModelType::HISTORY_DELETE_DIRECTIVES;
  return std::make_unique<SyncBasedUrlKeyedDataCollectionConsentHelper>(
      sync_service, sync_type);
}

void UrlKeyedDataCollectionConsentHelper::AddObserver(Observer* observer) {
  observer_list_.AddObserver(observer);
}
void UrlKeyedDataCollectionConsentHelper::RemoveObserver(Observer* observer) {
  observer_list_.RemoveObserver(observer);
}

void UrlKeyedDataCollectionConsentHelper::FireOnStateChanged() {
  for (auto& observer : observer_list_)
    observer.OnUrlKeyedDataCollectionConsentStateChanged(this);
}

}  // namespace unified_consent