// 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.

#include "chrome/browser/web_applications/web_app_sync_bridge.h"

#include <memory>
#include <vector>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/callback.h"
#include "base/containers/flat_set.h"
#include "base/logging.h"
#include "base/optional.h"
#include "base/util/type_safety/pass_key.h"
#include "chrome/browser/web_applications/components/web_app_helpers.h"
#include "chrome/browser/web_applications/web_app.h"
#include "chrome/browser/web_applications/web_app_database.h"
#include "chrome/browser/web_applications/web_app_database_factory.h"
#include "chrome/browser/web_applications/web_app_registry_update.h"
#include "chrome/browser/web_applications/web_app_sync_install_delegate.h"
#include "chrome/common/channel_info.h"
#include "components/sync/base/model_type.h"
#include "components/sync/base/report_unrecoverable_error.h"
#include "components/sync/model/metadata_batch.h"
#include "components/sync/model/metadata_change_list.h"
#include "components/sync/model/model_type_store.h"
#include "components/sync/model/mutable_data_batch.h"
#include "components/sync/model_impl/client_tag_based_model_type_processor.h"
#include "components/sync/protocol/web_app_specifics.pb.h"
#include "url/gurl.h"

namespace web_app {

bool AreAppsLocallyInstalledByDefault() {
#if defined(OS_CHROMEOS)
  // On Chrome OS, sync always locally installs an app.
  return true;
#else
  return false;
#endif
}

std::unique_ptr<syncer::EntityData> CreateSyncEntityData(const WebApp& app) {
  auto entity_data = std::make_unique<syncer::EntityData>();
  entity_data->name = app.name();

  sync_pb::WebAppSpecifics* sync_data =
      entity_data->specifics.mutable_web_app();
  sync_data->set_launch_url(app.launch_url().spec());
  sync_data->set_user_display_mode(
      ToWebAppSpecificsUserDisplayMode(app.user_display_mode()));
  sync_data->set_name(app.sync_data().name);
  if (app.sync_data().theme_color.has_value())
    sync_data->set_theme_color(app.sync_data().theme_color.value());

  return entity_data;
}

void ApplySyncDataToApp(const sync_pb::WebAppSpecifics& sync_data,
                        WebApp* app) {
  app->AddSource(Source::kSync);

  // app_id is a hash of launch_url. Parse launch_url first:
  GURL launch_url(sync_data.launch_url());
  if (launch_url.is_empty() || !launch_url.is_valid()) {
    DLOG(ERROR) << "ApplySyncDataToApp: launch_url parse error.";
    return;
  }
  if (app->app_id() != GenerateAppIdFromURL(launch_url)) {
    DLOG(ERROR) << "ApplySyncDataToApp: app_id doesn't match launch_url.";
    return;
  }

  if (app->launch_url().is_empty()) {
    app->SetLaunchUrl(std::move(launch_url));
  } else if (app->launch_url() != launch_url) {
    DLOG(ERROR)
        << "ApplySyncDataToApp: existing launch_url doesn't match launch_url.";
    return;
  }

  // Always override user_display mode with a synced value.
  app->SetUserDisplayMode(ToMojomDisplayMode(sync_data.user_display_mode()));

  WebApp::SyncData parsed_sync_data;
  parsed_sync_data.name = sync_data.name();
  if (sync_data.has_theme_color())
    parsed_sync_data.theme_color = sync_data.theme_color();
  app->SetSyncData(std::move(parsed_sync_data));
}

WebAppSyncBridge::WebAppSyncBridge(
    Profile* profile,
    AbstractWebAppDatabaseFactory* database_factory,
    WebAppRegistrarMutable* registrar,
    SyncInstallDelegate* install_delegate)
    : WebAppSyncBridge(
          profile,
          database_factory,
          registrar,
          install_delegate,
          std::make_unique<syncer::ClientTagBasedModelTypeProcessor>(
              syncer::WEB_APPS,
              base::BindRepeating(&syncer::ReportUnrecoverableError,
                                  chrome::GetChannel()))) {}

WebAppSyncBridge::WebAppSyncBridge(
    Profile* profile,
    AbstractWebAppDatabaseFactory* database_factory,
    WebAppRegistrarMutable* registrar,
    SyncInstallDelegate* install_delegate,
    std::unique_ptr<syncer::ModelTypeChangeProcessor> change_processor)
    : AppRegistryController(profile),
      syncer::ModelTypeSyncBridge(std::move(change_processor)),
      registrar_(registrar),
      install_delegate_(install_delegate) {
  DCHECK(database_factory);
  DCHECK(registrar_);
  database_ = std::make_unique<WebAppDatabase>(
      database_factory,
      base::BindRepeating(&WebAppSyncBridge::ReportErrorToChangeProcessor,
                          base::Unretained(this)));
}

WebAppSyncBridge::~WebAppSyncBridge() = default;

std::unique_ptr<WebAppRegistryUpdate> WebAppSyncBridge::BeginUpdate() {
  DCHECK(!is_in_update_);
  is_in_update_ = true;
  return std::make_unique<WebAppRegistryUpdate>(
      registrar_, util::PassKey<WebAppSyncBridge>());
}

void WebAppSyncBridge::CommitUpdate(
    std::unique_ptr<WebAppRegistryUpdate> update,
    CommitCallback callback) {
  DCHECK(is_in_update_);
  is_in_update_ = false;

  if (update == nullptr || update->update_data().IsEmpty()) {
    std::move(callback).Run(/*success*/ true);
    return;
  }

  CheckRegistryUpdateData(update->update_data());

  std::unique_ptr<RegistryUpdateData> update_data = update->TakeUpdateData();
  std::unique_ptr<syncer::MetadataChangeList> metadata_change_list =
      CreateMetadataChangeList();

  UpdateSync(*update_data, metadata_change_list.get());

  database_->Write(
      *update_data, std::move(metadata_change_list),
      base::BindOnce(&WebAppSyncBridge::OnDataWritten,
                     weak_ptr_factory_.GetWeakPtr(), std::move(callback)));

  UpdateRegistrar(std::move(update_data));
}

void WebAppSyncBridge::Init(base::OnceClosure callback) {
  database_->OpenDatabase(base::BindOnce(&WebAppSyncBridge::OnDatabaseOpened,
                                         weak_ptr_factory_.GetWeakPtr(),
                                         std::move(callback)));
}

void WebAppSyncBridge::SetAppUserDisplayMode(const AppId& app_id,
                                             DisplayMode user_display_mode) {
  ScopedRegistryUpdate update(this);
  WebApp* web_app = update->UpdateApp(app_id);
  if (web_app)
    web_app->SetUserDisplayMode(user_display_mode);
}

void WebAppSyncBridge::SetAppIsLocallyInstalledForTesting(
    const AppId& app_id,
    bool is_locally_installed) {
  ScopedRegistryUpdate update(this);
  WebApp* web_app = update->UpdateApp(app_id);
  if (web_app)
    web_app->SetIsLocallyInstalled(is_locally_installed);
}

WebAppSyncBridge* WebAppSyncBridge::AsWebAppSyncBridge() {
  return this;
}

void WebAppSyncBridge::CheckRegistryUpdateData(
    const RegistryUpdateData& update_data) const {
#if DCHECK_IS_ON()
  for (const std::unique_ptr<WebApp>& web_app : update_data.apps_to_create)
    DCHECK(!registrar_->GetAppById(web_app->app_id()));

  for (const std::unique_ptr<WebApp>& web_app : update_data.apps_to_update)
    DCHECK(registrar_->GetAppById(web_app->app_id()));

  for (const AppId& app_id : update_data.apps_to_delete)
    DCHECK(registrar_->GetAppById(app_id));
#endif
}

std::vector<std::unique_ptr<WebApp>> WebAppSyncBridge::UpdateRegistrar(
    std::unique_ptr<RegistryUpdateData> update_data) {
  registrar_->CountMutation();

  std::vector<std::unique_ptr<WebApp>> apps_unregistered;

  for (std::unique_ptr<WebApp>& web_app : update_data->apps_to_create) {
    AppId app_id = web_app->app_id();
    DCHECK(!registrar_->GetAppById(app_id));
    registrar_->registry().emplace(std::move(app_id), std::move(web_app));
  }

  for (std::unique_ptr<WebApp>& web_app : update_data->apps_to_update) {
    WebApp* original_web_app = registrar_->GetAppByIdMutable(web_app->app_id());
    DCHECK(original_web_app);
    // Commit previously created copy into original. Preserve original web_app
    // object pointer value (the object's identity) to support stored pointers.
    *original_web_app = std::move(*web_app);
  }

  for (const AppId& app_id : update_data->apps_to_delete) {
    auto it = registrar_->registry().find(app_id);
    DCHECK(it != registrar_->registry().end());

    apps_unregistered.push_back(std::move(it->second));
    registrar_->registry().erase(it);
  }

  return apps_unregistered;
}

void WebAppSyncBridge::UpdateSync(
    const RegistryUpdateData& update_data,
    syncer::MetadataChangeList* metadata_change_list) {
  // We don't block web app subsystems on WebAppSyncBridge::MergeSyncData: we
  // call WebAppProvider::OnRegistryControllerReady() right after
  // change_processor()->ModelReadyToSync. As a result, subsystems may produce
  // some local changes between OnRegistryControllerReady and MergeSyncData.
  // Return early in this case. The processor cannot do any useful metadata
  // tracking until MergeSyncData is called:
  if (!change_processor()->IsTrackingMetadata())
    return;

  for (const std::unique_ptr<WebApp>& new_app : update_data.apps_to_create) {
    if (new_app->IsSynced()) {
      change_processor()->Put(new_app->app_id(), CreateSyncEntityData(*new_app),
                              metadata_change_list);
    }
  }

  for (const std::unique_ptr<WebApp>& new_state : update_data.apps_to_update) {
    const AppId& app_id = new_state->app_id();
    // Find the current state of the app to be overritten.
    const WebApp* current_state = registrar_->GetAppById(app_id);
    DCHECK(current_state);

    // Include the app in the sync "view" if IsSynced flag becomes true. Update
    // the app if IsSynced flag stays true. Exclude the app from the sync "view"
    // if IsSynced flag becomes false.
    //
    // TODO(loyso): Send an update to sync server only if any sync-specific
    // data was changed. Implement some dirty flags in WebApp setter methods.
    if (new_state->IsSynced()) {
      change_processor()->Put(app_id, CreateSyncEntityData(*new_state),
                              metadata_change_list);
    } else if (current_state->IsSynced()) {
      change_processor()->Delete(app_id, metadata_change_list);
    }
  }

  for (const AppId& app_id_to_delete : update_data.apps_to_delete) {
    const WebApp* current_state = registrar_->GetAppById(app_id_to_delete);
    DCHECK(current_state);
    // Exclude the app from the sync "view" if IsSynced flag was true.
    if (current_state->IsSynced())
      change_processor()->Delete(app_id_to_delete, metadata_change_list);
  }
}

void WebAppSyncBridge::OnDatabaseOpened(
    base::OnceClosure callback,
    Registry registry,
    std::unique_ptr<syncer::MetadataBatch> metadata_batch) {
  // Provide sync metadata to the processor _before_ any local changes occur.
  change_processor()->ModelReadyToSync(std::move(metadata_batch));

  registrar_->InitRegistry(std::move(registry));
  std::move(callback).Run();

  MaybeInstallAppsInSyncInstall();
}

void WebAppSyncBridge::OnDataWritten(CommitCallback callback, bool success) {
  if (!success)
    DLOG(ERROR) << "WebAppSyncBridge commit failed";

  std::move(callback).Run(success);
}

void WebAppSyncBridge::ReportErrorToChangeProcessor(
    const syncer::ModelError& error) {
  change_processor()->ReportError(error);
}

void WebAppSyncBridge::MergeLocalAppsToSync(
    const syncer::EntityChangeList& entity_data,
    syncer::MetadataChangeList* metadata_change_list) {
  // Build a helper set of the sync server apps to speed up lookups. The
  // flat_set will reuse the underlying memory of this vector. app_id is storage
  // key.
  std::vector<AppId> storage_keys;
  storage_keys.reserve(entity_data.size());
  for (const auto& change : entity_data)
    storage_keys.push_back(change->storage_key());
  // Sort only once.
  base::flat_set<AppId> sync_server_apps(std::move(storage_keys));

  for (const WebApp& app : registrar_->AllApps()) {
    if (!app.IsSynced())
      continue;

    bool exists_remotely = sync_server_apps.contains(app.app_id());
    if (!exists_remotely) {
      change_processor()->Put(app.app_id(), CreateSyncEntityData(app),
                              metadata_change_list);
    }
  }
}

void WebAppSyncBridge::ApplySyncDataChange(
    const syncer::EntityChange& change,
    RegistryUpdateData* update_local_data) {
  // app_id is storage key.
  const AppId& app_id = change.storage_key();

  const WebApp* existing_web_app = registrar_->GetAppByIdMutable(app_id);

  // Handle deletion first.
  if (change.type() == syncer::EntityChange::ACTION_DELETE) {
    if (!existing_web_app) {
      DLOG(ERROR) << "ApplySyncDataChange error: no app to delete";
      return;
    }
    // Do copy on write:
    auto app_copy = std::make_unique<WebApp>(*existing_web_app);
    app_copy->RemoveSource(Source::kSync);

    if (app_copy->HasAnySources())
      update_local_data->apps_to_update.push_back(std::move(app_copy));
    else
      update_local_data->apps_to_delete.push_back(app_id);

    return;
  }

  // Handle EntityChange::ACTION_ADD and EntityChange::ACTION_UPDATE.
  DCHECK(change.data().specifics.has_web_app());
  const sync_pb::WebAppSpecifics& specifics = change.data().specifics.web_app();

  if (existing_web_app) {
    // Any entities that appear in both sets must be merged.
    // Do copy on write:
    auto app_copy = std::make_unique<WebApp>(*existing_web_app);
    ApplySyncDataToApp(specifics, app_copy.get());
    // Preserve web_app->is_locally_installed user's choice here.

    update_local_data->apps_to_update.push_back(std::move(app_copy));
  } else {
    // Any remote entities that don’t exist locally must be written to local
    // storage.
    auto web_app = std::make_unique<WebApp>(app_id);

    // Request a followup sync-initiated install for this stub app to fetch
    // full local data and all the icons.
    web_app->SetIsInSyncInstall(true);

    ApplySyncDataToApp(specifics, web_app.get());

    // For a new app, automatically choose if we want to install it locally.
    web_app->SetIsLocallyInstalled(AreAppsLocallyInstalledByDefault());

    update_local_data->apps_to_create.push_back(std::move(web_app));
  }
}

void WebAppSyncBridge::ApplySyncChangesToRegistrar(
    std::unique_ptr<RegistryUpdateData> update_local_data) {
  if (update_local_data->IsEmpty())
    return;

  std::vector<WebApp*> apps_to_install;
  for (const auto& web_app : update_local_data->apps_to_create)
    apps_to_install.push_back(web_app.get());

  std::vector<std::unique_ptr<WebApp>> apps_unregistered =
      UpdateRegistrar(std::move(update_local_data));

  // Do a full follow up install for all remote entities that don’t exist
  // locally.
  if (!apps_to_install.empty()) {
    install_delegate_->InstallWebAppsAfterSync(std::move(apps_to_install),
                                               base::DoNothing());
  }

  // Do a full follow up uninstall for all deleted remote entities that exist
  // locally and not needed by other sources. We need to clean up disk data
  // (icons).
  if (!apps_unregistered.empty()) {
    install_delegate_->UninstallWebAppsAfterSync(std::move(apps_unregistered),
                                                 base::DoNothing());
  }
}

std::unique_ptr<syncer::MetadataChangeList>
WebAppSyncBridge::CreateMetadataChangeList() {
  return syncer::ModelTypeStore::WriteBatch::CreateMetadataChangeList();
}

base::Optional<syncer::ModelError> WebAppSyncBridge::MergeSyncData(
    std::unique_ptr<syncer::MetadataChangeList> metadata_change_list,
    syncer::EntityChangeList entity_data) {
  CHECK(change_processor()->IsTrackingMetadata());

  auto update_local_data = std::make_unique<RegistryUpdateData>();

  for (const auto& change : entity_data) {
    DCHECK_NE(change->type(), syncer::EntityChange::ACTION_DELETE);
    ApplySyncDataChange(*change, update_local_data.get());
  }

  MergeLocalAppsToSync(entity_data, metadata_change_list.get());

  database_->Write(*update_local_data, std::move(metadata_change_list),
                   base::DoNothing());

  ApplySyncChangesToRegistrar(std::move(update_local_data));
  return base::nullopt;
}

base::Optional<syncer::ModelError> WebAppSyncBridge::ApplySyncChanges(
    std::unique_ptr<syncer::MetadataChangeList> metadata_change_list,
    syncer::EntityChangeList entity_changes) {
  CHECK(change_processor()->IsTrackingMetadata());

  auto update_local_data = std::make_unique<RegistryUpdateData>();

  for (const auto& change : entity_changes)
    ApplySyncDataChange(*change, update_local_data.get());

  database_->Write(*update_local_data, std::move(metadata_change_list),
                   base::DoNothing());

  ApplySyncChangesToRegistrar(std::move(update_local_data));
  return base::nullopt;
}

void WebAppSyncBridge::GetData(StorageKeyList storage_keys,
                               DataCallback callback) {
  auto data_batch = std::make_unique<syncer::MutableDataBatch>();

  for (const AppId& app_id : storage_keys) {
    const WebApp* app = registrar_->GetAppById(app_id);
    if (app && app->IsSynced())
      data_batch->Put(app->app_id(), CreateSyncEntityData(*app));
  }

  std::move(callback).Run(std::move(data_batch));
}

void WebAppSyncBridge::GetAllDataForDebugging(DataCallback callback) {
  auto data_batch = std::make_unique<syncer::MutableDataBatch>();

  for (const WebApp& app : registrar_->AllApps()) {
    if (app.IsSynced())
      data_batch->Put(app.app_id(), CreateSyncEntityData(app));
  }

  std::move(callback).Run(std::move(data_batch));
}

std::string WebAppSyncBridge::GetClientTag(
    const syncer::EntityData& entity_data) {
  DCHECK(entity_data.specifics.has_web_app());

  const GURL launch_url(entity_data.specifics.web_app().launch_url());
  DCHECK(!launch_url.is_empty());
  DCHECK(launch_url.is_valid());

  return GenerateAppIdFromURL(launch_url);
}

std::string WebAppSyncBridge::GetStorageKey(
    const syncer::EntityData& entity_data) {
  return GetClientTag(entity_data);
}

void WebAppSyncBridge::MaybeInstallAppsInSyncInstall() {
  std::vector<WebApp*> apps_in_sync_install;

  for (WebApp& app : registrar_->AllAppsMutable()) {
    if (app.is_in_sync_install())
      apps_in_sync_install.push_back(&app);
  }

  if (!apps_in_sync_install.empty()) {
    install_delegate_->InstallWebAppsAfterSync(std::move(apps_in_sync_install),
                                               base::DoNothing());
  }
}

}  // namespace web_app