/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "ServiceWorkerInterceptController.h"

#include "ServiceWorkerManager.h"
#include "mozilla/BasePrincipal.h"
#include "mozilla/StaticPrefs_dom.h"
#include "mozilla/StaticPrefs_privacy.h"
#include "mozilla/StorageAccess.h"
#include "mozilla/StoragePrincipalHelper.h"
#include "mozilla/dom/CanonicalBrowsingContext.h"
#include "mozilla/dom/InternalRequest.h"
#include "mozilla/net/HttpBaseChannel.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nsIChannel.h"
#include "nsICookieJarSettings.h"
#include "nsIPrincipal.h"
#include "nsQueryObject.h"

namespace mozilla::dom {

namespace {
bool IsWithinObjectOrEmbed(const nsCOMPtr<nsILoadInfo>& loadInfo) {
  RefPtr<BrowsingContext> browsingContext;
  loadInfo->GetTargetBrowsingContext(getter_AddRefs(browsingContext));

  for (BrowsingContext* cur = browsingContext.get(); cur;
       cur = cur->GetParent()) {
    if (cur->IsEmbedderTypeObjectOrEmbed()) {
      return true;
    }
  }

  return false;
}
}  // namespace

NS_IMPL_ISUPPORTS(ServiceWorkerInterceptController,
                  nsINetworkInterceptController)

NS_IMETHODIMP
ServiceWorkerInterceptController::ShouldPrepareForIntercept(
    nsIURI* aURI, nsIChannel* aChannel, bool* aShouldIntercept) {
  *aShouldIntercept = false;

  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->LoadInfo();

  // Block interception if the request's destination is within an object or
  // embed element.
  if (IsWithinObjectOrEmbed(loadInfo)) {
    return NS_OK;
  }

  RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();

  // For subresource requests we base our decision solely on the client's
  // controller value.  Any settings that would have blocked service worker
  // access should have been set before the initial navigation created the
  // window.
  if (!nsContentUtils::IsNonSubresourceRequest(aChannel)) {
    const Maybe<ServiceWorkerDescriptor>& controller =
        loadInfo->GetController();

    // If the controller doesn't handle fetch events, return false
    if (!controller.isSome()) {
      return NS_OK;
    }

    *aShouldIntercept = controller.ref().HandlesFetch();

    // The service worker has no fetch event handler, try to schedule a
    // soft-update through ServiceWorkerRegistrationInfo.
    // Get ServiceWorkerRegistrationInfo by the ServiceWorkerInfo's principal
    // and scope
    if (!*aShouldIntercept && swm) {
      nsCOMPtr<nsIPrincipal> principal =
          controller.ref().GetPrincipal().unwrap();
      RefPtr<ServiceWorkerRegistrationInfo> registration =
          swm->GetRegistration(principal, controller.ref().Scope());
      // Could not get ServiceWorkerRegistration here if unregister is
      // executed before getting here.
      if (NS_WARN_IF(!registration)) {
        return NS_OK;
      }
      registration->MaybeScheduleTimeCheckAndUpdate();
    }

    RequestMode requestMode =
        InternalRequest::MapChannelToRequestMode(aChannel);

    // Block ServiceWorker interception for ranged request from media, see bug
    // 1762078. Other request with Range header would be intercepted, ex.
    // Author-issued fetch() range request.
    RefPtr<net::HttpBaseChannel> httpChannel = do_QueryObject(aChannel);
    if (requestMode == RequestMode::No_cors && loadInfo->GetIsMediaRequest() &&
        httpChannel &&
        httpChannel->GetRequestHead()->HasHeader(net::nsHttp::Range)) {
      bool mayLoad = nsContentUtils::CheckMayLoad(
          loadInfo->GetLoadingPrincipal(), aChannel,
          /*allowIfInheritsPrincipal*/ false);
      if (!mayLoad) {
        *aShouldIntercept = false;
      }
    }

    return NS_OK;
  }

  nsCOMPtr<nsIPrincipal> principal;
  nsresult rv = StoragePrincipalHelper::GetPrincipal(
      aChannel,
      StaticPrefs::privacy_partition_serviceWorkers()
          ? StoragePrincipalHelper::eForeignPartitionedPrincipal
          : StoragePrincipalHelper::eRegularPrincipal,
      getter_AddRefs(principal));
  NS_ENSURE_SUCCESS(rv, rv);

  // First check with the ServiceWorkerManager for a matching service worker.
  if (!swm || !swm->IsAvailable(principal, aURI, aChannel)) {
    return NS_OK;
  }

  // Check if we're in a secure context, unless service worker testing is
  // enabled.
  if (!nsContentUtils::ComputeIsSecureContext(aChannel) &&
      !StaticPrefs::dom_serviceWorkers_testing_enabled()) {
    return NS_OK;
  }

  // Then check to see if we are allowed to control the window.
  // It is important to check for the availability of the service worker first
  // to avoid showing warnings about the use of third-party cookies in the UI
  // unnecessarily when no service worker is being accessed.
  auto storageAccess = StorageAllowedForChannel(aChannel);
  nsCOMPtr<nsICookieJarSettings> cookieJarSettings;
  loadInfo->GetCookieJarSettings(getter_AddRefs(cookieJarSettings));

  *aShouldIntercept =
      storageAccess == StorageAccess::eAllow ||
      (storageAccess == StorageAccess::ePrivateBrowsing &&
       StaticPrefs::dom_serviceWorkers_privateBrowsing_enabled()) ||
      (ShouldPartitionStorage(storageAccess) &&
       StaticPrefs::privacy_partition_serviceWorkers() &&
       StoragePartitioningEnabled(storageAccess, cookieJarSettings) &&
       (!principal->GetIsInPrivateBrowsing() ||
        StaticPrefs::dom_serviceWorkers_privateBrowsing_enabled()));
  return NS_OK;
}

NS_IMETHODIMP
ServiceWorkerInterceptController::ChannelIntercepted(
    nsIInterceptedChannel* aChannel) {
  // Note, do not cancel the interception here.  The caller will try to
  // ResetInterception() on error.

  RefPtr<ServiceWorkerManager> swm = ServiceWorkerManager::GetInstance();
  if (!swm) {
    return NS_ERROR_FAILURE;
  }

  ErrorResult error;
  swm->DispatchFetchEvent(aChannel, error);
  if (NS_WARN_IF(error.Failed())) {
    return error.StealNSResult();
  }

  return NS_OK;
}

}  // namespace mozilla::dom