Signal-Android/app/src/main/java/org/thoughtcrime/securesms/notifications/NotificationCancellationHelper.java

package org.thoughtcrime.securesms.notifications;

import android.app.Notification;
import android.app.NotificationManager;
import android.content.Context;
import android.os.Build;
import android.service.notification.StatusBarNotification;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;

import com.annimon.stream.Stream;

import org.signal.core.util.logging.Log;
import org.thoughtcrime.securesms.database.DatabaseFactory;
import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
import org.thoughtcrime.securesms.recipients.RecipientId;
import org.thoughtcrime.securesms.util.BubbleUtil;
import org.thoughtcrime.securesms.util.ConversationUtil;
import org.thoughtcrime.securesms.util.ServiceUtil;

import java.util.Objects;

/**
 * Consolidates Notification Cancellation logic to one class.
 *
 * Because Bubbles are tied to Notifications, and disappear when those Notificaitons are cancelled,
 * we want to be very surgical about what notifications we dismiss and when. Behaviour on API levels
 * previous to {@link org.thoughtcrime.securesms.util.ConversationUtil#CONVERSATION_SUPPORT_VERSION}
 * is preserved.
 *
 */
public final class NotificationCancellationHelper {

  private static final String TAG = Log.tag(NotificationCancellationHelper.class);

  private NotificationCancellationHelper() {}

  /**
   * Cancels all Message-Based notifications. Specifically, this is any notification that is not the
   * summary notification assigned to the {@link DefaultMessageNotifier#NOTIFICATION_GROUP} group.
   *
   * We utilize our wrapped cancellation methods and a counter to make sure that we do not lose
   * bubble notifications that do not have unread messages in them.
   */
  public static void cancelAllMessageNotifications(@NonNull Context context) {
    if (Build.VERSION.SDK_INT >= 23) {
      try {
        NotificationManager     notifications       = ServiceUtil.getNotificationManager(context);
        StatusBarNotification[] activeNotifications = notifications.getActiveNotifications();
        int                     activeCount         = 0;

        for (StatusBarNotification activeNotification : activeNotifications) {
          if (isSingleThreadNotification(activeNotification)) {
            activeCount++;
            if (cancel(context, activeNotification.getId())) {
              activeCount--;
            }
          }
        }

        if (activeCount == 0) {
          cancelLegacy(context, NotificationIds.MESSAGE_SUMMARY);
        }
      } catch (Throwable e) {
        // XXX Appears to be a ROM bug, see #6043
        Log.w(TAG, "Canceling all notifications.", e);
        ServiceUtil.getNotificationManager(context).cancelAll();
      }
    } else {
      cancelLegacy(context, NotificationIds.MESSAGE_SUMMARY);
    }
  }

  /**
   * @return whether this is a non-summary notification that is a member of the NOTIFICATION_GROUP group.
   */
  @RequiresApi(23)
  private static boolean isSingleThreadNotification(@NonNull StatusBarNotification statusBarNotification) {
    return statusBarNotification.getId() != NotificationIds.MESSAGE_SUMMARY &&
           Objects.equals(statusBarNotification.getNotification().getGroup(), DefaultMessageNotifier.NOTIFICATION_GROUP);
  }

  /**
   * Attempts to cancel the given notification. If the notification is allowed to be displayed as a
   * bubble, we do not cancel it.
   *
   * @return Whether or not the notification is considered cancelled.
   */
  public static boolean cancel(@NonNull Context context, int notificationId) {
    Log.d(TAG, "cancel() called with: notificationId = [" + notificationId + "]");
    if (Build.VERSION.SDK_INT >= ConversationUtil.CONVERSATION_SUPPORT_VERSION) {
      return cancelWithConversationSupport(context, notificationId);
    } else {
      cancelLegacy(context, notificationId);
      return true;
    }
  }

  /**
   * Bypasses bubble check.
   */
  public static void cancelLegacy(@NonNull Context context, int notificationId) {
    Log.d(TAG, "cancelLegacy() called with: notificationId = [" + notificationId + "]");
    ServiceUtil.getNotificationManager(context).cancel(notificationId);
  }

  /**
   * Cancel method which first checks whether the notification in question is tied to a bubble that
   * may or may not be displayed by the user.
   *
   * @return true if the notification was cancelled.
   */
  @RequiresApi(ConversationUtil.CONVERSATION_SUPPORT_VERSION)
  private static boolean cancelWithConversationSupport(@NonNull Context context, int notificationId) {
    Log.d(TAG, "cancelWithConversationSupport() called with: notificationId = [" + notificationId + "]");
    if (isCancellable(context, notificationId)) {
      cancelLegacy(context, notificationId);
      return true;
    } else {
      return false;
    }
  }

  /**
   * Checks whether the conversation for the given notification is allowed to be represented as a bubble.
   *
   * see {@link BubbleUtil#canBubble} for more information.
   */
  @RequiresApi(ConversationUtil.CONVERSATION_SUPPORT_VERSION)
  private static boolean isCancellable(@NonNull Context context, int notificationId) {
    NotificationManager     manager       = ServiceUtil.getNotificationManager(context);
    StatusBarNotification[] notifications = manager.getActiveNotifications();
    Notification            notification  = Stream.of(notifications)
                                                  .filter(n -> n.getId() == notificationId)
                                                  .findFirst()
                                                  .map(StatusBarNotification::getNotification)
                                                  .orElse(null);

    if (notification == null                     ||
        notification.getShortcutId() == null     ||
        notification.getBubbleMetadata() == null) {
      Log.d(TAG, "isCancellable: bubbles not available or notification does not exist");
      return true;
    }

    RecipientId recipientId = RecipientId.from(notification.getShortcutId());
    Long        threadId    = DatabaseFactory.getThreadDatabase(context).getThreadIdFor(recipientId);

    long focusedThreadId = ApplicationDependencies.getMessageNotifier().getVisibleThread();
    if (Objects.equals(threadId, focusedThreadId)) {
      Log.d(TAG, "isCancellable: user entered full screen thread.");
      return true;
    }

    return !BubbleUtil.canBubble(context, recipientId, threadId);
  }
}