Fix timed groups check + possibly ConcurrentModificationExceptions

Fixes #1875. Fixes #1827. Fixes #1687.

Author: zml2008

src/main/java/ru/tehkode/permissions/PermissionUser.java

@@ -18,13 +18,15 @@
  */
 package ru.tehkode.permissions;
 
+import com.google.common.collect.Maps;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import ru.tehkode.permissions.events.PermissionEntityEvent;
 import ru.tehkode.permissions.exceptions.RankingException;
 
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.logging.Level;
 
 /**
  * @author code
@@ -575,23 +577,31 @@ public boolean explainExpression(String expression) {
 
 	protected void updateTimedGroups() {
 		long nextExpiration = Long.MAX_VALUE;
+		final Set<Map.Entry<String, String>> removeGroups = new HashSet<>();
 		for (Map.Entry<String, Map<String, String>> world : getAllOptions().entrySet()) {
 			for (Map.Entry<String, String> entry : world.getValue().entrySet()) {
 				final String group = getTimedGroupName(entry.getKey());
 				if (group == null) { // Not a timed group
 					continue;
 				}
 				long groupLifetime = Long.parseLong(entry.getValue());
-				if (groupLifetime > 0 && groupLifetime < System.currentTimeMillis() / 1000) { // check for expiration
-					this.setOption("group-" + group + "-until", null, world.getKey()); // remove option
-					this.removeGroup(group, world.getKey()); // remove membership
-					// @TODO Make notification of player about expired memebership
+				if (groupLifetime > 0 && groupLifetime <= System.currentTimeMillis() / 1000) { // check for expiration
+					removeGroups.add(Maps.immutableEntry(group, world.getKey()));
 				} else {
 					nextExpiration = Math.min(nextExpiration, groupLifetime);
 				}
 			}
 		}
 
+		for (Map.Entry<String, String> ent : removeGroups) {
+			this.setOption("group-" + ent.getKey() + "-until", null, ent.getValue()); // remove option
+			this.removeGroup(ent.getKey(), ent.getValue()); // remove membership
+			if (isDebug()) {
+				manager.getLogger().log(Level.INFO, ent.getValue() != null ? "Timed group '{0}' in world '{1}' expired from user {2}/{3}"
+						: "Timed group {0} expired from user {2}/{3}", new Object[]{ent.getKey(), ent.getValue(), getIdentifier(), getName()});
+			}
+		}
+
 		if (nextExpiration < Long.MAX_VALUE) {
 			// Schedule the next timed groups check with the permissions manager
 			manager.scheduleTimedGroupsCheck(nextExpiration, getIdentifier());
@@ -602,9 +612,7 @@ static String getTimedGroupName(String option) {
 		if (!option.startsWith("group-") && !option.endsWith("-until")) {
 			return null;
 		}
-		String groupName = option.substring("group-".length(), option.length() - "-until".length());
-		System.out.println(groupName);
-		return groupName;
+		return option.substring("group-".length(), option.length() - "-until".length());
 	}
 
 	// Compatibility methods