Add RecipientsResolver API

api/src/main/java/net/draycia/carbon/api/channels/ChatChannel.java

@@ -22,7 +22,6 @@
 import java.util.List;
 import net.draycia.carbon.api.users.CarbonPlayer;
 import net.draycia.carbon.api.util.ChatComponentRenderer;
-import net.kyori.adventure.audience.Audience;
 import net.kyori.adventure.key.Keyed;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
@@ -46,13 +45,14 @@ public interface ChatChannel extends Keyed, ChatComponentRenderer {
     ChannelPermissions permissions();
 
     /**
-     * Returns a list of all recipients that will receive messages from the sender.
+     * Returns the {@link RecipientsResolver} for this channel. The return value is not cached,
+     * and {@link ChannelPermissions#speechPermitted(CarbonPlayer)} is checked before
+     * invoking this method.
      *
-     * @param sender the sender of messages
-     * @return the recipients
-     * @since 2.0.0
+     * @return the recipients resolver
+     * @since 3.0.0
      */
-    List<Audience> recipients(CarbonPlayer sender);
+    RecipientsResolver recipientsResolver();
 
     /**
      * Messages will be sent in this channel if they start with this prefix.

api/src/main/java/net/draycia/carbon/api/channels/RecipientsResolver.java

@@ -0,0 +1,176 @@
+/*
+ * CarbonChat
+ *
+ * Copyright (c) 2024 Josua Parks (Vicarious)
+ *                    Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package net.draycia.carbon.api.channels;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Predicate;
+import net.draycia.carbon.api.CarbonServer;
+import net.draycia.carbon.api.users.CarbonPlayer;
+import net.kyori.adventure.audience.Audience;
+import net.kyori.adventure.key.Key;
+import org.checkerframework.common.returnsreceiver.qual.This;
+
+/**
+ * Resolves the recipients for a message from a given sender.
+ *
+ * @see ChatChannel#recipientsResolver()
+ * @see #builder(CarbonServer)
+ * @since 3.0.0
+ */
+@FunctionalInterface
+public interface RecipientsResolver {
+
+    /**
+     * Resolves the recipients for a message from a given sender.
+     *
+     * @param sender the sender to resolve recipients for
+     * @return resolved recipients
+     * @since 3.0.0
+     */
+    List<Audience> recipients(CarbonPlayer sender);
+
+    /**
+     * Creates a new combined {@link RecipientsResolver} from this resolver and {@code resolver}.
+     *
+     * <p>
+     * Note that this method does not filter duplicate audiences.
+     * </p>
+     *
+     * @param resolver second resolver
+     * @return new combined resolver
+     * @since 3.0.0
+     */
+    default RecipientsResolver and(final RecipientsResolver resolver) {
+        return sender -> {
+            final List<Audience> recipients = new ArrayList<>(this.recipients(sender));
+            recipients.addAll(resolver.recipients(sender));
+            return recipients;
+        };
+    }
+
+    /**
+     * Creates a new {@link Builder}.
+     *
+     * @param server server instance
+     * @return new {@link Builder}
+     * @since 3.0.0
+     */
+    static Builder builder(final CarbonServer server) {
+        return new Builder(server);
+    }
+
+    /**
+     * Mutable builder for {@link RecipientsResolver}.
+     * <p>
+     * Custom implementations are supported, however the builder simplifies most use cases.
+     * </p>
+     *
+     * @since 3.0.0
+     */
+    final class Builder {
+        private final CarbonServer server;
+        private final List<Predicate<CarbonPlayer>> playerFilters = new ArrayList<>();
+        private boolean includeConsole;
+
+        private Builder(final CarbonServer server) {
+            this.server = server;
+        }
+
+        /**
+         * Includes online players with permission to hear the channel that have not left the channel,
+         * using {@link #players(Predicate)}.
+         *
+         * @param channel channel
+         * @return this builder
+         * @since 3.0.0
+         */
+        public @This Builder permittedPlayersInChannel(final ChatChannel channel) {
+            return this.permittedPlayersInChannel(channel.permissions(), channel.key());
+        }
+
+        /**
+         * Includes online players with permission to hear the channel that have not left the channel,
+         * using {@link #players(Predicate)}.
+         *
+         * @param permissions permissions
+         * @param channelKey channel
+         * @return this builder
+         * @since 3.0.0
+         */
+        public @This Builder permittedPlayersInChannel(final ChannelPermissions permissions, final Key channelKey) {
+            return this.players(player -> permissions.hearingPermitted(player).permitted()
+                && !player.leftChannels().contains(channelKey));
+        }
+
+        /**
+         * Includes online players matching the predicate in the resolved recipients. Adding multiple predicates
+         * will include players matching any one of the predicates.
+         *
+         * @param filter player filter
+         * @return this builder
+         * @since 3.0.0
+         */
+        public @This Builder players(final Predicate<CarbonPlayer> filter) {
+            this.playerFilters.add(filter);
+            return this;
+        }
+
+        /**
+         * Unconditionally includes the console in the resolved recipients.
+         *
+         * @return this builder
+         * @since 3.0.0
+         */
+        public @This Builder console() {
+            this.includeConsole = true;
+            return this;
+        }
+
+        /**
+         * Builds a new {@link RecipientsResolver} from the current state of this builder.
+         *
+         * @return new {@link RecipientsResolver} instance
+         * @since 3.0.0
+         */
+        public RecipientsResolver build() {
+            final boolean includeConsole = this.includeConsole;
+            final List<Predicate<CarbonPlayer>> playerFilters = List.copyOf(this.playerFilters);
+
+            return sender -> {
+                final List<Audience> recipients = new ArrayList<>();
+
+                if (!playerFilters.isEmpty()) {
+                    for (final CarbonPlayer player : this.server.players()) {
+                        if (playerFilters.stream().anyMatch(filter -> filter.test(player))) {
+                            recipients.add(player);
+                        }
+                    }
+                }
+
+                if (includeConsole) {
+                    recipients.add(this.server.console());
+                }
+
+                return recipients;
+            };
+        }
+    }
+}

common/src/main/java/net/draycia/carbon/common/channels/ConfigChatChannel.java

@@ -21,7 +21,6 @@
 
 import com.google.inject.Inject;
 import io.leangen.geantyref.TypeToken;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -31,6 +30,7 @@
 import net.draycia.carbon.api.CarbonServer;
 import net.draycia.carbon.api.channels.ChannelPermissions;
 import net.draycia.carbon.api.channels.ChatChannel;
+import net.draycia.carbon.api.channels.RecipientsResolver;
 import net.draycia.carbon.api.users.CarbonPlayer;
 import net.draycia.carbon.common.channels.messages.ConfigChannelMessageSource;
 import net.draycia.carbon.common.channels.messages.ConfigChannelMessages;
@@ -165,19 +165,11 @@ public ChannelPermissions permissions() {
     }
 
     @Override
-    public List<Audience> recipients(final CarbonPlayer sender) {
-        final List<Audience> recipients = new ArrayList<>();
-
-        for (final CarbonPlayer player : this.server.players()) {
-            if (this.permissions().hearingPermitted(player).permitted() && !player.leftChannels().contains(this.key)) {
-                recipients.add(player);
-            }
-        }
-
-        // console too!
-        recipients.add(this.server.console());
-
-        return recipients;
+    public RecipientsResolver recipientsResolver() {
+        return RecipientsResolver.builder(this.server)
+            .permittedPlayersInChannel(this)
+            .console()
+            .build();
     }
 
     @Override

common/src/main/java/net/draycia/carbon/common/channels/PartyChatChannel.java

@@ -25,6 +25,7 @@
 import java.util.Objects;
 import java.util.UUID;
 import net.draycia.carbon.api.channels.ChannelPermissions;
+import net.draycia.carbon.api.channels.RecipientsResolver;
 import net.draycia.carbon.api.users.CarbonPlayer;
 import net.draycia.carbon.api.users.Party;
 import net.draycia.carbon.common.channels.messages.ConfigChannelMessageSource;
@@ -66,18 +67,20 @@ public ChannelPermissions permissions() {
     }
 
     @Override
-    public List<Audience> recipients(final CarbonPlayer sender) {
-        final WrappedCarbonPlayer wrapped = (WrappedCarbonPlayer) sender;
-        final @Nullable UUID party = wrapped.partyId();
-        if (party == null) {
-            if (sender.online()) {
-                sender.sendMessage(this.messages.cannotUsePartyChannel(sender));
+    public RecipientsResolver recipientsResolver() {
+        return sender -> {
+            final WrappedCarbonPlayer wrapped = (WrappedCarbonPlayer) sender;
+            final @Nullable UUID party = wrapped.partyId();
+            if (party == null) {
+                if (sender.online()) {
+                    sender.sendMessage(this.messages.cannotUsePartyChannel(sender));
+                }
+                return new ArrayList<>();
             }
-            return new ArrayList<>();
-        }
-        final List<Audience> recipients = super.recipients(sender);
-        recipients.removeIf(r -> r instanceof WrappedCarbonPlayer p && !Objects.equals(p.partyId(), party));
-        return recipients;
+            final List<Audience> recipients = super.recipientsResolver().recipients(sender);
+            recipients.removeIf(r -> r instanceof WrappedCarbonPlayer p && !Objects.equals(p.partyId(), party));
+            return recipients;
+        };
     }
 
     @Override

common/src/main/java/net/draycia/carbon/common/listeners/ChatListenerInternal.java

@@ -117,7 +117,7 @@ protected ChatListenerInternal(
         final List<KeyedRenderer> renderers = new ArrayList<>();
         renderers.add(KeyedRenderer.keyedRenderer(Key.key("carbon", "default"), channel));
 
-        final List<Audience> recipients = channel.recipients(sender);
+        final List<Audience> recipients = channel.recipientsResolver().recipients(sender);
 
         final var chatEvent = new CarbonChatEventImpl(sender, message, recipients, renderers, channel, signedMessage);
 

common/src/main/java/net/draycia/carbon/common/messaging/CarbonChatPacketHandler.java

@@ -124,7 +124,7 @@ private boolean handleMessagePacket(final ChatMessagePacket messagePacket) {
 
         final List<KeyedRenderer> renderers = new ArrayList<>();
 
-        final List<Audience> recipients = channel.recipients(sender);
+        final List<Audience> recipients = channel.recipientsResolver().recipients(sender);
         final CarbonChatEventImpl chatEvent = new CarbonChatEventImpl(sender, messagePacket.message(), recipients, renderers, channel, null, false);
         this.events.emit(chatEvent);
 

paper/src/main/java/net/draycia/carbon/paper/integration/fuuid/AllianceChannel.java

@@ -29,6 +29,7 @@
 import java.util.List;
 import java.util.Map;
 import net.draycia.carbon.api.channels.ChannelPermissions;
+import net.draycia.carbon.api.channels.RecipientsResolver;
 import net.draycia.carbon.api.users.CarbonPlayer;
 import net.draycia.carbon.api.users.UserManager;
 import net.draycia.carbon.common.channels.messages.ConfigChannelMessageSource;
@@ -71,26 +72,28 @@ public ChannelPermissions permissions() {
     }
 
     @Override
-    public List<Audience> recipients(final CarbonPlayer sender) {
-        if (!this.hasRelations(sender, Relation.ALLY)) {
-            if (sender.online()) {
-                sender.sendMessage(this.messages.cannotUseFactionAllianceChannel(sender));
+    public RecipientsResolver recipientsResolver() {
+        return sender -> {
+            if (!this.hasRelations(sender, Relation.ALLY)) {
+                if (sender.online()) {
+                    sender.sendMessage(this.messages.cannotUseFactionAllianceChannel(sender));
+                }
+
+                return Collections.emptyList();
             }
 
-            return Collections.emptyList();
-        }
-
-        final List<Audience> recipients = new ArrayList<>();
-        for (final Player player : this.alliedPlayersTo(sender)) {
-            final @Nullable CarbonPlayer carbon = this.users.user(player.getUniqueId()).getNow(null);
-            if (carbon != null) {
-                recipients.add(carbon);
+            final List<Audience> recipients = new ArrayList<>();
+            for (final Player player : this.alliedPlayersTo(sender)) {
+                final @Nullable CarbonPlayer carbon = this.users.user(player.getUniqueId()).getNow(null);
+                if (carbon != null) {
+                    recipients.add(carbon);
+                }
             }
-        }
 
-        recipients.add(this.server.console());
+            recipients.add(this.server.console());
 
-        return recipients;
+            return recipients;
+        };
     }
 
     private List<Player> alliedPlayersTo(final CarbonPlayer player) {