GH-99 Support PlaceholderAPI Relational Placeholder (#122)

* Support PlaceholderAPI Relational Placeholder

* Use optional. Rename Bi -> Relational, otherTarget -> viewer.

---------

Co-authored-by: Rollczi <[email protected]>
Co-authored-by: Martin Sulikowski <[email protected]>

chatformatter-core/src/main/java/com/eternalcode/formatter/ChatFormatterPlugin.java

@@ -40,8 +40,13 @@ public ChatFormatterPlugin(Plugin plugin) {
         PluginConfig pluginConfig = configManager.getPluginConfig();
 
         this.placeholderRegistry = new PlaceholderRegistry();
+
+        PlaceholderAPIStack placeholderAPIStack = new PlaceholderAPIStack();
         this.placeholderRegistry.playerStack(new ConfiguredPlaceholderAPIStack(pluginConfig));
-        this.placeholderRegistry.playerStack(new PlaceholderAPIStack());
+        this.placeholderRegistry.playerStack(placeholderAPIStack);
+        this.placeholderRegistry.playerRelationalStack(placeholderAPIStack);
+
+
         this.templateService = new TemplateService(pluginConfig);
         this.rankProvider = new VaultRankProvider(server);
         UpdaterService updaterService = new UpdaterService(plugin.getDescription());

chatformatter-core/src/main/java/com/eternalcode/formatter/ChatHandlerImpl.java

@@ -1,5 +1,6 @@
 package com.eternalcode.formatter;
 
+import java.util.Optional;
 import static net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer.legacySection;
 
 import com.eternalcode.formatter.adventure.TextColorTagResolver;
@@ -90,11 +91,14 @@ class ChatHandlerImpl implements ChatHandler {
     @Override
     public ChatRenderedMessage process(ChatMessage chatMessage) {
         Player sender = chatMessage.sender();
+        Optional<Player> viewer = chatMessage.viewer();
 
         String format = this.settings.getRawFormat(this.rankProvider.getRank(sender));
 
         format = this.templateService.applyTemplates(format);
-        format = this.placeholderRegistry.format(format, sender);
+        format = viewer.isEmpty()
+            ? this.placeholderRegistry.format(format, sender)
+            : this.placeholderRegistry.format(format, sender, viewer.get());
 
         format = Legacy.clearSection(format);
         format = Legacy.legacyToAdventure(format);

chatformatter-core/src/main/java/com/eternalcode/formatter/ChatMessage.java

@@ -1,7 +1,7 @@
 package com.eternalcode.formatter;
 
+import java.util.Optional;
 import org.bukkit.entity.Player;
 
-public record ChatMessage(Player sender, String jsonMessage) {
-
+public record ChatMessage(Player sender, Optional<Player> viewer, String jsonMessage) {
 }

chatformatter-core/src/main/java/com/eternalcode/formatter/placeholder/PlaceholderAPIStack.java

@@ -2,13 +2,17 @@
 
 import me.clip.placeholderapi.PlaceholderAPI;
 import org.bukkit.entity.Player;
-import com.eternalcode.formatter.placeholder.PlayerPlaceholderStack;
 
-public class PlaceholderAPIStack implements PlayerPlaceholderStack {
+public class PlaceholderAPIStack implements PlayerPlaceholderStack, PlayerRelationalPlaceholderStack {
 
     @Override
     public String apply(String text, Player target) {
         return PlaceholderAPI.setPlaceholders(target, text);
     }
 
+    @Override
+    public String apply(String text, Player target, Player viewer) {
+        return PlaceholderAPI.setRelationalPlaceholders(target, viewer, text);
+    }
+
 }

chatformatter-core/src/main/java/com/eternalcode/formatter/placeholder/PlaceholderRegistry.java

@@ -11,9 +11,11 @@ public class PlaceholderRegistry {
 
     private final Map<String, Placeholder> placeholders = new HashMap<>();
     private final Map<String, PlayerPlaceholder> playerPlaceholders = new HashMap<>();
+    private final Map<String, PlayerRelationalPlaceholder> playerRelationalPlaceholders = new HashMap<>();
 
     private final Set<PlaceholderStack> stacks = new HashSet<>();
     private final Set<PlayerPlaceholderStack> playerStacks = new HashSet<>();
+    private final Set<PlayerRelationalPlaceholderStack> playerRelationalStacks = new HashSet<>();
 
     public void placeholder(String key, Placeholder placeholder) {
         this.placeholders.put(key, placeholder);
@@ -23,6 +25,10 @@ public void playerPlaceholder(String key, PlayerPlaceholder placeholder) {
         this.playerPlaceholders.put(key, placeholder);
     }
 
+    public void playerRelationalPlaceholder(String key, PlayerRelationalPlaceholder placeholder) {
+        this.playerRelationalPlaceholders.put(key, placeholder);
+    }
+
     public void stack(PlaceholderStack stack) {
         this.stacks.add(stack);
     }
@@ -31,6 +37,10 @@ public void playerStack(PlayerPlaceholderStack stack) {
         this.playerStacks.add(stack);
     }
 
+    public void playerRelationalStack(PlayerRelationalPlaceholderStack stack) {
+        this.playerRelationalStacks.add(stack);
+    }
+
     public String format(String text) {
         for (PlaceholderStack stack : this.stacks) {
             text = stack.apply(text);
@@ -55,4 +65,16 @@ public String format(String text, Player target) {
         return this.format(text);
     }
 
+    public String format(String text, Player target, Player viewer) {
+        for (PlayerRelationalPlaceholderStack stack : this.playerRelationalStacks) {
+            text = stack.apply(text, target, viewer);
+        }
+
+        for (Map.Entry<String, PlayerRelationalPlaceholder> entry : this.playerRelationalPlaceholders.entrySet()) {
+            text = text.replace(entry.getKey(), entry.getValue().extract(target, viewer));
+        }
+
+        return this.format(text, target);
+    }
+
 }

chatformatter-core/src/main/java/com/eternalcode/formatter/placeholder/PlayerRelationalPlaceholder.java

@@ -0,0 +1,10 @@
+package com.eternalcode.formatter.placeholder;
+
+import org.bukkit.entity.Player;
+
+@FunctionalInterface
+public interface PlayerRelationalPlaceholder {
+
+    String extract(Player target, Player viewer);
+
+}

chatformatter-core/src/main/java/com/eternalcode/formatter/placeholder/PlayerRelationalPlaceholderStack.java

@@ -0,0 +1,8 @@
+package com.eternalcode.formatter.placeholder;
+
+import org.bukkit.entity.Player;
+
+public interface PlayerRelationalPlaceholderStack {
+
+    String apply(String text, Player target, Player viewer);
+}

chatformatter-paper-plugin/src/main/java/com/eternalcode/formatter/paper/PaperChatEventExecutor.java

@@ -4,16 +4,20 @@
 import com.eternalcode.formatter.ChatMessage;
 import com.eternalcode.formatter.ChatRenderedMessage;
 import io.papermc.paper.event.player.AsyncChatEvent;
+import net.kyori.adventure.identity.Identity;
 import net.kyori.adventure.text.serializer.gson.GsonComponentSerializer;
+import org.bukkit.entity.Player;
 import org.bukkit.event.Event;
 import org.bukkit.event.EventException;
 import org.bukkit.event.Listener;
 import org.bukkit.plugin.EventExecutor;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Optional;
+
 class PaperChatEventExecutor implements EventExecutor {
 
-    private final static GsonComponentSerializer GSON = GsonComponentSerializer.gson();
+    private static final GsonComponentSerializer GSON = GsonComponentSerializer.gson();
 
     @Override
     public void execute(@NotNull Listener listener, @NotNull Event event) throws EventException {
@@ -27,8 +31,10 @@ public void execute(@NotNull Listener listener, @NotNull Event event) throws Eve
 
         paperEvent.renderer((source, sourceDisplayName, message, viewer) -> {
             String jsonMessage = GSON.serialize(message);
+            Optional<Player> optionalViewer = viewer.get(Identity.UUID)
+                .map(uuid -> source.getServer().getPlayer(uuid));
 
-            ChatMessage chatMessage = new ChatMessage(source, jsonMessage);
+            ChatMessage chatMessage = new ChatMessage(source, optionalViewer, jsonMessage);
             ChatRenderedMessage result = handler.process(chatMessage);
 
             return GSON.deserialize(result.jsonMessage());