Merge pull request #3256 from Multiverse/fix/generator-tab-complete

Improve generator provider tab-complete logic

Author: benwoo1110

src/main/java/org/mvplugins/multiverse/core/world/generators/GeneratorPlugin.java

@@ -17,7 +17,10 @@ public interface GeneratorPlugin {
      * <p>Suggest possible generator ids. To be used in command tab-completion.</p>
      *
      * <p>These suggestions can be static without relying on currentIdInput, or dynamically changed based
-     * on the currentIdInput.</p>
+     * on the currentIdInput. Add an entry of empty string "" if your plugin supports generator string without an id.</p>
+     *
+     * <p>These suggestions should be quick lookups, that gets from your cached or loaded data as tab-complete handler
+     * may be called multiple times a second.</p>
      *
      * @param currentIdInput    The current state user input. This may be null or empty if user has not started
      *                          any input for generator id.

src/main/java/org/mvplugins/multiverse/core/world/generators/GeneratorProvider.java

@@ -1,13 +1,12 @@
 package org.mvplugins.multiverse.core.world.generators;
 
 import java.io.File;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Stream;
 
 import com.dumptruckman.minecraft.util.Logging;
 import com.google.common.base.Strings;
@@ -176,16 +175,19 @@ public boolean isGeneratorPluginRegistered(@NotNull String pluginName) {
      */
     public Collection<String> suggestGeneratorString(@Nullable String currentInput) {
         String[] genSpilt = currentInput == null ? new String[0] : REPatterns.COLON.split(currentInput, 2);
-        List<String> suggestions = new ArrayList<>(generatorPlugins.keySet());
-        if (genSpilt.length < 2) {
-            return suggestions;
-        }
-        GeneratorPlugin generatorPlugin = generatorPlugins.get(genSpilt[0]);
-        if (generatorPlugin == null) {
-            return suggestions;
-        }
-        suggestions.addAll(generatorPlugin.suggestIds(genSpilt[1]).stream().map(id -> genSpilt[0] + ":" + id).toList());
-        return suggestions;
+        String generatorName = genSpilt[0];
+        String generatorId = genSpilt.length > 1 ? genSpilt[1] : "";
+        return generatorPlugins.entrySet().stream()
+                .flatMap(entry -> {
+                    var ids = entry.getValue().suggestIds(entry.getKey().equals(generatorName) ? generatorId : "");
+                    if (ids.isEmpty()) {
+                        return Stream.of(entry.getKey());
+                    }
+                    return ids.stream().map(id -> Strings.isNullOrEmpty(id)
+                            ? entry.getKey()
+                            : entry.getKey() + ":" + id);
+                })
+                .toList();
     }
 
     /**