From 581a41cd927ceea9cc783770ef6ea38864e5cffc Mon Sep 17 00:00:00 2001
From: Minecrell <minecrell@minecrell.net>
Date: Tue, 26 Sep 2017 18:59:37 +0200
Subject: [PATCH] Add console command completion

Register command completer for JLine to complete command names and
command arguments (if supported).

diff --git a/api/src/main/java/net/md_5/bungee/api/plugin/PluginManager.java b/api/src/main/java/net/md_5/bungee/api/plugin/PluginManager.java
index c122cad9..4180c995 100644
--- a/api/src/main/java/net/md_5/bungee/api/plugin/PluginManager.java
+++ b/api/src/main/java/net/md_5/bungee/api/plugin/PluginManager.java
@@ -220,6 +220,41 @@ public final class PluginManager
         return true;
     }
 
+    // Waterfall start - Add method to tab-complete command names
+    /**
+     * Searches for tab-complete suggestions for the given command line.
+     *
+     * <p>This is similar to {@link #dispatchCommand(CommandSender, String, List)}
+     * called with a list, but it also handles completing the command names itself
+     * instead of just the arguments.</p>
+     *
+     * @param sender The command sender
+     * @param commandLine The current command line
+     * @return The tab-complete suggestions
+     */
+    public List<String> tabCompleteCommand(CommandSender sender, String commandLine) {
+        List<String> suggestions = new java.util.ArrayList<>();
+
+        if (commandLine.indexOf(' ') == -1) {
+            // Complete command name
+            for (Command command : this.commandMap.values()) {
+                if (command.getName().startsWith(commandLine)) {
+                    // Check command permissions before adding it to the suggestions
+                    String permission = command.getPermission();
+                    if (permission == null || permission.isEmpty() || sender.hasPermission(permission)) {
+                        suggestions.add(command.getName());
+                    }
+                }
+            }
+        } else {
+            // Complete command arguments
+            dispatchCommand(sender, commandLine, suggestions);
+        }
+
+        return suggestions;
+    }
+    // Waterfall end
+
     /**
      * Returns the {@link Plugin} objects corresponding to all loaded plugins.
      *
diff --git a/proxy/src/main/java/io/github/waterfallmc/waterfall/console/ConsoleCommandCompleter.java b/proxy/src/main/java/io/github/waterfallmc/waterfall/console/ConsoleCommandCompleter.java
new file mode 100644
index 00000000..bfcb6e9f
--- /dev/null
+++ b/proxy/src/main/java/io/github/waterfallmc/waterfall/console/ConsoleCommandCompleter.java
@@ -0,0 +1,31 @@
+package io.github.waterfallmc.waterfall.console;
+
+import net.md_5.bungee.api.ProxyServer;
+import org.jline.reader.Candidate;
+import org.jline.reader.Completer;
+import org.jline.reader.LineReader;
+import org.jline.reader.ParsedLine;
+
+import java.util.List;
+
+final class ConsoleCommandCompleter implements Completer {
+
+    private final ProxyServer proxy;
+
+    ConsoleCommandCompleter(ProxyServer proxy) {
+        this.proxy = proxy;
+    }
+
+    @Override
+    public void complete(LineReader reader, ParsedLine line, List<Candidate> candidates) {
+        List<String> suggestions = this.proxy.getPluginManager().tabCompleteCommand(this.proxy.getConsole(), line.line());
+        if (suggestions.isEmpty()) {
+            return;
+        }
+
+        for (String suggestion : suggestions) {
+            candidates.add(new Candidate(suggestion));
+        }
+    }
+
+}
diff --git a/proxy/src/main/java/io/github/waterfallmc/waterfall/console/WaterfallConsole.java b/proxy/src/main/java/io/github/waterfallmc/waterfall/console/WaterfallConsole.java
index 765d24bc..6cec0b5a 100644
--- a/proxy/src/main/java/io/github/waterfallmc/waterfall/console/WaterfallConsole.java
+++ b/proxy/src/main/java/io/github/waterfallmc/waterfall/console/WaterfallConsole.java
@@ -15,6 +15,7 @@ public final class WaterfallConsole extends SimpleTerminalConsole {
         ProxyServer proxy = ProxyServer.getInstance();
         return super.buildReader(builder
                 .appName(proxy.getName())
+                .completer(new ConsoleCommandCompleter(proxy))
         );
     }
 
-- 
2.31.0