improve server side command line input (#415)

* improve server side command line input

* prevent multiline logs from covering typed commands

* reduce text in console

* resolve conflicts caused by multilanguage

Co-authored-by: Magix <kobedo11@gmail.com>

src/main/java/emu/grasscutter/Grasscutter.java

@@ -1,10 +1,9 @@
 package emu.grasscutter;
 
-import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.FileWriter;
-import java.io.InputStreamReader;
+import java.io.IOError;
 import java.net.InetSocketAddress;
 import java.util.Calendar;
 
@@ -13,6 +12,12 @@ import emu.grasscutter.plugin.PluginManager;
 import emu.grasscutter.plugin.api.ServerHook;
 import emu.grasscutter.scripts.ScriptLoader;
 import emu.grasscutter.utils.Utils;
+import org.jline.reader.EndOfFileException;
+import org.jline.reader.LineReader;
+import org.jline.reader.LineReaderBuilder;
+import org.jline.reader.UserInterruptException;
+import org.jline.terminal.Terminal;
+import org.jline.terminal.TerminalBuilder;
 import org.reflections.Reflections;
 import org.slf4j.LoggerFactory;
 
@@ -30,8 +35,9 @@ import emu.grasscutter.utils.Crypto;
 public final class Grasscutter {
 	private static final Logger log = (Logger) LoggerFactory.getLogger(Grasscutter.class);
 	private static Config config;
+	private static LineReader consoleLineReader = null;
 	private static Language language;
-	
+
 	private static final Gson gson = new GsonBuilder().setPrettyPrinting().create();
 	private static final File configFile = new File("./config.json");
 	
@@ -108,11 +114,12 @@ public final class Grasscutter {
 		
 		// Enable all plugins.
 		pluginManager.enablePlugins();
-		
-		// Open console.
-		startConsole();
+
 		// Hook into shutdown event.
 		Runtime.getRuntime().addShutdownHook(new Thread(Grasscutter::onShutdown));
+
+		// Open console.
+		startConsole();
     }
 
 	/**
@@ -122,7 +129,7 @@ public final class Grasscutter {
 		// Disable all plugins.
 		pluginManager.disablePlugins();
 	}
-	
+
 	public static void loadConfig() {
 		try (FileReader file = new FileReader(configFile)) {
 			config = gson.fromJson(file, Config.class);
@@ -167,23 +174,40 @@ public final class Grasscutter {
 	}
 	
 	public static void startConsole() {
-		String input;
+		// Console should not start in dispatch only mode.
+		if (getConfig().RunMode == ServerRunMode.DISPATCH_ONLY) {
+			getLogger().info(language.Dispatch_mode_not_support_command);
+			return;
+		}
+
 		getLogger().info(language.Start_done);
-		try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
-			while ((input = br.readLine()) != null) {
-				try {
-					if (getConfig().RunMode == ServerRunMode.DISPATCH_ONLY) {
-						getLogger().error(language.Dispatch_mode_not_support_command);
-						return;
-					}
-					
-					CommandMap.getInstance().invoke(null, input);
-				} catch (Exception e) {
-					Grasscutter.getLogger().error(language.Command_error, e);
+		String input = null;
+		boolean isLastInterrupted = false;
+		while (true) {
+			try {
+				input = consoleLineReader.readLine("> ");
+			} catch (UserInterruptException e) {
+				if (!isLastInterrupted) {
+					isLastInterrupted = true;
+					Grasscutter.getLogger().info("Press Ctrl-C again to shutdown.");
+					continue;
+				} else {
+					Runtime.getRuntime().exit(0);
 				}
+			} catch (EndOfFileException e) {
+				Grasscutter.getLogger().info("EOF detected.");
+				continue;
+			} catch (IOError e) {
+				Grasscutter.getLogger().error("An IO error occurred.", e);
+				continue;
+			}
+
+			isLastInterrupted = false;
+			try {
+				CommandMap.getInstance().invoke(null, input);
+			} catch (Exception e) {
+				Grasscutter.getLogger().error(language.Command_error, e);
 			}
-		} catch (Exception e) {
-			Grasscutter.getLogger().error(language.Error, e);
 		}
 	}
 
@@ -199,6 +223,26 @@ public final class Grasscutter {
 		return log;
 	}
 
+	public static LineReader getConsole() {
+		if (consoleLineReader == null) {
+			Terminal terminal = null;
+			try {
+				terminal = TerminalBuilder.builder().jna(true).build();
+			} catch (Exception e) {
+				try {
+					// Fallback to a dumb jline terminal.
+					terminal = TerminalBuilder.builder().dumb(true).build();
+				} catch (Exception ignored) {
+					// When dumb is true, build() never throws.
+				}
+			}
+			consoleLineReader = LineReaderBuilder.builder()
+					.terminal(terminal)
+					.build();
+		}
+		return consoleLineReader;
+	}
+
 	public static Gson getGsonFactory() {
 		return gson;
 	}