[WIP] Implementing a socket system for governing the bot from another instance, to turn on maintenance mode for example.

Signed-off-by: Louis Vallat <louis@louis-vallat.xyz>

build.gradle

@@ -11,8 +11,9 @@ ext {
     javaMainClass = 'xyz.vallat.louis.MoviesQuoteBot'
 }
 
+
 application {
-    mainClassName = javaMainClass
+    getMainClass().set(javaMainClass)
 }
 
 jar {

src/main/java/xyz/vallat/louis/MoviesQuoteBot.java

@@ -1,5 +1,6 @@
 package xyz.vallat.louis;
 
+import org.apache.commons.cli.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import xyz.vallat.louis.database.DBManager;
@@ -11,13 +12,22 @@ public class MoviesQuoteBot {
     public static final String PREFIX = "!";
     public static final String NAME = "Movies Quote Bot";
     public static final String DESCRIPTION = "I may know quotes from movies.";
-    public static final String VERSION = "0.3.7-SNAPSHOT";
+    public static final String VERSION = "0.3.8-SNAPSHOT";
     private static final Logger logger = LoggerFactory.getLogger(MoviesQuoteBot.class.getCanonicalName());
+    private static final Options options = new Options();
 
-    public static void main(String[] args) {
+    static {
+        options.addOption(Option.builder().longOpt("reimport").build());
+    }
+
+    public static void main(String[] args) throws ParseException {
+        CommandLine cmd = new DefaultParser().parse(options, args);
         DBManager.testConnection();
         DBManager.initDatabase();
         OpenSubtitles.login();
+
+        if (cmd.hasOption("reimport")) reimportAllSubtitleLines();
+
         DiscordManager.login();
 
         Runtime.getRuntime().addShutdownHook(new Thread(() -> {
@@ -28,4 +38,16 @@ public class MoviesQuoteBot {
 
         DiscordManager.onDisconnect();
     }
+
+    public static void switchToMaintenanceMode() {
+
+    }
+
+    public static void switchToNormalOperations() {
+
+    }
+
+    private static void reimportAllSubtitleLines() {
+        DiscordManager.setOnMaintenanceMode();
+    }
 }

src/main/java/xyz/vallat/louis/codes/ExitCodes.java

@@ -4,7 +4,9 @@ public enum ExitCodes {
     CANNOT_CONNECT_TO_DB(1),
     CANNOT_INITIALIZE_DB(2),
     CANNOT_INITIALIZE_LANGUAGES(3),
-    CANNOT_GET_PROPERTY(4);
+    CANNOT_GET_PROPERTY(4),
+    CANNOT_START_SOCKET_SERVER(5),
+    URGENT_EXIT_REQUIRED(6);
 
     private final int value;
 

src/main/java/xyz/vallat/louis/discord/DiscordManager.java

@@ -46,7 +46,7 @@ public final class DiscordManager {
     private static void registerDiscordCommands() {
         for (Command command : commands)
             discordClient.getEventDispatcher().on(MessageCreateEvent.class)
-                    .filter(event -> event.getMessage().getAuthor().map(user -> !user.isBot()).orElse(false))
+                    .filter(event -> !isInMaintenanceMode && event.getMessage().getAuthor().map(user -> !user.isBot()).orElse(false))
                     .filter(event -> event.getMessage().getContent().split(" ")[0].equals(command.getName()))
                     .flatMap(event -> command.execute(event).then())
                     .subscribe();
@@ -61,7 +61,7 @@ public final class DiscordManager {
                         }
                 ).block();
         assert discordClient != null;
-        discordClient.updatePresence(Presence.online(Activity.watching("more films"))).subscribe();
+        setOnline();
         discordClient.getEventDispatcher().on(ReadyEvent.class)
                 .subscribe(event -> {
                     User self = event.getSelf();
@@ -78,4 +78,12 @@ public final class DiscordManager {
         return discordClient.getGuilds().count();
     }
 
+    public static void setOnline() {
+        if (discordClient != null) discordClient.updatePresence(Presence.online(Activity.watching("more films"))).subscribe();
+    }
+
+    public static void setOnMaintenanceMode() {
+        if (discordClient != null) discordClient.updatePresence(Presence.idle(Activity.playing("maintenance mode."))).subscribe();
+        isInMaintenanceMode = true;
+    }
 }

src/main/java/xyz/vallat/louis/env/EnvironmentVariables.java

@@ -10,6 +10,7 @@ public enum EnvironmentVariables {
     OS_USERNAME("OPEN_SUBTITLES_USERNAME"),
     OS_PASSWORD("OPEN_SUBTITLES_PASSWORD"),
     OS_USER_AGENT("OPEN_SUBTITLES_USER_AGENT"),
+    SOCKET_PORT("SOCKET_PORT"),
     OMDB_API_KEY("OMDB_API_KEY");
 
     private final String value;

src/main/java/xyz/vallat/louis/sockets/Client.java

@@ -0,0 +1,4 @@
+package xyz.vallat.louis.sockets;
+
+public class Client {
+}

src/main/java/xyz/vallat/louis/sockets/Server.java

@@ -0,0 +1,70 @@
+package xyz.vallat.louis.sockets;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import xyz.vallat.louis.MoviesQuoteBot;
+import xyz.vallat.louis.codes.ExitCodes;
+import xyz.vallat.louis.env.EnvironmentVariables;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class Server {
+
+    public static final String KILL_SWITCH_FILE = "system_locked";
+    private static final Logger logger = LoggerFactory.getLogger(Server.class.getCanonicalName());
+    private static final int PORT;
+
+    static {
+        int port = 8888;
+        try {
+            port = Integer.parseInt(EnvironmentVariables.SOCKET_PORT.getValue());
+        } catch (NumberFormatException ignored) {
+            logger.warn("Port is not a valid numeric value. Using default one instead: '{}'.", port);
+        }
+        PORT = port;
+    }
+
+    private Server() {
+    }
+
+    public static void start() {
+        new Thread(() -> {
+            boolean everythingIsOkay = true;
+            while (everythingIsOkay) {
+                try (ServerSocket serverSocket = new ServerSocket(PORT)) {
+                    logger.info("Waiting for connections on port '{}'...", PORT);
+                    Socket socket = serverSocket.accept();
+                    logger.info("Connected!");
+                    BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+                    String message = reader.readLine();
+                    logger.debug("Received message '{}'.", message);
+                    if (message.equals(SocketsCommand.KILL_SWITCH_URGENT.getName())) everythingIsOkay = false;
+                    else if (message.equals(SocketsCommand.MAINTENANCE_MODE_ON.getName()))
+                        MoviesQuoteBot.switchToMaintenanceMode();
+                    else if (message.equals(SocketsCommand.MAINTENANCE_MODE_OFF.getName()))
+                        MoviesQuoteBot.switchToNormalOperations();
+                    else logger.warn("Be careful, I received a message that I don't understand: '{}'.", message);
+                } catch (IOException e) {
+                    everythingIsOkay = false;
+                    logger.error("Cannot start socket server.", e);
+                    logger.error("Exiting.");
+                    System.exit(ExitCodes.CANNOT_START_SOCKET_SERVER.getValue());
+                }
+            }
+            logger.error("Everything was not okay. Urgent exit required.");
+            try {
+                if (!new File(KILL_SWITCH_FILE).createNewFile())
+                    throw new IOException("File already existed apparently.");
+            } catch (IOException e) {
+                logger.error("Couldn't even create kill switch file... Exiting anyway.", e);
+            }
+            System.exit(ExitCodes.URGENT_EXIT_REQUIRED.getValue());
+        });
+    }
+
+}

src/main/java/xyz/vallat/louis/sockets/SocketsCommand.java

@@ -0,0 +1,17 @@
+package xyz.vallat.louis.sockets;
+
+public enum SocketsCommand {
+    MAINTENANCE_MODE_ON("maintenance_engaged"),
+    MAINTENANCE_MODE_OFF("maintenance_disengaged"),
+    KILL_SWITCH_URGENT("big_red_button_pressed");
+
+    private final String name;
+
+    SocketsCommand(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+}