Add basic command system

.gitignore

@@ -1,11 +1,14 @@
 # From https://github.com/github/gitignore/blob/master/Gradle.gitignore
 
 .gradle
-**/build/
+build/
 !src/**/build/
 gradle-app.setting
 !gradle-wrapper.jar
 .gradletasknamecache
 
+.idea/
+out/
+
 # # Work around https://youtrack.jetbrains.com/issue/IDEA-116898
 # gradle/wrapper/gradle-wrapper.properties

build.gradle

@@ -26,15 +26,19 @@ archivesBaseName = 'janitor_bot'
 version = getVersion()
 println("Version: ${version}")
 
+shadowJar {
+    configurations = [project.configurations.implementation]
+}
+
 dependencies {
-    shadow "net.dv8tion:JDA:${jda_version}"
-    shadow "com.electronwill.night-config:toml:${nightconfig_version}"
-    shadow "net.sf.jopt-simple:jopt-simple:${jopt_version}"
-    shadow "com.google.guava:guava:${guava_version}"
-    shadow "com.google.code.gson:gson:${gson_version}"
-    shadow "org.apache.logging.log4j:log4j-api:${log4j_version}"
-    shadow "org.apache.logging.log4j:log4j-core:${log4j_version}"
-    shadow "org.apache.logging.log4j:log4j-slf4j-impl:${log4j_version}"
+    implementation "net.dv8tion:JDA:${jda_version}"
+    implementation "com.electronwill.night-config:toml:${nightconfig_version}"
+    implementation "net.sf.jopt-simple:jopt-simple:${jopt_version}"
+    implementation "com.google.guava:guava:${guava_version}"
+    implementation "com.google.code.gson:gson:${gson_version}"
+    implementation "org.apache.logging.log4j:log4j-api:${log4j_version}"
+    implementation "org.apache.logging.log4j:log4j-core:${log4j_version}"
+    implementation "org.apache.logging.log4j:log4j-slf4j-impl:${log4j_version}"
 
     testImplementation "junit:junit:${junit_version}"
 }

src/main/java/sciwhiz12/janitor/CommandListener.java

@@ -0,0 +1,14 @@
+package sciwhiz12.janitor;
+
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import net.dv8tion.jda.api.hooks.ListenerAdapter;
+import org.jetbrains.annotations.NotNull;
+
+public class CommandListener extends ListenerAdapter {
+    public static final CommandListener INSTANCE = new CommandListener();
+
+    @Override
+    public void onMessageReceived(@NotNull MessageReceivedEvent event) {
+        JanitorBot.INSTANCE.getCommandRegistry().parseMessage(event);
+    }
+}

src/main/java/sciwhiz12/janitor/JanitorBot.java

@@ -1,5 +1,61 @@
 package sciwhiz12.janitor;
 
-public class JanitorBot
-{
+import joptsimple.ArgumentAcceptingOptionSpec;
+import joptsimple.OptionParser;
+import joptsimple.OptionSet;
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.JDABuilder;
+import net.dv8tion.jda.api.Permission;
+import net.dv8tion.jda.api.requests.GatewayIntent;
+import sciwhiz12.janitor.commands.CommandRegistry;
+import sciwhiz12.janitor.commands.OKCommand;
+import sciwhiz12.janitor.commands.PingCommand;
+
+import javax.security.auth.login.LoginException;
+
+public class JanitorBot {
+    public static JanitorBot INSTANCE;
+
+    private final JDA jda;
+    private final CommandRegistry cmdRegistry;
+
+    public JanitorBot(JDA jda, String prefix) {
+        this.jda = jda;
+        this.cmdRegistry = new CommandRegistry(this, prefix);
+    }
+
+    public JDA getDiscord() {
+        return this.jda;
+    }
+
+    public CommandRegistry getCommandRegistry() {
+        return this.cmdRegistry;
+    }
+
+    public static void main(String[] args) throws LoginException {
+        System.out.println("Starting...");
+
+        OptionParser parser = new OptionParser();
+        ArgumentAcceptingOptionSpec<String> token = parser
+                .accepts("token", "The Discord token for the bot user").withRequiredArg().required();
+        ArgumentAcceptingOptionSpec<String> prefix = parser
+                .accepts("prefix", "The prefix for commands").withRequiredArg().defaultsTo("!");
+
+        OptionSet options = parser.parse(args);
+
+        System.out.println("Configuring and connecting...");
+
+        JDABuilder builder = JDABuilder.createDefault(token.value(options));
+        builder.addEventListeners(CommandListener.INSTANCE);
+        builder.enableIntents(GatewayIntent.GUILD_MESSAGES, GatewayIntent.GUILD_MESSAGE_REACTIONS);
+        JDA jda = builder.build();
+        INSTANCE = new JanitorBot(jda, prefix.value(options));
+
+        String inviteURL = jda.getInviteUrl(Permission.ADMINISTRATOR);
+
+        INSTANCE.getCommandRegistry().addCommand("ping", new PingCommand());
+        INSTANCE.getCommandRegistry().addCommand("ok", new OKCommand());
+
+        System.out.println("Ready! Invite URL: " + inviteURL);
+    }
 }

src/main/java/sciwhiz12/janitor/commands/CommandRegistry.java

@@ -0,0 +1,44 @@
+package sciwhiz12.janitor.commands;
+
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import sciwhiz12.janitor.JanitorBot;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class CommandRegistry {
+    private final JanitorBot bot;
+    private final String prefix;
+    private final Pattern pattern;
+    private final Map<String, ICommand> registry = new HashMap<>();
+
+    public CommandRegistry(JanitorBot bot, String prefix) {
+        this.bot = bot;
+        this.prefix = prefix;
+        this.pattern = Pattern.compile("^" + prefix + "([A-Za-z0-9]+).*$");
+    }
+
+    public void addCommand(String cmd, ICommand instance) {
+        registry.put(cmd, instance);
+    }
+
+    public void parseMessage(MessageReceivedEvent event) {
+        try {
+            String msg = event.getMessage().getContentStripped();
+            Matcher matcher = pattern.matcher(msg);
+            if (!matcher.matches()) { return; }
+            String cmd = matcher.group(1);
+            if (registry.containsKey(cmd)) {
+                System.out.printf("Received command: %s ; full message: %s%n", cmd, msg);
+                registry.get(cmd).onCommand(bot, event);
+            }
+        }
+        catch (Exception e) {
+            System.err
+                    .printf("Error while parsing message: %s ; %s%n", event.getMessage().getContentStripped(),
+                            e);
+        }
+    }
+}

src/main/java/sciwhiz12/janitor/commands/ICommand.java

@@ -0,0 +1,8 @@
+package sciwhiz12.janitor.commands;
+
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import sciwhiz12.janitor.JanitorBot;
+
+public interface ICommand {
+    void onCommand(JanitorBot bot, MessageReceivedEvent event);
+}

src/main/java/sciwhiz12/janitor/commands/OKCommand.java

@@ -0,0 +1,11 @@
+package sciwhiz12.janitor.commands;
+
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import sciwhiz12.janitor.JanitorBot;
+
+public class OKCommand implements ICommand {
+    @Override
+    public void onCommand(JanitorBot bot, MessageReceivedEvent event) {
+        event.getMessage().addReaction("\uD83D\uDC4C").queue();
+    }
+}

src/main/java/sciwhiz12/janitor/commands/PingCommand.java

@@ -0,0 +1,11 @@
+package sciwhiz12.janitor.commands;
+
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import sciwhiz12.janitor.JanitorBot;
+
+public class PingCommand implements ICommand {
+    @Override
+    public void onCommand(JanitorBot bot, MessageReceivedEvent event) {
+        event.getMessage().getChannel().sendMessage("Pong!").queue();
+    }
+}