Added the link command

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

app/build.gradle

@@ -39,6 +39,8 @@ dependencies {
     implementation 'com.discord4j:discord4j-core:3.1.1'
     implementation 'ch.qos.logback:logback-classic:1.2.3'
     implementation 'org.postgresql:postgresql:42.2.18.jre7'
+    implementation 'org.apache.commons:commons-lang3:3.11'
+    implementation 'net.sf.biweekly:biweekly:0.6.5'
 }
 
 

app/src/main/java/xyz/vallat/louis/App.java

@@ -1,8 +1,26 @@
 package xyz.vallat.louis;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import xyz.vallat.louis.managers.discord.DiscordManager;
+
 public class App {
 
+    private static final Logger logger = LoggerFactory.getLogger(App.class.getCanonicalName());
+    public static final String PREFIX = "+";
+    public static final String NAME = "PrésencEirb";
+    public static final String DESCRIPTION = "Tu as pensé à pointer ?";
+    public static final String VERSION = "0.1-SNAPSHOT";
 
     public static void main(String[] args) {
+        logger.info("Starting {} ver. {}.", NAME, VERSION);
+        DiscordManager.login();
+
+        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+            logger.info("Received shut down signal. Bye!");
+            DiscordManager.logout();
+        }));
+
+        DiscordManager.onDisconnect();
     }
 }

app/src/main/java/xyz/vallat/louis/commands/Command.java

@@ -1,5 +1,57 @@
 package xyz.vallat.louis.commands;
 
+import discord4j.core.event.domain.message.MessageCreateEvent;
+import discord4j.core.object.reaction.ReactionEmoji;
+import discord4j.rest.util.Color;
+import org.apache.commons.lang3.RandomStringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Mono;
+
+import java.time.Instant;
+
 public abstract class Command {
 
+    protected static final ReactionEmoji WAITING = ReactionEmoji.unicode("⌛");
+    private static final Logger logger = LoggerFactory.getLogger(Command.class.getCanonicalName());
+    protected final String name;
+    protected final String description;
+    protected final String usage;
+
+    protected Command(String name, String description, String usage) {
+        this.name = name;
+        this.description = description;
+        this.usage = usage;
+    }
+
+    public abstract Mono<Void> execute(MessageCreateEvent event);
+
+    public String getUsage() {
+        return "``" + this.usage + "``";
+    }
+
+    public String getDescription() {
+        return this.description;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    protected Mono<Void> fatalError(MessageCreateEvent event, Throwable throwable) {
+        return event.getMessage().getChannel().flatMap(
+                channel -> channel.createEmbed(embed -> {
+                    event.getMessage().removeSelfReaction(WAITING);
+                    String errorCode = RandomStringUtils.random(8, true, true);
+                    logger.error("KERNEL PANIC: {}", errorCode, throwable);
+                    embed.setTitle("KERNEL PANIC").setColor(Color.RED)
+                            .setDescription("A fatal and unhandled error has been encountered. " +
+                                    "Please transfer this message to my administrator.")
+                            .addField("IDENTIFIER", errorCode, false).setTimestamp(Instant.now());
+                })).then();
+    }
+
+    protected String[] getArgArray(MessageCreateEvent event) {
+        return event.getMessage().getContent().substring(name.length()).split(" ");
+    }
 }

app/src/main/java/xyz/vallat/louis/commands/Lien.java

@@ -0,0 +1,20 @@
+package xyz.vallat.louis.commands;
+
+import discord4j.core.event.domain.message.MessageCreateEvent;
+import reactor.core.publisher.Mono;
+import xyz.vallat.louis.environment.EnvironmentVariables;
+
+public class Lien extends Command{
+
+    public Lien(String name) {
+        super(name, "Donne le lien vers le moodle de présence.", name);
+    }
+
+    @Override
+    public Mono<Void> execute(MessageCreateEvent event) {
+        return event.getMessage().getChannel().flatMap(messageChannel -> messageChannel.createMessage(
+                event.getMessage().getAuthor().isEmpty() ? "" :
+                        ("<@!" + event.getMessage().getAuthor().get().getId().asString() + "> ") +
+                                System.getenv(EnvironmentVariables.MOODLE_PRESENCE_LINK.getValue()))).then();
+    }
+}

app/src/main/java/xyz/vallat/louis/commands/Subscribe.java

@@ -0,0 +1,16 @@
+package xyz.vallat.louis.commands;
+
+import discord4j.core.event.domain.message.MessageCreateEvent;
+import reactor.core.publisher.Mono;
+
+public class Subscribe extends Command {
+
+    public Subscribe(String name) {
+        super(name, "S'inscrire aux rappels.", name + " <identifiant ressource>");
+    }
+
+    @Override
+    public Mono<Void> execute(MessageCreateEvent event) {
+        return event.getMessage().getChannel().flatMap(messageChannel -> messageChannel.createMessage("Ponnnng!")).then();
+    }
+}

app/src/main/java/xyz/vallat/louis/environment/EnvironmentVariables.java

@@ -1,17 +1,18 @@
 package xyz.vallat.louis.environment;
 
 public enum EnvironmentVariables {
-    DISCORD_TOKEN("DISCORD_TOKEN")
+    DISCORD_TOKEN("DISCORD_TOKEN"),
+    MOODLE_PRESENCE_LINK("MOODLE_PRESENCE_LINK")
     ;
 
 
-    private final String name;
+    private final String value;
 
     EnvironmentVariables(String name) {
-        this.name = name;
+        this.value = name;
     }
 
-    public String getName() {
-        return name;
+    public String getValue() {
+        return value;
     }
 }

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

@@ -1,12 +1,85 @@
 package xyz.vallat.louis.managers.discord;
 
+import discord4j.core.DiscordClientBuilder;
+import discord4j.core.GatewayDiscordClient;
+import discord4j.core.event.domain.lifecycle.ReadyEvent;
+import discord4j.core.event.domain.message.MessageCreateEvent;
+import discord4j.core.object.entity.User;
+import discord4j.core.object.presence.Activity;
+import discord4j.core.object.presence.Presence;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Mono;
+import xyz.vallat.louis.commands.Command;
+import xyz.vallat.louis.commands.Lien;
+import xyz.vallat.louis.commands.Subscribe;
+import xyz.vallat.louis.environment.EnvironmentVariables;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static xyz.vallat.louis.App.PREFIX;
+
 public class DiscordManager {
 
+    private static final List<Command> commands = new ArrayList<>();
+    private static final Logger logger = LoggerFactory.getLogger(DiscordManager.class.getCanonicalName());
+    private static GatewayDiscordClient discordClient;
+
+    static {
+        commands.add(new Subscribe(PREFIX + "subscribe"));
+        commands.add(new Lien(PREFIX + "lien"));
+    }
+
     private DiscordManager() {
     }
 
+    public static void logout() {
+        discordClient.logout().block();
+    }
+
+    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 -> event.getMessage().getContent().split(" ")[0].equals(command.getName()))
+                    .flatMap(event -> command.execute(event).then())
+                    .subscribe();
+    }
+
     public static void login() {
+        discordClient = DiscordClientBuilder.create(System.getenv(EnvironmentVariables.DISCORD_TOKEN.getValue()))
+                .build().login().retry(2)
+                .onErrorMap(throwable -> {
+                            logger.error("Cannot login to Discord right now. Reason: {}", throwable.getMessage());
+                            return throwable;
+                        }
+                ).block();
+        assert discordClient != null;
+        setOnline();
+        discordClient.getEventDispatcher().on(ReadyEvent.class)
+                .subscribe(event -> {
+                    User self = event.getSelf();
+                    logger.info("Logged in on Discord as {}#{}.", self.getUsername(), self.getDiscriminator());
+                });
+        registerDiscordCommands();
+    }
 
+    public static void onDisconnect() {
+        discordClient.onDisconnect().block();
+    }
+
+    public static Mono<Long> getGuilds() {
+        return discordClient.getGuilds().count();
+    }
+
+    public static List<Command> getCommands() {
+        return new ArrayList<>(commands);
+    }
+
+    public static void setOnline() {
+        if (discordClient != null)
+            discordClient.updatePresence(Presence.online(Activity.watching("vos emplois du temps"))).subscribe();
     }
 
 }