Changed the command interface to an abstract method and added better error handling

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

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

@@ -35,9 +35,9 @@ public class MovieQuoteBot {
     private static GatewayDiscordClient discordClient;
 
     static {
-        commands.put("ping", new Ping());
+        commands.put("ping", new Ping(PREFIX + "ping"));
-        commands.put("version", new Version());
+        commands.put("version", new Version(PREFIX + "version"));
-        commands.put("search", new Search());
+        commands.put("search", new Search(PREFIX + "search"));
     }
 
     public static void main(String[] args) {

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

@@ -3,7 +3,37 @@ package xyz.vallat.louis.commands;
 import discord4j.core.event.domain.message.MessageCreateEvent;
 import reactor.core.publisher.Mono;
 
-public interface Command {
+public abstract class Command {
 
-    Mono<Void> execute(MessageCreateEvent event);
+    protected final String name;
+    protected final String description;
+    protected final String usage;
+    protected final int minArgs;
+    protected final int maxArgs;
+
+    Command(String name, String description, String usage, int minArgs, int maxArgs) {
+        this.name = name;
+        this.description = description;
+        this.usage = usage;
+        this.minArgs = minArgs;
+        this.maxArgs = maxArgs;
+    }
+
+    public abstract Mono<Void> execute(MessageCreateEvent event);
+
+    public String getUsage() {
+        return this.usage;
+    }
+
+    public String getDescription() {
+        return this.description;
+    }
+
+    public int getMinArgs() {
+        return minArgs;
+    }
+
+    public int getMaxArgs() {
+        return maxArgs;
+    }
 }

src/main/java/xyz/vallat/louis/commands/Ping.java

@@ -3,7 +3,11 @@ package xyz.vallat.louis.commands;
 import discord4j.core.event.domain.message.MessageCreateEvent;
 import reactor.core.publisher.Mono;
 
-public class Ping implements Command {
+public class Ping extends Command {
+
+    public Ping(String name) {
+        super(name, "Replies as soon as possible to check the bot's health.", name, 0, 0);
+    }
 
     @Override
     public Mono<Void> execute(MessageCreateEvent event) {

src/main/java/xyz/vallat/louis/commands/Search.java

@@ -2,34 +2,51 @@ package xyz.vallat.louis.commands;
 
 import com.github.wtekiela.opensub4j.response.ListResponse;
 import com.github.wtekiela.opensub4j.response.MovieInfo;
+import com.github.wtekiela.opensub4j.response.ResponseStatus;
 import discord4j.core.event.domain.message.MessageCreateEvent;
 import discord4j.core.object.reaction.ReactionEmoji;
 import org.apache.xmlrpc.XmlRpcException;
 import reactor.core.publisher.Mono;
 import xyz.vallat.louis.subtitles.OpenSubtitles;
 
-public class Search implements Command {
+public class Search extends Command {
 
     private static final ReactionEmoji WAITING = ReactionEmoji.unicode("⌛");
+    String format = "%1$-7s - %2$s\n";
+
+    public Search(String name) {
+        super(name, "A command to search some subtitles.", name + " <name>", 1, 1);
+    }
 
     @Override
     public Mono<Void> execute(MessageCreateEvent event) {
         String[] args = event.getMessage().getContent().split(" ");
-        if (args.length != 1) return event.getMessage().getChannel().flatMap(channel -> channel.createMessage("Misuse")).then();
+        if (args.length < minArgs)
+            return event.getMessage().getChannel()
+                    .flatMap(channel -> channel.createMessage("Error.\n" + getUsage()))
+                    .then();
         return event.getMessage().getChannel()
                 .flatMap(channel -> {
                     if (OpenSubtitles.isLoggedIn()) {
                         return event.getMessage().addReaction(WAITING)
-                                .then(event.getMessage().getChannel().flatMap(messageChannel -> messageChannel.createMessage(args[1])))
                                 .then(event.getMessage().getChannel().flatMap(messageChannel -> {
                                     try {
                                         ListResponse<MovieInfo> response = OpenSubtitles.searchImdb(args[1]);
-                                        StringBuilder b = new StringBuilder();
+                                        if (response.getStatus() == ResponseStatus.OK) {
-                                        for (MovieInfo m : response.getData())
+                                            return messageChannel.createEmbed(
-                                            b.append(m.getId()).append(" > ").append(m.getTitle()).append("\n");
+                                                    embed -> {
-                                        return messageChannel.createMessage(String.valueOf(b));
+                                                        embed.setTitle("Results")
+                                                                .setDescription("Found " + response.getData().size() + " results.");
+                                                        StringBuilder s = new StringBuilder("```txt\n");
+                                                        for (MovieInfo info : response.getData().subList(0, 10))
+                                                            s.append(String.format(format, info.getId(), info.getTitle()));
+                                                        s.append("```");
+                                                        embed.addField("First 10 results:", s.toString(), false);
+                                                    });
+                                        } else
+                                            return messageChannel.createMessage("An error happened while fetching the results. Try again later, or contact my administrator.");
                                     } catch (XmlRpcException e) {
-                                        return channel.createMessage("Error");
+                                        return channel.createMessage("It seems like OpenSubtitles had a stroke.");
                                     }
                                 }))
                                 .then(event.getMessage().removeSelfReaction(WAITING))

src/main/java/xyz/vallat/louis/commands/Version.java

@@ -5,7 +5,11 @@ import discord4j.rest.util.Color;
 import reactor.core.publisher.Mono;
 import xyz.vallat.louis.MovieQuoteBot;
 
-public class Version implements Command {
+public class Version extends Command {
+
+    public Version(String name) {
+        super(name, "Give some information about the bot.", name, 0, 0);
+    }
 
     @Override
     public Mono<Void> execute(MessageCreateEvent event) {