Initial refactor to organize button interactions

app/src/main/java/musicbot/ButtonInteraction.java

@@ -0,0 +1,9 @@
+package musicbot;
+
+import net.dv8tion.jda.api.events.interaction.component.ButtonInteractionEvent;
+
+public interface ButtonInteraction {
+  String getName();
+
+  void execute(ButtonInteractionEvent event);
+}

app/src/main/java/musicbot/ButtonInteractionManager.java

@@ -0,0 +1,29 @@
+package musicbot;
+
+import net.dv8tion.jda.api.events.interaction.component.ButtonInteractionEvent;
+import net.dv8tion.jda.api.hooks.ListenerAdapter;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ButtonInteractionManager extends ListenerAdapter {
+  private final List<ButtonInteraction> buttonInteractions = new ArrayList<>();
+
+  @Override
+  public void onButtonInteraction(@NotNull ButtonInteractionEvent event) {
+    final String id = event.getComponent().getId();
+
+    final String[] args = id.split("_");
+
+    for (final ButtonInteraction buttonInteraction : buttonInteractions) {
+      if (args[0].equals(buttonInteraction.getName())) {
+        buttonInteraction.execute(event);
+      }
+    }
+  }
+
+  public void add(@NotNull final ButtonInteraction buttonInteraction) {
+    buttonInteractions.add(buttonInteraction);
+  }
+}

app/src/main/java/musicbot/Listeners.java

@@ -0,0 +1,53 @@
+package musicbot;
+
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.events.interaction.component.ButtonInteractionEvent;
+import net.dv8tion.jda.api.hooks.ListenerAdapter;
+import net.dv8tion.jda.api.interactions.components.buttons.Button;
+import org.jetbrains.annotations.NotNull;
+import java.util.List;
+
+public class Listeners extends ListenerAdapter {
+
+  @Override
+  public void onButtonInteraction(@NotNull ButtonInteractionEvent event) {
+    final String id = event.getComponent().getId();
+    final String label = event.getComponent().getLabel();
+
+    final String[] args = id.split("_");
+    event.deferReply().queue();
+
+    if (args[0].equalsIgnoreCase("recommend")) {
+
+      final YoutubeSearch youtubeSearch = new YoutubeSearch();
+      final String result = youtubeSearch.searchForMusic(label, args[1]);
+
+      event.getHook().sendMessage(result).queue();
+    }
+
+    if (args[0].equalsIgnoreCase("genre")) {
+      final int page = Integer.parseInt(args[1]);
+      final int offset = page * 10;
+      final int index = offset + 10;
+      final int nextPage = page + 1;
+
+      final SpotifyClient spotifyClient = new SpotifyClient();
+      final List<String> genres = spotifyClient.findGenres();
+      final int maxSize = genres.size();
+      final int maxPage = (int) Math.floor(maxSize / 10);
+
+      final EmbedBuilder eb = new EmbedBuilder();
+
+      if (nextPage <= maxPage) {
+        genres.subList(offset, index).forEach(genreItem -> eb.addField(genreItem, "", false));
+
+        event.getHook().sendMessageEmbeds(eb.build()).addActionRow(
+            Button.primary("genre_" + nextPage, "More")
+        ).queue();
+      } else {
+        genres.subList(offset, maxSize).forEach(genreItem -> eb.addField(genreItem, "", false));
+        event.getHook().sendMessageEmbeds(eb.build()).queue();
+      }
+    }
+  }
+}

app/src/main/java/musicbot/Main.java

@@ -1,5 +1,6 @@
 package musicbot;
 
+import musicbot.buttonInteractions.MoreRecommendation;
 import musicbot.commands.Artist;
 import musicbot.commands.Genres;
 import musicbot.commands.MusicVideo;
@@ -11,12 +12,21 @@ public class Main {
     final JDA jda = JDABuilder
         .createDefault(Token.TOKEN)
         .build();
-    final CommandManager manager = new CommandManager();
-    manager.add(new Artist());
-    manager.add(new Genres());
-    manager.add(new MusicVideo());
-    manager.add(new Recommend());
-    jda.addEventListener(manager);
+    final CommandManager commandManager = new CommandManager();
+    final ButtonInteractionManager buttonInteractionManager = new ButtonInteractionManager();
+
+    // commands
+    commandManager.add(new Artist());
+    commandManager.add(new Genres());
+    commandManager.add(new MusicVideo());
+    commandManager.add(new Recommend());
+
+    // button interactions
+    buttonInteractionManager.add(new MoreRecommendation());
+
+    // add the managers
+    jda.addEventListener(commandManager);
+    jda.addEventListener(buttonInteractionManager);
     jda.addEventListener(new Listeners());
   }
 }

app/src/main/java/musicbot/RecommendationService.java

@@ -0,0 +1,38 @@
+package musicbot;
+
+import com.google.common.collect.ImmutableList;
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.entities.MessageEmbed;
+import net.dv8tion.jda.api.interactions.commands.OptionMapping;
+import net.dv8tion.jda.api.interactions.components.buttons.Button;
+import se.michaelthelin.spotify.model_objects.specification.Artist;
+import se.michaelthelin.spotify.model_objects.specification.ArtistSimplified;
+import se.michaelthelin.spotify.model_objects.specification.Track;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+public class RecommendationService {
+
+  public List<Track> getRecommendations(final String artist, final String genre, final int page) {
+
+    if (artist.isEmpty() && genre.isEmpty()) {
+      return ImmutableList.of();
+    }
+    final SpotifyClient spotifyClient = new SpotifyClient();
+    final Optional<String> maybeArtistId = findArtistId(artist);
+    final String artistId = maybeArtistId.orElse("");
+    final List<Track> tracks = spotifyClient.findRecommendations(artistId, genre);
+
+    return tracks;
+  }
+
+  private Optional<String> findArtistId(final String artist) {
+    final SpotifyClient spotifyClient = new SpotifyClient();
+    final Optional<Artist> maybeArtist = spotifyClient.findArtist(artist);
+
+    return maybeArtist.map(Artist::getId);
+  }
+}

app/src/main/java/musicbot/buttonInteractions/MoreRecommendation.java

@@ -0,0 +1,86 @@
+package musicbot.buttonInteractions;
+
+import musicbot.ButtonInteraction;
+import musicbot.RecommendationService;
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.entities.MessageEmbed;
+import net.dv8tion.jda.api.events.interaction.component.ButtonInteractionEvent;
+import net.dv8tion.jda.api.interactions.components.buttons.Button;
+import se.michaelthelin.spotify.model_objects.specification.ArtistSimplified;
+import se.michaelthelin.spotify.model_objects.specification.Track;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class MoreRecommendation implements ButtonInteraction {
+  private static final int INCREMENT = 5;
+  private static final String ARGS_DELIMITER = "_";
+  private static final String ARTIST_GENRE_DELIMITER = "--";
+  private static final int NUM_RECOMMENDATIONS = 5;
+
+  @Override
+  public String getName() {
+    return "more-recommend";
+  }
+
+  @Override
+  public void execute(final ButtonInteractionEvent event) {
+    final String id = event.getComponent().getId();
+    final String[] args = id.split(ARGS_DELIMITER);
+    final String[] artistGenre = args[1].split(ARTIST_GENRE_DELIMITER);
+    final String artist = artistGenre[0];
+    final String genre = artistGenre.length < 2 ? "" : artistGenre[1];
+    final int page = Integer.parseInt(args[2]);
+    final int nextPage = page + 1;
+    final int maxIndex = INCREMENT * page;
+    final int baseIndex = maxIndex - INCREMENT;
+
+    final List<Track> tracks = new RecommendationService().getRecommendations(artist, genre, page);
+    final int maxSize = tracks.size();
+    final int maxPage = (int) Math.floor(maxSize / NUM_RECOMMENDATIONS);
+
+    final EmbedBuilder eb = new EmbedBuilder();
+    final List<Track> trackList = tracks.subList(baseIndex, maxIndex);
+    if (!trackList.isEmpty()) {
+      eb
+          .setTitle("More recommendations based on \"" + artist + "\"")
+          .setDescription("Here are more recommendations based on your input.");
+
+      trackList.forEach(track -> {
+        final List<String> trackArtists = Arrays.stream(track.getArtists())
+            .map(ArtistSimplified::getName)
+            .collect(Collectors.toList());
+        final String artists = String.join(", ", trackArtists);
+
+        eb.addField(track.getName(), artists, false);
+      });
+
+      final MessageEmbed embed = eb.build();
+
+      final List<Button> buttons = trackList.stream().map(track -> {
+        final String artists = Arrays.stream(track.getArtists()).map(ArtistSimplified::getName)
+            .collect(Collectors.joining(", "));
+
+        return Button.primary("recommend_" + artists, track.getName());
+      }).collect(Collectors.toList());
+
+      if (nextPage <= maxPage) {
+        final String buttonId = "more-recommend_" + artist + "--" + genre + "_" + nextPage;
+
+        event
+            .getHook()
+            .sendMessageEmbeds(embed)
+            .addActionRow(buttons)
+            .addActionRow(Button.secondary(buttonId, "Get more recommendations"))
+            .queue();
+      } else {
+        event
+            .getHook()
+            .sendMessageEmbeds(embed)
+            .addActionRow(buttons)
+            .queue();
+      }
+    }
+  }
+}