Make trivia loop through all questions

src/main/java/wtf/beatrice/hidekobot/runnables/TriviaTask.java

@@ -1,10 +1,107 @@
 package wtf.beatrice.hidekobot.runnables;
 
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.User;
+import net.dv8tion.jda.api.entities.channel.middleman.MessageChannel;
+import net.dv8tion.jda.api.interactions.components.buttons.Button;
+import org.json.JSONObject;
+import wtf.beatrice.hidekobot.Cache;
+import wtf.beatrice.hidekobot.objects.TriviaQuestion;
+import wtf.beatrice.hidekobot.util.CommandUtil;
+import wtf.beatrice.hidekobot.util.TriviaUtil;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ScheduledFuture;
+
 public class TriviaTask implements Runnable
 {
 
+    private final User author;
+    private final MessageChannel channel;
+
+    private Message previousMessage = null;
+
+    private final JSONObject triviaJson;
+    private final List<TriviaQuestion> questions;
+
+    ScheduledFuture<?> future = null;
+
+    private int iteration = 0;
+
+    public TriviaTask(User author, MessageChannel channel)
+    {
+        this.author = author;
+        this.channel = channel;
+
+        triviaJson = TriviaUtil.fetchTrivia();
+        questions = TriviaUtil.getQuestions(triviaJson); //todo: null check, rate limiting...
+    }
+
+    public void setScheduledFuture(ScheduledFuture<?> future)
+    {
+        this.future = future;
+    }
+
     @Override
     public void run() {
 
+        if(previousMessage != null)
+        {
+            // todo: we shouldn't use this method, since it messes with the database...
+            CommandUtil.disableExpired(previousMessage.getId());
+        }
+
+        if(iteration >= questions.size())
+        {
+            // todo: nicer-looking embed with stats
+            channel.sendMessage("Trivia session is over!").queue();
+
+            TriviaUtil.channelsRunningTrivia.remove(channel.getId());
+            future.cancel(false);
+            // we didn't implement null checks on the future on purpose, because we need to know if we were unable
+            // to cancel it (and console errors should make it clear enough).
+            return;
+        }
+
+        TriviaQuestion currentTriviaQuestion = questions.get(iteration);
+
+        List<Button> answerButtons = new ArrayList<>();
+
+        Button correctAnswerButton = Button.primary("trivia_correct", currentTriviaQuestion.correctAnswer());
+        answerButtons.add(correctAnswerButton);
+
+        int i = 0; // we need to add a number because buttons can't have the same id
+        for(String wrongAnswer : currentTriviaQuestion.wrongAnswers())
+        {
+            i++;
+            Button wrongAnswerButton = Button.primary("trivia_wrong_" + i, wrongAnswer);
+            answerButtons.add(wrongAnswerButton);
+        }
+
+        Collections.shuffle(answerButtons);
+
+        EmbedBuilder embedBuilder = new EmbedBuilder();
+
+        embedBuilder.setColor(Cache.getBotColor());
+        embedBuilder.setTitle("Trivia (" + (iteration+1) + "/" + questions.size() + ")");
+
+        embedBuilder.addField("Question", currentTriviaQuestion.question(), false);
+
+        previousMessage = channel
+                .sendMessageEmbeds(embedBuilder.build())
+                .setActionRow(answerButtons)
+                .complete();
+
+        Cache.getDatabaseSource().trackRanCommandReply(previousMessage, author);
+        // todo: ^ we should get rid of this tracking, since we don't need to know who started the trivia.
+        // todo: however, for now, that's the only way to avoid a thread-locking scenario as some data is
+        // todo: only stored in that table. this should be solved when we merge / fix the two main tables.
+        // todo: then, we can remove this instruction.
+        Cache.getDatabaseSource().queueDisabling(previousMessage);
+
+        iteration++;
     }
 }