feat: create role application command

Co-authored-by: Suraj Kumar <76599223+surajkumar@users.noreply.github.com>

application/src/main/java/org/togetherjava/tjbot/features/Features.java

@@ -64,6 +64,7 @@
 import org.togetherjava.tjbot.features.moderation.temp.TemporaryModerationRoutine;
 import org.togetherjava.tjbot.features.reminder.RemindRoutine;
 import org.togetherjava.tjbot.features.reminder.ReminderCommand;
+import org.togetherjava.tjbot.features.roleapplication.ApplicationCreateCommand;
 import org.togetherjava.tjbot.features.system.BotCore;
 import org.togetherjava.tjbot.features.system.LogLevelCommand;
 import org.togetherjava.tjbot.features.tags.TagCommand;
@@ -192,6 +193,7 @@ public static Collection<Feature> createFeatures(JDA jda, Database database, Con
         features.add(new BookmarksCommand(bookmarksSystem));
         features.add(new ChatGptCommand(chatGptService, helpSystemHelper));
         features.add(new JShellCommand(jshellEval));
+        features.add(new ApplicationCreateCommand(config));
 
         FeatureBlacklist<Class<?>> blacklist = blacklistConfig.normal();
         return blacklist.filterStream(features.stream(), Object::getClass).toList();

application/src/main/java/org/togetherjava/tjbot/features/roleapplication/ApplicationApplyHandler.java

@@ -0,0 +1,132 @@
+package org.togetherjava.tjbot.features.roleapplication;
+
+import com.github.benmanes.caffeine.cache.Cache;
+import com.github.benmanes.caffeine.cache.Caffeine;
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.entities.Guild;
+import net.dv8tion.jda.api.entities.Member;
+import net.dv8tion.jda.api.entities.MessageEmbed;
+import net.dv8tion.jda.api.entities.User;
+import net.dv8tion.jda.api.entities.channel.concrete.TextChannel;
+import net.dv8tion.jda.api.events.interaction.ModalInteractionEvent;
+import net.dv8tion.jda.api.interactions.modals.ModalMapping;
+
+import org.togetherjava.tjbot.config.ApplicationFormConfig;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.util.List;
+import java.util.Optional;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+
+/**
+ * Handles the actual process of submitting role applications.
+ * <p>
+ * This class is responsible for managing application submissions via modal interactions, ensuring
+ * that submissions are sent to the appropriate application channel, and enforcing cooldowns for
+ * users to prevent spamming.
+ */
+public class ApplicationApplyHandler {
+
+    private final Cache<Member, OffsetDateTime> applicationSubmitCooldown;
+    private final Predicate<String> applicationChannelPattern;
+    private final ApplicationFormConfig formConfig;
+
+    /**
+     * Constructs a new {@code ApplicationApplyHandler} instance.
+     *
+     * @param formConfig the configuration that contains the details for the application form
+     *        including the cooldown duration and channel pattern.
+     */
+    public ApplicationApplyHandler(ApplicationFormConfig formConfig) {
+        this.formConfig = formConfig;
+        this.applicationChannelPattern =
+                Pattern.compile(formConfig.applicationChannelPattern()).asMatchPredicate();
+
+        final Duration applicationSubmitCooldownDuration =
+                Duration.ofMinutes(formConfig.applicationSubmitCooldownMinutes());
+        applicationSubmitCooldown =
+                Caffeine.newBuilder().expireAfterWrite(applicationSubmitCooldownDuration).build();
+    }
+
+    /**
+     * Sends the result of an application submission to the designated application channel in the
+     * guild.
+     * <p>
+     * The {@code args} parameter should contain the applicant's name and the role they are applying
+     * for.
+     *
+     * @param event the modal interaction event triggering the application submission
+     * @param args the arguments provided in the application submission
+     * @param answer the answer provided by the applicant to the default question
+     */
+    protected void sendApplicationResult(final ModalInteractionEvent event, List<String> args,
+            String answer) {
+        Guild guild = event.getGuild();
+        if (args.size() != 2 || guild == null) {
+            return;
+        }
+
+        Optional<TextChannel> applicationChannel = getApplicationChannel(guild);
+        if (applicationChannel.isEmpty()) {
+            return;
+        }
+
+        User applicant = event.getUser();
+        EmbedBuilder embed =
+                new EmbedBuilder().setAuthor(applicant.getName(), null, applicant.getAvatarUrl())
+                    .setColor(ApplicationCreateCommand.AMBIENT_COLOR)
+                    .setTimestamp(Instant.now())
+                    .setFooter("Submitted at");
+
+        String roleString = args.getLast();
+        MessageEmbed.Field roleField = new MessageEmbed.Field("Role", roleString, false);
+        embed.addField(roleField);
+
+        MessageEmbed.Field answerField =
+                new MessageEmbed.Field(formConfig.defaultQuestion(), answer, false);
+        embed.addField(answerField);
+
+        applicationChannel.get().sendMessageEmbeds(embed.build()).queue();
+    }
+
+    /**
+     * Retrieves the application channel from the given {@link Guild}.
+     *
+     * @param guild the guild from which to retrieve the application channel
+     * @return an {@link Optional} containing the {@link TextChannel} representing the application
+     *         channel, or an empty {@link Optional} if no such channel is found
+     */
+    private Optional<TextChannel> getApplicationChannel(Guild guild) {
+        return guild.getChannels()
+            .stream()
+            .filter(channel -> applicationChannelPattern.test(channel.getName()))
+            .filter(channel -> channel.getType().isMessage())
+            .map(TextChannel.class::cast)
+            .findFirst();
+    }
+
+    public Cache<Member, OffsetDateTime> getApplicationSubmitCooldown() {
+        return applicationSubmitCooldown;
+    }
+
+    protected void submitApplicationFromModalInteraction(ModalInteractionEvent event,
+            List<String> args) {
+        Guild guild = event.getGuild();
+
+        if (guild == null) {
+            return;
+        }
+
+        ModalMapping modalAnswer = event.getValues().getFirst();
+
+        sendApplicationResult(event, args, modalAnswer.getAsString());
+        event.reply("Your application has been submitted. Thank you for applying! 😎")
+            .setEphemeral(true)
+            .queue();
+
+        applicationSubmitCooldown.put(event.getMember(), OffsetDateTime.now());
+    }
+}