added concept of undo actions

used undo actions to delete the mod mail thread channel, if it already reached a certain state when initially setting up the mod mail thread

abstracto-application/abstracto-modules/modmail/modmail-impl/src/main/java/dev/sheldan/abstracto/modmail/service/ModMailThreadServiceBean.java

@@ -5,6 +5,7 @@ import com.jagrosh.jdautilities.menu.ButtonMenu;
 import dev.sheldan.abstracto.core.exception.PostTargetException;
 import dev.sheldan.abstracto.core.models.FullGuild;
 import dev.sheldan.abstracto.core.models.FullUser;
+import dev.sheldan.abstracto.core.models.UndoActionInstance;
 import dev.sheldan.abstracto.core.models.database.*;
 import dev.sheldan.abstracto.core.service.*;
 import dev.sheldan.abstracto.core.service.management.ChannelManagementService;
@@ -83,6 +84,9 @@ public class ModMailThreadServiceBean implements ModMailThreadService {
     @Autowired
     private ModMailRoleManagementService modMailRoleManagementService;
 
+    @Autowired
+    private UndoActionService undoActionService;
+
     @Autowired
     private ModMailSubscriberManagementService modMailSubscriberManagementService;
 
@@ -102,7 +106,9 @@ public class ModMailThreadServiceBean implements ModMailThreadService {
         CompletableFuture<TextChannel> textChannel = channelService.createTextChannel(user.getName() + user.getDiscriminator(), aUserInAServer.getAUserInAServer().getServerReference(), categoryId);
 
         textChannel.thenAccept(channel -> {
-            self.performModMailThreadSetup(aUserInAServer, channel, userInitiated);
+            List<UndoActionInstance> undoActions = new ArrayList<>();
+            undoActions.add(UndoActionInstance.getChannelDeleteAction(channel.getIdLong(), aUserInAServer.getAUserInAServer().getServerReference().getId()));
+            self.performModMailThreadSetup(aUserInAServer, channel, userInitiated, undoActions);
         }).exceptionally(throwable -> {
             log.error("Failed to create mod mail thread", throwable);
             sendModMailFailure("modmail_exception_failed_to_create_mod_mail_thread",  aUserInAServer.getAUserInAServer(), null, feedBackChannel, throwable);
@@ -111,15 +117,20 @@ public class ModMailThreadServiceBean implements ModMailThreadService {
     }
 
     @Transactional
-    public void performModMailThreadSetup(FullUser aUserInAServer, TextChannel channel, Boolean userInitiated) {
+    public void performModMailThreadSetup(FullUser aUserInAServer, TextChannel channel, Boolean userInitiated, List<UndoActionInstance> undoActions) {
-        ModMailThread thread = createThreadObject(channel, aUserInAServer);
+        try {
-        sendModMailHeader(channel, aUserInAServer);
+            ModMailThread thread = createThreadObject(channel, aUserInAServer);
-        if(userInitiated) {
+            sendModMailHeader(channel, aUserInAServer, undoActions);
-            sendModMailNotification(aUserInAServer, thread);
+            if(userInitiated) {
+                sendModMailNotification(aUserInAServer, thread, undoActions);
+            }
+        } catch (Exception e) {
+            log.error("Failed to perform mod mail thread setup.", e);
+            undoActionService.performActions(undoActions);
         }
     }
 
-    private void sendModMailNotification(FullUser aUserInAServer, ModMailThread thread) {
+    private void sendModMailNotification(FullUser aUserInAServer, ModMailThread thread, List<UndoActionInstance> undoActions) {
         List<ModMailRole> rolesToPing = modMailRoleManagementService.getRolesForServer(thread.getServer());
         ModMailNotificationModel modMailNotificationModel = ModMailNotificationModel
                 .builder()
@@ -128,7 +139,13 @@ public class ModMailThreadServiceBean implements ModMailThreadService {
                 .roles(rolesToPing)
                 .build();
         MessageToSend messageToSend = templateService.renderEmbedTemplate("modmail_notification_message", modMailNotificationModel);
-        postTargetService.sendEmbedInPostTarget(messageToSend, "modmailping", thread.getServer().getId());
+        List<CompletableFuture<Message>> modmailping = postTargetService.sendEmbedInPostTarget(messageToSend, "modmailping", thread.getServer().getId());
+        CompletableFuture.allOf(modmailping.toArray(new CompletableFuture[0])).whenComplete((aVoid, throwable) -> {
+            if(throwable != null) {
+                log.error("Failed to send mod mail thread notification ping.", throwable);
+                undoActionService.performActions(undoActions);
+            }
+        });
     }
 
     public ModMailThread createThreadObject(TextChannel channel, FullUser user) {
@@ -203,7 +220,7 @@ public class ModMailThreadServiceBean implements ModMailThreadService {
     }
 
 
-    private void sendModMailHeader(TextChannel channel, FullUser aUserInAServer) {
+    private void sendModMailHeader(TextChannel channel, FullUser aUserInAServer, List<UndoActionInstance> undoActions) {
         ModMailThread latestThread = modMailThreadManagementService.getLatestModMailThread(aUserInAServer.getAUserInAServer());
         List<ModMailThread> oldThreads = modMailThreadManagementService.getModMailThreadForUser(aUserInAServer.getAUserInAServer());
         ModMailThreaderHeader header = ModMailThreaderHeader
@@ -212,7 +229,13 @@ public class ModMailThreadServiceBean implements ModMailThreadService {
                 .latestModMailThread(latestThread)
                 .pastModMailThreadCount((long)oldThreads.size())
                 .build();
-        channelService.sendTemplateInChannel("modmail_thread_header", header, channel);
+        List<CompletableFuture<Message>> messages = channelService.sendTemplateInChannel("modmail_thread_header", header, channel);
+        CompletableFuture.allOf(messages.toArray(new CompletableFuture[0])).whenComplete((aVoid, throwable)-> {
+            if(throwable != null) {
+                log.error("Failed to send mod mail header for for user {}.", aUserInAServer.getAUserInAServer().getUserReference().getId(), throwable);
+                undoActionService.performActions(undoActions);
+            }
+        });
     }
 
     @Override

abstracto-application/core/core-impl/src/main/java/dev/sheldan/abstracto/core/service/ChannelServiceBean.java

@@ -168,11 +168,16 @@ public class ChannelServiceBean implements ChannelService {
 
     @Override
     public CompletableFuture<Void> deleteTextChannel(AChannel channel) {
-        TextChannel textChannelById = botService.getInstance().getTextChannelById(channel.getId());
+       return deleteTextChannel(channel.getServer().getId(), channel.getId());
+    }
+
+    @Override
+    public CompletableFuture<Void> deleteTextChannel(Long serverId, Long channelId) {
+        TextChannel textChannelById = botService.getInstance().getTextChannelById(channelId);
         if(textChannelById != null) {
             return textChannelById.delete().submit();
         }
-        throw new ChannelException(String.format("Failed to delete channel %s in server %s", channel.getId(), channel.getServer().getId()));
+        throw new ChannelException(String.format("Failed to delete channel %s in server %s", channelId, serverId));
     }
 
     @Override

abstracto-application/core/core-impl/src/main/java/dev/sheldan/abstracto/core/service/UndoActionServiceBean.java

@@ -0,0 +1,43 @@
+package dev.sheldan.abstracto.core.service;
+
+import dev.sheldan.abstracto.core.exception.UndoActionException;
+import dev.sheldan.abstracto.core.models.UndoAction;
+import dev.sheldan.abstracto.core.models.UndoActionInstance;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+
+@Component
+@Slf4j
+public class UndoActionServiceBean implements UndoActionService {
+
+    @Autowired
+    private BotService botService;
+
+    @Autowired
+    private ChannelService channelService;
+
+    @Override
+    public void performActions(List<UndoActionInstance> actionsToPerform) {
+        actionsToPerform.forEach(undoActionInstance -> {
+            UndoAction action = undoActionInstance.getAction();
+            switch (action) {
+                case DELETE_CHANNEL:
+                    if(undoActionInstance.getIds().size() != 2) {
+                        throw new UndoActionException("Not the correct amount of ides provided for the channel deletion undo action");
+                    }
+                    deleteChannel(undoActionInstance.getIds().get(0), undoActionInstance.getIds().get(1));
+                    break;
+            }
+        });
+    }
+
+    private void deleteChannel(Long serverId, Long channelId) {
+        channelService.deleteTextChannel(serverId, channelId).exceptionally((throwable) -> {
+            log.error("Failed to execute undo action channel delete for channel {} in server {}", channelId, serverId, throwable);
+            return null;
+        });
+    }
+}

abstracto-application/core/core-interface/src/main/java/dev/sheldan/abstracto/core/exception/UndoActionException.java

@@ -0,0 +1,7 @@
+package dev.sheldan.abstracto.core.exception;
+
+public class UndoActionException extends AbstractoRunTimeException {
+    public UndoActionException(String message) {
+        super(message);
+    }
+}

abstracto-application/core/core-interface/src/main/java/dev/sheldan/abstracto/core/models/UndoAction.java

@@ -0,0 +1,5 @@
+package dev.sheldan.abstracto.core.models;
+
+public enum UndoAction {
+    DELETE_CHANNEL, DELETE_MESSAGE
+}

abstracto-application/core/core-interface/src/main/java/dev/sheldan/abstracto/core/models/UndoActionInstance.java

@@ -0,0 +1,24 @@
+package dev.sheldan.abstracto.core.models;
+
+import lombok.Builder;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.Arrays;
+import java.util.List;
+
+@Getter
+@Builder
+@Setter
+public class UndoActionInstance {
+    private List<Long> ids;
+    private UndoAction action;
+
+    public static UndoActionInstance getChannelDeleteAction(Long channelId, Long serverId) {
+        return UndoActionInstance
+                .builder()
+                .action(UndoAction.DELETE_CHANNEL)
+                .ids(Arrays.asList(serverId, channelId))
+                .build();
+    }
+}

abstracto-application/core/core-interface/src/main/java/dev/sheldan/abstracto/core/service/ChannelService.java

@@ -27,6 +27,7 @@ public interface ChannelService {
     void editMessageInAChannel(MessageToSend messageToSend, AChannel channel, Long messageId);
     void editMessageInAChannel(MessageToSend messageToSend, MessageChannel channel, Long messageId);
     CompletableFuture<Void> deleteTextChannel(AChannel channel);
+    CompletableFuture<Void> deleteTextChannel(Long serverId, Long channelId);
     List<CompletableFuture<Message>> sendTemplateInChannel(String templateKey, Object model, MessageChannel channel);
 
     CompletableFuture<TextChannel> createTextChannel(String name, AServer server, Long categoryId);

abstracto-application/core/core-interface/src/main/java/dev/sheldan/abstracto/core/service/UndoActionService.java

@@ -0,0 +1,9 @@
+package dev.sheldan.abstracto.core.service;
+
+import dev.sheldan.abstracto.core.models.UndoActionInstance;
+
+import java.util.List;
+
+public interface UndoActionService {
+    void performActions(List<UndoActionInstance> actionsToPerform);
+}