handling error when member left guild (#986)

* handling error when member left guild

* taking carre of debugging leftovers

* sonar fix

* refactor loggers, archiving thread incase of failure

* fallback archiving in same queue

* archive logic in supplier

* consumer only logs, so better name

* refactor error handling in rest chain

* refactor if check for clarity

* extra line for readabilty

* sonar fix

* handling error in pipeline

* cleaning up debugging leftovers

* renaming from logger -> LOGGER

* log level changed to info with better message

* logging all the errors, instead of just ErrorResponseException type

* refactoring
* replacing Function type with Supplier for sendEmbedWithoutMention
* changing variable for more clarity on fetched members

* reverting back LOGGER->logger based on project style

* removing unnecessary error handling

Author: ankitsmt211

application/src/main/java/org/togetherjava/tjbot/features/help/HelpThreadAutoArchiver.java

@@ -3,11 +3,14 @@
 import net.dv8tion.jda.api.EmbedBuilder;
 import net.dv8tion.jda.api.JDA;
 import net.dv8tion.jda.api.entities.Guild;
+import net.dv8tion.jda.api.entities.Member;
+import net.dv8tion.jda.api.entities.Message;
 import net.dv8tion.jda.api.entities.MessageEmbed;
 import net.dv8tion.jda.api.entities.channel.concrete.ForumChannel;
 import net.dv8tion.jda.api.entities.channel.concrete.ThreadChannel;
 import net.dv8tion.jda.api.entities.channel.middleman.MessageChannel;
-import net.dv8tion.jda.api.exceptions.ErrorResponseException;
+import net.dv8tion.jda.api.requests.RestAction;
+import net.dv8tion.jda.api.utils.Result;
 import net.dv8tion.jda.api.utils.TimeUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -19,7 +22,8 @@
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
-import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
 
 /**
  * Routine, which periodically checks all help threads and archives them if there has not been any
@@ -122,18 +126,27 @@ private static boolean shouldBeArchived(MessageChannel channel, Instant archiveA
     }
 
     private void handleArchiveFlow(ThreadChannel threadChannel, MessageEmbed embed) {
-        Consumer<Throwable> handleFailure = error -> {
-            if (error instanceof ErrorResponseException) {
-                logger.warn("Unknown error occurred during help thread auto archive routine",
-                        error);
-            }
-        };
+
+        Function<Result<Member>, RestAction<Message>> sendEmbedWithMention =
+                member -> threadChannel.sendMessage(member.get().getAsMention()).addEmbeds(embed);
+
+        Supplier<RestAction<Message>> sendEmbedWithoutMention =
+                () -> threadChannel.sendMessageEmbeds(embed);
 
         threadChannel.getGuild()
             .retrieveMemberById(threadChannel.getOwnerIdLong())
-            .flatMap(author -> threadChannel.sendMessage(author.getAsMention()).addEmbeds(embed))
+            .mapToResult()
+            .flatMap(foundMember -> {
+                if (foundMember.isSuccess()) {
+                    return sendEmbedWithMention.apply(foundMember);
+                }
+                logger.info(
+                        "Owner of thread with id: {} left the server, sending embed without mention",
+                        threadChannel.getId(), foundMember.getFailure());
+
+                return sendEmbedWithoutMention.get();
+            })
             .flatMap(any -> threadChannel.getManager().setArchived(true))
-            .queue(any -> {
-            }, handleFailure);
+            .queue();
     }
 }