feat: remove oldest vote before casting new one on reaching max_votes…

…_allowed

src/poll.ts

@@ -321,6 +321,25 @@ export class Poll<SCG extends ExtendableGenerics = DefaultGenerics> {
   };
 
   castVote = async (optionId: string, messageId: string) => {
+    const {max_votes_allowed, ownVotesByOptionId } = this.data;
+
+    const reachedVoteLimit =
+      max_votes_allowed && max_votes_allowed === Object.keys(ownVotesByOptionId).length;
+
+    if (reachedVoteLimit) {
+      let oldestVote = Object.values(ownVotesByOptionId)[0];
+      Object.values(ownVotesByOptionId).slice(1).forEach((vote) => {
+        if (
+          !oldestVote?.created_at ||
+          new Date(vote.created_at) < new Date(oldestVote.created_at)
+        ) {
+          oldestVote = vote;
+        }
+      });
+      if (oldestVote?.id) {
+        await this.removeVote(oldestVote.id, messageId);
+      }
+    }
     return await this.client.castPollVote(messageId, this.id as string, { option_id: optionId });
   };