Centralize periodic checks for mutes, tempbans, vcalerts, reminders, and scheduled posts

This should result in a significant performance improvement.
The new method is also more precise than the old one, allowing
the aforementioned checks to be performed with second-precision.

backend/src/plugins/ModActions/functions/clearTempban.ts

@@ -0,0 +1,60 @@
+import { Snowflake } from "discord.js";
+import humanizeDuration from "humanize-duration";
+import { GuildPluginData } from "knub";
+import moment from "moment-timezone";
+import { LogType } from "src/data/LogType";
+import { logger } from "src/logger";
+import { CaseTypes } from "../../../data/CaseTypes";
+import { resolveUser, SECONDS } from "../../../utils";
+import { CasesPlugin } from "../../Cases/CasesPlugin";
+import { IgnoredEventType, ModActionsPluginType } from "../types";
+import { formatReasonWithAttachments } from "./formatReasonWithAttachments";
+import { ignoreEvent } from "./ignoreEvent";
+import { isBanned } from "./isBanned";
+import { LogsPlugin } from "../../Logs/LogsPlugin";
+import { Tempban } from "../../../data/entities/Tempban";
+
+export async function clearTempban(pluginData: GuildPluginData<ModActionsPluginType>, tempban: Tempban) {
+  if (!(await isBanned(pluginData, tempban.user_id))) {
+    pluginData.state.tempbans.clear(tempban.user_id);
+    return;
+  }
+
+  pluginData.state.serverLogs.ignoreLog(LogType.MEMBER_UNBAN, tempban.user_id);
+  const reason = formatReasonWithAttachments(
+    `Tempban timed out.
+    Tempbanned at: \`${tempban.created_at} UTC\``,
+    [],
+  );
+  try {
+    ignoreEvent(pluginData, IgnoredEventType.Unban, tempban.user_id);
+    await pluginData.guild.bans.remove(tempban.user_id as Snowflake, reason ?? undefined);
+  } catch (e) {
+    pluginData.getPlugin(LogsPlugin).logBotAlert({
+      body: `Encountered an error trying to automatically unban ${tempban.user_id} after tempban timeout`,
+    });
+    logger.warn(`Error automatically unbanning ${tempban.user_id} (tempban timeout): ${e}`);
+    return;
+  }
+
+  // Create case and delete tempban
+  const casesPlugin = pluginData.getPlugin(CasesPlugin);
+  const createdCase = await casesPlugin.createCase({
+    userId: tempban.user_id,
+    modId: tempban.mod_id,
+    type: CaseTypes.Unban,
+    reason,
+    ppId: undefined,
+  });
+  pluginData.state.tempbans.clear(tempban.user_id);
+
+  // Log the unban
+  const banTime = moment(tempban.created_at).diff(moment(tempban.expires_at));
+  pluginData.getPlugin(LogsPlugin).logMemberTimedUnban({
+    mod: await resolveUser(pluginData.client, tempban.mod_id),
+    userId: tempban.user_id,
+    caseNumber: createdCase.case_number,
+    reason,
+    banTime: humanizeDuration(banTime),
+  });
+}