add initial help thread implementation

Author: tjjfvi

.env.example

@@ -20,6 +20,8 @@ ASK_CATEGORY=
 ONGOING_CATEGORY=
 DORMANT_CATEGORY=
 
+HELP_CATEGORY=
+
 ASK_COOLDOWN_ROLE=
 
 CHANNEL_NAMES=list,help,channel,names,here,seperated,by,commas

src/env.ts

@@ -22,6 +22,8 @@ export const categories = {
 	dormant: process.env.DORMANT_CATEGORY!,
 };
 
+export const helpCategory = process.env.HELP_CATEGORY!;
+
 export const askCooldownRoleId = process.env.ASK_COOLDOWN_ROLE!;
 
 export const trustedRoleId = process.env.TRUSTED_ROLE_ID!;
@@ -52,3 +54,7 @@ export const HOURGLASS_ORANGE = '#ffa647';
 export const BALLOT_BOX_BLUE = '#066696';
 // Picked from Discord's blockquote line
 export const BLOCKQUOTE_GREY = '#4f545c';
+
+export const timeBeforeHelperPing = parseInt(
+	process.env.TIME_BEFORE_HELPER_PING!,
+);

src/index.ts

@@ -6,6 +6,7 @@ import { getDB } from './db';
 import { AutoroleModule } from './modules/autorole';
 import { EtcModule } from './modules/etc';
 import { HelpChanModule } from './modules/helpchan';
+import { HelpThreadModule } from './modules/helpthread';
 import { PlaygroundModule } from './modules/playground';
 import { RepModule } from './modules/rep';
 import { TwoslashModule } from './modules/twoslash';
@@ -37,6 +38,7 @@ for (const mod of [
 	AutoroleModule,
 	EtcModule,
 	HelpChanModule,
+	HelpThreadModule,
 	PlaygroundModule,
 	RepModule,
 	TwoslashModule,

src/modules/helpthread.ts

@@ -0,0 +1,91 @@
+import { command, Module, listener } from 'cookiecord';
+import { ThreadAutoArchiveDuration } from 'discord-api-types';
+import { Message, TextChannel, Channel, ThreadChannel } from 'discord.js';
+import { trustedRoleId, helpCategory, timeBeforeHelperPing } from '../env';
+import { isTrustedMember } from '../util/inhibitors';
+
+const PINGED_HELPER_MESSAGE = '✅ Pinged helpers';
+
+export class HelpThreadModule extends Module {
+	@listener({ event: 'threadCreate' })
+	async onNewThread(thread: ThreadChannel) {
+		if (!this.isHelpThread(thread)) return;
+		this.fixThreadExpiry(thread);
+	}
+	@listener({ event: 'threadUpdate' })
+	async onThreadUpdated(thread: ThreadChannel) {
+		if (!this.isHelpThread(thread)) return;
+		this.fixThreadExpiry((await thread.fetch()) as ThreadChannel);
+	}
+
+	private async fixThreadExpiry(thread: ThreadChannel) {
+		if (thread.autoArchiveDuration !== ThreadAutoArchiveDuration.OneDay)
+			await thread.setAutoArchiveDuration(
+				ThreadAutoArchiveDuration.OneDay,
+			);
+	}
+
+	private isHelpThread(
+		channel: Omit<Channel, 'partial'>,
+	): channel is ThreadChannel & { parent: TextChannel } {
+		return (
+			channel instanceof ThreadChannel &&
+			channel.parent instanceof TextChannel &&
+			channel.parent.parentId == helpCategory
+		);
+	}
+
+	@command({
+		description: 'Pings a helper in a help-thread',
+		aliases: ['helpers'],
+	})
+	async helper(msg: Message) {
+		if (!this.isHelpThread(msg.channel)) {
+			return msg.channel.send(
+				':warning: You may only ping helpers from a help thread',
+			);
+		}
+
+		const thread = msg.channel;
+
+		// Ensure the user has permission to ping helpers
+		const isAsker = thread.ownerId === msg.author.id;
+		const isTrusted =
+			(await isTrustedMember(msg, this.client)) === undefined; // No error if trusted
+
+		if (!isAsker && !isTrusted) {
+			return msg.channel.send(
+				':warning: Only the asker can ping helpers',
+			);
+		}
+
+		const askTime = thread.createdTimestamp;
+		// Find the last time helpers were called, to avoid multiple successive !helper pings.
+		// It's possible that the last helper ping would not be within the most recent 20 messages,
+		// while still being more recent than allowed, but in that case the person has likely already
+		// recieved help, so them asking for further help is less likely to be spammy.
+		const lastHelperPing = (
+			await thread.messages.fetch({ limit: 20 })
+		).find(
+			msg =>
+				msg.author.id === this.client.user!.id &&
+				msg.content === PINGED_HELPER_MESSAGE,
+		)?.createdTimestamp;
+		const pingAllowedAfter =
+			(lastHelperPing ?? askTime) + timeBeforeHelperPing;
+
+		// Ensure they've waited long enough
+		// Trusted members (who aren't the asker) are allowed to disregard the timeout
+		if (isAsker && Date.now() < pingAllowedAfter) {
+			return msg.channel.send(
+				`:warning: Please wait a bit longer. You can ping helpers <t:${Math.ceil(
+					pingAllowedAfter / 1000,
+				)}:R>.`,
+			);
+		}
+
+		// The beacons are lit, Gondor calls for aid
+		thread.parent.send(`<@&${trustedRoleId}> ${msg.channel}`);
+		thread.send(PINGED_HELPER_MESSAGE);
+	}
+}