feat: /cron command to add recurring messages

Author: luca-montaigut

package.json

@@ -14,8 +14,9 @@
   },
   "dependencies": {
     "@keyv/redis": "2.7.0",
-    "discord.js": "14.13.0",
     "cheerio": "1.0.0-rc.12",
+    "cron": "2.4.3",
+    "discord.js": "14.13.0",
     "env-var": "7.4.1",
     "keyv": "4.5.3",
     "open-graph-scraper": "6.2.2",

pnpm-lock.yaml

@@ -0,0 +1,20 @@
+import { CronJob } from 'cron';
+import { ChatInputCommandInteraction } from 'discord.js';
+
+import { getCronTime } from './helpers/get-cron-time';
+
+export const addCron = (interaction: ChatInputCommandInteraction): void => {
+  const frequency = interaction.options.getString('every', true);
+  const message = interaction.options.getString('message', true);
+
+  const job = new CronJob(
+    getCronTime(frequency),
+    () => {
+      interaction.channel?.send(message).catch(console.error);
+    },
+    null,
+    true,
+    'Europe/Paris',
+  );
+  job.start();
+};

src/add-cron.ts

@@ -10,5 +10,28 @@ export const voiceOnDemandCommand = new SlashCommandBuilder()
 
 export const fartCommand = new SlashCommandBuilder()
   .setName('fart')
-  .setDescription("Replies with https://prout.dev")
+  .setDescription('Replies with https://prout.dev')
   .toJSON();
+
+export const cronCommand = new SlashCommandBuilder()
+  .setName('cron')
+  .setDescription('Manage recurring messages')
+  .addSubcommand((subcommand) =>
+    subcommand
+      .setName('add')
+      .setDescription('Add a recurring message')
+      .addStringOption((option) =>
+        option
+          .setName('every')
+          .setDescription('How often to send the message')
+          .addChoices(
+            { name: 'day', value: 'day' },
+            { name: 'week', value: 'week' },
+            { name: 'month', value: 'month' },
+          )
+          .setRequired(true),
+      )
+      .addStringOption((option) =>
+        option.setName('message').setDescription('The message to send').setRequired(true),
+      ),
+  );

src/commands.ts

@@ -1,13 +1,14 @@
 import type { Interaction } from 'discord.js';
 
+import { addCron } from '../add-cron';
 import { createLobby } from '../create-lobby';
 
 export const handleInteractionCreation = async (interaction: Interaction): Promise<void> => {
   if (
     !interaction.isCommand() ||
     !interaction.inGuild() ||
     !interaction.isChatInputCommand() ||
-    !['voice-on-demand', 'fart'].includes(interaction.commandName)
+    !['voice-on-demand', 'fart', 'cron'].includes(interaction.commandName)
   ) {
     return;
   }
@@ -23,5 +24,12 @@ export const handleInteractionCreation = async (interaction: Interaction): Promi
     case 'fart':
       await interaction.reply('https://prout.dev');
       break;
+    case 'cron':
+      if (interaction.options.getSubcommand(true) !== 'add') {
+        await interaction.reply('Unknown subcommand');
+        return;
+      }
+      addCron(interaction);
+      break;
   }
 };

src/handlers/handle-interaction-creation.ts

@@ -0,0 +1,12 @@
+export const getCronTime = (cron: string): string => {
+  switch (cron) {
+    case 'day':
+      return '0 0 9 * * *';
+    case 'week':
+      return '0 0 9 * * 0';
+    case 'month':
+      return '0 0 9 1 * *';
+    default:
+      throw new Error('Unknown cron time');
+  }
+};

src/helpers/get-cron-time.ts

@@ -1,6 +1,6 @@
 import { Client, REST, Routes } from 'discord.js';
 
-import { fartCommand, voiceOnDemandCommand } from './commands';
+import { cronCommand, fartCommand, voiceOnDemandCommand } from './commands';
 import { config } from './config';
 import { deleteExistingCommands } from './delete-existing-commands';
 import { handleGuildMessageCreation } from './handlers/handle-guild-message-creation';
@@ -51,7 +51,7 @@ const rest = new REST({ version: '10' }).setToken(discord.token);
 await deleteExistingCommands(rest, discord);
 
 await rest.put(Routes.applicationGuildCommands(discord.clientId, discord.guildId), {
-  body: [voiceOnDemandCommand, fartCommand],
+  body: [voiceOnDemandCommand, fartCommand, cronCommand],
 });
 
 console.log('Bot started.');