calendar-bot.ts

import * as ics from "ics";
import Discord, { GatewayIntentBits, REST, Routes } from "discord.js";
import {Readable} from "stream";
import moment from "moment";
import { z } from "zod";

const eventResponseSchema = z.object({
  id: z.string(),
  name: z.string(),
  description: z.string(),
  scheduled_start_time: z.string(),
  scheduled_end_time: z.string(),
  entity_metadata: z.object({
    location: z.string().nullish(),
  }),
}).array();

const client = new Discord.Client({
  intents: [GatewayIntentBits.Guilds],
});

const rest = new REST({ version: '10' }).setToken(process.env.TOKEN);

client.on('ready', () => {
  console.log(`Logged in as ${client.user?.tag}!`);
});

client.on('interactionCreate', async interaction => {
  if (!interaction.isChatInputCommand()) return;

  if (interaction.commandName === 'ping') {
    if (interaction.guildId == null) {
      console.error("Guild ID is null or undefined.");
    } else {
      const response = eventResponseSchema.parse(
        await rest.get(Routes.guildScheduledEvents(interaction.guildId))
      );
      await interaction.reply({
        files: [{
          contentType: "text/calendar",
          name: "events.ics",
          attachment: stringToStream(eventsToIcs(response)),
        }]
      })
    }
  }
});

function eventsToIcs(events: z.infer<typeof eventResponseSchema>): string {
  const { error, value } = ics.createEvents(events.map((eventData) => ({
    title: eventData.name,
    description: eventData.description,
    location: eventData.entity_metadata.location ?? undefined,
    start: isoDateToDateArray(eventData.scheduled_start_time),
    startInputType: "utc",
    startOutputType: "utc",
    end: isoDateToDateArray(eventData.scheduled_end_time),
    endInputType: "utc",
    endOutputType: "utc",
  })));

  if (value == null) {
    if (error) {
      throw error;
    } else {
      throw new Error("Failed to convert.");
    }
  }

  return value;
}

function stringToStream(str: string): Readable {
  const stream = new Readable();
  stream.push(str);
  stream.push(null);
  return stream;
}

function isoDateToDateArray(isoDate: string): ics.DateArray {
  const date = moment(isoDate).utc();
  const dateArray: ics.DateArray = [
    date.year(),
    date.month() + 1,
    date.date(),
    date.hour(),
    date.minute(),
  ];
  return dateArray;
}

client.login(process.env.TOKEN);