hikari/server/src/modules/announceOnDiscord.ts

/**
 * @copyright nhcarrigan
 * @license Naomi's Public License
 * @author Naomi Carrigan
 */
/* eslint-disable @typescript-eslint/naming-convention -- we are making raw API calls. */
/* eslint-disable max-lines-per-function -- Chunked sending requires more logic. */
/* eslint-disable max-statements -- Chunked sending requires more statements. */
/* eslint-disable no-await-in-loop -- Sequential chunk posting requires awaiting each request. */

import { chunkContent } from "../utils/chunkContent.js";
import type { AnnouncementType } from "../interfaces/announcementType.js";

const discordLimit = 2000;

const channelIds: Record<AnnouncementType, string> = {
  community: "1386105484313886820",
  company:   "1422472775695728661",
  products:  "1386105452881776661",
};
const roleIds: Record<Exclude<AnnouncementType, "company">, string> = {
  community: "1386107941224054895",
  products:  "1386107909699666121",
};

const getAnnouncementPing = (type: AnnouncementType): string => {
  return type === "company"
    ? "@everyone"
    : `<@&${roleIds[type]}>`;
};

/**
 * Forwards an announcement to our Discord server.
 * Sends content in sequential messages if it exceeds the 2000 character limit.
 * @param title - The title of the announcement.
 * @param content - The main body of the announcement.
 * @param type - Whether the announcement is for a product or community.
 * @returns A message indicating the success or failure of the operation.
 */
export const announceOnDiscord = async(
  title: string,
  content: string,
  type: AnnouncementType,
): Promise<string> => {
  const channelId = channelIds[type];
  const ping = getAnnouncementPing(type);
  const firstMessagePrefix = `# ${title}\n\n`;
  const firstMessageSuffix = `\n-# ${ping}`;
  const firstChunkLimit
    = discordLimit - firstMessagePrefix.length - firstMessageSuffix.length;

  const chunks = chunkContent(content, firstChunkLimit);
  const firstChunk = chunks[0] ?? "";
  const remainingChunks = chunks.slice(1);

  const messageRequest = await fetch(
    `https://discord.com/api/v10/channels/${channelId}/messages`,
    {
      body: JSON.stringify({
        allowed_mentions: { parse: [ "users", "roles" ] },
        content:          `${firstMessagePrefix}${firstChunk}${firstMessageSuffix}`,
      }),
      headers: {
        "Authorization": `Bot ${process.env.DISCORD_TOKEN ?? ""}`,
        "Content-Type":  "application/json",
      },
      method: "POST",
    },
  );

  if (messageRequest.status !== 200) {
    return `Failed to send message to Discord. Status: ${messageRequest.status.toString()} ${messageRequest.statusText}`;
  }

  // eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- fetch does not accept generics.
  const message = await messageRequest.json() as { id?: string };
  if (message.id === undefined) {
    return `Failed to parse message ID, cannot crosspost. ${JSON.stringify(message)}`;
  }

  const crosspostRequest = await fetch(
    `https://discord.com/api/v10/channels/${channelId}/messages/${message.id}/crosspost`,
    {
      headers: {
        "Authorization": `Bot ${process.env.DISCORD_TOKEN ?? ""}`,
        "Content-Type":  "application/json",
      },
      method: "POST",
    },
  );

  if (!crosspostRequest.ok) {
    return `Failed to crosspost message to Discord. Status: ${crosspostRequest.status.toString()} ${crosspostRequest.statusText}`;
  }

  for (const chunk of remainingChunks) {
    const chunkRequest = await fetch(
      `https://discord.com/api/v10/channels/${channelId}/messages`,
      {
        body: JSON.stringify({
          content: chunk,
        }),
        headers: {
          "Authorization": `Bot ${process.env.DISCORD_TOKEN ?? ""}`,
          "Content-Type":  "application/json",
        },
        method: "POST",
      },
    );

    if (!chunkRequest.ok) {
      return `Failed to send continuation chunk to Discord. Status: ${chunkRequest.status.toString()} ${chunkRequest.statusText}`;
    }
  }

  return "Successfully sent and published message to Discord.";
};