Stickers & Custom Emoji

// import-telegram-set.ts — Bun, or Node 18+ (global fetch, FormData, Blob)
const ARGON = "https://gateway.argon.zone";
const TG = "https://api.telegram.org";
const ARGON_AUTH = "Bot " + process.env.ARGON_TOKEN;
const TG_BOT = "bot" + process.env.TG_TOKEN;   // any Telegram bot: getStickerSet reads public sets

const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));

class ArgonError extends Error {
  constructor(readonly status: number, readonly code: string) { super(code); }
}

// One Argon call. Both 429s are waited out: rate_limited (this bot's window for the
// interface) and space_rate_limited (the budget all bots share in the space).
async function argon(method: string, path: string, body?: object | FormData): Promise<any> {
  const form = body instanceof FormData;
  for (;;) {
    const res = await fetch(ARGON + path, {
      method,
      headers: body && !form
        ? { Authorization: ARGON_AUTH, "Content-Type": "application/json" }
        : { Authorization: ARGON_AUTH },
      body: form ? body : body ? JSON.stringify(body) : undefined,
    });
    if (res.status === 429) {
      await sleep(Number(res.headers.get("Retry-After") ?? 60) * 1000);
      continue;
    }
    const data = await res.json();
    if (!res.ok) throw new ArgonError(res.status, data.error);
    return data;
  }
}

async function telegram(method: string, params: Record<string, string>): Promise<any> {
  const res = await fetch(TG + "/" + TG_BOT + "/" + method + "?" + new URLSearchParams(params));
  const data = await res.json();
  if (!data.ok) throw new Error(method + ": " + data.description);
  return data.result;
}

async function download(fileId: string): Promise<Blob> {
  const file = await telegram("getFile", { file_id: fileId });
  const res = await fetch(TG + "/file/" + TG_BOT + "/" + file.file_path);
  return await res.blob();
}

export async function importSet(spaceId: string, setName: string) {
  const set = await telegram("getStickerSet", { name: setName });
  const kind = set.sticker_type === "custom_emoji" ? "emoji" : "sticker";
  const slug = setName.toLowerCase();   // Telegram set names are [A-Za-z0-9_], up to 64

  // 1. Room: the space's free slots for this kind.
  const quota = await argon("GET", "/IExpressions/v1/GetQuota?spaceId=" + spaceId);
  const slots = kind === "emoji" ? quota.emoji : quota.stickers;
  let room = slots.max - slots.used;

  // 2. The pack. Asking again with the same slug returns the pack this bot made.
  const pack = await argon("POST", "/IExpressions/v1/CreatePack",
    { spaceId, kind, title: set.title.slice(0, 64).trim(), slug });

  // 3. What an earlier run added: every imported item carries tg:<file_unique_id>.
  const { packs } = await argon("GET", "/IExpressions/v1/List?spaceId=" + spaceId);
  const done = new Set<string>(packs.flatMap((p: any) => p.items)
    .flatMap((i: any) => i.keywords).filter((k: string) => k.startsWith("tg:")));

  // Emoji names are [a-z0-9_] and unique in the space; sticker names are plain text.
  let n = pack.items.length;
  const nameFor = (i: number) =>
    kind === "emoji" ? slug.slice(0, 24) + "_" + i : set.title.slice(0, 24).trim() + " " + i;

  for (const sticker of set.stickers) {
    const key = "tg:" + sticker.file_unique_id;
    if (done.has(key)) continue;
    if (room <= 0) {
      console.warn("No slots left in the space: boost it or remove items");
      return;
    }

    // 4. Download, and 5. add it with the file as an inline part.
    const ext = sticker.is_animated ? "tgs" : sticker.is_video ? "webm" : "webp";
    const form = new FormData();
    form.append("spaceId", spaceId);
    form.append("packId", pack.packId);
    if (sticker.emoji) form.append("emoji", sticker.emoji);
    form.append("keywords", key);
    if (sticker.needs_repainting) form.append("textColor", "true");
    form.append("file", await download(sticker.file_id), sticker.file_unique_id + "." + ext);

    // 6. Refusals. The 429s never get here; argon() waits them out.
    for (let attempt = 1; ; attempt++) {
      form.set("name", nameFor(++n));
      try {
        await argon("POST", "/IExpressions/v1/AddItem", form);
        done.add(key);
        room--;
        break;
      } catch (e) {
        if (!(e instanceof ArgonError)) throw e;
        // A person's emoji already has this name: try the next number.
        if (e.code === "name_taken" && attempt < 5) continue;
        // This file breaks a rule, or moderation refused it; it will be refused again.
        if (["invalid_format", "too_large", "content_rejected", "name_taken"].includes(e.code)) {
          console.warn("Skipped " + key + ": " + e.code);
          break;
        }
        // The pack (120 stickers, 200 emoji) or the space is full.
        if (e.code === "quota_exceeded") {
          console.warn("Quota reached; the rest of the set was not imported");
          return;
        }
        throw e;   // insufficient_permissions, not_found, invalid_request: a fault to fix
      }
    }
  }
}