import type { TextStreamCallback } from "../intelligence/stream-callback"; export const WEBHOOK_PATH = "/webhooks/telegram"; export const TELEGRAM_STREAM_SOFT_LIMIT = 3_400; export const TELEGRAM_FOLLOWUP_CHUNK_LIMIT = 3_500; const TELEGRAM_API_BASE = "https://api.telegram.org"; const TELEGRAM_DEDUPE_PREFIX = "dedupe:telegram:"; export type TelegramWebhookSetupResult = { ok: boolean; webhookUrl: string; alreadyConfigured: boolean; description: string; }; type TelegramApiResponse = | { ok: true; result: T; description?: string; } | { ok: false; description?: string; error_code?: number; }; type TelegramWebhookInfo = { url?: string; }; function jsonResponse(value: unknown, init?: ResponseInit): Response { return new Response(JSON.stringify(value, null, 2), { ...init, headers: { "content-type": "application/json; charset=utf-8", ...init?.headers } }); } async function telegramApi( token: string, method: string, body?: Record ): Promise> { const response = await fetch(`${TELEGRAM_API_BASE}/bot${token}/${method}`, { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify(body ?? {}) }); return (await response.json()) as TelegramApiResponse; } export async function setupTelegramWebhook( request: Request, env: Cloudflare.Env ): Promise { const requestUrl = new URL(request.url); const webhookUrl = `${requestUrl.origin}${WEBHOOK_PATH}`; if (requestUrl.protocol !== "https:") { return jsonResponse( { ok: false, webhookUrl, error: "Telegram webhooks require HTTPS. Open the Quick Tunnel or deployed Worker URL and click Set webhook here again." }, { status: 400 } ); } if (!env.TELEGRAM_BOT_TOKEN) { return jsonResponse( { ok: false, error: "TELEGRAM_BOT_TOKEN is not configured." }, { status: 400 } ); } if (!env.TELEGRAM_WEBHOOK_SECRET_TOKEN) { return jsonResponse( { ok: false, error: "TELEGRAM_WEBHOOK_SECRET_TOKEN is not configured." }, { status: 400 } ); } const current = await telegramApi( env.TELEGRAM_BOT_TOKEN, "getWebhookInfo" ); if (!current.ok) { return jsonResponse( { ok: false, webhookUrl, error: current.description ?? "Failed to inspect Telegram webhook." }, { status: 502 } ); } if (current.result.url === webhookUrl) { return jsonResponse({ ok: true, webhookUrl, alreadyConfigured: true, description: "Telegram webhook already points at this origin." } satisfies TelegramWebhookSetupResult); } const next = await telegramApi(env.TELEGRAM_BOT_TOKEN, "setWebhook", { url: webhookUrl, secret_token: env.TELEGRAM_WEBHOOK_SECRET_TOKEN }); if (!next.ok) { return jsonResponse( { ok: false, webhookUrl, error: next.description ?? "Failed to set Telegram webhook." }, { status: 502 } ); } return jsonResponse({ ok: true, webhookUrl, alreadyConfigured: false, description: next.description ?? "Telegram webhook configured." } satisfies TelegramWebhookSetupResult); } export function isIgnorableDeliveryError(error: unknown): boolean { if (error === undefined || error === null) { return false; } const candidate = error as { code?: unknown; message?: unknown }; const code = typeof candidate.code === "string" ? candidate.code : undefined; const message = typeof candidate.message === "string" ? candidate.message.toLowerCase() : String(error).toLowerCase(); return ( code === "VALIDATION_ERROR" && message.includes("message is not modified") ); } export function isExpectedFinalEditNoop( error: unknown, callback: Pick ): boolean { return callback.visibleLimitReached() && isIgnorableDeliveryError(error); } export function shardTelegramStateKey( key: string, shardThread: (threadId: string) => string ): string | undefined { if (!key.startsWith(TELEGRAM_DEDUPE_PREFIX)) { return undefined; } const chatId = key.slice(TELEGRAM_DEDUPE_PREFIX.length).split(":")[0]; return chatId ? shardThread(`telegram:${chatId}`) : undefined; } export function splitTelegramMessageText( text: string, limit = TELEGRAM_FOLLOWUP_CHUNK_LIMIT ): string[] { if (!text.trim()) { return []; } const chunks: string[] = []; let remaining = text; while (remaining.length > limit) { let splitAt = remaining.lastIndexOf("\n\n", limit); if (splitAt < Math.floor(limit * 0.5)) { splitAt = remaining.lastIndexOf("\n", limit); } if (splitAt < Math.floor(limit * 0.5)) { splitAt = remaining.lastIndexOf(" ", limit); } if (splitAt < Math.floor(limit * 0.5)) { splitAt = limit; } chunks.push(remaining.slice(0, splitAt)); remaining = remaining.slice(splitAt); } if (remaining) { chunks.push(remaining); } return chunks; }