#!/usr/bin/env node
/*
 * set-webhook.mjs — one-time setWebhook registration (D-16, D-17).
 * -----------------------------------------------------------------
 * Points Telegram at the Worker's /telegram/webhook route and arms the
 * secret-token channel: the `secret_token` value sent here is the one
 * Telegram echoes back in X-Telegram-Bot-Api-Secret-Token on every update,
 * which the Worker's webhook adapter constant-time-compares against
 * env.WEBHOOK_SECRET (T-02-03).
 *
 * Inputs come from bot/.dev.vars (gitignored, D-15): BOT_TOKEN,
 * WEBHOOK_URL, WEBHOOK_SECRET. The bot token is never echoed — on failure
 * only the API's error_code/description are printed (T-02-04).
 * Exit 0 only when Telegram answers ok:true.
 */
import { readFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

function readDevVars() {
  const devVarsPath = path.join(fileURLToPath(new URL(import.meta.url)), "..", "..", ".dev.vars");
  let raw = "";
  try {
    raw = readFileSync(devVarsPath, "utf8");
  } catch {
    return {};
  }
  const vars = {};
  for (const line of raw.split("\n")) {
    const trimmed = line.trim();
    if (trimmed.length === 0 || trimmed.startsWith("#")) continue;
    const eq = trimmed.indexOf("=");
    if (eq === -1) continue;
    vars[trimmed.slice(0, eq).trim()] = trimmed.slice(eq + 1).trim();
  }
  return vars;
}

const devVars = readDevVars();
const token = process.env.BOT_TOKEN ?? devVars.BOT_TOKEN;
const webhookUrl = process.env.WEBHOOK_URL ?? devVars.WEBHOOK_URL;
const secret = process.env.WEBHOOK_SECRET ?? devVars.WEBHOOK_SECRET;

const missing = ["BOT_TOKEN", "WEBHOOK_URL", "WEBHOOK_SECRET"].filter(
  (name) => !{ BOT_TOKEN: token, WEBHOOK_URL: webhookUrl, WEBHOOK_SECRET: secret }[name],
);
if (missing.length > 0) {
  console.error(`Missing ${missing.join(", ")} — set them in bot/.dev.vars (see .dev.vars.example; never commit).`);
  process.exit(1);
}

const payload = {
  url: webhookUrl,
  secret_token: secret,
  allowed_updates: ["message"],
};

const res = await fetch(`https://api.telegram.org/bot${token}/setWebhook`, {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify(payload),
});
const body = await res.json();

if (!body.ok) {
  console.error(`setWebhook failed: ${body.error_code ?? "?"} ${body.description ?? "unknown error"}`);
  process.exit(1);
}
console.log(`setWebhook ok:true — updates will be delivered to the configured URL with the secret-token header.`);
process.exit(0);