// Interactive Geetest hand-off, following the official HG account SDK. The user completes the provider's widget;
// only its proof is returned to the original login request. No phone, password or account token is sent here.
const scripts = new Map();
const PROVIDERS = {
  v4: { src: 'https://static.geetest.com/v4/gt4.js', init: 'initGeetest4' },
  v3: { src: 'https://static.geetest.com/static/tools/gt.js', init: 'initGeetest' },
};

async function loadProvider(version) {
  const provider = PROVIDERS[version];
  if (typeof globalThis[provider.init] === 'function') return;
  if (!scripts.has(version)) {
    const pending = new Promise((resolve, reject) => {
      const script = document.createElement('script');
      const fail = () => { clearTimeout(timer); script.remove(); reject(new Error('captcha_load')); };
      const timer = setTimeout(fail, 20_000);
      script.src = provider.src;
      script.async = true;
      script.onerror = fail;
      script.onload = () => {
        clearTimeout(timer);
        if (typeof globalThis[provider.init] === 'function') resolve();
        else fail();
      };
      document.head.append(script);
    });
    scripts.set(version, pending);
    pending.catch(() => scripts.delete(version));
  }
  await scripts.get(version);
}

/**
 * Called only by the user's captcha button. `scope` and `load` allow isolated widget contract tests without a
 * network call or a real challenge. Resolves null on user cancellation; never completes a real puzzle itself.
 */
export async function solveCaptcha(challenge, { scope = globalThis, load = loadProvider } = {}) {
  const version = challenge.geetestId ? 'v4' : challenge.gt && challenge.challenge ? 'v3' : null;
  if (!version) throw new Error('captcha_type');
  await load(version);
  return new Promise((resolve, reject) => {
    let settled = false;
    const init = scope[PROVIDERS[version].init];
    const options = version === 'v4'
      ? { captchaId: challenge.geetestId, riskType: challenge.riskType, product: 'bind', language: 'zho' }
      : { gt: challenge.gt, challenge: challenge.challenge, new_captcha: challenge.new_captcha,
        offline: false, product: 'bind', https: true, lang: 'zh-cn' };
    init(options, (widget) => {
      const finish = (proof, error) => {
        if (settled) return;
        settled = true;
        widget.destroy?.();
        if (error) reject(error); else resolve(proof);
      };
      widget.onSuccess(() => {
        const proof = widget.getValidate();
        if (!proof) { finish(null, new Error('captcha_validate')); return; }
        finish(version === 'v4' ? { ...proof, challenge: challenge.challenge } : proof);
      });
      widget.onError((error) => {
        if (error?.error_code !== 'error_01') finish(null, new Error('captcha_validate'));
      });
      widget.onClose(() => finish(null));
      widget.onReady(() => {
        if (version === 'v4') widget.showCaptcha(); else widget.verify();
      });
    });
  });
}