/**
 * Cloudflare / Turnstile 挑战页检测
 */

/**
 * @typedef {Object} CloudflareState
 * @property {boolean} blocked 是否处于 CF 挑战中
 * @property {string|null} challengeType turnstile|js_challenge|unknown|null
 * @property {boolean} hasCfClearance 是否已有 cf_clearance cookie
 * @property {string} url 当前页面 URL
 * @property {string} title 页面 title
 */

/**
 * 检测页面是否被 Cloudflare 拦截
 * @param {import('puppeteer').Page} page
 * @returns {Promise<CloudflareState>}
 */
async function detectCloudflare(page) {
    const url = page.url();
    const title = await page.title().catch(() => '');

    const cookies = await page.cookies().catch(() => []);
    const hasCfClearance = cookies.some((c) => c.name === 'cf_clearance');

    const domSignals = await page.evaluate(() => {
        const hasTurnstileInput = !!document.querySelector('[name="cf-turnstile-response"]');
        const hasTurnstileWidget = !!document.querySelector('.cf-turnstile, [data-sitekey]');
        const hasChallengeRunning = !!document.querySelector('#challenge-running, #cf-challenge-running');
        const titleText = document.title || '';
        const bodyText = (document.body && document.body.innerText) ? document.body.innerText.slice(0, 500) : '';
        return {
            hasTurnstileInput,
            hasTurnstileWidget,
            hasChallengeRunning,
            titleHasJustAMoment: titleText.includes('Just a moment'),
            bodyHasJustAMoment: bodyText.includes('Just a moment') || bodyText.includes('Checking your browser'),
        };
    }).catch(() => ({
        hasTurnstileInput: false,
        hasTurnstileWidget: false,
        hasChallengeRunning: false,
        titleHasJustAMoment: false,
        bodyHasJustAMoment: false,
    }));

    const urlChallenge = url.includes('/cdn-cgi/challenge-platform') || url.includes('/cdn-cgi/challenge');

    let challengeType = null;
    if (domSignals.hasTurnstileInput || domSignals.hasTurnstileWidget) {
        challengeType = 'turnstile';
    } else if (urlChallenge || domSignals.titleHasJustAMoment || domSignals.bodyHasJustAMoment) {
        challengeType = 'js_challenge';
    }

    const blocked = !hasCfClearance && (
        urlChallenge
        || domSignals.titleHasJustAMoment
        || domSignals.bodyHasJustAMoment
        || domSignals.hasTurnstileInput
        || domSignals.hasTurnstileWidget
        || domSignals.hasChallengeRunning
        || title.includes('Just a moment')
    );

    return {
        blocked,
        challengeType,
        hasCfClearance,
        url,
        title,
    };
}

/**
 * 检测 Turnstile 是否已通过
 * @param {import('puppeteer').Page} page
 * @returns {Promise<boolean>}
 */
async function isTurnstileSolved(page) {
    const cookies = await page.cookies().catch(() => []);
    if (cookies.some((c) => c.name === 'cf_clearance')) {
        return true;
    }

    const tokenLen = await page.evaluate(() => {
        const input = document.querySelector('[name="cf-turnstile-response"]');
        return input && input.value ? input.value.length : 0;
    }).catch(() => 0);

    return tokenLen > 20;
}

module.exports = {
    detectCloudflare,
    isTurnstileSolved,
};