(() => {
    'use strict';

    // Stable bootstrap installed in GetCourse once. URL exclusions and the
    // Foxplan/Naverivo fallback stay here; product behavior stays in Pixel.

    const loader = document.currentScript;

    if (!(loader instanceof HTMLScriptElement)) {
        return;
    }

    const pixelKey = loader.dataset.pixel;

    if (!pixelKey || !/^[0-9a-f-]{36}$/i.test(pixelKey)) {
        return;
    }

    const normalizePath = value => value.replace(/\/+$/, '') || '/';
    const currentPage = new URL(window.location.href);
    let excludedUrls = [];

    try {
        excludedUrls = JSON.parse(loader.dataset.exclude || '[]');
    } catch {
        excludedUrls = [];
    }

    const excluded = excludedUrls.some(value => {
        try {
            const page = new URL(value, currentPage.origin);

            return page.hostname.toLowerCase() === currentPage.hostname.toLowerCase()
                && normalizePath(page.pathname) === normalizePath(currentPage.pathname)
                && [...page.searchParams].every(([name, expected]) =>
                    currentPage.searchParams.get(name) === expected
                );
        } catch {
            return false;
        }
    });

    if (excluded || window.__foxplanLoaderStarted) {
        return;
    }

    window.__foxplanLoaderStarted = true;

    const load = url => new Promise(resolve => {
        const started = performance.now();
        const script = document.createElement('script');
        let finished = false;

        const finish = error => {
            if (finished) {
                return;
            }

            finished = true;
            window.clearTimeout(timeout);
            script.onload = null;
            script.onerror = null;

            if (error) {
                script.remove();
            }

            resolve({
                error,
                duration_ms: Math.round(performance.now() - started),
            });
        };

        const timeout = window.setTimeout(() => finish('timeout'), 8000);

        script.src = url;
        script.async = true;
        script.onload = () => finish(null);
        script.onerror = () => finish('network_or_block');
        document.head.appendChild(script);
    });

    const showReportButton = tests => {
        if (currentPage.searchParams.get('foxplan_debug') !== '1') {
            return;
        }

        const button = document.createElement('button');
        let publicIp = null;
        let ipLookup = 'pending';

        const report = () => JSON.stringify({
            generated_at: new Date().toISOString(),
            page: currentPage.origin + currentPage.pathname,
            public_ip: publicIp,
            ip_lookup: ipLookup,
            online: navigator.onLine,
            user_agent: navigator.userAgent,
            language: navigator.language || null,
            timezone: Intl.DateTimeFormat().resolvedOptions().timeZone || null,
            tests,
        }, null, 2);

        button.type = 'button';
        button.disabled = true;
        button.textContent = 'Подготовка отчёта Foxplan…';
        button.style.cssText = 'position:fixed;right:16px;bottom:16px;z-index:2147483647;padding:10px 14px;border:0;border-radius:8px;background:#f59e0b;color:#111827;font:bold 14px Arial;cursor:pointer';
        button.onclick = () => {
            const contents = report();
            const copy = navigator.clipboard?.writeText(contents);

            if (!copy) {
                window.prompt('Скопируйте отчёт', contents);

                return;
            }

            copy
                .then(() => { button.textContent = 'Отчёт скопирован'; })
                .catch(() => window.prompt('Скопируйте отчёт', contents));
        };

        const mount = () => document.body.appendChild(button);

        if (document.body) {
            mount();
        } else {
            document.addEventListener('DOMContentLoaded', mount, {once: true});
        }

        const controller = new AbortController();
        const timeout = window.setTimeout(() => controller.abort(), 3000);

        fetch('https://api64.ipify.org?format=json', {
            cache: 'no-store',
            credentials: 'omit',
            referrerPolicy: 'no-referrer',
            signal: controller.signal,
        })
            .then(response => response.ok ? response.json() : Promise.reject(new Error('http')))
            .then(result => {
                const value = String(result.ip || '').trim();

                if (!/^[0-9a-f:.]{3,45}$/i.test(value)) {
                    throw new Error('invalid_ip');
                }

                publicIp = value;
                ipLookup = 'ok';
            })
            .catch(error => {
                ipLookup = error.name === 'AbortError' ? 'timeout' : 'unavailable';
            })
            .finally(() => {
                window.clearTimeout(timeout);
                button.disabled = false;
                button.textContent = 'Скопировать отчёт Foxplan';
            });
    };

    const run = async () => {
        const direct = await load(`https://foxplan.online/assets/runtime/${pixelKey}.js`);

        if (!direct.error) {
            return;
        }

        const fallbackUrl = new URL(`https://naverivo.com/assets/runtime/${pixelKey}.js`);

        fallbackUrl.searchParams.set('direct_error', direct.error);
        fallbackUrl.searchParams.set('direct_ms', String(direct.duration_ms));
        const fallback = await load(fallbackUrl.toString());

        if (fallback.error) {
            showReportButton({direct, fallback});
        }
    };

    void run();
})();