// ==UserScript==
// @name         YouTube Reverse Hack (Mejorado)
// @namespace    https://chat.openai.com/
// @version      0.3
// @description  Simula reproducción reversa más suave en YouTube (solo vídeo)
// @match        https://www.youtube.com/watch*
// @grant        none
// ==/UserScript==

(function () {
    'use strict';

    let reverseActive = false;
    let rafId = null;
    const step = 0.04; // segundos por frame ~25fps
    const delay = 40; // ms entre frames

    function waitForVideo(callback) {
        const check = setInterval(() => {
            const video = document.querySelector('video');
            if (video && video.readyState >= 2) {
                clearInterval(check);
                callback(video);
            }
        }, 300);
    }

    function createButton(video) {
        const btn = document.createElement('button');
        btn.textContent = '⏪ Reverse';
        Object.assign(btn.style, {
            position: 'fixed',
            bottom: '100px',
            left: '20px',
            zIndex: 9999,
            padding: '10px',
            background: '#111',
            color: '#fff',
            border: 'none',
            borderRadius: '6px',
            cursor: 'pointer',
            fontSize: '14px',
            opacity: 0.85,
        });

        btn.onclick = () => {
            reverseActive = !reverseActive;
            if (reverseActive) {
                video.pause();
                stepBack(video);
                btn.textContent = '⏹️ Stop Reverse';
            } else {
                cancelAnimationFrame(rafId);
                btn.textContent = '⏪ Reverse';
            }
        };

        document.body.appendChild(btn);
    }

    function stepBack(video) {
        if (!reverseActive) return;
        const now = video.currentTime;
        if (now <= 0.04) {
            reverseActive = false;
            return;
        }
        video.currentTime = now - step;

        rafId = requestAnimationFrame(() => {
            setTimeout(() => stepBack(video), delay);
        });
    }

    waitForVideo((video) => {
        createButton(video);
    });
})();