YouTube English/Thai Caption Switcher HOPEFULLY THIS WORKS

// ==UserScript==
// @name         YouTube English/Thai Caption Switcher HOPEFULLY THIS WORKS
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  Switch between English and auto-generated Thai captions on YouTube
// @author       Your name
// @match        https://www.youtube.com/*
// @match        https://youtube.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // Style for our caption switcher
    const style = document.createElement('style');
    style.textContent = `
        .caption-switcher {
            position: fixed;
            bottom: 120px;
            right: 20px;
            background: rgba(33, 33, 33, 0.9);
            padding: 8px;
            border-radius: 8px;
            z-index: 9999;
            display: flex;
            flex-direction: column;
            gap: 6px;
            font-family: YouTube Sans, sans-serif;
            box-shadow: 0 2px 8px rgba(0,0,0,0.2);
        }
        .caption-button {
            background: #ffffff;
            border: none;
            padding: 8px 12px;
            border-radius: 4px;
            cursor: pointer;
            color: #030303;
            font-size: 14px;
            font-weight: 500;
            transition: all 0.2s;
            min-width: 100px;
            text-align: center;
        }
        .caption-button:hover {
            background: #e5e5e5;
        }
        .caption-button.active {
            background: #065fd4;
            color: white;
        }
        .caption-button:active {
            transform: scale(0.98);
        }
    `;
    document.head.appendChild(style);

    // Function to set caption language
    function setCaption(languageCode, isAuto = false) {
        const player = document.querySelector('.html5-video-player');
        if (!player) return;

        const playerApi = player.wrappedJSObject || player;

        if (playerApi && playerApi.setOption) {
            // For auto-generated captions, we need to specify the trackName
            const track = {
                languageCode: languageCode,
                // For Thai auto-generated captions
                kind: isAuto ? 'asr' : 'captions'
            };

            // Turn on captions with specified settings
            playerApi.setOption('captions', 'track', track);

            // Make sure captions are displayed
            setTimeout(() => {
                if (!playerApi.getOption('captions', 'track')) {
                    playerApi.toggleSubtitles();
                }
            }, 100);

            // Update button states
            updateButtonStates(languageCode);
        }
    }

    // Function to update button active states
    function updateButtonStates(activeLanguage) {
        document.querySelectorAll('.caption-button').forEach(button => {
            button.classList.remove('active');
            if (button.dataset.lang === activeLanguage) {
                button.classList.add('active');
            }
        });
    }

    // Create and inject the caption switcher UI
    function createSwitcher() {
        const switcher = document.createElement('div');
        switcher.className = 'caption-switcher';

        // English button
        const engButton = document.createElement('button');
        engButton.className = 'caption-button';
        engButton.textContent = '🇺🇸 English';
        engButton.dataset.lang = 'en';
        engButton.onclick = () => setCaption('en', false);
        switcher.appendChild(engButton);

        // Thai auto-generated button
        const thaiButton = document.createElement('button');
        thaiButton.className = 'caption-button';
        thaiButton.textContent = '🇹🇭 Thai (Auto)';
        thaiButton.dataset.lang = 'th';
        thaiButton.onclick = () => setCaption('th', true);
        switcher.appendChild(thaiButton);

        document.body.appendChild(switcher);
    }

    // Function to initialize the script
    function init() {
        if (document.querySelector('.html5-video-player')) {
            if (!document.querySelector('.caption-switcher')) {
                createSwitcher();
            }
        } else {
            // If player isn't loaded yet, wait and try again
            setTimeout(init, 1000);
        }
    }

    // Watch for navigation changes (for single-page app navigation)
    const observer = new MutationObserver((mutations) => {
        if (window.location.href.includes('watch')) {
            init();
        }
    });

    observer.observe(document.documentElement, {
        childList: true,
        subtree: true
    });

    // Initial setup
    init();
})();