// ==UserScript==
// @name         YouTube Screenshot Helper
// @name:zh-TW   YouTube 截圖助手
// @name:zh-CN   YouTube 截图助手
// @namespace    https://www.tampermonkey.net/
// @version      1.9
// @description  YouTube Screenshot Tool – supports hotkey capture, burst mode, customizable hotkeys, burst interval settings, and menu language switch between Chinese and English.
// @description:zh-TW YouTube截圖工具，支援快捷鍵截圖、連拍模式，自定義快捷鍵、連拍間隔設定、中英菜單切換
// @description:zh-CN YouTube截图工具，支援快捷键截图、连拍模式，自定义快捷键、连拍间隔设定、中英菜单切换
// @author       ChatGPT
// @match        https://www.youtube.com/*
// @grant        GM_registerMenuCommand
// @grant        GM_getValue
// @grant        GM_setValue
// @license MIT
// @downloadURL none
// ==/UserScript==

(function () {
    'use strict';

    // 預設參數
    const CONFIG = {
        defaultHotkey: 's',
        defaultInterval: 1000,
        minInterval: 100,
        defaultLang: 'EN',
    };

    // 取得設定值
    let screenshotKey = GM_getValue('screenshotKey', CONFIG.defaultHotkey);
    let interval = Math.max(parseInt(GM_getValue('captureInterval', CONFIG.defaultInterval)), CONFIG.minInterval);
    let lang = GM_getValue('lang', CONFIG.defaultLang);

    // 多語系
    const I18N = {
        EN: {
            langToggle: 'LANG EN',
            setHotkey: `Set Screenshot Key (Now: ${screenshotKey.toUpperCase()})`,
            setInterval: `Set Burst Interval (Now: ${interval}ms)`,
            promptKey: 'Enter new hotkey (a-z):',
            promptInterval: `Enter new interval (min ${CONFIG.minInterval}ms):`,
        },
        ZH: {
            langToggle: '語言 中文',
            setHotkey: `設定截圖快捷鍵（目前：${screenshotKey.toUpperCase()}）`,
            setInterval: `設定連拍間隔（目前：${interval}ms）`,
            promptKey: '請輸入新的快捷鍵（單一字母）:',
            promptInterval: `請輸入新的連拍間隔（單位ms，最低 ${CONFIG.minInterval}ms）：`,
        },
    };
    const t = I18N[lang];

    // 狀態變數
    let keyDown = false;
    let intervalId = null;

    // Shorts 影片切換偵測
    let lastShortsUrl = '';

    function onShortsVideoChange() {
        // 目前不需特別重設，因為 takeScreenshot 會即時抓取
    }

    // 監聽網址變化
    setInterval(() => {
        if (window.location.href.includes('/shorts/')) {
            if (window.location.href !== lastShortsUrl) {
                lastShortsUrl = window.location.href;
                onShortsVideoChange();
            }
        }
    }, 300);

    // 監聽 DOM 變化
    if (window.location.href.includes('/shorts/')) {
        const observer = new MutationObserver(() => {
            onShortsVideoChange();
        });
        observer.observe(document.body, { childList: true, subtree: true });
    }

    // 取得影片元素
    function getVideoElement() {
        // Shorts 影片有時會有多個 video，只取可見的那個
        const videos = Array.from(document.querySelectorAll('video'));
        if (window.location.href.includes('/shorts/')) {
            // 只取在畫面上的 video
            return videos.find(v => v.offsetParent !== null);
        }
        return videos[0] || null;
    }

    // 格式化時間
    function formatTime(seconds) {
        const h = String(Math.floor(seconds / 3600)).padStart(2, '0');
        const m = String(Math.floor((seconds % 3600) / 60)).padStart(2, '0');
        const s = String(Math.floor(seconds % 60)).padStart(2, '0');
        const ms = String(Math.floor((seconds % 1) * 1000)).padStart(3, '0');
        return `${h}_${m}_${s}_${ms}`;
    }

    // 取得影片ID
    function getVideoID() {
        let match = window.location.href.match(/\/shorts\/([a-zA-Z0-9_-]+)/);
        if (match) return match[1];
        match = window.location.href.match(/\/live\/([a-zA-Z0-9_-]+)/);
        if (match) return match[1];
        match = window.location.href.match(/[?&]v=([^&]+)/);
        return match ? match[1] : 'unknown';
    }

    // 取得影片標題（重點修正：Shorts 動態標題）
    function getVideoTitle() {
        if (window.location.href.includes('/shorts/')) {
            // 取得目前 active 的 Shorts 標題
            let h2 = document.querySelector('ytd-reel-video-renderer[is-active] h2');
            if (h2 && h2.textContent.trim()) return h2.textContent.trim().replace(/[\\/:*?"<>|]/g, '').trim();
            // Fallback: 取第一個 h2
            h2 = document.querySelector('ytd-reel-video-renderer h2');
            if (h2 && h2.textContent.trim()) return h2.textContent.trim().replace(/[\\/:*?"<>|]/g, '').trim();
            // Fallback: meta
            let meta = document.querySelector('meta[name="title"]');
            if (meta) return meta.getAttribute('content').replace(/[\\/:*?"<>|]/g, '').trim();
            return (document.title || 'unknown').replace(/[\\/:*?"<>|]/g, '').trim();
        }
        // Live
        if (window.location.href.includes('/live/')) {
            let title = document.querySelector('meta[name="title"]')?.getAttribute('content')
                || document.title
                || 'unknown';
            return title.replace(/[\\/:*?"<>|]/g, '').trim();
        }
        // 一般影片
        let title = document.querySelector('h1.ytd-watch-metadata')?.textContent
            || document.querySelector('h1.title')?.innerText
            || document.querySelector('h1')?.innerText
            || document.querySelector('meta[name="title"]')?.getAttribute('content')
            || document.title
            || 'unknown';
        return title.replace(/[\\/:*?"<>|]/g, '').trim();
    }

    // 取得 Shorts 影片唯一標識（用 video.src 或影片ID）
    function getCurrentShortsUniqueKey() {
        const video = getVideoElement();
        if (video && video.src) return video.src;
        return getVideoID();
    }

    // 等待 Shorts 影片切換完成再截圖
    function waitForShortsReadyAndScreenshot(prevKey, tryCount = 0) {
        const newKey = getCurrentShortsUniqueKey();
        if (newKey && newKey !== prevKey) {
            takeScreenshot();
        } else if (tryCount < 20) { // 最多等2秒
            setTimeout(() => waitForShortsReadyAndScreenshot(prevKey, tryCount + 1), 100);
        }
        // 超時則放棄
    }

    // 截圖主程式
    function takeScreenshot() {
        const video = getVideoElement();
        if (!video || video.videoWidth === 0 || video.videoHeight === 0) {
            // video 尚未載入，略過這次
            return;
        }
        const canvas = document.createElement('canvas');
        canvas.width = video.videoWidth;
        canvas.height = video.videoHeight;
        canvas.getContext('2d').drawImage(video, 0, 0, canvas.width, canvas.height);

        const link = document.createElement('a');
        const timestamp = formatTime(video.currentTime);
        const title = getVideoTitle();
        const id = getVideoID();
        const resolution = `${canvas.width}x${canvas.height}`;
        link.download = `${timestamp}_${title}_${id}_${resolution}.png`;
        link.href = canvas.toDataURL('image/png');
        link.click();
    }

    // 快捷鍵事件
    document.addEventListener('keydown', (e) => {
        if (
            e.key.toLowerCase() === screenshotKey &&
            !keyDown &&
            !['INPUT', 'TEXTAREA'].includes(e.target.tagName)
        ) {
            keyDown = true;
            if (window.location.href.includes('/shorts/')) {
                // Shorts 模式下，等待新影片載入
                const prevKey = getCurrentShortsUniqueKey();
                waitForShortsReadyAndScreenshot(prevKey);
                intervalId = setInterval(() => waitForShortsReadyAndScreenshot(getCurrentShortsUniqueKey()), interval);
            } else {
                takeScreenshot();
                intervalId = setInterval(takeScreenshot, interval);
            }
        }
    });

    document.addEventListener('keyup', (e) => {
        if (e.key.toLowerCase() === screenshotKey) {
            keyDown = false;
            clearInterval(intervalId);
        }
    });

    // 油猴選單
    GM_registerMenuCommand(t.setHotkey, () => {
        const input = prompt(t.promptKey, screenshotKey);
        if (input && /^[a-zA-Z]$/.test(input)) {
            GM_setValue('screenshotKey', input.toLowerCase());
            location.reload();
        }
    });

    GM_registerMenuCommand(t.setInterval, () => {
        const input = parseInt(prompt(t.promptInterval, interval));
        if (!isNaN(input) && input >= CONFIG.minInterval) {
            GM_setValue('captureInterval', input);
            location.reload();
        }
    });

    GM_registerMenuCommand(t.langToggle, () => {
        GM_setValue('lang', lang === 'EN' ? 'ZH' : 'EN');
        location.reload();
    });
})();