// ==UserScript==
// @name         南方医科大学继续教育网课助手
// @namespace    http://tampermonkey.net/
// @version      0.1.0
// @description  自动关闭学习提醒并在 nfykcj-kfkc.webtrn.cn 上保持视频播放
// @author       You
// @match        https://nfykcj-kfkc.webtrn.cn/*
// @run-at       document-idle
// @grant        none
// ==/UserScript==

(function () {
    'use strict';

    const CONFIRM_TEXT_SNIPPET = '确定';
    const LAYER_BUTTON_SELECTOR = '.layui-layer-btn0';
    const PLAY_CHECK_INTERVAL_MS = 5000;
    const MUTE = true;
    const CONFIRM_CHECK_INTERVAL_MS = 1000;
    const PLAY_BUTTON_SELECTORS = [
        '.vjs-big-play-button',
        '.prism-big-play-btn',
        '.prism-controlbar .prism-play-btn',
        '.xgplayer-play',
        '.video-play-button',
        '.play-btn',
        '.play-button',
        '.btn-play'
    ];

    function clickConfirmButtons(rootDoc) {
        if (!rootDoc) {
            return;
        }
        const buttons = rootDoc.querySelectorAll(LAYER_BUTTON_SELECTOR);
        buttons.forEach((btn) => {
            const text = btn.textContent || btn.innerText;
            if (text && text.indexOf(CONFIRM_TEXT_SNIPPET) !== -1) {
                btn.click();
            }
        });
    }

    function ensureVideosArePlaying(rootDoc) {
        if (!rootDoc) {
            return;
        }
        const videos = rootDoc.getElementsByTagName('video');
        Array.from(videos).forEach((video) => {
            if (MUTE) {
                video.muted = true;
                video.volume = 0;
            }
            if (video.paused && !video.ended) {
                const playPromise = video.play();
                if (playPromise && typeof playPromise.catch === 'function') {
                    playPromise.catch(() => {
                        clickFallbackPlayButton(rootDoc);
                    });
                }
            }
        });
    }

    function ensureAudioMuted(rootDoc) {
        if (!rootDoc || !MUTE) {
            return;
        }
        const audios = rootDoc.getElementsByTagName('audio');
        Array.from(audios).forEach((audio) => {
            audio.muted = true;
            audio.volume = 0;
        });
    }

    function clickFallbackPlayButton(rootDoc) {
        for (const selector of PLAY_BUTTON_SELECTORS) {
            const btn = rootDoc.querySelector(selector);
            if (btn) {
                btn.click();
                break;
            }
        }
    }

    function processWindow(targetWindow) {
        let targetDoc;
        try {
            targetDoc = targetWindow.document;
        } catch (err) {
            return;
        }
        clickConfirmButtons(targetDoc);
        ensureVideosArePlaying(targetDoc);
        ensureAudioMuted(targetDoc);
    }

    function watchSelfAndFrames() {
        processWindow(window);
        Array.from(document.getElementsByTagName('iframe')).forEach((frame) => {
            try {
                if (frame.contentWindow) {
                    processWindow(frame.contentWindow);
                }
            } catch (err) {
                // Ignore cross-origin frames.
            }
        });
    }

    setInterval(() => {
        clickConfirmButtons(document);
    }, CONFIRM_CHECK_INTERVAL_MS);

    setInterval(() => {
        watchSelfAndFrames();
    }, PLAY_CHECK_INTERVAL_MS);

    document.addEventListener('visibilitychange', () => {
        if (!document.hidden) {
            watchSelfAndFrames();
        }
    });
})();