// ==UserScript==
// @name         超星网课解除复制粘贴限制（自用）
// @namespace    http://tampermonkey.net/
// @version      2.0
// @description  解除网课复制粘贴限制（只测试超星可以，别的网站自测）
// @author       You
// @match      	 *://*.zhihuishu.com/*
// @match        *://*.chaoxing.com/*
// @match      	 *://*.edu.cn/*
// @match      	 *://*.org.cn/*
// @match      	 *://*.xueyinonline.com/*
// @match      	 *://*.hnsyu.net/*
// @match      	 *://*.qutjxjy.cn/*
// @match      	 *://*.ynny.cn/*
// @match      	 *://*.hnvist.cn/*
// @match      	 *://*.fjlecb.cn/*
// @match      	 *://*.gdhkmooc.com/*
// @match      	 *://*.cugbonline.cn/*
// @match      	 *://*.zjelib.cn/*
// @match      	 *://*.cqrspx.cn/*
// @match      	 *://*.neauce.com/*
// @match      	 *://*.zhihui-yun.com/*
// @match      	 *://*.cqie.cn/*
// @match      	 *://*.ccqmxx.com/*
// @match      	 *://*.icve.com.cn/*
// @match      	 *://*.course.icve.com.cn/*
// @match      	 *://*.courshare.cn/*
// @match      	 *://*.webtrn.cn/*
// @match      	 *://*.zjy2.icve.com.cn/*
// @match        *://*.zyk.icve.com.cn/*
// @match        *://*.icourse163.org/*
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        none
// ==/UserScript==


(function() {
    'use strict';

    const originalAddEventListener = EventTarget.prototype.addEventListener;
    const originalRemoveEventListener = EventTarget.prototype.removeEventListener;


    const eventListeners = new WeakMap();

    EventTarget.prototype.addEventListener = function(type, listener, options) {

        if (!eventListeners.has(this)) {
            eventListeners.set(this, []);
        }
        eventListeners.get(this).push({
            type,
            listener,
            options
        });


        return originalAddEventListener.call(this, type, listener, options);
    };


    EventTarget.prototype.removeEventListener = function(type, listener, options) {

        if (eventListeners.has(this)) {
            const listeners = eventListeners.get(this);
            const index = listeners.findIndex(l =>
                l.type === type &&
                l.listener === listener &&
                (l.options === options || (l.options && options && l.options.capture === options.capture))
            );
            if (index !== -1) {
                listeners.splice(index, 1);
            }
        }


        return originalRemoveEventListener.call(this, type, listener, options);
    };


    function removeAllEventListeners() {

        const walk = document.createTreeWalker(
            document.body,
            NodeFilter.SHOW_ELEMENT,
            null,
            false
        );


        const root = document.body;
        if (eventListeners.has(root)) {
            const listeners = [...eventListeners.get(root)];
            listeners.forEach(listener => {
                originalRemoveEventListener.call(
                    root,
                    listener.type,
                    listener.listener,
                    listener.options
                );
            });
            eventListeners.delete(root);
        }


        while (walk.nextNode()) {
            const node = walk.currentNode;
            if (eventListeners.has(node)) {
                const listeners = [...eventListeners.get(node)];
                listeners.forEach(listener => {
                    originalRemoveEventListener.call(
                        node,
                        listener.type,
                        listener.listener,
                        listener.options
                    );
                });
                eventListeners.delete(node);
            }
        }

    }


    function removeGlobalEventHandlers() {

        document.oncopy = null;
        document.oncut = null;
        document.onpaste = null;
        document.onselectstart = null;
        document.oncontextmenu = null;


        document.body.oncopy = null;
        document.body.oncut = null;
        document.body.onpaste = null;
        document.body.onselectstart = null;
        document.body.oncontextmenu = null;


        window.oncopy = null;
        window.oncut = null;
        window.onpaste = null;
        window.onselectstart = null;
        window.oncontextmenu = null;

    }


    function removeAntiCopyCSS() {

        const style = document.createElement('style');
        style.textContent = `
            * {
                user-select: text !important;
                -webkit-user-select: text !important;
                -moz-user-select: text !important;
                -ms-user-select: text !important;
                pointer-events: auto !important;
            }
            [oncopy], [oncut], [onpaste], [onselectstart], [oncontextmenu] {
                oncopy="return true;"
                oncut="return true;"
                onpaste="return true;"
                onselectstart="return true;"
                oncontextmenu="return true;"
            }
        `;
        document.head.appendChild(style);
    }


    function enableInteractions() {

        window.addEventListener('contextmenu', function(e) { e.stopPropagation(); }, true);
        window.addEventListener('copy', function(e) { e.stopPropagation(); }, true);
        window.addEventListener('cut', function(e) { e.stopPropagation(); }, true);
        window.addEventListener('paste', function(e) { e.stopPropagation(); }, true);
        window.addEventListener('selectstart', function(e) { e.stopPropagation(); }, true);

    }


    window.addEventListener('load', function() {

        removeAllEventListeners();
        removeGlobalEventHandlers();
        removeAntiCopyCSS();
        enableInteractions();

        // 为方便测试，添加一个快捷键来重新执行移除操作（Ctrl+Shift+R）
        document.addEventListener('keydown', function(e) {
            if (e.ctrlKey && e.shiftKey && e.keyCode === 82) {
                e.preventDefault();
                removeAllEventListeners();
                removeGlobalEventHandlers();
                removeAntiCopyCSS();
                enableInteractions();
            }
        });
    });


    const observer = new MutationObserver(function(mutations) {
        mutations.forEach(function(mutation) {
            if (mutation.addedNodes && mutation.addedNodes.length > 0) {

                for (let i = 0; i < mutation.addedNodes.length; i++) {
                    const node = mutation.addedNodes[i];
                    if (node.nodeType === 1) {
                        if (eventListeners.has(node)) {
                            const listeners = [...eventListeners.get(node)];
                            listeners.forEach(listener => {
                                originalRemoveEventListener.call(
                                    node,
                                    listener.type,
                                    listener.listener,
                                    listener.options
                                );
                            });
                            eventListeners.delete(node);
                        }
                    }
                }
            }
        });
    });

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

})();