// ==UserScript==
// @name         一键复制HTML表格/网页代码/latex公式
// @namespace    https://greasyfork.org/zh-CN/scripts/454641
// @version      0.8.2
// @description  在指定网站的表格上方添加按钮，点击将表格以Markdown格式复制到剪贴板
// @author       lsovaber
// @match        https://blog.csdn.net/*
// @match        https://www.cnblogs.com/*
// @match        https://www.runoob.com/*
// @match        https://www.jianshu.com/*
// @match        https://*.zhihu.com/*
// @match        https://www.quanxiaoha.com/*
// @match        https://www.geeksforgeeks.org/*
// @match        https://online.stat.psu.edu/stat800/*
// @match        https://www.javatpoint.com/*
// @match        https://cloud.tencent.com/*
// @match        https://scikit-learn.org/*
// @match        https://www.w3school.com.cn/*
// @match        https://www.w3cschool.cn/*
// @match        https://c.biancheng.net/*
// @match        https://juejin.cn/*
// @match        https://www.statology.org/*
// @match        https://stats.stackexchange.com/*
// @run-at       document-end
// @license      MIT
// @downloadURL none
// ==/UserScript==

(function () {
    'use strict';

    const NL = "\n";

    // 存放Markdown表格
    let processor = document.createElement("processor");
    // 获取<table>
    let table = document.getElementsByTagName("table");
    // 大多数网站块代码在<pre>里
    let pre = document.getElementsByTagName("pre");

    // 设置延迟，防止elements还未创建
    setTimeout(init, 1000);


    function convertTableElementToMarkdown(tableEl) {
        const rows = [];
        const trEls = tableEl.getElementsByTagName('tr');
        for (let i = 0; i < trEls.length; i++) {
            const tableRow = trEls[i];
            const markdownRow = convertTableRowElementToMarkdown(tableRow, i);
            rows.push(markdownRow);
        }
        return rows.join(NL);
    }

    function convertTableRowElementToMarkdown(tableRowEl, rowNumber) {
        const cells = [];
        const cellEls = tableRowEl.children;
        for (let i = 0; i < cellEls.length; i++) {
            const cell = cellEls[i];
            cells.push(cell.innerText + ' |');
        }
        let row = '| ' + cells.join(" ");

        if (rowNumber === 0) {
            row = row + NL + createMarkdownDividerRow(cellEls.length);
        }

        return row;
    }

    function createMarkdownDividerRow(cellCount) {
        const dividerCells = [];
        for (let i = 0; i < cellCount; i++) {
            dividerCells.push('--- |');
        }
        return '| ' + dividerCells.join(" ");
    }


    function convertTable(x) {
        const content = "<table>" + x.innerHTML + "</table>";
        processor.innerHTML = content.replace(/\s+/g, ' ');

        const tables = processor.getElementsByTagName('table');
        let markdownResults = '';
        if (tables) {
            for (let e of tables) {
                const markdownTable = convertTableElementToMarkdown(e);
                markdownResults += markdownTable + NL + NL;
            }
            let p = document.createElement("p");
            p.innerHTML = "复制成功";
            navigator.clipboard.writeText(markdownResults)
                .then(() => {
                    console.log('文本已经成功复制到剪切板');
                })
                .catch(err => {
                    // 如果用户没有授权，则抛出异常
                    console.error('无法复制此文本：', err);
                });
            // GM.setClipboard(markdownResults);
            x.parentNode.insertBefore(p, x);
        } else {
            console.log('No table found');
        }
    }

    function copyCode(x) {
        let text = window.location.href.includes("juejin") ? x.innerText.replace(/^.*\n.*复制代码/g, "") : x.innerText;
        navigator.clipboard.writeText(text)
            .then(() => {
                console.log('文本已经成功复制到剪切板');
            })
            .catch(err => {
                // 如果用户没有授权，则抛出异常
                console.error('无法复制此文本：', err);
            });
    }

    function copyMathFormula(x) {
        navigator.clipboard.writeText(x.innerText)
            .then(() => {
                console.log('文本已经成功复制到剪切板');
            })
            .catch(err => {
                // 如果用户没有授权，则抛出异常
                console.error('无法复制此文本：', err);
            });
    }

    function createButtons(x, type) {
        [...x].forEach((value, index) => {
            let button = document.createElement("button");
            button.innerText = `Copy ${type}`;
            // button.style.zIndex = '999';
            button.addEventListener('click',
                () => (type === "Table")
                    ? convertTable(x[index])
                    : (type === "Code")
                        ? copyCode(x[index])
                        : copyMathFormula(x[index])
            )
            x[index].parentNode.insertBefore(button, x[index]);
        })
    }

    function init() {
        createButtons(table, "Table");
        createButtons(pre, "Code");
        // 获取使用MathJax渲染的latex公式
        createButtons(document.querySelectorAll('script[type^="math/tex"]'), "Math");

        let url = window.location.href
        if (url.includes("runoob")) {
            // 菜鸟教程的代码块
            let example_code = document.getElementsByClassName("example_code");
            createButtons(example_code, "Code");
        } else if (url.includes("cnblogs") || url.includes("www.geeksforgeeks.org")) {
            let cn_blogs = document.getElementsByClassName("code");
            createButtons(cn_blogs, "Code");
        }
    }
})();