// ==UserScript==
// @name         HTML表格转化为Markdown表格
// @namespace    http://tampermonkey.net/
// @version      0.2
// @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       You
// @match        https://blog.csdn.net/*
// @match        https://www.cnblogs.com/*
// @match        https://www.runoob.com/*
// @match        https://www.jianshu.com/*
// @match        https://www.zhihu.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=csdn.net
// @grant        none
// @license      MIT
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const NL = "\n";

    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(() => {
                    x.parentNode.insertBefore(p, x)
                })
                .catch(err => {
                    p.innerHTML = "复制失败" + err;
                    x.parentNode.insertBefore(p, x)
                });
        }
        else {
            console.log('No table found');
        }
    }


    let processor = document.createElement("processor");
    let x = document.getElementsByTagName("table")
    for (let i = 0; i < x.length; i++){

        let button = document.createElement("button");
        button.innerText = "Copy";
        button.addEventListener('click', function () {
            convertTable(x[i])
        })
        x[i].parentNode.insertBefore(button, x[i])
    }


})();