// ==UserScript==
// @name         4chan /g/ code linenumbers
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  end the pain
// @author       You
// @match        https://boards.4chan.org/g/thread/*
// @grant        GM_addStyle
// ==/UserScript==
GM_addStyle ( `
    span.lineNumber {
    color: #6E9B98;
}
` );
(function() {
    'use strict';

    var codeblocks=document.getElementsByClassName("prettyprint prettyprinted")
    for (var i=0; i < codeblocks.length; i++) {
        var breakRowFromOneBlock=codeblocks[i].getElementsByTagName("br");
        var indent=breakRowFromOneBlock.length.toString().length
        var firstRowNum = document.createElement("SPAN");
            firstRowNum.className="lineNumber"
            firstRowNum.innerHTML="1"+" ".repeat(indent-1)+"|"
        codeblocks[i].insertBefore(firstRowNum, codeblocks[i].firstChild)
        if(breakRowFromOneBlock.length===1){
            continue;
        }
        for (var j=0; j < breakRowFromOneBlock.length; j++) {
            var singleBR = breakRowFromOneBlock[j]
            var lineNumberElement = document.createElement("SPAN");
            lineNumberElement.className="lineNumber"
            var sub=(j+2).toString().length
            lineNumberElement.innerHTML=(j+2).toString()+" ".repeat(indent-sub)+"|"
            singleBR.parentNode.insertBefore(lineNumberElement, singleBR.nextSibling)

        }
    }
})();