const fs = require('fs');
const webshot = require('webshot');
const request = require('request');
const utility = require('./utility/utility.js');
const styleNames = require('./utility/styleNames.js');
const prettier = require('prettier');
const gm = require('gm').subClass({
'imageMagick': true
});
const path = require('path');
const VERSION = '9.10.0';
const opts = {
resolution: 1,
theme: 'hybrid',
font: 'Source Code Pro',
fontSize: 20,
background: '#fff'
}
/**
* Function to check whether file is JS or JSX.
* This is used to define the parser to prettify code.
* Currently only JS is supported. More formats are in development.
* @param fileName: Name of the file.
* @returns string: '.js' or '.jsx'
*/
function checkFileExtension(fileName) {
const ext = '';
if (fileName.endsWith('.js'))
return '.js';
return ext;
}
function insertMissingOptions(options) {
return Object.assign(opts, options);
}
/**
* Prettify code based on the extension of the file.
*/
const prettify = (source, ext) => {
switch (ext) {
case '.js':
{
return prettier.format(source, {
printWidth: 80,
tabWidth: 4,
singleQuote: true,
trailingComma: "none",
bracketSpacing: true,
parser: 'babylon'
});
}
default: {
return source;
}
}
}
function checkIfThemeExists(themeName){
if(styleNames.indexOf(themeName)!==-1) return true;
return false;
}
function setBackground(cssURL, options) {
request(cssURL, function (error, response, html) {
if (!error && response.statusCode == 200) {
let location,
firstOccurence,
backgroundOccurence,
semiColonOccurence,
colonOccurence;
let sliced;
location = html
.toString()
.indexOf('.hljs{');
sliced = html.slice(location);
firstOccurence = sliced.indexOf('}') + 1;
sliced = sliced.slice(0, firstOccurence);
backgroundOccurence = sliced.indexOf('background');
sliced = sliced.slice(backgroundOccurence);
colonOccurence = sliced.indexOf(':') + 1;
semiColonOccurence = sliced.indexOf(';');
sliced = sliced.slice(colonOccurence, semiColonOccurence);
options['background'] = sliced;
}
});
}
function generateHTML(sourceCode, options) {
let htmlTag = 'html';
let bodyTag = 'body';
let headTag = 'head';
let preTag = 'pre';
let codeTag = 'code';
let styleTag = 'style'
let themeName = options.theme.toLowerCase();
let theme = checkIfThemeExists(themeName) ? `${themeName}.min.css` : 'hybrid.min.css';
let cssURL = `https://cdnjs.cloudflare.com/ajax/libs/highlight.js/${VERSION}/styles/${theme}`;
setBackground(cssURL, options);
let scriptURL = `https://cdnjs.cloudflare.com/ajax/libs/highlight.js/${VERSION}/highlight.min.js`;
let style = options.style || `code{font-family: '${options.font}'; font-size:${options.fontSize}px; padding:20px}`;
return `<${htmlTag}>
<${headTag}>
<${styleTag}>
${style}
</${styleTag}>
<link href="https://fonts.googleapis.com/css?family=Source+Code+Pro" rel="stylesheet">
<link rel="stylesheet" href="${cssURL}" />
<script src="${scriptURL}"></script>
<script>hljs.initHighlightingOnLoad();</script>
</${headTag}>
<${bodyTag}>
<${preTag}>
<${codeTag}>
${sourceCode}
</${codeTag}>
</${preTag}>
</${bodyTag}}
</${htmlTag}>
`;
}
/**Main function.
* Set default arguments,
* if options are not passed
*/
function codeSnipper(fileName, options = opts) {
//Add extension to the options
options['ext'] = checkFileExtension(fileName);
options = insertMissingOptions(options);
// Initialize webshot's configuration, setting resolution(zoomFactor) if passed.
var webshotConfig = {
siteType: 'html',
zoomFactor: options.resolution || 2.5
}
const imagePath = process.cwd() + path.sep + fileName;
const imageName = imagePath + '.png';
//Read File and prettify code. Synchronous version is used for simplicity
var sourceCode = '';
fs.readFile(imagePath, (err, data) => {
if (err) {
throw new Error(err);
}
sourceCode = prettify(data.toString(), options.ext);
//Generate HTML
const htmlString = generateHTML(sourceCode, options);
webshot(htmlString, imageName, webshotConfig, (err) => {
if (!err) {
console.log('Image successfully saved as %s', imageName);
gm(imageName)
.trim()
.trim()
.borderColor(options.background)
.border(20, 20)
.write(imageName, (err) => {
if (err) {
throw new Error(err)
}
});
} else {
throw new Error(err)
}
return;
});
});
return 0;
}
module.exports = codeSnipper;