Wilfred/metawiki

var prettier = require("prettier");
var restify = require("restify");

var postcss = require("postcss");
var stylefmt = require("stylefmt");

function SyntaxError(message) {
  this.name = "SyntaxError";
  this.message = message;
  this.stack = new Error().stack;
}
SyntaxError.prototype = new Error();

// TODO: it would be nice to move the formatting into the browser,
// wherever possible.
function format(req, res, next) {
  var code = req.query.code;
  var mimeType = req.query.mimeType;

  try {
    if (mimeType == "application/javascript") {
      res.send({ code: formatJs(code) });
      next();
    } else if (mimeType == "text/css") {
      formatCss(code, function(err, formatted) {
        if (err) {
          next(new restify.BadRequestError(err.message));
          return;
        }
        res.send({ code: formatted });
        next();
      });
    } else {
      next(new restify.BadRequestError("Invalid MIME type: " + mimeType));
    }
  } catch (e) {
    if (e.name == "SyntaxError") {
      next(new restify.BadRequestError(e.message));
    } else {
      throw e;
    }
  }
}

function formatJs(src) {
  return prettier.format(src);
}

// Format CSS text `src` and call `cb` with the result.
function formatCss(src, cb) {
  postcss([stylefmt])
    .process(src)
    .then(function(result) {
      cb(null, result.css);
    })
    .catch(function() {
      cb(new SyntaxError("CSS syntax error"));
    });
}

module.exports = {
  format: format
};