github auth

github.js

var url = require("url")
  , https = require("https")

exports.Application = function(options) {
  if (!options.secret) throw "No application secret provided."
  if (!options.clientId) throw "No application client ID provided."

  return function(req, res) {
    var protocol = res.socket.encrypted ? "https" : "http"
      , uri = protocol + "://" + req.headers.host + req.url
      , query = url.parse(uri, true).query

    function error(message) {
      message = "An error occurred: " + message

      res.writeHead(500, {
        "Content-Type": "text/plain",
        "Content-Length": message.length
      })

      res.end(message)
    }

    if (query.code) {
      https
        .request({
          method: "POST",
          host: "github.com",
          path:
            "/login/oauth/access_token" +
            url.format({query: {
              client_id: options.clientId,
              client_secret: options.secret,
              code: query.code
            }})
        }, function(response) {
          var data = ""

          response
            .on("data", function(chunk){ data += chunk })
            .on("end", function() {
              data = url.parse("?" + data, true).query
              console.log(data)
              res.end(data.access_token)
            })
        })
        .on('error', function(err){ error(err.message) })
        .end()
    }

    else if (query.error) error(query.error)

    else {
      res.writeHead(302, {
        Location: url.format({
          protocol: "https", host: "github.com",
          pathname: "/login/oauth/authorize",
          query: {
            client_id: options.clientId,
            scopes: options.scopes || [],
            redirect_uri: uri
          }
        })
      })

      res.end()
    }
  }
}