index.js

require('dotenv').load() // Load env variables

var express = require('express')
  , cache = new (require("node-cache"))()
  , path = require('path')
  , port = process.env.PORT || 3000
  , app = express()
  , badger = require('./lib/badger')
  , slack = require('./lib/slack')
  , linkUtils = require('./lib/link-utils.js')

var ttls = {
  users: 604800, // one week
  presence: 900 // 15 minutes
}

app.use(express.static(path.join(__dirname, 'public')));
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'hjs');

function isEmpty(obj) {
  return Object.keys(obj).length === 0
}

function fetchUsers(cb) {
  var users = cache.get('users').users

  if (users) {
    cb(null, users)
  } else {
    slack.user.list(function(err, users) {
      if (err) {
        cb(err, null)
      } else {
        cache.set('users', users, ttls.users)
        cb(null, users)
      }
    })
  }
}

function fetchUser(username, cb) {
  function findUser(name, list) {
    return list.filter(function(u) { return u.name === name }).pop()
  }

  fetchUsers(function(err, users) {
    if (err) {
      cb(err, null)
    } else {
      cb(null, findUser(username, users))
    }
  })
}

function fetchPresence(id, cb) {
  var key = id + ':presence'
    , val = cache.get(key)[key]

  if (val) {
    cb(null, val)
  } else {
    slack.user.presence(id, function(err, presence) {
      if (err) {
        cb(err, null)
      } else {
        cache.set(key, presence, ttls.presence)
        cb(null, presence)
      }
    })
  }
}

function getUser(req, res, next) {
  fetchUser(req.params.name, function(err, user) {
    if (!err && !user) {
      err = new Error('User "'+req.params.name+'" could not be found')
    }

    res.user = user
    next(err)
  })
}

function getPresence(req, res, next) {
  fetchPresence(res.user.id, function(err, presence) {
    res.user.presence = presence
    next(err)
  })
}

function drawUser(req, res, next) {
  badger.draw(res.user, {width: 350, height: 60}, function(err, canvas) {
    res.canvas = canvas
    next(err)
  })
}

app.get('/', function(req, res) {
  var paulUser = {
    name: 'paulsweeney',
    presence: 'active',
    profile: {
      first_name: 'Paul',
      last_name: 'Sweeney'
    }
  }

  res.render('index', {
    anchorExample: linkUtils.userAnchor({name: '<username>'}),
    mdExample: linkUtils.userMarkdown({name: '<username>'}),
    badge: linkUtils.userAnchor(paulUser)
  })
})

app.get('/users/:name.json', getUser, getPresence, function(req, res) {
  res.send({
    anchorBadge: linkUtils.userAnchor(res.user),
    markdownBadge: linkUtils.userMarkdown(res.user),
  })
})

app.get('/users/:name.png', getUser, getPresence, drawUser, function(req, res) {
  res.setHeader('content-type', 'image/png')
  res.canvas.pngStream().pipe(res)
})

// Boot our server
app.listen(port, function() {
  console.log('Listening for requests on port', port)
})