server/web/middlewares/timezone.js

   1 'use strict';
   2
   3 var env = require('gitter-web-env');
   4 var logger = env.logger;
   5 var errorReporter = env.errorReporter;
   6 var userService = require('gitter-web-users');
   7 var debug = require('debug')('gitter:infra:timezone-middleware');
   8
   9 function parseOffset(value) {
  10   if (value.length !== 5) return;
  11   var sign = value[0];
  12   var hours = parseInt(value.substr(1, 2), 10);
  13   var mins = parseInt(value.substr(3, 2), 10);
  14
  15   if (sign !== '+' && sign !== '-') return;
  16   if (isNaN(hours) || isNaN(mins)) return;
  17
  18   return (sign === '-' ? -1 : 1) * hours * 60 + mins;
  19 }
  20
  21 function parseTimezoneCookie(value) {
  22   if (!value) return;
  23   var parts = value.split(':');
  24
  25   if (parts.length < 1) return;
  26
  27   var offsetString = parts[0];
  28   var abbr = parts[1];
  29   var iana = parts[2];
  30
  31   var offset = parseOffset(offsetString);
  32   if (offset === undefined) return;
  33
  34   return { offset: offset, abbr: abbr, iana: iana };
  35 }
  36
  37 /**
  38  * Note, does not return a promise as it's indented to be
  39  * called outside of the promise-chain.
  40  */
  41 function updateUserTzInfo(user, timezoneInfo) {
  42   debug('Saving timezone information for user %s: %j', user.username, timezoneInfo);
  43   userService
  44     .updateTzInfo(user._id, timezoneInfo)
  45     .catch(function(err) {
  46       logger.error('Unable to save timezone info for user', { exception: err });
  47       errorReporter(err, { user: user.username }, { module: 'timezone-middleware' });
  48     })
  49     .done();
  50 }
  51
  52 // eslint-disable-next-line complexity
  53 module.exports = function(req, res, next) {
  54   /** Parse the cookie if one exists */
  55   var parsed = parseTimezoneCookie(req.cookies.gitter_tz);
  56   var userTz = req.user && req.user.tz;
  57
  58   debug('User presented timezone cookie %j', parsed);
  59
  60   if (parsed) {
  61     if (userTz) {
  62       /* Its possible that the users browser can't do IANA,
  63        * so just used the saved value if possible */
  64       if (userTz.offset === parsed.offset && userTz.abbr === parsed.abbr) {
  65         if (userTz.iana && !parsed.iana) {
  66           parsed.iana = userTz.iana;
  67         }
  68       }
  69
  70       /* Has the user presented us with new timezone information? If so, update */
  71       if (
  72         userTz.offset !== parsed.offset ||
  73         userTz.abbr !== parsed.abbr ||
  74         userTz.iana !== parsed.iana
  75       ) {
  76         updateUserTzInfo(req.user, parsed);
  77       }
  78     } else if (req.user) {
  79       /* First time we've got timezone information from this user, so save it */
  80       updateUserTzInfo(req.user, parsed);
  81     }
  82
  83     res.locals.tz = parsed;
  84     res.locals.tzOffset = parsed.offset;
  85   } else {
  86     /* The user did not present a cookie.
  87      * Do we have some saved state for the user? If so, let's use that */
  88     if (userTz) {
  89       res.locals.tz = userTz;
  90       res.locals.tzOffset = userTz.offset;
  91     } else {
  92       /* No cookie, no saved state, default to UTC */
  93       res.locals.tzOffset = 0;
  94     }
  95   }
  96
  97   next();
  98 };