Mongo async query

/**
 * List of Posts
 */
exports.all = function(req, res) {
  // async.waterfall([

  //   function(done) {
  var query;
  var group_list = req.user.groups;
  group_list.push(null);
  if (req.query.group) {
    query = Post.find({
      group: req.query.group
    });
  } else if (req.query.wallUser) {
    query = Post.find({
      $or: [{
        user: req.query.wallUser,
        status: true
      }, {
        wallUser: req.query.wallUser
      }]
    });
  } else {
    query = Post.find({
      $and: [{
        pinPost: false,
        status: true
      }, {
        $or: [{
          $and: [{
            group: null
          }, {
            wallUser: null
          }]
        }, {
          $and: [{
            wallUser: {
              $exists: true,
              $ne: null
            }
          }, {
            $or: [{
              wallUser: req.user._id
            }, {
              user: req.user._id
            }, {
              wallUser: {
                $in: [] // Have to update this to req.user.following
              }
            }]
          }],
        }, {
          $and: [{
            group: {
              $exists: true,
              $ne: null
            }
          }, {
            group: {
              $in: group_list
            }
          }]
        }]
      }]
    });
  }
  if (req.query.limit) {
    query.limit(req.query.limit);
  }
  if (req.query.skip) {
    query.skip(req.query.skip);
  }
  query.sort('-created')
    .populate('user', 'name username picture followers')
    .populate('likes', 'name username picture')
    .populate('mentionsUser', 'name email picture')
    .populate('wallUser', 'name username picture')
    .populate('group', 'name members')
    .exec(function(err, posts) {
      if (err) {
        return res.json(500, {
          error: 'Cannot list the posts'
        });
      }
      // if (req.query.wallUser || req.query.group)
      res.json(posts);
      // else
      //   done(err, posts, posts[0].created, posts[9].created);
    });
  //   },
  //   function(postLists, start, end, done) {
  //     console.log('here is end ', end);
  //     var query = User.find({
  //       $and: [{
  //         'awards.created': {
  //           $gte: end
  //         }
  //       }, {
  //         'awards.0': {
  //           $exists: true
  //         }
  //       }]
  //     });
  //     query.sort('-created');
  //     if (req.query.awardsLimit)
  //       query.limit(req.query.awardsLimit);
  //     if (req.query.awardSkip)
  //       query.skip(req.query.awardSkip);
  //     query.populate('awards.award')
  //       .exec(function(err, awards) {
  //         if (err) {
  //           res.render('error', {
  //             status: 500
  //           });
  //         } else {
  //           var awrds = [];
  //           awards.forEach(function(usr) {
  //             if (usr.name) {
  //               var aw = [{
  //                 '_id': usr._id,
  //                 'name': usr.name,
  //                 'picture': usr.picture,
  //                 'awards': _.last(usr.awards)
  //               }];
  //               awrds = awrds.concat(aw);
  //             }
  //           });
  //           awrds = _.sortBy(awrds, 'date');
  //           var result = postLists.concat(awrds);
  //           done(err, result, start, end);
  //         }
  //       });
  //   },
  //   function(postLists, start, end, done) {
  //     console.log('start date', start);
  //     console.log('end date', end);

  //     var query = Events.find({
  //       $and: [{
  //         created: {
  //           $gte: end
  //         }
  //       }, {
  //         showevent: true
  //       }]
  //     });
  //     query.sort('-created');
  //     if (req.query.eventLimit)
  //       query.limit(req.query.eventLimit);
  //     if (req.query.eventSkip)
  //       query.skip(req.query.eventSkip);
  //     query.populate('user').exec(function(err, events) {
  //       console.log('here is event', events)
  //       if (err) {
  //         return res.json(500, {
  //           error: 'Cannot list the events'
  //         });
  //       }
  //       var result = postLists.concat(events);
  //       result.sort(function(a, b) {
  //         var c = new Date(a.created);
  //         var d = new Date(b.created);
  //         return c - d;
  //       });
  //       res.json(result);
  //     });
  //   }
  // ]);
};