def httpUpdate(pname: String) = (for {
    u    <- liftK(signed(_:JReq))
    meId <- pathParam[BSONObjectID](pname)
    ume  <- jsonFromReq[UpdateMetricEvent]
    me1  <- constK(liftFO(findOne[MetricEvent](cname)(mkFindByIdQry(u, meId)), E404("Inexistent MetricEvent")).run)
    me2  =  me1.copy(value = ume.value getOrElse me1.value, date = ume.date getOrElse me1.date)
    m    <- constK(liftFO(findOneById[Metric](metrics.cname)(me2.metricId), E400("Metric not found")).run)
    doT  =  !((me1.value == me2.value) && (me1.date == me2.date))
    pme  <- constK(findFirst[MetricEvent](cname)(mkPrevQry(u, me2.metricId, me2.date)))
    qry  <- constK(mkUpdateQry(u, meId)(ume))
    upd  <- constK(update(cname)(qry))
    meta <- constK(aggregate[List[MetricEventMeta]](cname)(mkMetaP(u, me2.metricId)))
    _    <- constK(update(mname)(mkMetaUpdate(me2)(meta.headOption)))
    _    <- constK(eventFeeds.doMetricFeed("metricEventUpdate", 4.some)
              (owner = u.some, itemId = me2.metricId.some, itemName = m.name.some,
               value = me2.value.some, category = me2.category.some, unit = me2.unit.some))
    _    <- constK(if (doT) doNextTargetReached(u, pme, me2, m) else ().right.point[Future])
    utr  <- constK(if (doT) doUserTargetReached(u, pme, me2, m) else none.right.point[Future])
    _    <- constK(users.doRetireTarget(u, me2.metricId, utr))
  } yield upd) >>> toJsonResult