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{-# LANGUAGE DataKinds #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedLists #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE TypeApplications #-}
module Server.GTFS_RT (gtfsRealtimeServer) where
import Prelude hiding (id)
import API (GtfsRealtimeAPI)
import Control.Monad (forM)
import Control.Monad.IO.Class (MonadIO (..))
import Data.ByteString.Lazy (fromStrict)
import Data.Functor ((<&>))
import qualified Data.Map as M
import Data.Maybe (catMaybes)
import Data.Pool (Pool)
import Data.Sequence (Seq)
import qualified Data.Sequence as Seq
import Data.Text (Text)
import qualified Data.Text as T
import Data.Text.Encoding (encodeUtf8)
import Data.Time.Calendar (Day, toGregorian)
import Data.Time.Clock (UTCTime (utctDay),
getCurrentTime)
import Data.Time.Clock.POSIX (getPOSIXTime)
import Data.Time.Clock.System (SystemTime (systemSeconds),
getSystemTime,
utcToSystemTime)
import qualified Data.UUID as UUID
import Data.Word (Word64)
import Database.Persist (Entity (..),
PersistQueryRead (selectFirst),
selectList, (==.))
import Database.Persist.Postgresql (SqlBackend)
import GHC.Float (double2Float,
int2Double)
import GTFS (GTFS (..),
Seconds (..),
Stop (..),
Trip (..), TripID)
import GTFS.Realtime.Alert as AL (Alert (..))
import GTFS.Realtime.Alert.SeverityLevel (SeverityLevel (WARNING))
import GTFS.Realtime.EntitySelector as ES (EntitySelector (..))
import GTFS.Realtime.FeedEntity as FE (FeedEntity (..))
import GTFS.Realtime.FeedHeader (FeedHeader (FeedHeader))
import GTFS.Realtime.FeedHeader.Incrementality (Incrementality (FULL_DATASET))
import GTFS.Realtime.FeedMessage as FM (FeedMessage (..))
import GTFS.Realtime.Position as POS (Position (..))
import GTFS.Realtime.TimeRange (TimeRange (TimeRange))
import GTFS.Realtime.TranslatedString (TranslatedString (TranslatedString))
import GTFS.Realtime.TranslatedString.Translation (Translation (Translation))
import GTFS.Realtime.TripDescriptor as TD (TripDescriptor (..))
import GTFS.Realtime.TripUpdate as TU (TripUpdate (..))
import GTFS.Realtime.TripUpdate.StopTimeEvent as STE (StopTimeEvent (..))
import GTFS.Realtime.TripUpdate.StopTimeUpdate as STU (StopTimeUpdate (..))
import GTFS.Realtime.VehicleDescriptor as VD (VehicleDescriptor (..))
import GTFS.Realtime.VehiclePosition as VP (VehiclePosition (..))
import Persist (Announcement (..),
EntityField (..),
Key (..),
Running (..),
Token (..),
TrainAnchor (..),
TrainPing (..),
runSql)
import Servant.API ((:<|>) (..))
import Text.ProtocolBuffers (Utf8 (Utf8),
defaultValue)
import Control.Monad.Extra (mapMaybeM)
import Data.List.NonEmpty (nonEmpty)
import Data.UUID (toASCIIBytes,
toLazyASCIIBytes)
import qualified Data.Vector as V
import Extrapolation (Extrapolator (extrapolateAtPosition, extrapolateAtSeconds),
LinearExtrapolator)
import GTFS (Depth (..))
import GTFS.Realtime.TripUpdate (TripUpdate (TripUpdate))
import Server.Util (Service,
secondsNow)
uuidUtf8 :: UUID.UUID -> Utf8
uuidUtf8 = Utf8 . fromStrict . UUID.toASCIIBytes
toUtf8 :: Text -> Utf8
toUtf8 = Utf8 . fromStrict . encodeUtf8
-- | formats a day in the "stupid" format used by gtfs realtime
toStupidDate :: Day -> Utf8
toStupidDate date = toUtf8
$ pad 4 year <> pad 2 month <> pad 2 day
where (year, month, day) = toGregorian date
pad len num = T.pack $ if ndigits < len
then replicate (len - ndigits) '0' <> show num
else show num
where ndigits = length (show num)
-- | basically unix timestamps, raw (because why not i guess)
toStupidTime :: UTCTime -> Word64
toStupidTime = fromIntegral . systemSeconds . utcToSystemTime
gtfsRealtimeServer :: GTFS -> Pool SqlBackend -> Service GtfsRealtimeAPI
gtfsRealtimeServer gtfs@GTFS{..} dbpool = handleServiceAlerts :<|> handleTripUpdates :<|> handleVehiclePositions
where handleServiceAlerts = runSql dbpool $ do
-- TODO filter: only select current & future days
announcements <- selectList [] []
dFeedMessage $ Seq.fromList $ fmap mkAlert announcements
where mkAlert (Entity (AnnouncementKey uuid) Announcement{..}) =
(dFeedEntity (uuidUtf8 uuid))
{ alert = Just $ Alert
{ active_period = [TimeRange Nothing Nothing defaultValue]
-- TODO: is this time range reasonable, needed, etc.?
, informed_entity =
[dEntitySelector
{ ES.trip =
Just (dTripDescriptor announcementTrip (Just announcementDay))
}
]
, cause = Nothing
, effect = Nothing
, url = fmap (lang "de" . toUtf8) announcementUrl
, header_text = Just $ lang "de" (toUtf8 announcementHeader)
, description_text = Just $ lang "de" (toUtf8 announcementMessage)
, tts_header_text = Nothing
, tts_description_text = Nothing
, severity_level = Nothing
, image = Nothing
, image_alternative_text = Nothing
, AL.ext'field = defaultValue
}
}
handleTripUpdates = runSql dbpool $ do
today <- liftIO $ getCurrentTime <&> utctDay
nowSeconds <- secondsNow today
running <- selectList [RunningDay ==. today] []
anchors <- flip mapMaybeM running $ \r@(Entity key Running{..}) -> do
entities <- selectList [TrainAnchorTrip ==. runningTrip, TrainAnchorDay ==. today] []
case nonEmpty (fmap entityVal entities) of
Nothing -> pure Nothing
Just anchors -> case M.lookup runningTrip trips of
Nothing -> pure Nothing
Just trip -> pure (Just (r, trip, anchors))
dFeedMessage $ Seq.fromList $ mkTripUpdate nowSeconds <$> anchors
where mkTripUpdate nowSeconds (Entity (RunningKey (Token uuid)) Running{..}, Trip{..} :: Trip Deep Deep, anchors) =
let lastCall = extrapolateAtSeconds @LinearExtrapolator anchors nowSeconds
stations = tripStops
<&> (\stop@Stop{..} -> fmap (, stop) $ extrapolateAtPosition @LinearExtrapolator anchors (int2Double stopSequence))
in (dFeedEntity (Utf8 $ toLazyASCIIBytes uuid))
{ FE.trip_update = Just $ TripUpdate
{ TU.trip = dTripDescriptor runningTrip (Just runningDay)
, TU.vehicle = Nothing
, TU.stop_time_update = Seq.fromList
$ fmap (\(TrainAnchor{..}, Stop{..}) -> StopTimeUpdate
{ STU.stop_sequence = Just (fromIntegral stopSequence)
, STU.stop_id = Nothing
, STU.arrival = Just (
defaultValue { STE.delay = Just $ fromIntegral $ unSeconds $ trainAnchorDelay })
, STU.departure = Nothing
, STU.departure_occupancy_status = Nothing
, STU.schedule_relationship = Nothing
, STU.stop_time_properties = Nothing
, STU.ext'field = defaultValue
})
$ catMaybes $ V.toList stations
, TU.delay = lastCall <&> (fromIntegral . unSeconds . trainAnchorDelay)
, TU.timestamp = lastCall <&> (toStupidTime . trainAnchorCreated)
, TU.trip_properties = Nothing
, TU.ext'field = defaultValue
}
}
handleVehiclePositions = runSql dbpool $ do
(running :: [Entity Running]) <- selectList [] []
pings <- forM running $ \(Entity key entity) -> do
selectFirst [TrainPingToken ==. key] [] <&> fmap (, entity)
dFeedMessage $ Seq.fromList $ mkPosition <$> catMaybes pings
where mkPosition (Entity (TrainPingKey key) TrainPing{..}, Running{..}) =
(dFeedEntity (toUtf8 . T.pack . show $ key))
{ FE.vehicle = Just $ VehiclePosition
{ trip = Just (dTripDescriptor runningTrip Nothing)
, VP.vehicle = case runningVehicle of
Nothing -> Nothing
Just trainset -> Just $ VehicleDescriptor
{ VD.id = Nothing
, VD.label = Just (toUtf8 trainset)
, VD.license_plate = Nothing
, VD.ext'field = defaultValue
}
, position = Just $ Position
{ latitude = double2Float trainPingLat
, longitude = double2Float trainPingLong
, odometer = Nothing
, speed = Nothing
, bearing = Nothing
, POS.ext'field = defaultValue
}
-- TODO: at least one of these should probably be given
, current_stop_sequence = Nothing
, stop_id = Nothing
, current_status = Nothing
, timestamp = Just (toStupidTime trainPingTimestamp)
, congestion_level = Nothing
, occupancy_status = Nothing
, occupancy_percentage = Nothing
, multi_carriage_details = []
, VP.ext'field = defaultValue
}
}
lang :: Utf8 -> Utf8 -> TranslatedString
lang code msg = TranslatedString [Translation msg (Just code) defaultValue] defaultValue
-- | a default FeedMessage, issued at the current system time
-- TODO: do we ever need incremental updates?
-- TODO: maybe instead use last update time?
dFeedMessage :: MonadIO m => Seq FeedEntity -> m FeedMessage
dFeedMessage entities = do
now <- liftIO getSystemTime <&> systemSeconds
pure $ FeedMessage
{ header = FeedHeader "2.0" (Just FULL_DATASET) (Just $ fromIntegral now) defaultValue
, entity = entities
, FM.ext'field = defaultValue
}
-- | a dummy FeedEntity (use record updates to add meaningful values to this)
dFeedEntity :: Utf8 -> FeedEntity
dFeedEntity id = FeedEntity
{ id
, is_deleted = Nothing
, trip_update = Nothing
, vehicle = Nothing
, alert = Nothing
, shape = Nothing
, FE.ext'field = defaultValue
}
dEntitySelector :: EntitySelector
dEntitySelector = EntitySelector
{ agency_id = Nothing
, route_id = Nothing
, route_type = Nothing
, trip = Nothing
, stop_id = Nothing
, direction_id = Nothing
, ES.ext'field = defaultValue
}
dTripDescriptor :: TripID -> Maybe Day -> TripDescriptor
dTripDescriptor tripID day = TripDescriptor
{ trip_id = Just (toUtf8 tripID)
, route_id = Nothing
, direction_id = Nothing
, start_time = Nothing
, start_date = fmap toStupidDate day
, schedule_relationship = Nothing
, TD.ext'field = defaultValue
}
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