aboutsummaryrefslogtreecommitdiff
path: root/lib/Server/GTFS_RT.hs
blob: d7717369b8145dfe284b3c2449dbd5ffe9c1c110 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
{-# LANGUAGE NamedFieldPuns    #-}
{-# LANGUAGE OverloadedLists   #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards   #-}
{-# LANGUAGE TupleSections     #-}

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           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)
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 (Entity),
                                                             PersistQueryRead (selectFirst),
                                                             selectList, (==.))
import           Database.Persist.Postgresql                (SqlBackend)
import           GHC.Float                                  (double2Float)
import           GTFS                                       (GTFS, 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.VehicleDescriptor            as VD (VehicleDescriptor (..))
import           GTFS.Realtime.VehiclePosition              as VP (VehiclePosition (..))
import           Persist                                    (Announcement (..),
                                                             EntityField (..),
                                                             Key (..),
                                                             RunningTrip (..),
                                                             TripPing (..),
                                                             runSql)
import           Servant.API                                ((:<|>) (..))
import           Text.ProtocolBuffers                       (Utf8 (Utf8),
                                                             defaultValue)

import           Server.Util                                (Service)

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 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
          error "unimplemented!"
          -- TODO: how to propagate delay values to next stops?
          pure undefined
        handleVehiclePositions = runSql dbpool $ do
          (running :: [Entity RunningTrip]) <- selectList [] []
          pings <- forM running $ \(Entity key entity) -> do
            selectFirst [TripPingToken ==. key] [] <&> fmap (, entity)
          dFeedMessage $ Seq.fromList $ mkPosition <$> catMaybes pings
          where mkPosition (Entity (TripPingKey key) TripPing{..}, RunningTrip{..}) =
                  (dFeedEntity (toUtf8 . T.pack . show $ key))
                  { FE.vehicle = Just $ VehiclePosition
                    { trip = Just (dTripDescriptor runningTripTripNumber Nothing)
                    , VP.vehicle = case runningTripVehicle 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 tripPingLat
                      , longitude = double2Float tripPingLong
                      , 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 tripPingTimestamp)
                    , 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
  }