basic server setup

1 files changed, 20 insertions, 287 deletions

diff --git a/app/Main.hs b/app/Main.hs
index 31c9882..de77adc 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -7,302 +7,35 @@
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RecordWildCards #-}
-
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+-- | 
 
 module Main where
 
 
-import qualified Data.ByteString.Lazy as LB
-import qualified Data.ByteString as BS
-import qualified Data.Csv as CSV
-import Data.Csv ((.:))
-import qualified Codec.Archive.Zip as Zip
-import qualified Data.Vector as V
-import Data.Vector (Vector)
-import Text.Regex.TDFA ( (=~) )
-import Data.Text (Text)
-import Fmt ( (+|), (|+) )
-import Data.Kind (Type)
 import Data.Maybe (fromMaybe, fromJust)
-import Data.Functor ((<&>))
-import qualified Data.Time.Calendar.OrdinalDate as Day
-import Data.Time.Calendar.OrdinalDate (Day)
 import Data.Time.Calendar.MonthDay (monthAndDayToDayOfYearValid)
-import Data.Time (getCurrentTime, UTCTime (utctDay), dayOfWeek)
-import Data.Time.Calendar.WeekDate (DayOfWeek(..))
-
-
-newtype Time = Time { toSeconds :: Int }
-
-instance CSV.FromField Time where
-  parseField f = do
-    text :: String <- CSV.parseField f
-    let (_,_,_,subs) = text =~ ("([0-9][0-9]?):([0-9][0-9]?):([0-9][0-9]?)" :: Text)
-          :: (String, String, String, [String])
-    case subs of
-      [hh,mm,ss] -> pure $ Time $ read hh * 3600 + read mm * 60 + read ss
-      _ -> fail $ "encountered an invalid date: " <> text
-
-instance Show Time where
-  show (Time seconds) = ""
-    +|seconds `div` 3600|+":"
-    +|(seconds `mod` 3600) `div` 60|+":"
-    +|seconds `mod` 60|+""
-
-instance CSV.FromField Day where
-  parseField f = do
-    text :: String <- CSV.parseField f
-    let (_,_,_,subs) = text =~ ("([0-9][0-9][0-9][0-9])([0-9][0-9])([0-9][0-9])" :: Text)
-          :: (String, String, String, [String])
-    case subs of
-      [yyyy,mm,dd] -> do
-        let Just dayOfYear = monthAndDayToDayOfYearValid (Day.isLeapYear (read yyyy)) (read mm) (read dd)
-        pure $ Day.fromOrdinalDate (read yyyy) dayOfYear
-      _ -> fail $ "invalid date encountered: " <> show f
-
-
-
-data Depth = Shallow | Deep
-type Switch :: Depth -> Type -> Type -> Type
-type family Switch c a b where
-  Switch Deep a b = a
-  Switch Shallow a b = b
-
-type StationID = Text
-
--- | This is what's called a Stop in GTFS
-data Station = Station
-  { stationId :: StationID
-  , stationName :: Text
-  , stationLat :: Float
-  , stationLon :: Float
-  } deriving Show
-
--- | This is what's called a stop time in GTFS
-data Stop (deep :: Depth) = Stop
-  { stopTrip :: Int
-  , stopArrival :: Time
-  , stopDeparture :: Time
-  , stopStation:: Switch deep Station StationID
-  , stopSequence :: Int
-  }
-
-deriving instance Show (Stop 'Shallow)
-deriving instance Show (Stop 'Deep)
-
-
-data Calendar = Calendar
-  { calServiceId :: Text
-  , calMonday :: Bool
-  , calTuesday :: Bool
-  , calWednesday :: Bool
-  , calThursday :: Bool
-  , calFriday :: Bool
-  , calSaturday :: Bool
-  , calSunday :: Bool
-  , calStartDate :: Day
-  , calEndDate :: Day
-  } deriving Show
-
-data CalendarExceptionType = ServiceAdded | ServiceRemoved
-  deriving (Show, Eq)
-
-data CalendarDate = CalendarDate
-  { caldateServiceId :: Text
-  , caldateDate :: Day
-  , caldateExceptionType :: CalendarExceptionType
-  } deriving Show
-
-type TripID = Text
-type ServiceID = Text
-
-data Trip = Trip
-  { tripRoute :: Text
-  , tripTripID :: TripID
-  , tripHeadsign :: Maybe Text
-  , tripShortName :: Maybe Text
-  , tripDirection :: Maybe Bool
-  -- NOTE: there's also block_id, which we're unlikely to ever need
-  , tripServiceId :: Text
-  -- , tripWheelchairAccessible :: Bool
-  -- , tripBikesAllowed :: Bool
-  , tripShapeId :: Text
-  } deriving Show
-
--- | helper function to find things in Vectors of things
-tableLookup :: Eq key => (a -> key) -> key -> Vector a -> Maybe a
-tableLookup proj key = V.find (\a -> proj a == key)
-
-instance CSV.FromNamedRecord Station where
-  parseNamedRecord r = Station
-    <$> r .: "stop_id"
-    <*> r .: "stop_name"
-    <*> r .: "stop_lat"
-    <*> r .: "stop_lon"
-
-instance CSV.FromNamedRecord (Stop 'Shallow) where
-  parseNamedRecord r = Stop
-    <$> r .: "trip_id"
-    <*> r .: "arrival_time"
-    <*> r .: "departure_time"
-    <*> r .: "stop_id"
-    <*> r .: "stop_sequence"
-
-instance CSV.FromNamedRecord Calendar where
-  parseNamedRecord r = Calendar
-    <$> r .: "service_id"
-    <*> intAsBool' r "monday"
-    <*> intAsBool' r "tuesday"
-    <*> intAsBool' r "wednesday"
-    <*> intAsBool' r "thursday"
-    <*> intAsBool' r "friday"
-    <*> intAsBool' r "saturday"
-    <*> intAsBool' r "sunday"
-    <*> r .: "start_date"
-    <*> r .: "end_date"
-
-intAsBool :: CSV.NamedRecord -> BS.ByteString -> CSV.Parser (Maybe Bool)
-intAsBool r field = do
-  int <- r .: field
-  pure $ case int :: Int of
-    1 -> Just True
-    0 -> Just False
-    _ -> Nothing
-
-intAsBool' :: CSV.NamedRecord -> BS.ByteString -> CSV.Parser Bool
-intAsBool' r field = intAsBool r field >>= maybe
-  (fail "unexpected value for a boolean.")
-  pure
-
-
-instance CSV.FromNamedRecord CalendarDate where
-  parseNamedRecord r = CalendarDate
-    <$> r .: "service_id"
-    <*> r .: "date"
-    <*> do
-      int <- r .: "exception_type"
-      case int :: Int of
-        1 -> pure ServiceAdded
-        2 -> pure ServiceRemoved
-        _ -> fail $ "unexpected value in exception_type: "+|int|+"."
-
-
-instance CSV.FromNamedRecord Trip where
-  parseNamedRecord r = Trip
-    <$> r .: "route_id"
-    <*> r .: "trip_id"
-    <*> r .: "trip_headsign"
-    <*> r .: "trip_short_name"
-    <*> intAsBool r "direction_id"
-    <*> r .: "service_id"
-    -- NOTE: these aren't booleans but triple-values
-    -- <*> intAsBool r "wheelchair_accessible"
-    -- <*> intAsBool r "bikes_allowed"
-    <*> r .: "shape_id"
-
-data GTFS (depth :: Depth) = GTFS
-  { stations :: Vector Station
-  , stops :: Vector (Stop depth)
-  , trips :: Vector Trip
-  , calendar :: Maybe (Vector Calendar)
-  , calendarDates :: Maybe (Vector CalendarDate)
-  }
-
-deriving instance Show (GTFS Shallow)
-deriving instance Show (GTFS Deep)
-
-class Loadable depth where
-  loadGtfs :: FilePath -> IO (GTFS depth)
-
-instance Loadable Shallow where
-  loadGtfs path = do
-    zip <- Zip.toArchive <$> LB.readFile "./gtfs.zip"
-    GTFS <$> decodeTable' "stops.txt" zip
-         <*> decodeTable' "stop_times.txt" zip
-         <*> decodeTable' "trips.txt" zip
-         <*> decodeTable "calendar.txt" zip
-         <*> decodeTable "calendar_dates.txt" zip
-    where
-      decodeTable :: CSV.FromNamedRecord a => FilePath -> Zip.Archive -> IO (Maybe (Vector a))
-      decodeTable path zip = do
-        case Zip.findEntryByPath path zip of
-          Nothing -> pure Nothing
-          Just csv -> case CSV.decodeByName (Zip.fromEntry csv) of
-            Left err -> error "blah"
-            Right (_,v :: a) -> pure (Just v)
-      decodeTable' path zip =
-        decodeTable path zip >>= \case
-          Nothing -> fail $ "required file "+|path|+" not found in gtfs.zip"
-          Just a -> pure a
-
-instance Loadable Deep where
-  loadGtfs path = do
-    shallow <- loadGtfs @Shallow path
-    stops' <- V.mapM (pushStop (stations shallow)) (stops shallow)
-    pure $ shallow { stops = stops' }
-    where
-      pushStop :: Vector Station -> Stop Shallow -> IO (Stop Deep)
-      pushStop stations stop = do
-        station <- case tableLookup stationId (stopStation stop) stations of
-          Just a -> pure a
-          Nothing -> fail $ "station with id "+|stopStation stop|+"is mentioned but not defined."
-        pure $ stop { stopStation = station }
-
-
-
-servicesOnDay :: GTFS Deep -> Day -> Vector ServiceID
-servicesOnDay GTFS{..} day =
-  fmap caldateServiceId added <> V.filter notCancelled regular
-  where (added,removed) = case calendarDates of
-          Nothing -> (mempty,mempty)
-          Just exs ->
-            V.partition (\cd -> caldateExceptionType cd == ServiceAdded)
-            $ V.filter (\cd -> caldateDate cd == day) exs
-        regular = case calendar of
-          Nothing -> mempty
-          Just cs -> V.mapMaybe (\cal -> if isRunning cal then Just (calServiceId cal) else Nothing) cs
-          where isRunning Calendar{..} =
-                  day >= calStartDate &&
-                  day <= calEndDate &&
-                  case weekday of
-                    Monday -> calMonday
-                    Tuesday -> calTuesday
-                    Wednesday -> calWednesday
-                    Thursday -> calThursday
-                    Friday -> calFriday
-                    Saturday -> calSaturday
-                    Sunday -> calSunday
-        weekday = dayOfWeek day
-        notCancelled serviceID =
-          null (tableLookup caldateServiceId serviceID removed)
+import qualified Data.Time.Calendar.OrdinalDate as Day
+import qualified Data.ByteString.Lazy as LB
+import qualified Data.Aeson as A
+import           Network.Wai.Middleware.RequestLogger (OutputFormat (..),
+                                                       RequestLoggerSettings (..),
+                                                       mkRequestLogger)
+import Network.Wai.Handler.Warp (run)
+import Data.Default.Class (def)
 
-tripsOfService :: GTFS Deep -> ServiceID -> Vector Trip
-tripsOfService GTFS{..} serviceId =
-  V.filter (\trip -> tripServiceId trip == serviceId ) trips
+import GTFS
+import Server
 
 
 main :: IO ()
 main = do
   gtfs <- loadGtfs @Deep "./gtfs.zip"
-
-  -- today <- getCurrentTime <&> utctDay
-  -- print (calendar gtfs)
-  let today = Day.fromOrdinalDate 2022 (fromJust $ monthAndDayToDayOfYearValid False 6 6)
-  print today
-
-  putStrLn "trips today:"
-  print (fmap (tripsOfService gtfs)  (servicesOnDay gtfs today))
-
-
-{-
-TODO:
-there should be a basic API allowing the questions:
- - what are the next trips leaving from $station? (or $geolocation?)
- - all stops of a given tripID
-
-then the "ingress" API:
- - train ping (location, estimated delay, etc.)
- - cancel trip
- - add trip?
-
--}
+  app <- application gtfs
+  loggerMiddleware <- mkRequestLogger
+    $ def { outputFormat = Detailed True }
+  putStrLn "starting server …"
+  run 4000 (loggerMiddleware app)