fun

-- This is a little script that reads and returns the different stops that are

-- being visited by the buses of De Lijn. It's necessary to do it this way

-- because the stops.txt file also includes stops that are not visited anymore.

import Data.Set as S

import qualified Data.Vector as V

import Data.Gtfs.StopTimes

import Data.Gtfs.Stops

import Data.Text

import qualified Data.ByteString.Lazy as BL

import Data.Either (fromRight)

import Data.Csv (decodeByName)

extractStopTimes :: String -> IO (V.Vector StopTime)

extractStopTimes filepath = do

  x <- BL.readFile filepath

  let decodeE = decodeByName x

  --let stoptimes = snd $ fromRight (V.empty, V.empty) decodeE

  return (snd $ fromRight (V.empty, V.empty) decodeE)

stot :: StopID -> Text

stot (StopID a) = a

allStopIDs :: V.Vector StopTime -> S.Set Text -> S.Set Text

allStopIDs stopTimes set = case stopTimes V.!? 0 of

  Just x -> case stoptime_stop_id x of

    Just y ->  allStopIDs (V.tail stopTimes) $ S.insert (stot y) set

    Nothing -> allStopIDs (V.tail stopTimes) set

  Nothing -> set