Loop.hs

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards   #-}


module Main where

import           RIO
import qualified RIO.Map as M

data Question = Question
    { qId    :: Text
    , qText  :: Text
    , qScore :: Int
    }
    deriving (Show, Eq)

data Report = Report
    { rId       :: Text
    , rName     :: Text
    , questions :: Map Text Int
    }
    deriving (Show, Eq)

reports' :: [Report]
reports' = [ Report "id1" "name1" mempty
           , Report "id2" "name2" mempty
           , Report "id3" "name3" mempty
           ]

questions' :: [Question]
questions' = [ Question "id1" "Q1" 10
             , Question "id1" "Q2" 20
             , Question "id2" "Q3" 30
             , Question "id2" "Q4" 40
             , Question "id3" "Q5" 50
             , Question "id3" "Q5" 60
             ]

myfunc :: [Question] -> [Report] -> [Report]
myfunc questions oldCallsReports = do

  let testMerge :: Question -> Report -> Maybe Report
      testMerge Question{..} Report{..} =
        if rId == qId
          then Just $ Report {questions = M.insert qText qScore questions, ..}
          else Nothing

  t <- questions
  take 1 $ mapMaybe (testMerge t) oldCallsReports

poop :: [Report]
poop = myfunc questions' reports'

main :: IO ()
main = print poop

--
-- Returns:
-- [ Report {rId = "id1", rName = "name1", questions = fromList [("Q1",10)]}
-- , Report {rId = "id1", rName = "name1", questions = fromList [("Q2",10)]}
-- , Report {rId = "id1", rName = "name1", questions = fromList [("Q3",10)]}
-- , Report {rId = "id1", rName = "name1", questions = fromList [("Q4",10)]}
-- , Report {rId = "id1", rName = "name1", questions = fromList [("Q5",10)]}
-- , Report {rId = "id1", rName = "name1", questions = fromList [("Q6",10)]}
-- ]
--
-- But expected:
-- [ Report {rId = "id1", rName = "name1", questions = fromList [("Q1",10), ("Q2",20)]}
-- , Report {rId = "id2", rName = "name1", questions = fromList [("Q3",30), ("Q4",40)]}
-- , Report {rId = "id3", rName = "name1", questions = fromList [("Q5",50), ("Q6",60)]}
-- ]