{-

Your task is to write a program that can outputs to stdout
the answers to the following questions:

- Given only yellow customers, what are the average and maximum
  customer waiting times?
- Given only red customers, what are the average and maximum queue
  lengths in-front of the teller?
- Which type of customer(yellow, red or blue) gives the
  closest value between the average and maximum customer waiting times?

-}


module Main where

import           Holmusk

import           Data.List
import           Options.Applicative
import           System.Random


data Options = Options {
    interval :: Double
  }


options :: Parser Options
options =
  Options
    <$> (option
          auto
          (  long "interval"
          <> short 'i'
          <> help "interval between checks in queueLengthR"
          <> showDefault
          <> value 0.1
          <> metavar "DOUBLE"
          )
        )


main :: IO ()
main = do
  Options {..} <- execParser $ info
    (options <**> helper)
    (fullDesc <> progDesc "Run holmusk simulations")

  -- Q1
  putStrLn
    "Given only yellow customers, what are the average and maximum customer waiting times?"
  g1 <- getStdGen
  g2 <- getStdGen
  let yAvgPt = avgCustomerProcTime Yellow
      yMaxPt = maxCustomerProcTime Yellow
      yAvgQl = queueLengthR yAvgPt interval g1
      yMaxQl = queueLengthR yMaxPt interval g2
      yAvgW  = avgWaitingTime yAvgQl yAvgPt
      yMaxW  = maxWaitingTime yMaxQl yMaxPt
  putStrLn $ "Avg: " ++ show yAvgW
  putStrLn $ "Max: " ++ show yMaxW
  putStrLn ""

  -- Q2
  putStrLn
    "Given only red customers, what are the average and maximum queue lengths in-front of the teller?"
  g1 <- getStdGen
  g2 <- getStdGen
  let rAvgPt = avgCustomerProcTime Red
      rMaxPt = maxCustomerProcTime Red
      rAvgQl = queueLengthR rAvgPt interval g1
      rMaxQl = queueLengthR rMaxPt interval g2
      rAvgW  = avgWaitingTime rAvgQl rAvgPt
      rMaxW  = maxWaitingTime rMaxQl rMaxPt
  putStrLn $ "Avg: " ++ show rAvgQl
  putStrLn $ "Max: " ++ show rMaxQl
  putStrLn ""

  -- Q3
  putStrLn
    "Which type of customer(yellow, red or blue) gives the closest value between the average and maximum customer waiting times?"
  g1 <- getStdGen
  g2 <- getStdGen
  let bAvgPt = avgCustomerProcTime Blue
      bMaxPt = maxCustomerProcTime Blue
      bAvgQl = queueLengthR bAvgPt interval g1
      bMaxQl = queueLengthR bMaxPt interval g2
      bAvgW  = avgWaitingTime bAvgQl bAvgPt
      bMaxW  = maxWaitingTime bMaxQl bMaxPt

  let dist =
        [(Yellow, yMaxW - yAvgW), (Red, rMaxW - rAvgW), (Blue, bMaxW - bAvgW)]
      min = minimumBy (\(_, x) (_, y) -> compare x y) $ dist
  putStrLn (show min)