Ticket #2484: randil.hs

#!/usr/local/bin/runhaskell

import System.Locale
import System.Random
import System.Time

main :: IO ()
main = do
  clockTime <- getClockTime
  comicNumber <- getStdRandom (randomR (0,comics clockTime))
  putStrLn (command comicNumber)

command :: Int -> String
command n = "open http://www.dilbert.com/fast/" ++ formatCalendarTime defaultTimeLocale (iso8601DateFormat Nothing) (toUTCTime (nthComicClockTime n))

nthComicClockTime :: Int -> ClockTime
nthComicClockTime n = addToClockTime (TimeDiff 0 0 n 0 0 0 0) firstComicClockTime

firstComicClockTime :: ClockTime
firstComicClockTime = toClockTime (CalendarTime {ctYear = 1996, ctMonth = January, ctDay = 1, ctHour = 0, ctMin = 0, ctSec = 0, ctPicosec = 0, ctWDay = undefined, ctYDay = undefined, ctTZName = undefined, ctTZ = 0, ctIsDST = undefined})

comics :: ClockTime -> Int
comics clockTime = comics' 1
 where
  comics' n = if nthComicClockTime d > clockTime then comics'' n d else comics' d
   where
    d = 2 * n
  comics'' a z = if a + 1 == z 
    then z
    else if nthComicClockTime(m) > clockTime
      then comics'' a m
      else comics'' m z
   where
    m = (a + z) `div` 2