{-# OPTIONS -fglasgow-exts #-}

module Eg.Music.Music where

import System.Time
import Data.Char
import Data.Dynamic

data Music = Music
  { musicTitle :: String
  , musicArtist :: String
  , musicAlbum :: String
  , musicGenre :: String
  , musicSize :: Integer
  , musicSecs :: Int
  , musicTrackNum :: Int
  , musicTrackCount :: Int
  , musicYear :: Int
  , musicDate :: CalendarTime
  , musicSelected :: Bool
  }
  deriving (Eq, Show, Typeable)

musicTime :: Music -> Double
musicTime m =
  fromIntegral (round ((fromIntegral (musicSecs m)) / 0.6)) / 100.0;

musicTrack :: Music -> String
musicTrack m = (show (musicTrackNum m)) ++ " of " ++ (show (musicTrackCount m))

parseMusic line =
  let tokens = tokenise line in
  Music
  { musicTitle = tokens !! 0
  , musicArtist = tokens !! 1
  , musicAlbum = tokens !! 2
  , musicGenre = tokens !! 3
  , musicSize = read (tokens !! 4)
  , musicSecs = read (tokens !! 5)
  , musicTrackNum = read (tokens !! 6)
  , musicTrackCount = read (tokens !! 7)
  , musicYear = read (tokens !! 8)
  , musicDate = parseDatetime (tokens !! 9)
  , musicSelected = False
  }

tokenise line = tokenise' line []

tokenise' [] acc = reverse acc
tokenise' line acc =
  let (f, fs) = span ('\t' /=) line in
  tokenise' (myTail fs) (f:acc)

myTail [] = []
myTail (x:xs) = xs

parseDatetime s =
  let
    (m, r1) = span isDigit s
    (d, r2) = span isDigit (tail r1)
    (y, r3) = span isDigit (tail r2)
    (h, r4) = span isDigit (tail r3)
    (mi, r5) = span isDigit (tail r4)
    hour = if head (tail r5) == 'A'
      then (read h) else (read h) + 12
    yr = read y
    year = case () of
      _ | yr < 50 -> 2000 + yr
        | yr >= 50 && yr < 100 -> 1900 + yr
        | otherwise -> yr
  in CalendarTime
  { ctYear = year
  , ctMonth = toEnum ((read m) - 1)
  , ctDay = read d
  , ctHour = hour
  , ctMin = read mi
  , ctSec = 0
  , ctPicosec = 0
  , ctWDay = Sunday
  , ctYDay = 0
  , ctTZ = 0
  , ctTZName = ""
  , ctIsDST = False
  }