chards/Cards.hs
2017-12-28 00:11:46 +00:00

116 lines
2.6 KiB
Haskell

module Cards
( Element
, Card
, Comment
, fromElement
, toElement
, isDue
, sides
, reset
, update
, showElement
, showElements
, parseElement
, parseElements
, testElements
) where
import Data.List
import Data.Time
testElements =
[ card ["first card", "really"]
, card ["second card", "really"]
, comment "first comment"
, card ["third card", "really"]
, comment "second comment"
]
where card = ECard . Unrevised
comment = EComment . Comment
data Element = ECard Card | EComment Comment
deriving (Show)
data Comment = Comment String
deriving (Show)
data Card = Unrevised [String]
| Revised [String] Tier UTCTime NominalDiffTime
deriving (Show)
data Tier = One | Two | Three | Four | Five | Six | Seven | Eight | Nine | Ten
deriving (Show, Eq, Ord, Enum, Bounded)
{-
- Basic utility functions
-}
isCard :: Element -> Bool
isCard (ECard _) = True
isCard _ = False
fromElement :: Element -> Maybe Card
fromElement (ECard c) = Just c
fromElement _ = Nothing
toElement :: Card -> Element
toElement = ECard
tierDiff :: Tier -> NominalDiffTime
tierDiff One = 60 * 10
tierDiff Two = 60 * 20
tierDiff Three = 60 * 40
tierDiff Four = 3600 * ( 1 * 24 - 8)
tierDiff Five = 3600 * ( 2 * 24 - 8)
tierDiff Six = 3600 * ( 4 * 24 - 8)
tierDiff Seven = 3600 * ( 8 * 24 - 8)
tierDiff Eight = 3600 * (16 * 24 - 8)
tierDiff Nine = 3600 * (32 * 24 - 8)
tierDiff Ten = 3600 * (64 * 24 - 8)
tierName :: Tier -> String
tierName One = "10min"
tierName Two = "20min"
tierName Three = "40min"
tierName Four = "1d"
tierName Five = "2d"
tierName Six = "4d"
tierName Seven = "8d"
tierName Eight = "16d"
tierName Nine = "32d"
tierName Ten = "64d"
isDue :: UTCTime -> Card -> Bool
isDue _ (Unrevised _) = True
isDue time (Revised _ tier ctime cdiff) =
let tdiff = tierDiff tier
in diffUTCTime time ctime >= cdiff + tdiff
sides :: Card -> [String]
sides (Unrevised s) = s
sides (Revised s _ _ _) = s
reset :: Card -> Card
reset (Revised s _ _ _) = Unrevised s
reset c@(Unrevised _) = c
-- Uses the global RNG.
-- TODO: Add random offset based on tierDiff.
update :: UTCTime -> Card -> IO Card
update time (Unrevised s) =
return $ Revised s minBound time (fromInteger 0)
update time (Revised s t _ _) =
return $ Revised s (if t < maxBound then succ t else t) time (fromInteger 0)
showElements :: [Element] -> String
showElements = intercalate "\n\n" . map showElement
showElement :: Element -> String
showElement = undefined
{-
- Parsing
-}
parseElements = undefined
parseElement = undefined