{-# LANGUAGE FlexibleInstances, OverlappingInstances #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
{-# OPTIONS_HADDOCK not-home #-}

module Text.StringTemplate.Instances where
import Text.StringTemplate.Classes

import qualified Data.Map as M
import Numeric
import Data.Ratio
import Data.Array
import Data.Maybe
import qualified Data.Foldable as F
import qualified System.Time as OldTime
import System.Locale
import Data.Time

{--------------------------------------------------------------------
  Additional instances for items that may be set as StringTemplate
  attributes. The code should provide examples of how to proceed.
--------------------------------------------------------------------}

--Basics
instance ToSElem Char where
    toSElem = STR . (:[])
    toSElemList = STR

instance ToSElem Bool where
    toSElem True = STR ""
    toSElem _ = SNull

instance (ToSElem a) => ToSElem (Maybe a) where
    toSElem (Just x) = toSElem x
    toSElem _ = SNull

instance (ToSElem a) => ToSElem (M.Map String a) where
    toSElem = SM . fmap toSElem

instance (ToSElem a) => ToSElem [a] where
    toSElem = toSElemList

instance (ToSElem a, Ix i) => ToSElem (Array i a) where
   toSElem = toSElem . elems

instance (ToSElem a, F.Foldable t) => ToSElem (t a) where
    toSElem = toSElemList . F.toList

--Numbers
instance StringTemplateShows Float where
    stringTemplateShow = flip showFloat ""
    stringTemplateFormattedShow = flip flip [] . showGFloat . fmap fst . listToMaybe . reads
instance ToSElem Float where
    toSElem = stShowsToSE

instance StringTemplateShows Double where
    stringTemplateShow = flip showFloat ""
    stringTemplateFormattedShow = flip flip [] . showGFloat . fmap fst . listToMaybe . reads
instance ToSElem Double where
    toSElem = stShowsToSE

instance ToSElem Int where
    toSElem = STR . show

instance ToSElem Integer where
    toSElem = STR . show

instance Integral a => ToSElem (Ratio a) where
    toSElem = STR . show

--Dates and Times
instance StringTemplateShows OldTime.CalendarTime where
    stringTemplateShow = OldTime.calendarTimeToString
    stringTemplateFormattedShow = OldTime.formatCalendarTime defaultTimeLocale
instance ToSElem OldTime.CalendarTime where
    toSElem = stShowsToSE

instance StringTemplateShows OldTime.TimeDiff where
    stringTemplateShow = OldTime.timeDiffToString
    stringTemplateFormattedShow = OldTime.formatTimeDiff defaultTimeLocale
instance ToSElem OldTime.TimeDiff where
    toSElem = stShowsToSE

instance StringTemplateShows Day where
    stringTemplateShow = show
    stringTemplateFormattedShow = formatTime defaultTimeLocale    
instance ToSElem Day where
    toSElem = stShowsToSE

instance StringTemplateShows LocalTime where
    stringTemplateShow = show
    stringTemplateFormattedShow = formatTime defaultTimeLocale    
instance ToSElem LocalTime where
    toSElem = stShowsToSE

instance StringTemplateShows TimeOfDay where
    stringTemplateShow = show
    stringTemplateFormattedShow = formatTime defaultTimeLocale    
instance ToSElem TimeOfDay where
    toSElem = stShowsToSE

instance StringTemplateShows UTCTime where
    stringTemplateShow = show
    stringTemplateFormattedShow = formatTime defaultTimeLocale    
instance ToSElem UTCTime where
    toSElem = stShowsToSE

instance StringTemplateShows TimeZone where
    stringTemplateShow = show
    stringTemplateFormattedShow = formatTime defaultTimeLocale    
instance ToSElem TimeZone where
    toSElem = stShowsToSE

instance StringTemplateShows ZonedTime where
    stringTemplateShow = show
    stringTemplateFormattedShow = formatTime defaultTimeLocale    
instance ToSElem ZonedTime where
    toSElem = stShowsToSE

--Tuples
instance (ToSElem a, ToSElem b) => ToSElem (a, b) where
   toSElem (a,b) = LI [toSElem a, toSElem b]
instance (ToSElem a, ToSElem b, ToSElem c) => ToSElem (a, b, c) where
   toSElem (a,b,c) = LI [toSElem a, toSElem b, toSElem c]
instance (ToSElem a, ToSElem b, ToSElem c, ToSElem d) => ToSElem (a, b, c, d) where
   toSElem (a,b,c,d) = LI [toSElem a, toSElem b, toSElem c, toSElem d]
instance (ToSElem a, ToSElem b, ToSElem c, ToSElem d, ToSElem e) => ToSElem (a, b, c, d, e) where
   toSElem (a,b,c,d,e) = LI [toSElem a, toSElem b, toSElem c, toSElem d, toSElem e]