module System.Time.Parse (parseCalendarTime) where

import Data.List
import Data.Maybe
import System.Locale
import System.Time

import Data.Time
import Data.Time.Calendar.OrdinalDate
import Data.Time.Parse


-- | Parse a date string to a 'CalendarTime'.
--   This is the same as 'parseTime', but specialized to 'CalendarTime'
--   for compatibility with earlier versions of the parsedate package.
parseCalendarTime :: TimeLocale            -- ^ Time locale
                  -> String             -- ^ Date format
                  -> String             -- ^ String to parse
                  -> Maybe CalendarTime -- ^ 'Nothing' if parsing failed.
parseCalendarTime l f s = fmap zonedTimeToCalendarTime (parseTime l f s)

zonedTimeToCalendarTime :: ZonedTime -> CalendarTime
zonedTimeToCalendarTime t = 
    CalendarTime {
		  ctYear    = fromInteger y,
		  ctMonth   = toEnum (mo-1),
		  ctDay     = d,
		  ctHour    = todHour time,
		  ctMin     = todMin time,
		  ctSec     = s,
		  ctPicosec = truncate (10^12 * sd),
		  ctWDay    = toEnum (snd (sundayStartWeek day)),
		  ctYDay    = snd (toOrdinalDate day),
		  ctTZName  = timeZoneName tz,
		  ctTZ      = 60 * timeZoneMinutes tz,
		  ctIsDST   = timeZoneSummerOnly tz
		 }
        where
          day      = localDay (zonedTimeToLocalTime t)
          (y,mo,d) = toGregorian day
          time     = localTimeOfDay (zonedTimeToLocalTime t)
          (s,sd)   = properFraction (todSec time)
          tz       = zonedTimeZone t