{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

module Data.FuzzyTime.Types
  ( module Data.FuzzyTime.Types,
    DayOfWeek (..),
  )
where

import Control.DeepSeq
import Data.Fixed
import Data.Int
import Data.Time
import Data.Validity
import Data.Validity.Time ()
import GHC.Generics (Generic)

data FuzzyZonedTime
  = ZonedNow
  deriving (Show, Eq, Generic)

instance Validity FuzzyZonedTime

instance NFData FuzzyZonedTime

data AmbiguousLocalTime
  = OnlyDaySpecified Day
  | BothTimeAndDay LocalTime
  deriving (Show, Eq, Generic)

instance Validity AmbiguousLocalTime

instance NFData AmbiguousLocalTime

newtype FuzzyLocalTime = FuzzyLocalTime
  { unFuzzyLocalTime :: Some FuzzyDay FuzzyTimeOfDay
  }
  deriving (Show, Eq, Generic)

instance Validity FuzzyLocalTime

instance NFData FuzzyLocalTime

data Some a b
  = One a
  | Other b
  | Both a b
  deriving (Show, Eq, Generic)

instance (Validity a, Validity b) => Validity (Some a b)

instance (NFData a, NFData b) => NFData (Some a b)

data FuzzyTimeOfDay
  = SameTime
  | Noon
  | Midnight
  | Morning
  | Evening
  | AtHour Int
  | AtMinute Int Int
  | AtExact TimeOfDay
  | HoursDiff Int -- Max 24
  | MinutesDiff Int -- Max 24 * 60
  | SecondsDiff Pico -- Max 24 * 60 * 60
  deriving (Show, Eq, Generic)

instance Validity FuzzyTimeOfDay where
  validate ftod =
    mconcat
      [ genericValidate ftod,
        case ftod of
          AtHour h ->
            mconcat
              [ declare "The hour is positive" $ h >= 0,
                declare "The hours are fewer than 24" $ h < 24
              ]
          AtMinute h m ->
            mconcat
              [ declare "The hour is positive" $ h >= 0,
                declare "The hours are fewer than 24" $ h < 24,
                declare "The minute is positive" $ m >= 0,
                declare "The minutes are fewer than 60" $ m < 60
              ]
          HoursDiff hs ->
            mconcat
              [declare "The hours difference is no less than 24h" $ abs hs < 24]
          MinutesDiff ms ->
            mconcat
              [ declare "The minutes difference is no less than 1440m" $
                  abs ms < 24 * 60
              ]
          SecondsDiff ms ->
            mconcat
              [ declare "The seconds difference is no less than 86400s" $
                  abs ms < 24 * 60 * 60
              ]
          _ -> valid
      ]

instance NFData FuzzyTimeOfDay

data FuzzyDay
  = Yesterday
  | Now
  | Today
  | Tomorrow
  | OnlyDay Int
  | DayInMonth Int Int
  | DiffDays Int16
  | DiffWeeks Int16
  | DiffMonths Int16
  | NextDayOfTheWeek DayOfWeek
  | ExactDay Day
  deriving (Show, Eq, Generic)

instance Validity FuzzyDay where
  validate fd =
    mconcat
      [ genericValidate fd,
        case fd of
          OnlyDay di ->
            decorate "OnlyDay" $
              mconcat
                [ declare "The day is strictly positive" $ di >= 1,
                  declare "The day is less than or equal to 31" $ di <= 31
                ]
          DayInMonth mi di ->
            decorate "DayInMonth" $
              mconcat
                [ declare "The day is strictly positive" $ di >= 1,
                  declare "The day is less than or equal to 31" $ di <= 31,
                  declare "The month is strictly positive" $ mi >= 1,
                  declare "The month is less than or equal to 12" $ mi <= 12,
                  declare "The number of days makes sense for the month" $
                    maybe False (>= di) $ lookup (numMonth mi) (daysInMonth 2004)
                ]
          _ -> valid
      ]

instance NFData FuzzyDay

deriving instance Generic DayOfWeek

instance NFData DayOfWeek

dayOfTheWeekNum :: DayOfWeek -> Int
dayOfTheWeekNum = fromEnum

numDayOfTheWeek :: Int -> DayOfWeek
numDayOfTheWeek = toEnum

data Month
  = January
  | February
  | March
  | April
  | May
  | June
  | July
  | August
  | September
  | October
  | November
  | December
  deriving (Show, Eq, Generic, Enum, Bounded)

instance Validity Month

instance NFData Month

daysInMonth :: Integer -> [(Month, Int)]
daysInMonth y =
  [ (January, 31),
    ( February,
      if isLeapYear y
        then 29
        else 28
    ),
    (March, 31),
    (April, 30),
    (May, 31),
    (June, 30),
    (July, 31),
    (August, 31),
    (September, 30),
    (October, 31),
    (November, 30),
    (December, 31)
  ]

monthNum :: Month -> Int
monthNum = (+ 1) . fromEnum

numMonth :: Int -> Month
numMonth = toEnum . (\x -> x - 1)