{-# LANGUAGE CPP #-}
{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ViewPatterns #-}

#include "thyme.h"
#if HLINT
#include "cabal_macros.h"
#endif

-- | Calendar date reckoned by year, month-of-year, and n-th day-of-week.
module Data.Thyme.Calendar.WeekdayOfMonth
    ( Year, Month, DayOfWeek
    , module Data.Thyme.Calendar.WeekdayOfMonth
    ) where

import Prelude
#if !MIN_VERSION_base(4,8,0)
import Control.Applicative
#endif
import Control.Arrow
import Control.DeepSeq
import Control.Lens
import Control.Monad
import Data.AffineSpace
import Data.Bits
import Data.Data
import Data.Hashable
import Data.Thyme.Calendar
import Data.Thyme.Calendar.Internal
#if __GLASGOW_HASKELL__ == 704
import qualified Data.Vector.Generic
import qualified Data.Vector.Generic.Mutable
#endif
import Data.Vector.Unboxed.Deriving
import GHC.Generics (Generic)
import System.Random
import Test.QuickCheck hiding ((.&.))

-- | Calendar date with year, month-of-year, and n-th day-of-week.
data WeekdayOfMonth = WeekdayOfMonth
    { WeekdayOfMonth -> Year
womYear :: {-# UNPACK #-}!Year
        -- ^ Calendar year.
    , WeekdayOfMonth -> Year
womMonth :: {-# UNPACK #-}!Month
        -- ^ Month of year.
    , WeekdayOfMonth -> Year
womNth :: {-# UNPACK #-}!Int
        -- ^ /N/-th 'DayOfWeek'. Range /±1–5/; negative means the /N/-th
        -- last 'DayOfWeek' of the month.
    , WeekdayOfMonth -> Year
womDayOfWeek :: {-# UNPACK #-}!DayOfWeek
        -- ^ Day of week. /1 = Monday, 7 = Sunday/, like ISO 8601 'WeekDate'.
    } deriving (INSTANCES_USUAL, Show)

LENS(WeekdayOfMonth,womYear,Year)
LENS(WeekdayOfMonth,womMonth,Month)
LENS(WeekdayOfMonth,womNth,Int)
LENS(WeekdayOfMonth,womDayOfWeek,DayOfWeek)

derivingUnbox "WeekdayOfMonth"
    [t| WeekdayOfMonth -> Int |]
    [| \ WeekdayOfMonth {..} -> shiftL womYear 11 .|. shiftL womMonth 7
        .|. shiftL (womNth + 5) 3 .|. womDayOfWeek |]
    [| \ n -> WeekdayOfMonth (shiftR n 11) (shiftR n 7 .&. 0xf)
        (shiftR n 3 - 5) (n .&. 0x7) |]

instance Hashable WeekdayOfMonth
instance NFData WeekdayOfMonth

instance Bounded WeekdayOfMonth where
    minBound :: WeekdayOfMonth
minBound = forall a. Bounded a => a
minBound forall s a. s -> Getting a s a -> a
^. Iso' Day WeekdayOfMonth
weekdayOfMonth
    maxBound :: WeekdayOfMonth
maxBound = forall a. Bounded a => a
maxBound forall s a. s -> Getting a s a -> a
^. Iso' Day WeekdayOfMonth
weekdayOfMonth

instance Random WeekdayOfMonth where
    randomR :: forall g.
RandomGen g =>
(WeekdayOfMonth, WeekdayOfMonth) -> g -> (WeekdayOfMonth, g)
randomR = forall s g a.
(Random s, RandomGen g) =>
Iso' s a -> (a, a) -> g -> (a, g)
randomIsoR Iso' Day WeekdayOfMonth
weekdayOfMonth
    random :: forall g. RandomGen g => g -> (WeekdayOfMonth, g)
random = forall (a :: * -> * -> *) b c d.
Arrow a =>
a b c -> a (b, d) (c, d)
first (forall s a. s -> Getting a s a -> a
^. Iso' Day WeekdayOfMonth
weekdayOfMonth) forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a g. (Random a, RandomGen g) => g -> (a, g)
random

instance Arbitrary WeekdayOfMonth where
    arbitrary :: Gen WeekdayOfMonth
arbitrary = forall a s. Getting a s a -> s -> a
view Iso' Day WeekdayOfMonth
weekdayOfMonth forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall a. Arbitrary a => Gen a
arbitrary
    shrink :: WeekdayOfMonth -> [WeekdayOfMonth]
shrink WeekdayOfMonth
wom = forall a s. Getting a s a -> s -> a
view Iso' Day WeekdayOfMonth
weekdayOfMonth forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall a. Arbitrary a => a -> [a]
shrink (Iso' Day WeekdayOfMonth
weekdayOfMonth forall s t a b. AReview s t a b -> b -> t
# WeekdayOfMonth
wom)

instance CoArbitrary WeekdayOfMonth where
    coarbitrary :: forall b. WeekdayOfMonth -> Gen b -> Gen b
coarbitrary (WeekdayOfMonth Year
y Year
m Year
n Year
d)
        = forall a b. CoArbitrary a => a -> Gen b -> Gen b
coarbitrary Year
y forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. CoArbitrary a => a -> Gen b -> Gen b
coarbitrary Year
m
        forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. CoArbitrary a => a -> Gen b -> Gen b
coarbitrary Year
n forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. CoArbitrary a => a -> Gen b -> Gen b
coarbitrary Year
d

-- | Conversion between a 'Day' and and 'WeekdayOfMonth'.
--
-- This is a proper 'Iso' if and only if all of the 'WeekdayOfMonth' fields
-- are valid and positive.
--
-- For example, the last /Monday/ in /January 2016/ is also the fourth
-- /Monday/:
--
-- @
-- > 'weekdayOfMonth' 'Control.Lens.#' 'WeekdayOfMonth' 2016 1 (-1) 1
-- 2016-01-25
-- > 'YearMonthDay' 2016 01 25 '^.' 'from' 'gregorian' '.' 'weekdayOfMonth'
-- 'WeekdayOfMonth' {'womYear' = 2016, 'womMonth' = 1, 'womNth' = 4, 'womDayOfWeek' = 1}
-- @
{-# INLINE weekdayOfMonth #-}
weekdayOfMonth :: Iso' Day WeekdayOfMonth
weekdayOfMonth :: Iso' Day WeekdayOfMonth
weekdayOfMonth = forall s a b t. (s -> a) -> (b -> t) -> Iso s t a b
iso Day -> WeekdayOfMonth
toWeekday WeekdayOfMonth -> Day
fromWeekday where

    {-# INLINEABLE toWeekday #-}
    toWeekday :: Day -> WeekdayOfMonth
    toWeekday :: Day -> WeekdayOfMonth
toWeekday day :: Day
day@(forall a s. Getting a s a -> s -> a
view Iso' Day OrdinalDate
ordinalDate -> OrdinalDate
ord) = Year -> Year -> Year -> Year -> WeekdayOfMonth
WeekdayOfMonth Year
y Year
m Year
n Year
wd where
        YearMonthDay Year
y Year
m Year
d = OrdinalDate
ord forall s a. s -> Getting a s a -> a
^. Iso' OrdinalDate YearMonthDay
yearMonthDay
        WeekDate Year
_ Year
_ Year
wd = OrdinalDate -> Day -> WeekDate
toWeekOrdinal OrdinalDate
ord Day
day
        n :: Year
n = Year
1 forall a. Num a => a -> a -> a
+ forall a. Integral a => a -> a -> a
div (Year
d forall a. Num a => a -> a -> a
- Year
1) Year
7

    {-# INLINEABLE fromWeekday #-}
    fromWeekday :: WeekdayOfMonth -> Day
    fromWeekday :: WeekdayOfMonth -> Day
fromWeekday (WeekdayOfMonth Year
y Year
m Year
n Year
wd) = Day
refDay forall p. AffineSpace p => p -> Diff p -> p
.+^ Year
s forall a. Num a => a -> a -> a
* Year
offset where
        refOrd :: OrdinalDate
refOrd = Iso' OrdinalDate YearMonthDay
yearMonthDay forall s t a b. AReview s t a b -> b -> t
# Year -> Year -> Year -> YearMonthDay
YearMonthDay Year
y Year
m
            (if Year
n forall a. Ord a => a -> a -> Bool
< Year
0 then Bool -> Year -> Year
monthLength (Year -> Bool
isLeapYear Year
y) Year
m else Year
1)
        refDay :: Day
refDay = Iso' Day OrdinalDate
ordinalDate forall s t a b. AReview s t a b -> b -> t
# OrdinalDate
refOrd
        WeekDate Year
_ Year
_ Year
wd1 = OrdinalDate -> Day -> WeekDate
toWeekOrdinal OrdinalDate
refOrd Day
refDay
        s :: Year
s = forall a. Num a => a -> a
signum Year
n
        wo :: Year
wo = Year
s forall a. Num a => a -> a -> a
* (Year
wd forall a. Num a => a -> a -> a
- Year
wd1)
        offset :: Year
offset = (forall a. Num a => a -> a
abs Year
n forall a. Num a => a -> a -> a
- Year
1) forall a. Num a => a -> a -> a
* Year
7 forall a. Num a => a -> a -> a
+ if Year
wo forall a. Ord a => a -> a -> Bool
< Year
0 then Year
wo forall a. Num a => a -> a -> a
+ Year
7 else Year
wo

-- | Convert a 'WeekdayOfMonth' to a 'Day'.
-- Returns 'Nothing' for invalid input.
--
-- For example, the third /Sunday/ of /January 2016/ is /2016-01-27/, but
-- there is no fifth /Monday/ in /January 2016/.
--
-- @
-- > 'weekdayOfMonthValid' ('WeekdayOfMonth' 2016 1 3 7)
-- 'Just' 2016-01-17
-- > 'weekdayOfMonthValid' ('WeekdayOfMonth' 2016 1 5 1)
-- 'Nothing'
-- @
{-# INLINEABLE weekdayOfMonthValid #-}
weekdayOfMonthValid :: WeekdayOfMonth -> Maybe Day
weekdayOfMonthValid :: WeekdayOfMonth -> Maybe Day
weekdayOfMonthValid (WeekdayOfMonth Year
y Year
m Year
n Year
wd) = (Day
refDay forall p. AffineSpace p => p -> Diff p -> p
.+^ Year
s forall a. Num a => a -> a -> a
* Year
offset)
        forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall (f :: * -> *). Alternative f => Bool -> f ()
guard (Year
n forall a. Eq a => a -> a -> Bool
/= Year
0 Bool -> Bool -> Bool
&& Year
1 forall a. Ord a => a -> a -> Bool
<= Year
wd Bool -> Bool -> Bool
&& Year
wd forall a. Ord a => a -> a -> Bool
<= Year
7 Bool -> Bool -> Bool
&& Year
offset forall a. Ord a => a -> a -> Bool
< Year
len) where
    len :: Year
len = Bool -> Year -> Year
monthLength (Year -> Bool
isLeapYear Year
y) Year
m
    refOrd :: OrdinalDate
refOrd = Iso' OrdinalDate YearMonthDay
yearMonthDay forall s t a b. AReview s t a b -> b -> t
# Year -> Year -> Year -> YearMonthDay
YearMonthDay Year
y Year
m (if Year
n forall a. Ord a => a -> a -> Bool
< Year
0 then Year
len else Year
1)
    refDay :: Day
refDay = Iso' Day OrdinalDate
ordinalDate forall s t a b. AReview s t a b -> b -> t
# OrdinalDate
refOrd
    WeekDate Year
_ Year
_ Year
wd1 = OrdinalDate -> Day -> WeekDate
toWeekOrdinal OrdinalDate
refOrd Day
refDay
    s :: Year
s = forall a. Num a => a -> a
signum Year
n
    wo :: Year
wo = Year
s forall a. Num a => a -> a -> a
* (Year
wd forall a. Num a => a -> a -> a
- Year
wd1)
    offset :: Year
offset = (forall a. Num a => a -> a
abs Year
n forall a. Num a => a -> a -> a
- Year
1) forall a. Num a => a -> a -> a
* Year
7 forall a. Num a => a -> a -> a
+ if Year
wo forall a. Ord a => a -> a -> Bool
< Year
0 then Year
wo forall a. Num a => a -> a -> a
+ Year
7 else Year
wo