{-# LANGUAGE BangPatterns        #-}
{-# LANGUAGE CPP                 #-}
{-# LANGUAGE ConstraintKinds     #-}
{-# LANGUAGE ScopedTypeVariables #-}

-- |
-- Module:      Data.Time.Parsers (Data.Aeson.Parser.Time)
-- Copyright:   (c) 2015 Bryan O'Sullivan, 2015 Oleg Grenrus
-- License:     BSD3
-- Maintainer:  Oleg Grenrus <oleg.grenrus@iki.fi>
--
-- Parsers for parsing dates and times.

module Data.Time.Parsers
    ( day
    , month
    , localTime
    , timeOfDay
    , timeZone
    , utcTime
    , zonedTime
    , DateParsing
    ) where

import Control.Applicative     (optional, some, (<|>))
import Control.Monad           (void, when)
import Data.Bits               ((.&.))
import Data.Char               (isDigit, ord)
import Data.Fixed              (Pico)
import Data.Int                (Int64)
import Data.List               (foldl')
import Data.Maybe              (fromMaybe)
import Data.Time.Calendar      (Day, fromGregorianValid)
import Data.Time.Clock         (UTCTime (..))
import Text.Parser.Char        (CharParsing (..), digit)
import Text.Parser.Combinators (unexpected)
import Text.Parser.LookAhead   (LookAheadParsing (..))
import Unsafe.Coerce           (unsafeCoerce)

import qualified Data.Time.LocalTime as Local

#if !MIN_VERSION_base(4,8,0)
import Control.Applicative ((*>), (<$), (<$>), (<*), (<*>))
#endif

type DateParsing m = (CharParsing m, LookAheadParsing m, Monad m)

toPico :: Integer -> Pico
toPico :: Integer -> Pico
toPico = Integer -> Pico
forall a b. a -> b
unsafeCoerce

-- | Parse a month of the form @YYYY-MM@
month :: DateParsing m => m (Integer, Int)
month :: forall (m :: * -> *). DateParsing m => m (Integer, Int)
month = do
  Integer -> Integer
s <- Integer -> Integer
forall a. Num a => a -> a
negate (Integer -> Integer) -> m Char -> m (Integer -> Integer)
forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-' m (Integer -> Integer)
-> m (Integer -> Integer) -> m (Integer -> Integer)
forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> Integer -> Integer
forall a. a -> a
id (Integer -> Integer) -> m Char -> m (Integer -> Integer)
forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'+' m (Integer -> Integer)
-> m (Integer -> Integer) -> m (Integer -> Integer)
forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> (Integer -> Integer) -> m (Integer -> Integer)
forall (m :: * -> *) a. Monad m => a -> m a
return Integer -> Integer
forall a. a -> a
id
  Integer
y <- m Integer
forall (m :: * -> *) a. (DateParsing m, Integral a) => m a
decimal
  Char
_ <- Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-'
  Int
m <- m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits
  if (Int
1 Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
<= Int
m Bool -> Bool -> Bool
&& Int
m Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
<= Int
12)
      then (Integer, Int) -> m (Integer, Int)
forall (m :: * -> *) a. Monad m => a -> m a
return (Integer -> Integer
s Integer
y, Int
m)
      else String -> m (Integer, Int)
forall (m :: * -> *) a. Parsing m => String -> m a
unexpected String
"Invalid month"
{-# INLINE month #-}

-- | Parse a date of the form @YYYY-MM-DD@.
day :: DateParsing m => m Day
day :: forall (m :: * -> *). DateParsing m => m Day
day = do
  Integer -> Integer
s <- Integer -> Integer
forall a. Num a => a -> a
negate (Integer -> Integer) -> m Char -> m (Integer -> Integer)
forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-' m (Integer -> Integer)
-> m (Integer -> Integer) -> m (Integer -> Integer)
forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> Integer -> Integer
forall a. a -> a
id (Integer -> Integer) -> m Char -> m (Integer -> Integer)
forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'+' m (Integer -> Integer)
-> m (Integer -> Integer) -> m (Integer -> Integer)
forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> (Integer -> Integer) -> m (Integer -> Integer)
forall (m :: * -> *) a. Monad m => a -> m a
return Integer -> Integer
forall a. a -> a
id
  Integer
y <- m Integer
forall (m :: * -> *) a. (DateParsing m, Integral a) => m a
decimal
  Char
_ <- Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-'
  Int
m <- m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits
  Char
_ <- Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-'
  Int
d <- m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits
  m Day -> (Day -> m Day) -> Maybe Day -> m Day
forall b a. b -> (a -> b) -> Maybe a -> b
maybe (String -> m Day
forall (m :: * -> *) a. Parsing m => String -> m a
unexpected String
"invalid date") Day -> m Day
forall (m :: * -> *) a. Monad m => a -> m a
return (Integer -> Int -> Int -> Maybe Day
fromGregorianValid (Integer -> Integer
s Integer
y) Int
m Int
d)

-- | Parse a two-digit integer (e.g. day of month, hour).
twoDigits :: DateParsing m => m Int
twoDigits :: forall (m :: * -> *). DateParsing m => m Int
twoDigits = do
  Char
a <- m Char
forall (m :: * -> *). CharParsing m => m Char
digit
  Char
b <- m Char
forall (m :: * -> *). CharParsing m => m Char
digit
  let c2d :: Char -> Int
c2d Char
c = Char -> Int
ord Char
c Int -> Int -> Int
forall a. Bits a => a -> a -> a
.&. Int
15
  Int -> m Int
forall (m :: * -> *) a. Monad m => a -> m a
return (Int -> m Int) -> Int -> m Int
forall a b. (a -> b) -> a -> b
$! Char -> Int
c2d Char
a Int -> Int -> Int
forall a. Num a => a -> a -> a
* Int
10 Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Char -> Int
c2d Char
b

-- | Parse a time of the form @HH:MM:SS[.SSS]@.
timeOfDay :: DateParsing m => m Local.TimeOfDay
timeOfDay :: forall (m :: * -> *). DateParsing m => m TimeOfDay
timeOfDay = do
  Int
h <- m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits m Int -> m Char -> m Int
forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
':'
  Int
m <- m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits m Int -> m Char -> m Int
forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* Char -> m Char
forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
':'
  Pico
s <- m Pico
forall (m :: * -> *). DateParsing m => m Pico
seconds
  if Int
h Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
24 Bool -> Bool -> Bool
&& Int
m Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
60 Bool -> Bool -> Bool
&& Pico
s Pico -> Pico -> Bool
forall a. Ord a => a -> a -> Bool
< Pico
61
    then TimeOfDay -> m TimeOfDay
forall (m :: * -> *) a. Monad m => a -> m a
return (Int -> Int -> Pico -> TimeOfDay
Local.TimeOfDay Int
h Int
m Pico
s)
    else String -> m TimeOfDay
forall (m :: * -> *) a. Parsing m => String -> m a
unexpected String
"invalid time"

data T = T {-# UNPACK #-} !Int {-# UNPACK #-} !Int64

-- | Parse a count of seconds, with the integer part being two digits
-- long.
seconds :: DateParsing m => m Pico
seconds :: forall (m :: * -> *). DateParsing m => m Pico
seconds = do
  Int
real <- m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits
  Maybe Char
mc <- m (Maybe Char)
forall (m :: * -> *). DateParsing m => m (Maybe Char)
peekChar
  case Maybe Char
mc of
    Just Char
'.' -> do
      String
t <- m Char
forall (m :: * -> *). CharParsing m => m Char
anyChar m Char -> m String -> m String
forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> m Char -> m String
forall (f :: * -> *) a. Alternative f => f a -> f [a]
some m Char
forall (m :: * -> *). CharParsing m => m Char
digit
      Pico -> m Pico
forall (m :: * -> *) a. Monad m => a -> m a
return (Pico -> m Pico) -> Pico -> m Pico
forall a b. (a -> b) -> a -> b
$! Int -> String -> Pico
forall {t :: * -> *} {p}.
(Foldable t, Integral p) =>
p -> t Char -> Pico
parsePicos Int
real String
t
    Maybe Char
_ -> Pico -> m Pico
forall (m :: * -> *) a. Monad m => a -> m a
return (Pico -> m Pico) -> Pico -> m Pico
forall a b. (a -> b) -> a -> b
$! Int -> Pico
forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
real
 where
  parsePicos :: p -> t Char -> Pico
parsePicos p
a0 t Char
t = Integer -> Pico
toPico (Int64 -> Integer
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Int64
t' Int64 -> Int64 -> Int64
forall a. Num a => a -> a -> a
* Int64
10Int64 -> Int -> Int64
forall a b. (Num a, Integral b) => a -> b -> a
^Int
n))
    where T Int
n Int64
t'  = (T -> Char -> T) -> T -> t Char -> T
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' T -> Char -> T
step (Int -> Int64 -> T
T Int
12 (p -> Int64
forall a b. (Integral a, Num b) => a -> b
fromIntegral p
a0)) t Char
t
          step :: T -> Char -> T
step ma :: T
ma@(T Int
m Int64
a) Char
c
              | Int
m Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
<= Int
0    = T
ma
              | Bool
otherwise = Int -> Int64 -> T
T (Int
mInt -> Int -> Int
forall a. Num a => a -> a -> a
-Int
1) (Int64
10 Int64 -> Int64 -> Int64
forall a. Num a => a -> a -> a
* Int64
a Int64 -> Int64 -> Int64
forall a. Num a => a -> a -> a
+ Int -> Int64
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Char -> Int
ord Char
c) Int64 -> Int64 -> Int64
forall a. Bits a => a -> a -> a
.&. Int64
15)

-- | Parse a time zone, and return 'Nothing' if the offset from UTC is
-- zero. (This makes some speedups possible.)
timeZone :: DateParsing m => m (Maybe Local.TimeZone)
timeZone :: forall (m :: * -> *). DateParsing m => m (Maybe TimeZone)
timeZone = do
  let maybeSkip :: Char -> m ()
maybeSkip Char
c = do Char
ch <- m Char
forall (m :: * -> *). DateParsing m => m Char
peekChar'; Bool -> m () -> m ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (Char
ch Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
c) (m Char -> m ()
forall (f :: * -> *) a. Functor f => f a -> f ()
void m Char
forall (m :: * -> *). CharParsing m => m Char
anyChar)
  Char -> m ()
forall {m :: * -> *}.
(Monad m, CharParsing m, LookAheadParsing m) =>
Char -> m ()
maybeSkip Char
' '
  Char
ch <- (Char -> Bool) -> m Char
forall (m :: * -> *). CharParsing m => (Char -> Bool) -> m Char
satisfy ((Char -> Bool) -> m Char) -> (Char -> Bool) -> m Char
forall a b. (a -> b) -> a -> b
$ \Char
c -> Char
c Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
'Z' Bool -> Bool -> Bool
|| Char
c Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
'+' Bool -> Bool -> Bool
|| Char
c Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
'-'
  if Char
ch Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
'Z'
    then Maybe TimeZone -> m (Maybe TimeZone)
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe TimeZone
forall a. Maybe a
Nothing
    else do
      Int
h <- m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits
      Maybe Char
mm <- m (Maybe Char)
forall (m :: * -> *). DateParsing m => m (Maybe Char)
peekChar
      Int
m <- case Maybe Char
mm of
             Just Char
':'           -> m Char
forall (m :: * -> *). CharParsing m => m Char
anyChar m Char -> m Int -> m Int
forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits
             Just Char
d | Char -> Bool
isDigit Char
d -> m Int
forall (m :: * -> *). DateParsing m => m Int
twoDigits
             Maybe Char
_                  -> Int -> m Int
forall (m :: * -> *) a. Monad m => a -> m a
return Int
0
      let off :: Int
off | Char
ch Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
'-' = Int -> Int
forall a. Num a => a -> a
negate Int
off0
              | Bool
otherwise = Int
off0
          off0 :: Int
off0 = Int
h Int -> Int -> Int
forall a. Num a => a -> a -> a
* Int
60 Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
m
      case Any
forall a. HasCallStack => a
undefined of
        Any
_   | Int
off Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
0 ->
              Maybe TimeZone -> m (Maybe TimeZone)
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe TimeZone
forall a. Maybe a
Nothing
            | Int
off Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< -Int
720 Bool -> Bool -> Bool
|| Int
off Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
> Int
840 Bool -> Bool -> Bool
|| Int
m Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
> Int
59 ->
              String -> m (Maybe TimeZone)
forall (m :: * -> *) a. Parsing m => String -> m a
unexpected String
"invalid time zone offset"
            | Bool
otherwise ->
              let !tz :: TimeZone
tz = Int -> TimeZone
Local.minutesToTimeZone Int
off
              in Maybe TimeZone -> m (Maybe TimeZone)
forall (m :: * -> *) a. Monad m => a -> m a
return (TimeZone -> Maybe TimeZone
forall a. a -> Maybe a
Just TimeZone
tz)

-- | Parse a date and time, of the form @YYYY-MM-DD HH:MM:SS@.
-- The space may be replaced with a @T@.  The number of seconds may be
-- followed by a fractional component.
localTime :: DateParsing m => m Local.LocalTime
localTime :: forall (m :: * -> *). DateParsing m => m LocalTime
localTime = Day -> TimeOfDay -> LocalTime
Local.LocalTime (Day -> TimeOfDay -> LocalTime)
-> m Day -> m (TimeOfDay -> LocalTime)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m Day
forall (m :: * -> *). DateParsing m => m Day
day m (TimeOfDay -> LocalTime) -> m Char -> m (TimeOfDay -> LocalTime)
forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* m Char
daySep m (TimeOfDay -> LocalTime) -> m TimeOfDay -> m LocalTime
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> m TimeOfDay
forall (m :: * -> *). DateParsing m => m TimeOfDay
timeOfDay
  where daySep :: m Char
daySep = (Char -> Bool) -> m Char
forall (m :: * -> *). CharParsing m => (Char -> Bool) -> m Char
satisfy (\Char
c -> Char
c Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
'T' Bool -> Bool -> Bool
|| Char
c Char -> Char -> Bool
forall a. Eq a => a -> a -> Bool
== Char
' ')

-- | Behaves as 'zonedTime', but converts any time zone offset into a
-- UTC time.
utcTime :: DateParsing m => m UTCTime
utcTime :: forall (m :: * -> *). DateParsing m => m UTCTime
utcTime = LocalTime -> Maybe TimeZone -> UTCTime
f (LocalTime -> Maybe TimeZone -> UTCTime)
-> m LocalTime -> m (Maybe TimeZone -> UTCTime)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m LocalTime
forall (m :: * -> *). DateParsing m => m LocalTime
localTime m (Maybe TimeZone -> UTCTime) -> m (Maybe TimeZone) -> m UTCTime
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> m (Maybe TimeZone)
forall (m :: * -> *). DateParsing m => m (Maybe TimeZone)
timeZone
  where
    f :: Local.LocalTime -> Maybe Local.TimeZone -> UTCTime
    f :: LocalTime -> Maybe TimeZone -> UTCTime
f (Local.LocalTime Day
d TimeOfDay
t) Maybe TimeZone
Nothing =
        let !tt :: DiffTime
tt = TimeOfDay -> DiffTime
Local.timeOfDayToTime TimeOfDay
t
        in Day -> DiffTime -> UTCTime
UTCTime Day
d DiffTime
tt
    f LocalTime
lt (Just TimeZone
tz) = TimeZone -> LocalTime -> UTCTime
Local.localTimeToUTC TimeZone
tz LocalTime
lt

-- | Parse a date with time zone info. Acceptable formats:
--
-- @YYYY-MM-DD HH:MM:SS Z@
--
-- The first space may instead be a @T@, and the second space is
-- optional.  The @Z@ represents UTC.  The @Z@ may be replaced with a
-- time zone offset of the form @+0000@ or @-08:00@, where the first
-- two digits are hours, the @:@ is optional and the second two digits
-- (also optional) are minutes.
zonedTime :: DateParsing m => m Local.ZonedTime
zonedTime :: forall (m :: * -> *). DateParsing m => m ZonedTime
zonedTime = LocalTime -> TimeZone -> ZonedTime
Local.ZonedTime (LocalTime -> TimeZone -> ZonedTime)
-> m LocalTime -> m (TimeZone -> ZonedTime)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m LocalTime
forall (m :: * -> *). DateParsing m => m LocalTime
localTime m (TimeZone -> ZonedTime) -> m TimeZone -> m ZonedTime
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> (TimeZone -> Maybe TimeZone -> TimeZone
forall a. a -> Maybe a -> a
fromMaybe TimeZone
utc (Maybe TimeZone -> TimeZone) -> m (Maybe TimeZone) -> m TimeZone
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> m (Maybe TimeZone)
forall (m :: * -> *). DateParsing m => m (Maybe TimeZone)
timeZone)

utc :: Local.TimeZone
utc :: TimeZone
utc = Int -> Bool -> String -> TimeZone
Local.TimeZone Int
0 Bool
False String
""

decimal :: (DateParsing m, Integral a) => m a
decimal :: forall (m :: * -> *) a. (DateParsing m, Integral a) => m a
decimal = (a -> Char -> a) -> a -> String -> a
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' a -> Char -> a
forall {a}. Num a => a -> Char -> a
step a
0 (String -> a) -> m String -> m a
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` m Char -> m String
forall (f :: * -> *) a. Alternative f => f a -> f [a]
some m Char
forall (m :: * -> *). CharParsing m => m Char
digit
  where step :: a -> Char -> a
step a
a Char
w = a
a a -> a -> a
forall a. Num a => a -> a -> a
* a
10 a -> a -> a
forall a. Num a => a -> a -> a
+ Int -> a
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Char -> Int
ord Char
w Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
48)

peekChar :: DateParsing m => m (Maybe Char)
peekChar :: forall (m :: * -> *). DateParsing m => m (Maybe Char)
peekChar = m Char -> m (Maybe Char)
forall (f :: * -> *) a. Alternative f => f a -> f (Maybe a)
optional m Char
forall (m :: * -> *). DateParsing m => m Char
peekChar'

peekChar' :: DateParsing m => m Char
peekChar' :: forall (m :: * -> *). DateParsing m => m Char
peekChar' = m Char -> m Char
forall (m :: * -> *) a. LookAheadParsing m => m a -> m a
lookAhead m Char
forall (m :: * -> *). CharParsing m => m Char
anyChar