{-# 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
    , year
    , 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 = forall a b. a -> b
unsafeCoerce

-- | Parse a year @YYYY@, with at least 4 digits. Does not include any sign.
--
-- @since 0.2
year :: DateParsing m => m Integer
year :: forall (m :: * -> *). DateParsing m => m Integer
year = do
  [Char]
ds <- forall (f :: * -> *) a. Alternative f => f a -> f [a]
some forall (m :: * -> *). CharParsing m => m Char
digit
  if forall (t :: * -> *) a. Foldable t => t a -> Int
length [Char]
ds forall a. Ord a => a -> a -> Bool
< Int
4
  then forall (m :: * -> *) a. Parsing m => [Char] -> m a
unexpected [Char]
"expected year with at least 4 digits"
  else forall (m :: * -> *) a. Monad m => a -> m a
return (forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' forall {a}. Num a => a -> Char -> a
step Integer
0 [Char]
ds)
  where step :: a -> Char -> a
step a
a Char
w = a
a forall a. Num a => a -> a -> a
* a
10 forall a. Num a => a -> a -> a
+ forall a b. (Integral a, Num b) => a -> b
fromIntegral (Char -> Int
ord Char
w forall a. Num a => a -> a -> a
- Int
48)

-- | 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 <- forall a. Num a => a -> a
negate forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-' forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> forall a. a -> a
id forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'+' forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> forall (m :: * -> *) a. Monad m => a -> m a
return forall a. a -> a
id
  Integer
y <- forall (m :: * -> *). DateParsing m => m Integer
year
  Char
_ <- forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-'
  Int
m <- forall (m :: * -> *). DateParsing m => m Int
twoDigits
  if Int
1 forall a. Ord a => a -> a -> Bool
<= Int
m Bool -> Bool -> Bool
&& Int
m forall a. Ord a => a -> a -> Bool
<= Int
12
      then forall (m :: * -> *) a. Monad m => a -> m a
return (Integer -> Integer
s Integer
y, Int
m)
      else forall (m :: * -> *) a. Parsing m => [Char] -> m a
unexpected [Char]
"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 <- forall a. Num a => a -> a
negate forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-' forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> forall a. a -> a
id forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'+' forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> forall (m :: * -> *) a. Monad m => a -> m a
return forall a. a -> a
id
  Integer
y <- forall (m :: * -> *). DateParsing m => m Integer
year
  Char
_ <- forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-'
  Int
m <- forall (m :: * -> *). DateParsing m => m Int
twoDigits
  Char
_ <- forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
'-'
  Int
d <- forall (m :: * -> *). DateParsing m => m Int
twoDigits
  forall b a. b -> (a -> b) -> Maybe a -> b
maybe (forall (m :: * -> *) a. Parsing m => [Char] -> m a
unexpected [Char]
"invalid date") 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 <- forall (m :: * -> *). CharParsing m => m Char
digit
  Char
b <- forall (m :: * -> *). CharParsing m => m Char
digit
  let c2d :: Char -> Int
c2d Char
c = Char -> Int
ord Char
c forall a. Bits a => a -> a -> a
.&. Int
15
  forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! Char -> Int
c2d Char
a forall a. Num a => a -> a -> a
* Int
10 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 <- forall (m :: * -> *). DateParsing m => m Int
twoDigits forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
':'
  Int
m <- forall (m :: * -> *). DateParsing m => m Int
twoDigits forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* forall (m :: * -> *). CharParsing m => Char -> m Char
char Char
':'
  Pico
s <- forall (m :: * -> *). DateParsing m => m Pico
seconds
  if Int
h forall a. Ord a => a -> a -> Bool
< Int
24 Bool -> Bool -> Bool
&& Int
m forall a. Ord a => a -> a -> Bool
< Int
60 Bool -> Bool -> Bool
&& Pico
s forall a. Ord a => a -> a -> Bool
< Pico
61
    then forall (m :: * -> *) a. Monad m => a -> m a
return (Int -> Int -> Pico -> TimeOfDay
Local.TimeOfDay Int
h Int
m Pico
s)
    else forall (m :: * -> *) a. Parsing m => [Char] -> m a
unexpected [Char]
"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 <- forall (m :: * -> *). DateParsing m => m Int
twoDigits
  Maybe Char
mc <- forall (m :: * -> *). DateParsing m => m (Maybe Char)
peekChar
  case Maybe Char
mc of
    Just Char
'.' -> do
      [Char]
t <- forall (m :: * -> *). CharParsing m => m Char
anyChar forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> forall (f :: * -> *) a. Alternative f => f a -> f [a]
some forall (m :: * -> *). CharParsing m => m Char
digit
      forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! forall {t :: * -> *} {p}.
(Foldable t, Integral p) =>
p -> t Char -> Pico
parsePicos Int
real [Char]
t
    Maybe Char
_ -> forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! 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 (forall a b. (Integral a, Num b) => a -> b
fromIntegral (Int64
t' forall a. Num a => a -> a -> a
* Int64
10forall a b. (Num a, Integral b) => a -> b -> a
^Int
n))
    where T Int
n Int64
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 (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 forall a. Ord a => a -> a -> Bool
<= Int
0    = T
ma
              | Bool
otherwise = Int -> Int64 -> T
T (Int
mforall a. Num a => a -> a -> a
-Int
1) (Int64
10 forall a. Num a => a -> a -> a
* Int64
a forall a. Num a => a -> a -> a
+ forall a b. (Integral a, Num b) => a -> b
fromIntegral (Char -> Int
ord Char
c) 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 <- forall (m :: * -> *). DateParsing m => m Char
peekChar'; forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (Char
ch forall a. Eq a => a -> a -> Bool
== Char
c) (forall (f :: * -> *) a. Functor f => f a -> f ()
void forall (m :: * -> *). CharParsing m => m Char
anyChar)
  forall {m :: * -> *}.
(Monad m, CharParsing m, LookAheadParsing m) =>
Char -> m ()
maybeSkip Char
' '
  Char
ch <- forall (m :: * -> *). CharParsing m => (Char -> Bool) -> m Char
satisfy forall a b. (a -> b) -> a -> b
$ \Char
c -> Char
c forall a. Eq a => a -> a -> Bool
== Char
'Z' Bool -> Bool -> Bool
|| Char
c forall a. Eq a => a -> a -> Bool
== Char
'+' Bool -> Bool -> Bool
|| Char
c forall a. Eq a => a -> a -> Bool
== Char
'-'
  if Char
ch forall a. Eq a => a -> a -> Bool
== Char
'Z'
    then forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
    else do
      Int
h <- forall (m :: * -> *). DateParsing m => m Int
twoDigits
      Maybe Char
mm <- forall (m :: * -> *). DateParsing m => m (Maybe Char)
peekChar
      Int
m <- case Maybe Char
mm of
             Just Char
':'           -> forall (m :: * -> *). CharParsing m => m Char
anyChar forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> forall (m :: * -> *). DateParsing m => m Int
twoDigits
             Just Char
d | Char -> Bool
isDigit Char
d -> forall (m :: * -> *). DateParsing m => m Int
twoDigits
             Maybe Char
_                  -> forall (m :: * -> *) a. Monad m => a -> m a
return Int
0
      let off :: Int
off | Char
ch forall a. Eq a => a -> a -> Bool
== Char
'-' = forall a. Num a => a -> a
negate Int
off0
              | Bool
otherwise = Int
off0
          off0 :: Int
off0 = Int
h forall a. Num a => a -> a -> a
* Int
60 forall a. Num a => a -> a -> a
+ Int
m
      case forall a. HasCallStack => a
undefined of
        Any
_   | Int
off forall a. Eq a => a -> a -> Bool
== Int
0 ->
              forall (m :: * -> *) a. Monad m => a -> m a
return forall a. Maybe a
Nothing
            | Int
off forall a. Ord a => a -> a -> Bool
< -Int
720 Bool -> Bool -> Bool
|| Int
off forall a. Ord a => a -> a -> Bool
> Int
840 Bool -> Bool -> Bool
|| Int
m forall a. Ord a => a -> a -> Bool
> Int
59 ->
              forall (m :: * -> *) a. Parsing m => [Char] -> m a
unexpected [Char]
"invalid time zone offset"
            | Bool
otherwise ->
              let !tz :: TimeZone
tz = Int -> TimeZone
Local.minutesToTimeZone Int
off
              in forall (m :: * -> *) a. Monad m => a -> m a
return (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 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *). DateParsing m => m Day
day forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* m Char
daySep forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> forall (m :: * -> *). DateParsing m => m TimeOfDay
timeOfDay
  where daySep :: m Char
daySep = forall (m :: * -> *). CharParsing m => (Char -> Bool) -> m Char
satisfy (\Char
c -> Char
c forall a. Eq a => a -> a -> Bool
== Char
'T' Bool -> Bool -> Bool
|| Char
c 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 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *). DateParsing m => m LocalTime
localTime forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> 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 forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *). DateParsing m => m LocalTime
localTime forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> (forall a. a -> Maybe a -> a
fromMaybe TimeZone
utc forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall (m :: * -> *). DateParsing m => m (Maybe TimeZone)
timeZone)

utc :: Local.TimeZone
utc :: TimeZone
utc = Int -> Bool -> [Char] -> TimeZone
Local.TimeZone Int
0 Bool
False [Char]
""

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

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

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