{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE TypeFamilies #-}

module Web.Apiary.Cookie 
    ( -- * setter
      setCookie
    , deleteCookie
    -- * getter
    , getCookies
    -- * filter
    , cookie
    , cookie'
    -- * Reexport
    -- | SetCookie(..)
    , module Web.Cookie
    ) where

import Control.Applicative((<$>))

import qualified Network.Wai as Wai

import Web.Cookie (SetCookie(..))
import qualified Web.Cookie as Cookie

import Control.Monad.Apiary(ApiaryT)
import Control.Monad.Apiary.Action(ActionT, getHeaders, addHeader)
import Control.Monad.Apiary.Filter

import Data.Apiary.Compat(KnownSymbol, symbolVal)
import Data.Apiary.Dict(NotMember)
import Data.Apiary.Param(Strategy(..))

import Data.Maybe(mapMaybe)
import Data.Time(UTCTime(UTCTime), Day(ModifiedJulianDay))
import Data.Monoid((<>))
import Blaze.ByteString.Builder(toByteString)
import Text.Blaze.Html(toHtml)
import qualified Data.ByteString as S
import qualified Data.ByteString.Char8 as SC

cond :: (a -> Bool) -> (a -> b) -> (a -> b) -> a -> b
cond p t f a = if p a then t a else f a
{-# INLINE cond #-}

-- | cookie filter. since 0.5.1.0.
--
-- can use like 'query' function.
--
-- example:
--
-- @
-- cookie [key|foo|] (pFirst pInt)  -- get first Int parameter from foo.
-- cookie [key|bar|] (pOption pDouble)  -- get first Double parameter from bar, allows no cookie.
-- cookie [key|baz|] (pMany (pMaybe pString))  -- get zero or more baz cookies. allows cookie decrypt failure.
-- cookie [key|baz|] (Proxy :: Proxy (LimitSome [int|100|] ByteString)) -- get raw cookies up to 100 entries.
-- @
cookie :: (Strategy w, Monad actM, NotMember k prms, KnownSymbol k)
       => proxy k
       -> w S.ByteString
       -> ApiaryT exts (SNext w k S.ByteString prms) actM m ()
       -> ApiaryT exts prms actM m ()
cookie k p = function (DocPrecondition $ toHtml (symbolVal k) <> " cookie required") $ \l r ->
    strategy p k (map (Just . snd) . filter ((SC.pack (symbolVal k) ==) . fst) $ cookie' r) l

cookie' :: Wai.Request -> [(S.ByteString, S.ByteString)]
cookie' = 
    concatMap Cookie.parseCookies .
    mapMaybe (cond (("cookie" ==) . fst) (Just . snd) (const Nothing)) .
    Wai.requestHeaders

getCookies :: Monad m => ActionT exts prms m [(S.ByteString, S.ByteString)]
getCookies =
    concatMap (Cookie.parseCookies . snd) .
    filter (("cookie" ==) . fst) <$>
    getHeaders

-- | delete cookie. since 0.6.1.0.
deleteCookie :: Monad m => S.ByteString -> ActionT exts prms m ()
deleteCookie k = setCookie Cookie.def
    { setCookieName    = k 
    , setCookieExpires = Just $ UTCTime (ModifiedJulianDay 0) 0
    , setCookieMaxAge  = Just 0
    }

-- | set raw cookie header.
setCookie :: Monad m => SetCookie -> ActionT exts prms m ()
setCookie =
    addHeader "set-cookie" . toByteString . Cookie.renderSetCookie