{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE NoMonomorphismRestriction #-} -- FIXME remove
-- | Some fields spiced up with jQuery UI.
module Yesod.Form.Jquery
    ( YesodJquery (..)
    , jqueryDayField
    , maybeJqueryDayField
    , jqueryDayTimeField
    , jqueryDayTimeFieldProfile
    , jqueryAutocompleteField
    , maybeJqueryAutocompleteField
    , jqueryDayFieldProfile
    , googleHostedJqueryUiCss
    , JqueryDaySettings (..)
    , Default (..)
    ) where

import Yesod.Handler
import Yesod.Form.Core
import Yesod.Form.Profiles
import Yesod.Widget
import Data.Time (UTCTime (..), Day, TimeOfDay (..), timeOfDayToTime,
                  timeToTimeOfDay)
import Data.Char (isSpace)
import Data.Default
import Text.Hamlet (hamlet)
import Text.Julius (julius)
import Control.Monad.Trans.Class (lift)
import Data.Text (Text, pack, unpack)
import Data.Monoid (mconcat)

#if __GLASGOW_HASKELL__ >= 700
#define HAMLET hamlet
#define CASSIUS cassius
#define JULIUS julius
#else
#define HAMLET $hamlet
#define CASSIUS $cassius
#define JULIUS $julius
#endif

-- | Gets the Google hosted jQuery UI 1.8 CSS file with the given theme.
googleHostedJqueryUiCss :: Text -> Text
googleHostedJqueryUiCss theme = mconcat
    [ "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/"
    , theme
    , "/jquery-ui.css"
    ]

class YesodJquery a where
    -- | The jQuery 1.4 Javascript file.
    urlJqueryJs :: a -> Either (Route a) Text
    urlJqueryJs _ = Right "http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"

    -- | The jQuery UI 1.8 Javascript file.
    urlJqueryUiJs :: a -> Either (Route a) Text
    urlJqueryUiJs _ = Right "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"

    -- | The jQuery UI 1.8 CSS file; defaults to cupertino theme.
    urlJqueryUiCss :: a -> Either (Route a) Text
    urlJqueryUiCss _ = Right $ googleHostedJqueryUiCss "cupertino"

    -- | jQuery UI time picker add-on.
    urlJqueryUiDateTimePicker :: a -> Either (Route a) Text
    urlJqueryUiDateTimePicker _ = Right "http://github.com/gregwebs/jquery.ui.datetimepicker/raw/master/jquery.ui.datetimepicker.js"

jqueryDayField = requiredFieldHelper . jqueryDayFieldProfile

maybeJqueryDayField = optionalFieldHelper . jqueryDayFieldProfile

jqueryDayFieldProfile jds = FieldProfile
    { fpParse = maybe
                  (Left "Invalid day, must be in YYYY-MM-DD format")
                  Right
              . readMay
              . unpack
    , fpRender = pack . show
    , fpWidget = \theId name val isReq -> do
        addHtml [HAMLET|\
<input id="#{theId}" name="#{name}" type="date" :isReq:required="" value="#{val}">
|]
        addScript' urlJqueryJs
        addScript' urlJqueryUiJs
        addStylesheet' urlJqueryUiCss
        addJulius [JULIUS|
$(function(){$("##{theId}").datepicker({
    dateFormat:'yy-mm-dd',
    changeMonth:#{jsBool $ jdsChangeMonth jds},
    changeYear:#{jsBool $ jdsChangeYear jds},
    numberOfMonths:#{mos $ jdsNumberOfMonths jds},
    yearRange:"#{jdsYearRange jds}"
})});
|]
    }
  where
    jsBool True = "true" :: Text
    jsBool False = "false" :: Text
    mos (Left i) = show i
    mos (Right (x, y)) = concat
        [ "["
        , show x
        , ","
        , show y
        , "]"
        ]

ifRight :: Either a b -> (b -> c) -> Either a c
ifRight e f = case e of
            Left l  -> Left l
            Right r -> Right $ f r

showLeadingZero :: (Show a) => a -> String
showLeadingZero time = let t = show time in if length t == 1 then "0" ++ t else t

jqueryDayTimeField = requiredFieldHelper jqueryDayTimeFieldProfile

-- use A.M/P.M and drop seconds and "UTC" (as opposed to normal UTCTime show)
jqueryDayTimeUTCTime :: UTCTime -> String
jqueryDayTimeUTCTime (UTCTime day utcTime) =
  let timeOfDay = timeToTimeOfDay utcTime
  in (replace '-' '/' (show day)) ++ " " ++ showTimeOfDay timeOfDay
  where
    showTimeOfDay (TimeOfDay hour minute _) =
      let (h, apm) = if hour < 12 then (hour, "AM") else (hour - 12, "PM")
      in (show h) ++ ":" ++ (showLeadingZero minute) ++ " " ++ apm

jqueryDayTimeFieldProfile = FieldProfile
    { fpParse  = parseUTCTime . unpack
    , fpRender = pack . jqueryDayTimeUTCTime
    , fpWidget = \theId name val isReq -> do
        addHtml [HAMLET|\
<input id="#{theId}" name="#{name}" :isReq:required="" value="#{val}">
|]
        addScript' urlJqueryJs
        addScript' urlJqueryUiJs
        addScript' urlJqueryUiDateTimePicker
        addStylesheet' urlJqueryUiCss
        addJulius [JULIUS|
$(function(){$("##{theId}").datetimepicker({dateFormat : "yyyy/mm/dd h:MM TT"})});
|]
    }

parseUTCTime :: String -> Either Text UTCTime
parseUTCTime s =
    let (dateS, timeS) = break isSpace (dropWhile isSpace s)
        dateE = parseDate dateS
     in case dateE of
            Left l -> Left l
            Right date ->
                ifRight (parseTime timeS)
                    (UTCTime date . timeOfDayToTime)

jqueryAutocompleteField = requiredFieldHelper . jqueryAutocompleteFieldProfile

maybeJqueryAutocompleteField src =
    optionalFieldHelper $ jqueryAutocompleteFieldProfile src

jqueryAutocompleteFieldProfile :: YesodJquery master => Route master -> FieldProfile (GWidget sub master ()) Text
jqueryAutocompleteFieldProfile src = FieldProfile
    { fpParse = Right
    , fpRender = id
    , fpWidget = \theId name val isReq -> do
        addHtml [HAMLET|\
<input id="#{theId}" name="#{name}" type="text" :isReq:required="" value="#{val}" .autocomplete>
|]
        addScript' urlJqueryJs
        addScript' urlJqueryUiJs
        addStylesheet' urlJqueryUiCss
        addJulius [JULIUS|
$(function(){$("##{theId}").autocomplete({source:"@{src}",minLength:2})});
|]
    }

addScript' f = do
    y <- lift getYesod
    addScriptEither $ f y

addStylesheet' :: (y -> Either (Route y) Text) -> GWidget sub y ()
addStylesheet' f = do
    y <- lift getYesod
    addStylesheetEither $ f y

readMay :: Read a => String -> Maybe a
readMay s = case reads s of
                (x, _):_ -> Just x
                [] -> Nothing

-- | Replaces all instances of a value in a list by another value.
-- from http://hackage.haskell.org/packages/archive/cgi/3001.1.7.1/doc/html/src/Network-CGI-Protocol.html#replace
replace :: Eq a => a -> a -> [a] -> [a]
replace x y = map (\z -> if z == x then y else z)

data JqueryDaySettings = JqueryDaySettings
    { jdsChangeMonth :: Bool
    , jdsChangeYear :: Bool
    , jdsYearRange :: String
    , jdsNumberOfMonths :: Either Int (Int, Int)
    }

instance Default JqueryDaySettings where
    def = JqueryDaySettings
        { jdsChangeMonth = False
        , jdsChangeYear = False
        , jdsYearRange = "c-10:c+10"
        , jdsNumberOfMonths = Left 1
        }