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

import Yesod.Handler
import Yesod.Core (Route)
import Yesod.Form
import Yesod.Widget
import Data.Time (Day)
import Data.Default
import Text.Hamlet (shamlet)
import Text.Julius (julius)
import Data.Text (Text, pack, unpack)
import Data.Monoid (mconcat)
import Yesod.Core (RenderMessage, SomeMessage (..))

-- | 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"

blank :: (RenderMessage master FormMessage, Monad m) => (Text -> Either FormMessage a) -> [Text] -> m (Either (SomeMessage master) (Maybe a))
blank _ [] = return $ Right Nothing
blank _ ("":_) = return $ Right Nothing
blank f (x:_) = return $ either (Left . SomeMessage) (Right . Just) $ f x

jqueryDayField :: (RenderMessage master FormMessage, YesodJquery master) => JqueryDaySettings -> Field sub master Day
jqueryDayField jds = Field
    { fieldParse = blank $ maybe
                  (Left MsgInvalidDay)
                  Right
              . readMay
              . unpack
    , fieldView = \theId name attrs val isReq -> do
        toWidget [shamlet|
<input id="#{theId}" name="#{name}" *{attrs} type="date" :isReq:required="" value="#{showVal val}">
|]
        addScript' urlJqueryJs
        addScript' urlJqueryUiJs
        addStylesheet' urlJqueryUiCss
        toWidget [julius|
$(function(){
    var i = $("##{theId}");
    if (i.attr("type") != "date") {
        i.datepicker({
            dateFormat:'yy-mm-dd',
            changeMonth:#{jsBool $ jdsChangeMonth jds},
            changeYear:#{jsBool $ jdsChangeYear jds},
            numberOfMonths:#{mos $ jdsNumberOfMonths jds},
            yearRange:"#{jdsYearRange jds}"
        });
    }
});
|]
    }
  where
    showVal = either id (pack . show)
    jsBool True = "true" :: Text
    jsBool False = "false" :: Text
    mos (Left i) = show i
    mos (Right (x, y)) = concat
        [ "["
        , show x
        , ","
        , show y
        , "]"
        ]

jqueryAutocompleteField :: (RenderMessage master FormMessage, YesodJquery master)
                        => Route master -> Field sub master Text
jqueryAutocompleteField src = Field
    { fieldParse = blank $ Right
    , fieldView = \theId name attrs val isReq -> do
        toWidget [shamlet|
<input id="#{theId}" name="#{name}" *{attrs} type="text" :isReq:required="" value="#{either id id val}" .autocomplete>
|]
        addScript' urlJqueryJs
        addScript' urlJqueryUiJs
        addStylesheet' urlJqueryUiCss
        toWidget [julius|
$(function(){$("##{theId}").autocomplete({source:"@{src}",minLength:2})});
|]
    }

addScript' :: (master -> Either (Route master) Text) -> GWidget sub master ()
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

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
        }