{-# LANGUAGE OverloadedStrings, DeriveGeneric #-}
module Internal.Elements (getTitle, Find(..), find) where

import Text.XML
import qualified Data.Map as M
import Data.Text as Txt hiding (find)
import Control.Concurrent.MVar

import Internal

import Data.Aeson
import Data.Text (Text, pack)
import GHC.Generics

-- Selector engines
import qualified Text.XML.Cursor as X
import qualified XML.Selectors.CSS as CSS

getTitle :: Session -> IO Text
getTitle session = getTitle' <$> documentRoot <$> document <$> readMVar session

getTitle' (Element "title" _ childs) = Txt.concat [txt | NodeContent txt <- childs]
getTitle' (Element "h1" _ childs) = Txt.concat [txt | NodeContent txt <- childs]
getTitle' (Element _ _ childs)
    -- FIXME: Caught Rhapsode bug repaired here, needs that filtering condition.
    | title:_ <- [getTitle' el | NodeElement el <- childs, getTitle' el /= ""] = title
    | otherwise = ""

---

data Find = Find { using :: Text, value :: String } deriving Generic
instance FromJSON Find
find :: Find -> X.Cursor -> Either (Bool, String) [X.Cursor]
find (Find "css selector" sel) root = case CSS.parsePath sel of
    Right sel' -> Right $ CSS.toAxis sel' root
    Left msg -> Left (True, msg)
find (Find type_ _) _ = Left (False, "Invalid selector type: " ++ Txt.unpack type_)