{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE PatternGuards #-}

import qualified Data.Conduit as C
import qualified Data.Conduit.List as CL
import qualified Data.Text.IO as T
import qualified Data.Text as T
import System.Process
import Control.Monad
import Control.Monad.IO.Class
import Control.Applicative
import System.FilePath
import System.Directory
import Data.Conduit
import qualified Data.Conduit.Binary as CB
import Network.HTTP.Conduit as HTTP

import Web.Twitter.Conduit
import Web.Twitter.Types.Lens
import Common
import Control.Lens

ensureDirectoryExist :: FilePath -> IO FilePath
ensureDirectoryExist dir = do
    createDirectoryIfMissing True dir
    return dir

confdir :: IO FilePath
confdir = fmap (</> ".twitter-conduit") getHomeDirectory >>= ensureDirectoryExist

iconPath :: IO FilePath
iconPath = (</> "icons") <$> confdir >>= ensureDirectoryExist

main :: IO ()
main = runTwitterFromEnv' $ do
    src <- stream userstream
    src C.$$+- CL.mapM_ (^! act (liftIO . printTL))

showStatus :: AsStatus s => s -> T.Text
showStatus s = T.concat [ s ^. user . userScreenName
                        , ":"
                        , s ^. text
                        ]

printTL :: StreamingAPI -> IO ()
printTL (SStatus s) = T.putStrLn . showStatus $ s
printTL (SRetweetedStatus s) = T.putStrLn $ T.concat [ s ^. user . userScreenName
                                                     , ": RT @"
                                                     , showStatus (s ^. rsRetweetedStatus)
                                                     ]
printTL (SEvent event)
    | (event^.evEvent) == "favorite" || (event^.evEvent) == "unfavorite",
      Just (ETStatus st) <- (event ^. evTargetObject) = do
          let (fromUser, fromIcon) = evUserInfo (event^.evSource)
              (toUser, _toIcon) = evUserInfo (event^.evTarget)
              evUserInfo (ETUser u) = (u ^. userScreenName, u ^. userProfileImageURL)
              evUserInfo _ = ("", Nothing)
              header = T.concat [ event ^. evEvent, "[", fromUser, " -> ", toUser, "]"]
          T.putStrLn $ T.concat [ header, " :: ", showStatus st ]
          icon <- case fromIcon of
              Just iconUrl -> Just <$> fetchIcon (T.unpack fromUser) (T.unpack iconUrl)
              Nothing -> return Nothing
          notifySend header (showStatus st) icon
printTL s = print s

notifySend :: T.Text -> T.Text -> Maybe FilePath -> IO ()
notifySend header content icon = do
    let ic = maybe [] (\i -> ["-i", i]) icon
    void $ rawSystem "notify-send" $ [T.unpack header, T.unpack content] ++ ic

fetchIcon :: String -- ^ screen name
          -> String -- ^ icon url
          -> IO String
fetchIcon sn url = do
    ipath <- iconPath
    let fname = ipath </> sn ++ "__" ++ takeFileName url
    exists <- doesFileExist fname
    unless exists $ withManager $ \mgr -> do
        req <- liftIO $ parseUrl url
        body <- http req mgr
        HTTP.responseBody body $$+- CB.sinkFile fname
    return fname