{-# LANGUAGE BlockArguments    #-}
{-# LANGUAGE DataKinds         #-}
{-# LANGUAGE ExplicitForAll    #-}
{-# LANGUAGE FlexibleContexts  #-}
{-# LANGUAGE LambdaCase        #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards   #-}

module Handlers (
                -- , submitImpl
                 statusImpl
                -- , relintImpl
                , stateImpl
                , AdminOverview(..)
                , MapService(..),relintImpl,realtimeImpl) where

import           Universum

import           CheckDir               (DirResult (dirresultMaps))
import           CheckMap               (MapResult (..))
import           Control.Concurrent.STM (TQueue, dupTChan, readTChan,
                                         writeTQueue)
import           Data.Aeson             (ToJSON (..), (.=))
import qualified Data.Aeson             as A
import qualified Data.Aeson.Key         as A
import           Data.Coerce            (coerce)
import qualified Data.Map               as M
import           Network.WebSockets     (PendingConnection, acceptRequest,
                                         rejectRequest, sendTextData,
                                         withPingThread)
import           Servant                (Handler, err404, throwError)
import           Server                 (JobStatus (..), Org (orgUrl),
                                         RemoteRef (reponame), ServerState,
                                         Sha1, getJobStatus,
                                         unState, adjustedWebPath)
import           Worker                 (Job (Job))


-- | an info type wrapped around the server state, to carry serialisation instances.
newtype AdminOverview =
  AdminOverview { unAdminOverview :: ServerState }

newtype MapService =
  MapService { unMapService :: ServerState }

instance ToJSON MapService where
  toJSON (MapService state) =
    toJSON . map orgObject $ view unState state
     where
      orgObject (org, statuses) =
        A.object
        . mapMaybe worldObject
        $ M.elems statuses
       where
        worldObject (remote,  _current, result) = case result of
          Just (Linted res rev _) ->
            Just (A.fromText (reponame remote) .=
                    M.mapWithKey (mapInfo rev) (dirresultMaps res))
          _ -> Nothing
        mapInfo rev mappath MapResult { .. } = A.object
                [ "badges" .= mapresultBadges
                -- TODO: type-safe url library for adding the slash?
                , "jitsi" .= mapresultJitsis
                , "url" .= (orgUrl org <> adjustedWebPath rev org <> "/" <> toText mappath) ]



statusImpl :: MVar ServerState -> Text -> Sha1 -> Handler (Org True, RemoteRef, JobStatus, Maybe JobStatus)
statusImpl state orgslug sha1 = do
   status <- liftIO $ getJobStatus state orgslug sha1
   case status of
     Just stuff -> pure stuff
     Nothing    -> throwError err404

-- | since there are multiple apis that just get state information …
stateImpl
  :: forall s
  .  Coercible s ServerState
  => MVar ServerState
  -> Handler s
stateImpl state = readMVar state <&> coerce

relintImpl :: TQueue Job -> MVar ServerState -> Text -> Sha1 -> Handler Text
relintImpl queue state orgslug sha1 =
  liftIO $ getJobStatus state orgslug sha1 >>= \case
    Nothing -> pure "there isn't a job here to restart"
    Just (org, ref, _oldjob, _veryoldjob) -> do
      atomically $ writeTQueue queue (Job ref org)
      pure "hello"


realtimeImpl :: MVar ServerState -> Text -> Sha1 -> PendingConnection -> Handler ()
realtimeImpl state orgslug sha1 pending =
  liftIO (getJobStatus state orgslug sha1) >>= \case
    Just (_org, _ref, Linted _ _ (_, realtime), _) -> do
      conn <- liftIO $ acceptRequest pending
      incoming <- atomically $ dupTChan realtime
      liftIO $ withPingThread conn 30 pass $ forever $ do
        next <- atomically $ readTChan incoming
        sendTextData conn (A.encode next)
    _ -> liftIO $ rejectRequest pending "no!"