{-# LANGUAGE OverloadedStrings #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

module PgInit (
  runConn

  , MonadIO
  , persistSettings
  , MkPersistSettings (..)
  , db
  , BackendKey(..)
  , GenerateKey(..)

   -- re-exports
  , module Control.Monad.Trans.Reader
  , module Control.Monad
  , module Database.Persist.Sql
  , module Database.Persist
  , module Database.Persist.Sql.Raw.QQ
  , module Init
  , module Test.Hspec
  , module Test.HUnit
  , BS.ByteString
  , Int32, Int64
  , liftIO
  , mkPersist, mkMigrate, share, sqlSettings, persistLowerCase, persistUpperCase
  , SomeException
  , Text
  , TestFn(..)
  ) where

import Init
    ( TestFn(..), truncateTimeOfDay, truncateUTCTime
    , truncateToMicro, arbText, liftA2, GenerateKey(..)
    , (@/=), (@==), (==@), MonadFail
    , assertNotEqual, assertNotEmpty, assertEmpty, asIO
    , isTravis, RunDb
    )

-- re-exports
import Control.Exception (SomeException)
import Control.Monad (void, replicateM, liftM, when, forM_)
import Control.Monad.Trans.Reader
import Data.Aeson (Value(..))
import Database.Persist.TH (mkPersist, mkMigrate, share, sqlSettings, persistLowerCase, persistUpperCase, MkPersistSettings(..))
import Database.Persist.Sql.Raw.QQ
import Database.Persist.Postgresql.JSON()
import Test.Hspec
import Test.QuickCheck.Instances ()

-- testing
import Test.HUnit ((@?=),(@=?), Assertion, assertFailure, assertBool)
import Test.QuickCheck

import Control.Monad (unless, (>=>))
import Control.Monad.IO.Class
import Control.Monad.IO.Unlift (MonadUnliftIO)
import Control.Monad.Logger
import Control.Monad.Trans.Resource (ResourceT, runResourceT)
import qualified Data.ByteString as BS
import qualified Data.HashMap.Strict as HM
import Data.Int (Int32, Int64)
import Data.Maybe (fromMaybe)
import Data.Monoid ((<>))
import Data.Text (Text)
import System.Environment (getEnvironment)
import System.Log.FastLogger (fromLogStr)

import Database.Persist
import Database.Persist.Postgresql
import Database.Persist.Sql
import Database.Persist.TH ()

_debugOn :: Bool
_debugOn = False

dockerPg :: IO (Maybe BS.ByteString)
dockerPg = do
  env <- liftIO getEnvironment
  return $ case lookup "POSTGRES_NAME" env of
    Just _name -> Just "postgres" -- /persistent/postgres
    _ -> Nothing

persistSettings :: MkPersistSettings
persistSettings = sqlSettings { mpsGeneric = True }

runConn :: MonadUnliftIO m => SqlPersistT (LoggingT m) t -> m ()
runConn f = do
  travis <- liftIO isTravis
  let debugPrint = not travis && _debugOn
  let printDebug = if debugPrint then print . fromLogStr else void . return
  flip runLoggingT (\_ _ _ s -> printDebug s) $ do
    _ <- if travis
      then withPostgresqlPool "host=localhost port=5432 user=postgres dbname=persistent" 1 $ runSqlPool f
      else do
        host <- fromMaybe "localhost" <$> liftIO dockerPg
        withPostgresqlPool ("host=" <> host <> " port=5432 user=postgres dbname=test") 1 $ runSqlPool f
    return ()

db :: SqlPersistT (LoggingT (ResourceT IO)) () -> Assertion
db actions = do
  runResourceT $ runConn $ actions >> transactionUndo

instance Arbitrary Value where
  arbitrary = frequency [ (1, pure Null)
                        , (1, Bool <$> arbitrary)
                        , (2, Number <$> arbitrary)
                        , (2, String <$> arbText)
                        , (3, Array <$> limitIt 4 arbitrary)
                        , (3, Object <$> arbObject)
                        ]
    where limitIt i x = sized $ \n -> do
            let m = if n > i then i else n
            resize m x
          arbObject = limitIt 4 -- Recursion can make execution divergent
                    $ fmap HM.fromList -- HashMap -> [(,)]
                    . listOf -- [(,)] -> (,)
                    . liftA2 (,) arbText -- (,) -> Text and Value
                    $ limitIt 4 arbitrary -- Again, precaution against divergent recursion.