module Hasql.Private.Settings where

import qualified Data.ByteString as B
import qualified Data.ByteString.Builder as BB
import qualified Data.ByteString.Lazy as BL
import Hasql.Private.Prelude

-- |
-- All settings encoded in a single byte-string according to
-- <http://www.postgresql.org/docs/9.4/static/libpq-connect.html#LIBPQ-CONNSTRING the PostgreSQL format>.
type Settings =
  ByteString

-- |
-- Encode a host, a port, a user, a password and a database into the PostgreSQL settings byte-string.
{-# INLINE settings #-}
settings :: ByteString -> Word16 -> ByteString -> ByteString -> ByteString -> Settings
settings host port user password database =
  BL.toStrict $
    BB.toLazyByteString $
      mconcat $
        intersperse (BB.char7 ' ') $
          catMaybes $
            [ mappend (BB.string7 "host=") . BB.byteString
                <$> mfilter (not . B.null) (pure host),
              mappend (BB.string7 "port=") . BB.word16Dec
                <$> mfilter (/= 0) (pure port),
              mappend (BB.string7 "user=") . BB.byteString
                <$> mfilter (not . B.null) (pure user),
              mappend (BB.string7 "password=") . BB.byteString
                <$> mfilter (not . B.null) (pure password),
              mappend (BB.string7 "dbname=") . BB.byteString
                <$> mfilter (not . B.null) (pure database)
            ]