-- | EsounD player streams.
module Sound.EsounD.Player
    ( Player
    , openPlayer
    )
    where

import Bindings.EsounD
import Control.Monad.IO.Class
import Control.Monad.Trans.Region
import Control.Monad.Trans.Region.OnExit
import Control.Monad.Unicode
import Data.Bits
import Foreign.C.String
import Network
import Prelude.Unicode
import Sound.EsounD.Internals
import System.IO
import System.IO.SaferFileHandles.Unsafe


-- ^ An opaque ESD handle for playing a stream.
data Player fr ch (r ∷ * → *)
    = Player {
        plRate   ∷ !Int
      -- THINKME: We really want to use RegionalFileHandle but we
      -- can't, because safer-file-handles currently provides no ways
      -- to wrap ordinary handles.
      , plHandle ∷ !Handle
      , plCloseH ∷ !(CloseHandle r)
      }

instance Dup (Player fr ch) where
    dup pl = do ch' ← dup (plCloseH pl)
                return pl { plCloseH = ch' }

-- | Open an ESD handle for playing a stream.
openPlayer ∷ ∀fr ch s pr.
               ( Frame fr
               , Channels ch
               , MonadIO pr
               )
           ⇒ Int          -- ^ sample rate for the stream.
           → HostName     -- ^ host to connect to.
           → Maybe String -- ^ name used to identify this stream to
                           --   ESD (if any).
           → RegionT s pr (Player fr ch (RegionT s pr))
openPlayer rate host name
    = do h  ← liftIO openSocket
         ch ← onExit $ sanitizeIOError $ closeSocket h
         return Player {
                      plRate   = rate
                    , plHandle = h
                    , plCloseH = ch
                    }
    where
      fmt :: C'esd_format_t
      fmt = frameFmt   ((⊥) ∷ fr) .&.
            channelFmt ((⊥) ∷ ch) .&.
            c'ESD_STREAM            .&.
            c'ESD_PLAY

      openSocket :: IO Handle
      openSocket = withCString    host $ \hostPtr →
                   withCStrOrNull name $ \namePtr →
                       c'esd_play_stream
                       fmt
                       (fromIntegral rate)
                       hostPtr
                       namePtr
                       ≫= wrapSocket "esd_play_stream() returned an error"