-- | Type-safe bindings to EsounD with monadic regions.
module Sound.EsounD
    ( Frame

    , Channels
    , Mono
    , Stereo

    , Player
    , openPlayer
    )
    where

import Bindings.EsounD
import Control.Monad.CatchIO
import Control.Monad.Trans.Region
import Data.Bits
import Data.Int
import Network
import Prelude.Unicode
import System.IO.SaferFileHandles

class Frame fr where
    frameFmt ∷ fr → C'esd_format_t

instance Frame Int8 where
    frameFmt _ = c'ESD_BITS8

instance Frame Int16 where
    frameFmt _ = c'ESD_BITS16

class Channels ch where
    channelFmt ∷ ch → C'esd_format_t

data Mono
instance Channels Mono where
    channelFmt _ = c'ESD_MONO

data Stereo
instance Channels Stereo where
    channelFmt _ = c'ESD_STEREO


-- ^ An ESD handle for playing a stream.
data Player fr ch (r ∷ * → *)
    = Player {
        plRate   ∷ Int
      , plHandle ∷ RegionalFileHandle WriteMode r
      }

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

-- | Open an ESD handle for playing a stream.
openPlayer ∷ ∀ fr ch s pr.
               ( Frame fr
               , Channels ch
               , MonadCatchIO 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 let fmt = frameFmt   ((⊥) ∷ fr) .&.
                   channelFmt ((⊥) ∷ ch) .&.
                   c'ESD_STREAM            .&.
                   c'ESD_PLAY
         return Player {
                      plRate   = rate
                    , plHandle = error "FIXME: not implemented"
                    }