-- | Module containing enums from GEGL
module GEGL.Enums
  ( GeglAccessMode(..)
  , GeglAbyssPolicy(..)
  , GeglOrientation(..)
  , GeglSamplerType(..)
  , GeglBlitFlag(..)
  ) where

-- | Access mode to buffers
data GeglAccessMode
  = GeglAccessRead
  | GeglAccessWrite
  | GeglAccessReadWrite
  deriving (Eq, Show)

instance Enum GeglAccessMode where
  fromEnum GeglAccessRead      = 1
  fromEnum GeglAccessWrite     = 2
  fromEnum GeglAccessReadWrite = 3

  toEnum 1 = GeglAccessRead
  toEnum 2 = GeglAccessWrite
  toEnum 3 = GeglAccessReadWrite
  toEnum unmatched = error ("GeglAccessMode.toEnum: Cannot match " ++ show unmatched)

-- | I don't know
data GeglAbyssPolicy
  = GeglAbyssNone
  | GeglAbyssClamp
  | GeglAbyssLoop
  | GeglAbyssBlack
  | GeglAbyssWhite
  deriving (Eq, Show)

instance Enum GeglAbyssPolicy where
  fromEnum GeglAbyssNone  = 0
  fromEnum GeglAbyssClamp = 1
  fromEnum GeglAbyssLoop  = 2
  fromEnum GeglAbyssBlack = 3
  fromEnum GeglAbyssWhite = 4

  toEnum 0 = GeglAbyssNone
  toEnum 1 = GeglAbyssClamp
  toEnum 2 = GeglAbyssLoop
  toEnum 3 = GeglAbyssBlack
  toEnum 4 = GeglAbyssWhite
  toEnum unmatched = error ("GeglAbyssPolicy.toEnum: cannot match " ++ show unmatched)

-- | Orientation of a buffer
data GeglOrientation
  = GeglOrientationHorizontal
  | GeglOrientationVertical
  deriving (Eq, Show)

instance Enum GeglOrientation where
  fromEnum GeglOrientationHorizontal = 0
  fromEnum GeglOrientationVertical   = 1

  toEnum 0 = GeglOrientationHorizontal
  toEnum 1 = GeglOrientationVertical
  toEnum unmatched = error ("GeglOrientation.toEnum: cannot match " ++ show unmatched)

data GeglSamplerType
  = GeglSamplerNearest
  | GeglSamplerLinear
  | GeglSamplerCubic
  | GeglSamplerNohalo
  | GeglSamplerLohalo
  deriving (Eq, Show)

instance Enum GeglSamplerType where
  fromEnum GeglSamplerNearest = 0
  fromEnum GeglSamplerLinear  = 1
  fromEnum GeglSamplerCubic   = 2
  fromEnum GeglSamplerNohalo  = 3
  fromEnum GeglSamplerLohalo  = 4

  toEnum 0 = GeglSamplerNearest
  toEnum 1 = GeglSamplerLinear
  toEnum 2 = GeglSamplerCubic
  toEnum 3 = GeglSamplerNohalo
  toEnum 4 = GeglSamplerLohalo
  toEnum unmatched = error ("GeglSamplerType.toEnum: cannot match " ++ show unmatched)

-- | enum type for blit flags
data GeglBlitFlag
  = GeglBlitDefault -- ^ Default blitting. nothing special and sufficient in
                    --   most cases
  | GeglBlitCache   -- ^ Set up a cache for any subsequent requests of image
                    --   data from this node.
  | GeglBlitDirty   -- ^ Return the latest rendered results in cache without
                    --   regard to wether the regions had been rendered or not.

instance Enum GeglBlitFlag where
  fromEnum GeglBlitDefault = 0
  fromEnum GeglBlitCache   = 1
  fromEnum GeglBlitDirty   = 2
  toEnum 0 = GeglBlitDefault
  toEnum 1 = GeglBlitCache
  toEnum 2 = GeglBlitDirty
  toEnum u = error ("GeglBlitFlag.toEnum: cannot match " ++ show u)