{-# LANGUAGE ConstraintKinds            #-}
{-# LANGUAGE DeriveDataTypeable         #-}
{-# LANGUAGE DeriveFoldable             #-}
{-# LANGUAGE DeriveFunctor              #-}
{-# LANGUAGE FlexibleContexts           #-}
{-# LANGUAGE FlexibleInstances          #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE MultiParamTypeClasses      #-}
{-# LANGUAGE NoMonomorphismRestriction  #-}
{-# LANGUAGE StandaloneDeriving         #-}
{-# LANGUAGE TypeFamilies               #-}
{-# LANGUAGE TypeOperators              #-}

-------------------------------------------------------------------------------------
-- |
-- Copyright   : (c) Hans Hoglund 2012-2014
--
-- License     : BSD-style
--
-- Maintainer  : hans@hanshoglund.se
-- Stability   : experimental
-- Portability : non-portable (TF,GNTD)
--
-- Provides a representation of musical /slides/, commonly known as /glissando/ or
-- /portamento/. 
--
-- /Warning/ This module is experimental.
--
-------------------------------------------------------------------------------------


module Music.Score.Slide (

        -- * Slides and glissando
        HasSlide(..),
        SlideT(..),
        slide,
        glissando,

  ) where

import           Control.Applicative
import           Control.Comonad
import           Control.Lens            hiding (transform)
import           Data.Foldable
import           Data.Foldable
import           Data.Functor.Couple
import           Data.Ratio
import           Data.Semigroup
import           Data.Typeable
import           Data.Word

import           Music.Dynamics.Literal
import           Music.Pitch.Alterable
import           Music.Pitch.Augmentable
import           Music.Pitch.Literal
import           Music.Score.Part
import           Music.Score.Phrases
import           Music.Time


class HasSlide a where
    setBeginGliss :: Bool -> a -> a
    setBeginSlide :: Bool -> a -> a
    setEndGliss   :: Bool -> a -> a
    setEndSlide   :: Bool -> a -> a

instance HasSlide a => HasSlide (b, a) where
    setBeginGliss n = fmap (setBeginGliss n)
    setBeginSlide n = fmap (setBeginSlide n)
    setEndGliss   n = fmap (setEndGliss n)
    setEndSlide   n = fmap (setEndSlide n)

instance HasSlide a => HasSlide (Couple b a) where
    setBeginGliss n = fmap (setBeginGliss n)
    setBeginSlide n = fmap (setBeginSlide n)
    setEndGliss   n = fmap (setEndGliss n)
    setEndSlide   n = fmap (setEndSlide n)

instance HasSlide a => HasSlide [a] where
    setBeginGliss n = fmap (setBeginGliss n)
    setBeginSlide n = fmap (setBeginSlide n)
    setEndGliss   n = fmap (setEndGliss n)
    setEndSlide   n = fmap (setEndSlide n)

instance HasSlide a => HasSlide (Score a) where
    setBeginGliss n = fmap (setBeginGliss n)
    setBeginSlide n = fmap (setBeginSlide n)
    setEndGliss   n = fmap (setEndGliss n)
    setEndSlide   n = fmap (setEndSlide n)


-- (eg,es,a,bg,bs)
newtype SlideT a = SlideT { getSlideT :: Couple ((Any, Any), (Any, Any)) a }
    deriving (Eq, Show, Ord, Functor, Foldable, Typeable, Applicative, Monad, Comonad)

-- | Unsafe: Do not use 'Wrapped' instances
instance Wrapped (SlideT a) where
  type Unwrapped (SlideT a) = Couple ((Any, Any), (Any, Any)) a
  _Wrapped' = iso getSlideT SlideT

instance Rewrapped (SlideT a) (SlideT b)

_bg, _bs, _eg, _es :: Lens' (SlideT a) Any
_bg = (_Wrapped'._Wrapped') . _1 . _2 . _1
_bs = (_Wrapped'._Wrapped') . _1 . _2 . _2
_eg = (_Wrapped'._Wrapped') . _1 . _1 . _1
_es = (_Wrapped'._Wrapped') . _1 . _1 . _2

instance HasSlide (SlideT a) where
    setBeginGliss x = _bg .~ Any x
    setBeginSlide x = _bs .~ Any x
    setEndGliss   x = _eg .~ Any x
    setEndSlide   x = _es .~ Any x

-- Lifted instances
deriving instance Num a => Num (SlideT a)
deriving instance Fractional a => Fractional (SlideT a)
deriving instance Floating a => Floating (SlideT a)
deriving instance Enum a => Enum (SlideT a)
deriving instance Bounded a => Bounded (SlideT a)
deriving instance (Num a, Ord a, Real a) => Real (SlideT a)
deriving instance (Real a, Enum a, Integral a) => Integral (SlideT a)

-- |
-- Add a slide between the first and the last note.
--
slide :: (HasPhrases' s a, HasSlide a) => s -> s
slide = mapPhraseWise3 (setBeginSlide True) id (setEndSlide True)
  where
    mapPhraseWise3 f g h = over phrases' (over headV f . over middleV g . over lastV h)

-- |
-- Add a glissando between the first and the last note.
--
glissando :: (HasPhrases' s a, HasSlide a) => s -> s
glissando = mapPhraseWise3 (setBeginGliss True) id (setEndGliss True)
  where
    mapPhraseWise3 f g h = over phrases' (over headV f . over middleV g . over lastV h)


headV :: Traversal' (Voice a) a
headV = (eventsV._head._2)

middleV :: Traversal' (Voice a) a
middleV = (eventsV._middle.traverse._2)

lastV :: Traversal' (Voice a) a
lastV = (eventsV._last._2)

-- Traverse writing to all elements *except* first and last
_middle :: (Snoc s s a a, Cons s s b b) => Traversal' s s
_middle = _tail._init