{-# LANGUAGE FlexibleContexts      #-}
{-# LANGUAGE QuantifiedConstraints #-}
{-# LANGUAGE RankNTypes            #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TupleSections         #-}
{-# LANGUAGE TypeOperators         #-}
{-# LANGUAGE TypeFamilies          #-}
module Data.Profunctor.Optic.Prelude (
    re
  , invert
  , (&)
    -- * Composition
  , (.) 
  , (%)
  , (#)
    -- * View operators
  , view
  , (^.)
  , iview
  , (^%)
  , review
  , (#^)
    -- * Setter operators
  , set
  , (.~)
  , iset
  , (%~)
  , kset
  , (#~)
  , over
  , (..~)
  , iover
  , (%%~)
  , kover
  , (##~)
  , (<>~)
    -- * Fold operators
  , preview
  , (^?)
  , is
  , isnt
  , matches
  , lists
  , (^..)
  , ilists
  , ilistsFrom
  , (^%%)
  , folds
  , foldsa
  , foldsr
  , ifoldsr
  , ifoldsrFrom
  , foldsl
  , ifoldsl
  , ifoldslFrom
  , foldsr'
  , ifoldsr'
  , foldsl'
  , ifoldsl'
  , foldsrM
  , ifoldsrM
  , foldslM
  , ifoldslM
  , traverses_
  , itraverses_
  , sums
  , multiplies
  , asums
  , concats
  , iconcats
  , endo
  , endoM
  , finds
  , ifinds
  , has
  , hasnt 
  , elem
  , pelem
  , joins
  , joins'
  , meets
  , meets'
  , mins 
  , maxes 
) where

import Control.Monad.Reader as Reader hiding (lift)
import Data.Function
import Data.Maybe
import Data.Monoid
import Data.Profunctor.Optic.Carrier
import Data.Profunctor.Optic.Types
import Data.Profunctor.Optic.Iso
import Data.Profunctor.Optic.View
import Data.Profunctor.Optic.Import
import Data.Profunctor.Optic.Index
import Data.Profunctor.Optic.Setter
import Data.Profunctor.Optic.Fold
import Data.Profunctor.Optic.Option
import Data.Profunctor.Optic.Affine
import Data.Prd (Prd, Minimal(..), Maximal(..))
import Data.Semilattice

import qualified Control.Applicative as A
import Data.Semiring as Rng
import qualified Prelude as Pre

-- $setup
-- >>> :set -XNoOverloadedStrings
-- >>> :set -XTypeApplications
-- >>> :set -XFlexibleContexts
-- >>> import Control.Exception hiding (catches)
-- >>> import Data.Functor.Identity
-- >>> import Data.List.Optic
-- >>> import Data.Map as Map
-- >>> import Data.Maybe
-- >>> import Data.Monoid
-- >>> import Data.Semiring hiding (unital,nonunital,presemiring)
-- >>> import Data.Sequence as Seq hiding ((*))
-- >>> :load Data.Profunctor.Optic


---------------------------------------------------------------------
-- Fold operators
---------------------------------------------------------------------

-- | The sum of a collection.
--
sums :: (Additive-Monoid) a => AFold ((Endo-Endo) a) s a -> s -> a
sums o = foldsl' o (+) zero

-- | The product of a collection.
--
multiplies :: (Multiplicative-Monoid) a => AFold ((Endo-Endo) a) s a -> s -> a
multiplies o = foldsl' o (*) one

-- | The sum of a collection of actions, generalizing 'concats'.
--
-- >>> asums both ("hello","world")
-- "helloworld"
--
-- >>> asums both (Nothing, Just "hello")
-- Just "hello"
--
-- @
-- 'asum' ≡ 'asums' 'folded'
-- @
--
asums :: Alternative f => AFold ((Endo-Endo) (f a)) s (f a) -> s -> f a
asums o = foldsl' o (<|>) A.empty
{-# INLINE asums #-}

-- | Map a function over the foci of an optic and concatenate the resulting lists.
--
-- >>> concats both (\x -> [x, x + 1]) (1,3)
-- [1,2,3,4]
--
-- @
-- 'concatMap' ≡ 'concats' 'folded'
-- @
--
concats :: AFold [r] s a -> (a -> [r]) -> s -> [r]
concats = withFold
{-# INLINE concats #-}

-- | Concatenate the results of a function of the foci of an indexed optic.
--
-- @
-- 'concats' o ≡ 'iconcats' o '.' 'const'
-- @
--
-- >>> iconcats itraversed (\i x -> [i + x, i + x + 1]) [1,2,3,4]
-- [1,2,3,4,5,6,7,8]
--
iconcats :: (Additive-Monoid) i => AIxfold [r] i s a -> (i -> a -> [r]) -> s -> [r]
iconcats o f = withIxfold o f zero
{-# INLINE iconcats #-}

-- | TODO: Document
--
endo :: AFold (Endo (a -> a)) s (a -> a) -> s -> a -> a
endo o = foldsr o (.) id

-- | TODO: Document
--
endoM :: Monad m => AFold (Endo (a -> m a)) s (a -> m a) -> s -> a -> m a
endoM o = foldsr o (<=<) pure

-- | Find the first focus of an optic that satisfies a predicate, if one exists.
--
-- >>> finds both even (1,4)
-- Just 4
--
-- >>> finds folded even [1,3,5,7]
-- Nothing
--
-- @
-- 'Data.Foldable.find' ≡ 'finds' 'folded'
-- @
--
finds :: AFold ((Maybe-Endo) a) s a -> (a -> Bool) -> s -> Maybe a
finds o f = foldsr o (\a y -> if f a then Just a else y) Nothing
{-# INLINE finds #-}

-- | Find the first focus of an indexed optic that satisfies a predicate, if one exists.
--
ifinds :: (Additive-Monoid) i => AIxfold ((Maybe-Endo) (i, a)) i s a -> (i -> a -> Bool) -> s -> Maybe (i, a)
ifinds o f = ifoldsr o (\i a y -> if f i a then Just (i,a) else y) Nothing
{-# INLINE ifinds #-}

-- | Determine whether an optic has at least one focus.
--
has :: AFold (Additive Bool) s a -> s -> Bool
has o s = unAdditive $ withFold o (const $ Additive True) s
{-# INLINE has #-}

-- | Determine whether an optic does not have a focus.
--
hasnt :: AFold (Multiplicative Bool) s a -> s -> Bool
hasnt o s = unMultiplicative $ withFold o (const $ Multiplicative False) s
{-# INLINE hasnt #-}

-- | Determine whether the targets of a `Fold` contain a given element.
--
elem :: Eq a => AFold (Additive Bool) s a -> a -> s -> Bool
elem o a s = unAdditive $ withFold o (\x -> Additive $ x == a) s

-- | Determine whether the foci of an optic contain an element equivalent to a given element.
--
pelem :: Prd a => AFold (Additive Bool) s a -> a -> s -> Bool
pelem o a s = unAdditive $ withFold o (\x -> Additive $ x =~ a) s
{-# INLINE pelem #-}

-- | Compute the minimum of the targets of a totally ordered fold. 
--
mins :: Pre.Ord a => AFold ((Endo-Endo) a) s a -> a -> s -> a
mins o = foldsl' o Pre.min

-- | Compute the maximum of the targets of a totally ordered fold.
--
maxes :: Pre.Ord a => AFold ((Endo-Endo) a) s a -> a -> s -> a
maxes o = foldsl' o Pre.max

-- | Compute the join of the foci of an optic. 
--
joins :: Lattice a => AFold ((Endo-Endo) a) s a -> a -> s -> a
joins o = foldsl' o (∨)
{-# INLINE joins #-}

-- | Compute the join of the foci of an optic including a least element.
--
joins' :: Lattice a => Minimal a => AFold ((Endo-Endo) a) s a -> s -> a
joins' o = joins o minimal
{-# INLINE joins' #-}

-- | Compute the meet of the foci of an optic .
--
meets :: Lattice a => AFold ((Endo-Endo) a) s a -> a -> s -> a
meets o = foldsl' o (∧)
{-# INLINE meets #-}

-- | Compute the meet of the foci of an optic including a greatest element.
--
meets' :: Lattice a => Maximal a => AFold ((Endo-Endo) a) s a -> s -> a
meets' o = meets o maximal
{-# INLINE meets' #-}