{-# OPTIONS_GHC -fno-warn-orphans #-}

module Pandora.Paradigm.Primary.Linear.Vector where

import Pandora.Pattern.Category (($), (#))
import Pandora.Pattern.Functor.Pointable (point)
import Pandora.Pattern.Object.Semigroup (Semigroup ((+)))
import Pandora.Pattern.Object.Ringoid (Ringoid ((*)))
import Pandora.Pattern.Object.Monoid (Monoid (zero))
import Pandora.Pattern.Object.Quasiring (Quasiring (one))
import Pandora.Pattern.Object.Group (Group (invert))
import Pandora.Pattern.Object.Setoid (Setoid ((==)))
import Pandora.Paradigm.Primary.Functor.Maybe (Maybe)
import Pandora.Paradigm.Primary.Functor.Product (Product ((:*:)), type (:*:))
import Pandora.Paradigm.Primary.Transformer.Construction (Construction)
import Pandora.Paradigm.Structure.Ability.Nonempty (Nonempty)
import Pandora.Paradigm.Structure.Ability.Monotonic (Monotonic (reduce))
import Pandora.Paradigm.Structure.Ability.Morphable (Morphable (Morphing, morphing), Morph (Into, Push), premorph, into, item)
import Pandora.Paradigm.Structure.Some.List (List)

data Vector r a where
	Scalar :: a -> Vector a a
	Vector :: a -> Vector r a -> Vector (a :*: r) a

instance Semigroup a => Semigroup (Vector a a) where
	~(Scalar x) + ~(Scalar y) = Scalar $ x + y

instance (Semigroup a, Semigroup r, Semigroup (a :*: r), Semigroup (Vector r a)) => Semigroup (Vector (a :*: r) a) where
	Vector x xs + Vector y ys = Vector # x + y # xs + ys

instance Ringoid a => Ringoid (Vector a a) where
	~(Scalar x) * ~(Scalar y) = Scalar $ x * y

instance (Ringoid a, Ringoid r, Ringoid (a :*: r), Ringoid (Vector r a)) => Ringoid (Vector (a :*: r) a) where
	Vector x xs * Vector y ys = Vector # x * y # xs * ys

instance Monoid a => Monoid (Vector a a) where
	zero = Scalar zero

instance (Monoid a, Monoid r, Monoid (a :*: r), Monoid (Vector r a)) => Monoid (Vector (a :*: r) a) where
	zero = Vector zero zero

instance Quasiring a => Quasiring (Vector a a) where
	one = Scalar one

instance (Quasiring a, Quasiring r, Quasiring (a :*: r), Quasiring (Vector r a)) => Quasiring (Vector (a :*: r) a) where
	one = Vector one one

instance Group a => Group (Vector a a) where
	invert ~(Scalar x) = Scalar $ invert x

instance (Group a, Group r, Group (a :*: r), Group (Vector r a)) => Group (Vector (a :*: r) a) where
	invert (Vector x xs) = Vector # invert x # invert xs

instance Setoid a => Setoid (Vector a a) where
	~(Scalar x) == ~(Scalar y) = x == y

instance (Setoid a, Setoid (Vector r a)) => Setoid (Vector (a :*: r) a) where
	Vector x xs == Vector y ys = (x == y) * (xs == ys)

instance Monotonic a (Vector a a) where
	reduce f r ~(Scalar x) = f x r

instance Monotonic a (Vector r a) => Monotonic a (Vector (a :*: r) a) where
	reduce f r (Vector x xs) = reduce f # f x r # xs

instance Morphable (Into List) (Vector r) where
	type Morphing (Into List) (Vector r) = List
	morphing (premorph -> Scalar x) = point x
	morphing (premorph -> Vector x xs) = item @Push x $ into @List xs

instance Morphable (Into (Construction Maybe)) (Vector r) where
	type Morphing (Into (Construction Maybe)) (Vector r) = Construction Maybe
	morphing (premorph -> Scalar x) = point x
	morphing (premorph -> Vector x xs) = item @Push x $ into @(Nonempty List) xs

class Vectorize a r where
	vectorize :: r -> Vector r a

instance Vectorize a a where
	vectorize x = Scalar x

instance Vectorize a r => Vectorize a (a :*: r) where
	vectorize (x :*: r) = Vector x $ vectorize r