package generic

import (
	"time"

	ET "github.com/ibm/fp-go/either"
	"github.com/ibm/fp-go/errors"
	F "github.com/ibm/fp-go/function"
	C "github.com/ibm/fp-go/internal/chain"
	"github.com/ibm/fp-go/internal/eithert"
	FE "github.com/ibm/fp-go/internal/fromeither"
	FI "github.com/ibm/fp-go/internal/fromio"
	IO "github.com/ibm/fp-go/io/generic"
	O "github.com/ibm/fp-go/option"
)

// type IOEither[E, A any] = func() Either[E, A]

func MakeIO[GA ~func() ET.Either[E, A], E, A any](f GA) GA {
	return f
}

func Left[GA ~func() ET.Either[E, A], E, A any](l E) GA {
	return MakeIO(eithert.Left(IO.MonadOf[GA, ET.Either[E, A]], l))
}

func Right[GA ~func() ET.Either[E, A], E, A any](r A) GA {
	return MakeIO(eithert.Right(IO.MonadOf[GA, ET.Either[E, A]], r))
}

func Of[GA ~func() ET.Either[E, A], E, A any](r A) GA {
	return Right[GA](r)
}

func MonadOf[GA ~func() ET.Either[E, A], E, A any](r A) GA {
	return Of[GA](r)
}

func LeftIO[GA ~func() ET.Either[E, A], GE ~func() E, E, A any](ml GE) GA {
	return MakeIO(eithert.LeftF(IO.MonadMap[GE, GA, E, ET.Either[E, A]], ml))
}

func RightIO[GA ~func() ET.Either[E, A], GR ~func() A, E, A any](mr GR) GA {
	return MakeIO(eithert.RightF(IO.MonadMap[GR, GA, A, ET.Either[E, A]], mr))
}

func FromEither[GA ~func() ET.Either[E, A], E, A any](e ET.Either[E, A]) GA {
	return IO.Of[GA](e)
}

func FromOption[GA ~func() ET.Either[E, A], E, A any](onNone func() E) func(o O.Option[A]) GA {
	return FE.FromOption(
		FromEither[GA, E, A],
		onNone,
	)
}

func ChainOptionK[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](onNone func() E) func(func(A) O.Option[B]) func(GA) GB {
	return FE.ChainOptionK(
		MonadChain[GA, GB, E, A, B],
		FromEither[GB, E, B],
		onNone,
	)
}

func FromIO[GA ~func() ET.Either[E, A], GR ~func() A, E, A any](mr GR) GA {
	return RightIO[GA](mr)
}

func MonadMap[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](fa GA, f func(A) B) GB {
	return eithert.MonadMap(IO.MonadMap[GA, GB, ET.Either[E, A], ET.Either[E, B]], fa, f)
}

func Map[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](f func(A) B) func(GA) GB {
	return F.Bind2nd(MonadMap[GA, GB, E, A, B], f)
}

func MonadMapTo[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](fa GA, b B) GB {
	return MonadMap[GA, GB](fa, F.Constant1[A](b))
}

func MapTo[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](b B) func(GA) GB {
	return F.Bind2nd(MonadMapTo[GA, GB, E, A, B], b)
}

func MonadChain[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](fa GA, f func(A) GB) GB {
	return eithert.MonadChain(IO.MonadChain[GA, GB, ET.Either[E, A], ET.Either[E, B]], IO.MonadOf[GB, ET.Either[E, B]], fa, f)
}

func Chain[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](f func(A) GB) func(GA) GB {
	return F.Bind2nd(MonadChain[GA, GB, E, A, B], f)
}

func MonadChainTo[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](fa GA, fb GB) GB {
	return MonadChain(fa, F.Constant1[A](fb))
}

func ChainTo[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](fb GB) func(GA) GB {
	return F.Bind2nd(MonadChainTo[GA, GB, E, A, B], fb)
}

func MonadChainEitherK[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](ma GA, f func(A) ET.Either[E, B]) GB {
	return FE.MonadChainEitherK(
		MonadChain[GA, GB, E, A, B],
		FromEither[GB, E, B],
		ma,
		f,
	)
}

func MonadChainIOK[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], GR ~func() B, E, A, B any](ma GA, f func(A) GR) GB {
	return FI.MonadChainIOK(
		MonadChain[GA, GB, E, A, B],
		FromIO[GB, GR, E, B],
		ma,
		f,
	)
}

func ChainIOK[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], GR ~func() B, E, A, B any](f func(A) GR) func(GA) GB {
	return FI.ChainIOK(
		MonadChain[GA, GB, E, A, B],
		FromIO[GB, GR, E, B],
		f,
	)
}

func ChainEitherK[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](f func(A) ET.Either[E, B]) func(GA) GB {
	return F.Bind2nd(MonadChainEitherK[GA, GB, E, A, B], f)
}

func MonadAp[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], GAB ~func() ET.Either[E, func(A) B], E, A, B any](mab GAB, ma GA) GB {
	return eithert.MonadAp(
		IO.MonadAp[GA, GB, func() func(ET.Either[E, A]) ET.Either[E, B], ET.Either[E, A], ET.Either[E, B]],
		IO.MonadMap[GAB, func() func(ET.Either[E, A]) ET.Either[E, B], ET.Either[E, func(A) B], func(ET.Either[E, A]) ET.Either[E, B]],
		mab, ma)
}

func Ap[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], GAB ~func() ET.Either[E, func(A) B], E, A, B any](ma GA) func(GAB) GB {
	return F.Bind2nd(MonadAp[GA, GB, GAB, E, A, B], ma)
}

func Flatten[GA ~func() ET.Either[E, A], GAA ~func() ET.Either[E, GA], E, A any](mma GAA) GA {
	return MonadChain(mma, F.Identity[GA])
}

func TryCatch[GA ~func() ET.Either[E, A], E, A any](f func() (A, error), onThrow func(error) E) GA {
	return MakeIO(func() ET.Either[E, A] {
		return ET.TryCatch(f, onThrow)
	})
}

func TryCatchError[GA ~func() ET.Either[error, A], A any](f func() (A, error)) GA {
	return TryCatch[GA](f, errors.IdentityError)
}

func Eitherize0[GEA ~func() ET.Either[error, A], GA ~func() (A, error), A any](f GA) func() GEA {
	ef := ET.Eitherize0(f)
	return func() GEA {
		return MakeIO(ef)
	}
}

func Uneitherize0[GEA ~func() ET.Either[error, A], GTA ~func() GEA, A any](f GTA) func() (A, error) {
	return func() (A, error) {
		return ET.Unwrap(f()())
	}
}

func Eitherize1[GEA ~func() ET.Either[error, A], GA ~func(t1 T1) (A, error), T1, A any](f GA) func(T1) GEA {
	ef := ET.Eitherize1(f)
	return func(t1 T1) GEA {
		return MakeIO[GEA](func() ET.Either[error, A] {
			return ef(t1)
		})
	}
}

func Uneitherize1[GEA ~func() ET.Either[error, A], GTA ~func(t1 T1) GEA, T1, A any](f GTA) func(T1) (A, error) {
	return func(t1 T1) (A, error) {
		return ET.Unwrap(f(t1)())
	}
}

func Eitherize2[GEA ~func() ET.Either[error, A], GA ~func(t1 T1, t2 T2) (A, error), T1, T2, A any](f GA) func(T1, T2) GEA {
	ef := ET.Eitherize2(f)
	return func(t1 T1, t2 T2) GEA {
		return MakeIO[GEA](func() ET.Either[error, A] {
			return ef(t1, t2)
		})
	}
}

func Uneitherize2[GEA ~func() ET.Either[error, A], GTA ~func(t1 T1, t2 T2) GEA, T1, T2, A any](f GTA) func(T1, T2) (A, error) {
	return func(t1 T1, t2 T2) (A, error) {
		return ET.Unwrap(f(t1, t2)())
	}
}

func Eitherize3[GEA ~func() ET.Either[error, A], GA ~func(t1 T1, t2 T2, t3 T3) (A, error), T1, T2, T3, A any](f GA) func(T1, T2, T3) GEA {
	ef := ET.Eitherize3(f)
	return func(t1 T1, t2 T2, t3 T3) GEA {
		return MakeIO[GEA](func() ET.Either[error, A] {
			return ef(t1, t2, t3)
		})
	}
}

func Uneitherize3[GEA ~func() ET.Either[error, A], GTA ~func(t1 T1, t2 T2, t3 T3) GEA, T1, T2, T3, A any](f GTA) func(T1, T2, T3) (A, error) {
	return func(t1 T1, t2 T2, t3 T3) (A, error) {
		return ET.Unwrap(f(t1, t2, t3)())
	}
}

func Eitherize4[GEA ~func() ET.Either[error, A], GA ~func(t1 T1, t2 T2, t3 T3, t4 T4) (A, error), T1, T2, T3, T4, A any](f GA) func(T1, T2, T3, T4) GEA {
	ef := ET.Eitherize4(f)
	return func(t1 T1, t2 T2, t3 T3, t4 T4) GEA {
		return MakeIO[GEA](func() ET.Either[error, A] {
			return ef(t1, t2, t3, t4)
		})
	}
}

func Uneitherize4[GEA ~func() ET.Either[error, A], GTA ~func(t1 T1, t2 T2, t3 T3, t4 T4) GEA, T1, T2, T3, T4, A any](f GTA) func(T1, T2, T3, T4) (A, error) {
	return func(t1 T1, t2 T2, t3 T3, t4 T4) (A, error) {
		return ET.Unwrap(f(t1, t2, t3, t4)())
	}
}

// Memoize computes the value of the provided IO monad lazily but exactly once
func Memoize[GA ~func() ET.Either[E, A], E, A any](ma GA) GA {
	return IO.Memoize(ma)
}

func MonadMapLeft[GA1 ~func() ET.Either[E1, A], GA2 ~func() ET.Either[E2, A], E1, E2, A any](fa GA1, f func(E1) E2) GA2 {
	return eithert.MonadMapLeft(IO.MonadMap[GA1, GA2, ET.Either[E1, A], ET.Either[E2, A]], fa, f)
}

func MapLeft[GA1 ~func() ET.Either[E1, A], GA2 ~func() ET.Either[E2, A], E1, E2, A any](f func(E1) E2) func(GA1) GA2 {
	return F.Bind2nd(MonadMapLeft[GA1, GA2, E1, E2, A], f)
}

// Delay creates an operation that passes in the value after some delay
func Delay[GA ~func() ET.Either[E, A], E, A any](delay time.Duration) func(GA) GA {
	return IO.Delay[GA](delay)
}

func MonadBiMap[GA ~func() ET.Either[E1, A], GB ~func() ET.Either[E2, B], E1, E2, A, B any](fa GA, f func(E1) E2, g func(A) B) GB {
	return eithert.MonadBiMap(IO.MonadMap[GA, GB, ET.Either[E1, A], ET.Either[E2, B]], fa, f, g)
}

// BiMap maps a pair of functions over the two type arguments of the bifunctor.
func BiMap[GA ~func() ET.Either[E1, A], GB ~func() ET.Either[E2, B], E1, E2, A, B any](f func(E1) E2, g func(A) B) func(GA) GB {
	return eithert.BiMap(IO.MonadMap[GA, GB, ET.Either[E1, A], ET.Either[E2, B]], f, g)
}

// Fold convers an IOEither into an IO
func Fold[GA ~func() ET.Either[E, A], GB ~func() B, E, A, B any](onLeft func(E) GB, onRight func(A) GB) func(GA) GB {
	return eithert.MatchE(IO.MonadChain[GA, GB, ET.Either[E, A], B], onLeft, onRight)
}

func MonadFold[GA ~func() ET.Either[E, A], GB ~func() B, E, A, B any](ma GA, onLeft func(E) GB, onRight func(A) GB) GB {
	return eithert.FoldE(IO.MonadChain[GA, GB, ET.Either[E, A], B], ma, onLeft, onRight)
}

// GetOrElse extracts the value or maps the error
func GetOrElse[GA ~func() ET.Either[E, A], GB ~func() A, E, A any](onLeft func(E) GB) func(GA) GB {
	return eithert.GetOrElse(IO.MonadChain[GA, GB, ET.Either[E, A], A], IO.MonadOf[GB, A], onLeft)
}

// MonadChainFirst runs the monad returned by the function but returns the result of the original monad
func MonadChainFirst[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](ma GA, f func(A) GB) GA {
	return C.MonadChainFirst(
		MonadChain[GA, GA, E, A, A],
		MonadMap[GB, GA, E, B, A],
		ma,
		f,
	)
}

// ChainFirst runs the monad returned by the function but returns the result of the original monad
func ChainFirst[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](f func(A) GB) func(GA) GA {
	return C.ChainFirst(
		MonadChain[GA, GA, E, A, A],
		MonadMap[GB, GA, E, B, A],
		f,
	)
}

// MonadChainFirstIOK runs the monad returned by the function but returns the result of the original monad
func MonadChainFirstIOK[GA ~func() ET.Either[E, A], GIOB ~func() B, E, A, B any](first GA, f func(A) GIOB) GA {
	return FI.MonadChainFirstIOK(
		MonadChain[GA, GA, E, A, A],
		MonadMap[func() ET.Either[E, B], GA, E, B, A],
		FromIO[func() ET.Either[E, B], GIOB, E, B],
		first,
		f,
	)
}

// ChainFirstIOK runs the monad returned by the function but returns the result of the original monad
func ChainFirstIOK[GA ~func() ET.Either[E, A], GIOB ~func() B, E, A, B any](f func(A) GIOB) func(GA) GA {
	return FI.ChainFirstIOK(
		MonadChain[GA, GA, E, A, A],
		MonadMap[func() ET.Either[E, B], GA, E, B, A],
		FromIO[func() ET.Either[E, B], GIOB, E, B],
		f,
	)
}

// Swap changes the order of type parameters
func Swap[GEA ~func() ET.Either[E, A], GAE ~func() ET.Either[A, E], E, A any](val GEA) GAE {
	return MonadFold(val, Right[GAE], Left[GAE])
}

// FromImpure converts a side effect without a return value into a side effect that returns any
func FromImpure[GA ~func() ET.Either[E, any], IMP ~func(), E any](f IMP) GA {
	return F.Pipe2(
		f,
		IO.FromImpure[func() any, IMP],
		FromIO[GA, func() any],
	)
}

// Defer creates an IO by creating a brand new IO via a generator function, each time
func Defer[GEA ~func() ET.Either[E, A], E, A any](gen func() GEA) GEA {
	return IO.Defer[GEA](gen)
}