module Utils exposing (..)

import Array as A exposing (..)
import Base exposing (Word, WordStatus(..))
import Time exposing (Posix, posixToMillis)


isNothing : Maybe a -> Bool
isNothing p =
    case p of
        Nothing ->
            True

        Just a ->
            False


isJust : Maybe a -> Bool
isJust p =
    not (isNothing p)


flip : (a -> b -> c) -> (b -> a -> c)
flip f =
    \x y -> f y x


diffDuration : Posix -> Posix -> Float
diffDuration t1 t2 =
    let
        m1 =
            posixToMillis t1

        m2 =
            posixToMillis t2
    in
    toFloat (m2 - m1) / 1000


wordCountWith : Array Word -> (WordStatus -> Bool) -> Int
wordCountWith words predicate =
    words |> A.map .status |> A.filter predicate |> A.length


triple : a -> b -> c -> ( a, b, c )
triple a b c =
    ( a, b, c )


listIdx : List a -> Int -> Maybe a
listIdx ls idx =
    List.head (List.drop idx ls)