import "./stdlib/Bitwise" as Bitwise
import "./stdlib/List" as List

exposing ( getNameFromPath, isTestFile, hashCode )

getNameFromPath: string -> string
getNameFromPath path =
    let
        splitByPathSymbol: List string
        splitByPathSymbol =
            path.split "/"

        lastElement: string
        lastElement =
            case splitByPathSymbol.slice -1 of
                x :: [] ->
                    x.split "."
                        |> (\y -> y[0])

                default ->
                    ""
    in
        lastElement

isTestFile: string -> boolean
isTestFile name =
    name.endsWith "_test.derw"

hashCodeStep: number -> number -> number
hashCodeStep charCode hash =
    let
        added: number
        added =
            hash + charCode

        shift: number
        shift =
            Bitwise.leftShift hash 5

        subtracted: number
        subtracted =
            shift - added
    in
        Bitwise.or subtracted 0

hashCode: string -> number
hashCode str =
    List.map (\letter -> letter.charCodeAt 0) (str.split "")
        |> List.foldl hashCodeStep 0
        |> (\y -> Math.abs y)