module BasicAuth
    exposing
        ( buildAuthorizationHeader
        , buildAuthorizationToken
        )

{-| A helper library for Elm that provides building basic authentication token and header.

# Http header
@docs buildAuthorizationHeader

# Just the string token
@docs buildAuthorizationToken
-}

import Http
import Base64


{-| Builds an authorization header based on provided username and password.
This can be put directly into the Http.request headers array.

    loadAuthenticated : Int -> Cmd Msg
    loadAuthenticated id =
        let
            url =
                "https://reqres.in/api/users/" ++ (toString id)

            request =
                Http.request
                    { method = "GET"
                    , headers =
                        [ buildAuthorizationHeader "username" "password" ]
                    , url = url
                    , body = Http.emptyBody
                    , expect = Http.expectJson userDecoder
                    , timeout = Nothing
                    , withCredentials = False
                    }
        in
            Http.send UserResult request
-}
buildAuthorizationHeader : String -> String -> Http.Header
buildAuthorizationHeader username password =
    Http.header "Authorization" ("Basic " ++ (buildAuthorizationToken username password))


{-| Builds just the authorization token based on provided username and password.
Use this if you need just the token for some reason.
Use buildAuthorizationHeader if you need the header anyway.
-}
buildAuthorizationToken : String -> String -> String
buildAuthorizationToken username password =
    let
        result =
            Base64.encode (username ++ ":" ++ password)
    in
        case result of
            Ok value ->
                value

            Err error ->
                "error: " ++ error