Simple EitherCall example for retrofit

EitherCall

internal class EitherCall<R>(
    private val delegate: Call<R>,
    private val successType: Type
) : Call<Either<Failure, R>> {

    override fun clone(): Call<Either<Failure, R>> {
        TODO("Not yet implemented")
    }

    override fun execute(): Response<Either<Failure, R>> {
        TODO("Not yet implemented")
    }

    override fun enqueue(callback: Callback<Either<Failure, R>>) {
        return delegate.enqueue(
            object : Callback<R> {

                override fun onResponse(call: Call<R>, response: Response<R>) {
                    callback.onResponse(
                        this@EitherCall,
                        Response.success(response.toEither(successType))
                    )
                }

                //Called when connection with the server error NOT on 400..500
                override fun onFailure(call: Call<R>, throwable: Throwable) {
                    val failure = when (throwable) {
                        is NoConnectionException, is IOException -> Failure.NetworkConnection
                        else -> Failure.Unknown
                    }

                    callback.onResponse(
                        this@EitherCall,
                        Response.success(failure.left())
                    ) // either left for failure
                }
            }
        )
    }

    override fun isExecuted(): Boolean = delegate.isExecuted

    override fun cancel() {
        delegate.cancel()
    }

    override fun isCanceled(): Boolean = delegate.isCanceled

    override fun request(): Request {
        return delegate.request()
    }

    override fun timeout(): Timeout {
        return delegate.timeout()
    }
}