defmodule Scopes.CSys do
  alias Scopes.Core.Actor

  def neuron(scope) do
    Actor.create(fn msg -> process(msg, scope) end)
  end

  def synapse(rcvr, op) do
    fn msg -> Actor.send(rcvr, op.(msg)) end
  end

  # predefined neuron processors

  def process(msg, scope) do
    hd(elem(scope, 1)).(msg, scope)
  end

  def echo(msg, {_state, _code, _syns, env}) do
    send(env, msg)
  end

  def forward(msg, {_state, _code, syns, _env}) do
    Enum.reduce(syns, false, fn s, _acc -> s.(msg); true end)
  end

  def std_proc({:parent}, {_state, _code, _syns, env}) do
    syn = synapse(self(), &Function.identity/1)
    new = neuron({[], [&std_proc/2], [syn], env})
    send(env, {:created, new})
  end

  def std_proc(msg, scope) do
    unless forward(msg, scope), do: echo(msg, scope)
  end
end