concept G22Network > ConceptWithChangeListeners {

  delegate Port to G22NetworkElement.

  settableWithVar S description;

  Cl<G22NetworkElement> elements = syncL();

  settableWithVar int magneticDistance = 100;

  // Is the network safe to auto-calculate?

  settableWithVar bool autoCalculate = true;

  toString { ret or2(description, super.toString()); }

  // return new connections made

  Cl<G22NetworkCable> doMagneticConnections() {

    //deleteMagneticConnections();

    new L<G22NetworkCable> newCables;

    new L<Port> inputPorts;

    new L<Port> outputPorts;

    for (element : elements)

      for (port : element.ports())

        (port.isOutput() ? outputPorts : inputPorts).add(port);

    for (port1 : inputPorts) {

      if (port1.isConnected()) continue;

      Rect bounds1 = port1.bounds();

      new Lowest<G22NetworkElement.Port> best;

      for (port2 : outputPorts) {

        double distance = rectDistance(bounds1, port2.bounds());

        // too far away? skip

        if (distance >= magneticDistance) continue;

        // wrong type? skip

        if (!isSubclassOf(port2.dataType(), port1.dataType())) continue;

        // candidate found - store with distance

        best.put(port2, distance);

      }

      var port2 = best!;

      if (port2 != null) {

        var cable = new G22NetworkCable().from(port2).to(port1);

        newCables.add(cable);

        cable.connect();

        print("Made cable: " + cable);

      }

    }

    ret newCables;

  }

  void deleteMagneticConnections {

    for (cable : allCables())

      if (cable.isAutomatic())

        cable.remove();

  }

  Set<G22NetworkCable> allCables() {

    new Set<G22NetworkCable> set;

    for (element : elements)

      for (port : element.ports())

        addIfNotNull(set, port.cable);

    ret set;

  }

}