% Common shared database loaded by every deployment node.
% Holds the family relations used in the tutorial's local and distributed
% Prolog sections.

ancestor_descendant(X, Y) :- parent_child(X, Y).
ancestor_descendant(X, Z) :-
    parent_child(X, Y),
    ancestor_descendant(Y, Z).

parent_child(X, Y) :- mother_child(X, Y).
parent_child(X, Y) :- father_child(X, Y).

mother_child(trude, sally).

father_child(tom, sally).
father_child(tom, erica).
father_child(mike, tom).


list_price(widget, 100).
list_price(gadget, 250).
list_price(gizmo, 400).

price(Item, Price) :-
    list_price(Item, Price).

% Shared database loaded by all ACTOR-profile deployment nodes (n3, n4).
% Holds the actor predicates that the tutorial expects to find on either
% public actor node, plus the public service directory.

service(counter, meta(actor, protocol(count_v1))).
service(pubsub_service, meta(actor, protocol(pubsub_v1))).


echo_actor :-
    receive({
        echo(From, Msg) ->
            From ! echo(Msg),
            echo_actor
    }).


count_actor(Count0) :-
    receive({
        count(From) ->
            Count is Count0 + 1,
            From ! count(Count),
            count_actor(Count) ;
        stop ->
            true
    }).

% n3 is the public actor-demo node.
% The shared actor predicates are in shared_db_actor_common.pl. This overlay
% holds only n3-specific predicates: the deployment marker and the
% mortal/human chain that the tutorial's distributed proof tree pulls
% through to n4.

:- dynamic mortal/1, human/1.

mortal(X) :- human(X).

human(socrates).
human(X) :- rpc('https://n4.elfenbenstornet.se', human(X)).

% Shared database used by example 13 shared-database.xml.

shared_fact(n3_shared_db).

% The statechart datamodel defines local_label/1 too.  Its local definition
% shadows this shared one while the chart is running.
local_label(n3_shared_db).

shared_transition_enabled.