ct(initializeEmptyNode, (
	not(emptyNode(_))
),(
	add(emptyNode(_))
)).

ct(registerService(S), (
    serviceNode(S),
    upStateRelation(R,S,S)
    
    %not(fieldDefT(FLAG , CLASS, _, 'flag', _)),
    %new_id(R),new_id(S)
),(
	%replace(upStateRelation(R,S,S),activeStateRelation(R,S,S))
    delete(upStateRelation(R,S,S)),
    add(activeStateRelation(_a,S,S))
    %add(fieldDefT(FLAG , CLASS, type(basic, int, 0), 'flag', null))
)).

ct(unregisterService(S), (
    serviceNode(S),
    activeStateRelation(A,S,S),
    not(
    	serviceNode(S2),
    	backupStateRelation(_b,S,S2)
    )
),(
	delete(activeStateRelation(A,S,S)),
	add(upStateRelation(_u,S,S))
)).

ct(standbyService(A,U), (
	serviceNode(A),
	serviceNode(U),
	A \= U,
	upStateRelation(Ru,U,U),
	activeStateRelation(_a,A,A),
	not( backupStateRelation(B,A,U) )
	
		%new_id(B)
),(
	delete(upStateRelation(Ru,U,U)),
	add(standbyStateRelation(_s,U,U)),
	add(backupStateRelation(B,A,U))
)).

ct(detachService(A,S), (
	serviceNode(A),
	serviceNode(S),
	A \= S,
	standsyStateRelation(Rs,S,S),
	activeStateRelation(_a,A,A),
	backupStateRelation(B,A,S)
	%new_id(B)
),(
	delete(backupStateRelation(B,A,S)),
	delete(standbyStateRelation(Rs,S,S)),
	add(upStateRelation(_u,S,S))
)).

ct(failoverService(D,S), (
	serviceNode(D),
	serviceNode(S),
	D \= S,
	standbyStateRelation(Rs,S,S),
	downStateRelation(_d,D,D),
	backupStateRelation(B,D,S)
),(
	delete(standbyStateRelation(Rs,S,S)),
	delete(backupStateRelation(B,D,S)),
	add(activeStateRelation(_a,S,S))	
)).


ct(powerOnService(E), ( 
	emptyNode(E)
),(
	add(serviceNode(A)),
	add(upStateRelation(_,A,A)),
	delete(emptyNode(E))
)).
	% let's say we can only have 6 services
	%not(
	%	serviceNode(S1),
	%	serviceNode(S2),
	%	S1 \= S2,
	%	serviceNode(S3),
	%	S1 \= S3, S2 \= S3,
	%	serviceNode(S4),
	%	S1 \= S4, S2 \= S4, S3 \= S4,
	%	serviceNode(S5),
	%	S1 \= S5, S2 \= S5, S3 \= S5, S4 \= S5,
	%	serviceNode(S6),
	%	S1 \= S6, S2 \= S6, S3 \= S6, S4 \= S6, S5 \= S6
	%)

ct(removeService(D), (
	serviceNode(D),
	downStateRelation(Rd,D,D),
	not(
		serviceNode(S),
		D \= S,
		backupStateRelation(_,D,S)
	)
),(
	delete(downStateRelation(Rd,D,D)),
	delete(serviceNode(D)),
	add(emptyNode(_))
)).

open_world_cts([
	powerOnService,standbyService,detachService,failoverService,
	registerService,unregisterService,removeService,initializeEmptyNode
	]).