multisig.pl

owner(owner).
tx(id, calldata, addr).
approved(owner, tx).
executed(tx).
quorum(quorum).

public(add_tx).
public(approve).
public(execute).

add_owners([]).
add_owners([Owner|Others]) :-
	assert owner(Owner),
	add_owners(Others).

constructor(Owners, Quorum) :-
	add_owners(Owners),
	assert quorum(Quorum).

add_tx(Id, Calldata, Addr) :-
	owner(msg.sender),
	not tx(Id, _, _),
	assert tx(Id, Calldata, Addr).

len([], 0).
len([_|T], N) :-
	len(T, N1),
	N is N1 + 1.

all_approved([], _).
all_approved([H|T], Id) :-
	approved(H, Id),
	all_approved(T, Id).

is_approved(Id, Q, Approvers) :-
	tx(Id, _, _),
	quorum(Q),
	len(Approvers) >= Q,
	all_approved(Approvers, Id).

approve(Id) :-
	owner(msg.sender),
	tx(Id, _, _),
	not approved(msg.sender, Id),
	assert approved(msg.sender, Id).

execute(Id, Q, Approvers) :-
	tx(Id, Calldata, Addr),
	is_approved(Id, Q, Approvers),
	not executed(Id),
	evm_exec(Addr, Calldata),
	assert executed(Id).