/**
 * ConnectionRegistry — BILATERAL connection materialization (T03.h).
 *
 * A connection is live only when BOTH sides have asserted the other. A unilateral
 * (self-declared) assertion yields no neighbour — the defence against a reader who
 * fakes a connection to an owner to read that owner's protected documents.
 */
import { test, expect } from "bun:test";
import { ConnectionRegistry, bilateralConnections } from "../src/connections";

test("a UNILATERAL assertion yields NO neighbour", () => {
  const reg = new ConnectionRegistry();
  reg.assert("mallory", "alice"); // mallory self-declares; alice never asserts back
  expect([...reg.neighbors("mallory")]).toEqual([]);
  expect([...reg.neighbors("alice")]).toEqual([]);
});

test("a BILATERAL assertion (both sides) materializes the link", () => {
  const reg = new ConnectionRegistry();
  reg.assert("alice", "bob");
  reg.assert("bob", "alice");
  expect([...reg.neighbors("alice")]).toEqual(["bob"]);
  expect([...reg.neighbors("bob")]).toEqual(["alice"]);
});

test("mixed: only the reciprocated peers surface", () => {
  const reg = new ConnectionRegistry();
  reg.assert("alice", "bob"); // reciprocated below
  reg.assert("bob", "alice");
  reg.assert("alice", "carol"); // NOT reciprocated by carol
  reg.assert("dave", "alice"); // dave asserts alice, alice never asserts dave
  expect([...reg.neighbors("alice")].sort()).toEqual(["bob"]);
});

test("self-assertion and empty are ignored", () => {
  const reg = new ConnectionRegistry();
  reg.assert("alice", "alice");
  reg.assert("", "bob");
  reg.assert("alice", "");
  expect([...reg.neighbors("alice")]).toEqual([]);
});

test("bilateralConnections adapts to the Connections interface", () => {
  const reg = new ConnectionRegistry();
  reg.assertAll([
    { from: "alice", to: "bob" },
    { from: "bob", to: "alice" },
  ]);
  const conns = bilateralConnections(reg);
  expect([...conns.neighbors("alice")]).toEqual(["bob"]);
  expect([...conns.neighbors("carol")]).toEqual([]);
});

test("clear() removes all assertions", () => {
  const reg = new ConnectionRegistry();
  reg.assert("alice", "bob");
  reg.assert("bob", "alice");
  reg.clear();
  expect([...reg.neighbors("alice")]).toEqual([]);
});