import test from "node:test";
import assert from "node:assert/strict";

import { preferredPartnerGroupId, resolvedPartnerGroups } from "./partner-groups.js";

test("preferredPartnerGroupId picks a real partner group over a solo row", () => {
  const groups = [
    { id: "solo", member_ids: [], participant_ids: ["u1"] },
    { id: "pair", member_ids: ["u2"], participant_ids: ["u1", "u2"] },
  ];
  assert.equal(preferredPartnerGroupId(groups), "pair");
});

test("preferredPartnerGroupId preserves a valid explicit selection", () => {
  const groups = [
    { id: "solo", member_ids: [] },
    { id: "pair", member_ids: ["u2"] },
  ];
  assert.equal(preferredPartnerGroupId(groups, "solo"), "solo");
});

test("preferredPartnerGroupId falls back to first group when no partner group exists", () => {
  assert.equal(preferredPartnerGroupId([{ id: "solo", member_ids: [] }]), "solo");
  assert.equal(preferredPartnerGroupId([]), "");
});

test("resolvedPartnerGroups prefers non-empty user.partner_groups over stale empty groups query", () => {
  const user = { partner_groups: [{ id: "g1", name: "Together" }] };
  const groupsQuery = { items: [] };
  assert.deepEqual(resolvedPartnerGroups(user, groupsQuery), [{ id: "g1", name: "Together" }]);
});

test("resolvedPartnerGroups uses groups GET when user list not loaded yet", () => {
  const groupsQuery = { items: [{ id: "g2" }] };
  assert.deepEqual(resolvedPartnerGroups(null, groupsQuery), [{ id: "g2" }]);
});

test("resolvedPartnerGroups returns an empty array for empty or malformed sources", () => {
  assert.deepEqual(resolvedPartnerGroups({ partner_groups: [] }, { items: [] }), []);
  assert.deepEqual(resolvedPartnerGroups({ partner_groups: "bad" }, { items: "bad" }), []);
});

test("preferredPartnerGroupId ignores stale selections and empty member placeholders", () => {
  const groups = [
    { id: "solo", member_ids: [] },
    { id: "empty-member", member_ids: [""] },
    { id: "pair", member_ids: ["u2"] },
  ];

  assert.equal(preferredPartnerGroupId(groups, "missing"), "pair");
});