import { test } from "node:test";
import assert from "node:assert/strict";
import {
  byUploadDateDesc,
  byCreatedAtThenId,
  rankByUploadDateDesc,
  rankThread,
} from "./rank";

test("rankByUploadDateDesc is newest-first and stable within a date", () => {
  const rows = [
    { uploadDate: "20240101", id: "a" },
    { uploadDate: "20250601", id: "b" },
    { uploadDate: "20240101", id: "c" },
    { uploadDate: "20251231", id: "d" },
  ];
  assert.deepEqual(
    rankByUploadDateDesc(rows).map((r) => r.id),
    ["d", "b", "a", "c"],
  );
  assert.equal(byUploadDateDesc({ uploadDate: "x" }, { uploadDate: "x" }), 0);
});

test("rankThread is oldest-first, tie-broken by id so the order is total", () => {
  const posts = [
    { createdAt: "2025-01-02T00:00:00Z", id: "b" },
    { createdAt: "2025-01-01T00:00:00Z", id: "z" },
    { createdAt: "2025-01-01T00:00:00Z", id: "a" },
  ];
  assert.deepEqual(
    rankThread(posts).map((p) => p.id),
    ["a", "z", "b"],
  );
  assert.ok(
    byCreatedAtThenId({ createdAt: "t", id: "a" }, { createdAt: "t", id: "b" }) < 0,
  );
});