import { describe, expect, test } from "bun:test";
import { DEFAULT_STALE_MINUTES, getStaleWarning, isStale } from "./freshness";

// isStale is the shared rule every billable surface (invoices/reports) uses to
// decide whether the local activity data is recent enough. Stale when: ingest
// predates the report window end (coverage gap), or ingest is older than
// maxAgeMinutes. A null/unparseable timestamp is "unknown" (no history) — NOT
// stale, so the hub / fresh installs don't emit false warnings.

const asOf = new Date("2026-01-01T12:00:00Z");
const minsBefore = (n: number) =>
  new Date(asOf.getTime() - n * 60_000).toISOString();

describe("isStale", () => {
  test("never ingested → unknown, not stale (no false warning)", () => {
    expect(isStale({ lastIngestAt: null, asOf })).toBe(false);
  });

  test("unparseable timestamp → unknown, not stale", () => {
    expect(isStale({ lastIngestAt: "not-a-date", asOf })).toBe(false);
  });

  test("ingest within default threshold → fresh", () => {
    expect(isStale({ lastIngestAt: minsBefore(30), asOf })).toBe(false);
  });

  test("ingest exactly at the default threshold → fresh (not strictly older)", () => {
    expect(
      isStale({ lastIngestAt: minsBefore(DEFAULT_STALE_MINUTES), asOf }),
    ).toBe(false);
  });

  test("ingest older than default threshold → stale", () => {
    expect(
      isStale({ lastIngestAt: minsBefore(DEFAULT_STALE_MINUTES + 1), asOf }),
    ).toBe(true);
  });

  test("custom maxAgeMinutes is respected", () => {
    expect(
      isStale({ lastIngestAt: minsBefore(20), asOf, maxAgeMinutes: 15 }),
    ).toBe(true);
    expect(
      isStale({ lastIngestAt: minsBefore(10), asOf, maxAgeMinutes: 15 }),
    ).toBe(false);
  });

  test("ingest before window end → stale (coverage gap) even if recent", () => {
    // Ingested 5 min ago (well within 60), but the invoice window ends after
    // the last ingest, so the period isn't fully captured.
    const windowEnd = new Date(asOf.getTime() + 60 * 60_000);
    expect(isStale({ lastIngestAt: minsBefore(5), asOf, windowEnd })).toBe(
      true,
    );
  });

  test("ingest after window end → fresh (window fully captured)", () => {
    const windowEnd = new Date(asOf.getTime() - 24 * 60 * 60_000);
    expect(isStale({ lastIngestAt: minsBefore(5), asOf, windowEnd })).toBe(
      false,
    );
  });

  test("null windowEnd is ignored", () => {
    expect(
      isStale({ lastIngestAt: minsBefore(5), asOf, windowEnd: null }),
    ).toBe(false);
  });
});

describe("getStaleWarning", () => {
  test("fresh data → no warning", () => {
    expect(
      getStaleWarning({ lastIngestAt: minsBefore(5) }, { asOf }),
    ).toBeNull();
  });

  test("never ingested → no warning (unknown, not a false 'stale')", () => {
    expect(getStaleWarning({ lastIngestAt: null }, { asOf })).toBeNull();
  });

  test("stale by age → warning reports a humanized age", () => {
    const msg = getStaleWarning({ lastIngestAt: minsBefore(180) }, { asOf });
    expect(msg).toContain("3h ago");
    expect(msg).toContain("run sync/ingest");
  });
});