import { describe, it, expect, vi, afterEach } from "vitest";
import { timeAgo } from "../time.js";

describe("timeAgo", () => {
  afterEach(() => {
    vi.useRealTimers();
  });

  function setNow(iso: string) {
    vi.useFakeTimers();
    vi.setSystemTime(new Date(iso));
  }

  it("returns 'just now' for under 60 seconds", () => {
    setNow("2026-01-01T12:00:30Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("just now");
  });

  it("returns '1 minute ago' (singular)", () => {
    setNow("2026-01-01T12:01:00Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("1 minute ago");
  });

  it("returns 'N minutes ago' for under 60 minutes", () => {
    setNow("2026-01-01T12:05:00Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("5 minutes ago");
  });

  it("returns '1 hour ago' (singular)", () => {
    setNow("2026-01-01T13:00:00Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("1 hour ago");
  });

  it("returns 'N hours ago' for under 24 hours", () => {
    setNow("2026-01-01T15:00:00Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("3 hours ago");
  });

  it("returns '1 day ago' (singular)", () => {
    setNow("2026-01-02T12:00:00Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("1 day ago");
  });

  it("returns 'N days ago' for under 30 days", () => {
    setNow("2026-01-08T12:00:00Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("7 days ago");
  });

  it("returns ISO date (YYYY-MM-DD) for 30+ days old", () => {
    setNow("2026-02-01T12:00:00Z");
    expect(timeAgo(new Date("2026-01-01T12:00:00Z"))).toBe("2026-01-01");
  });
});