import { describe, expect, test } from "vitest";

import { absoluteTime, isoTime, relativeTime, shortId } from "../../src/lib/format";

/** A fixed "now" so these never depend on when they run. */
const NOW = Date.UTC(2024, 0, 15, 12, 0, 0);
const seconds = (date: number) => Math.floor(date / 1000);

describe("relativeTime", () => {
  test("reads as how long ago, since that is how commit dates are read", () => {
    expect(relativeTime(seconds(NOW) - 3 * 24 * 60 * 60, NOW)).toBe("3 days ago");
    expect(relativeTime(seconds(NOW) - 2 * 60 * 60, NOW)).toBe("2 hours ago");
    expect(relativeTime(seconds(NOW) - 90, NOW)).toBe("1 minute ago");
  });

  test("picks the largest unit that fits", () => {
    expect(relativeTime(seconds(NOW) - 400 * 24 * 60 * 60, NOW)).toContain("year");
    expect(relativeTime(seconds(NOW) - 45 * 24 * 60 * 60, NOW)).toContain("month");
    expect(relativeTime(seconds(NOW) - 10 * 24 * 60 * 60, NOW)).toContain("week");
  });

  test("falls back to seconds for something that just happened", () => {
    expect(relativeTime(seconds(NOW) - 5, NOW)).toContain("second");
  });

  test("handles a commit dated in the future rather than going strange", () => {
    // Clock skew puts commits ahead of now more often than you would think.
    expect(relativeTime(seconds(NOW) + 2 * 60 * 60, NOW)).toBe("in 2 hours");
  });
});

describe("isoTime", () => {
  test("is machine readable, for the datetime attribute", () => {
    expect(isoTime(seconds(NOW))).toBe("2024-01-15T12:00:00.000Z");
  });
});

describe("absoluteTime", () => {
  test("gives a full timestamp for the tooltip", () => {
    // Locale-dependent, so this checks it produced something with the date in
    // it rather than pinning a format the test machine may not use.
    const formatted = absoluteTime(seconds(NOW));

    expect(formatted).toMatch(/2024/u);
    expect(formatted.length).toBeGreaterThan(8);
  });
});

describe("shortId", () => {
  test("abbreviates the way git does", () => {
    expect(shortId("0123456789abcdef0123456789abcdef01234567")).toBe("0123456");
  });
});