import { afterEach, describe, expect, it, vi } from "vitest";
import {
  fmtDateRange,
  fmtShortDate,
  pad2,
  rangeDayCount,
  todayIso,
} from "@/domain/work-orders/utils/wizard-date-utils";

describe("fmtShortDate", () => {
  it("formats ISO dates as Mon D", () => {
    expect(fmtShortDate("2026-06-08")).toBe("Jun 8");
  });

  it("returns em dash for invalid input", () => {
    expect(fmtShortDate("")).toBe("—");
    expect(fmtShortDate("nope")).toBe("—");
  });
});

describe("fmtDateRange", () => {
  it("joins start and end with en dash", () => {
    expect(fmtDateRange("2026-06-08", "2026-06-12")).toBe("Jun 8 – Jun 12");
  });
});

describe("rangeDayCount", () => {
  it("counts inclusive days order-independently", () => {
    expect(rangeDayCount("2026-06-08", "2026-06-12")).toBe(5);
    expect(rangeDayCount("2026-06-12", "2026-06-08")).toBe(5);
    expect(rangeDayCount("2026-06-08", "2026-06-08")).toBe(1);
  });
});

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

  it("uses local calendar day, not UTC ISO date, near midnight", () => {
    // 02:30 UTC is still the previous local evening in Americas (UTC−N).
    vi.useFakeTimers();
    vi.setSystemTime(new Date("2026-08-11T02:30:00.000Z"));

    const now = new Date();
    const expectedLocal = `${now.getFullYear()}-${pad2(now.getMonth() + 1)}-${pad2(now.getDate())}`;
    const utcSlice = now.toISOString().slice(0, 10);

    expect(todayIso()).toBe(expectedLocal);
    expect(utcSlice).toBe("2026-08-11");

    if (now.getTimezoneOffset() > 0) {
      expect(todayIso()).toBe("2026-08-10");
      expect(todayIso()).not.toBe(utcSlice);
    }
  });
});