import { describe, expect, it } from "vitest";
import {
  daysFromToday,
  dueLabel,
  dueTone,
  nextFriday,
  untilMidnight,
} from "../src/lib/due";

describe("due helpers read the day they are given", () => {
  it("labels against the given today, not the wall clock", () => {
    expect(dueLabel("2026-08-23", "2026-08-23")).toBe("today");
    expect(dueLabel("2026-08-24", "2026-08-23")).toBe("tomorrow");
    expect(dueLabel("2026-08-22", "2026-08-23")).toBe("yesterday");
    expect(dueLabel("2026-08-23", "2026-08-30")).toBe("Aug 23");
  });

  it("tones against the given today", () => {
    expect(dueTone("2026-08-22", "2026-08-23")).toBe("overdue");
    expect(dueTone("2026-08-24", "2026-08-23")).toBe("soon");
    expect(dueTone("2026-09-24", "2026-08-23")).toBe("normal");
    expect(daysFromToday("2026-09-02", "2026-08-23")).toBe(10);
  });

  it("finds the friday after the given day, never the same one", () => {
    expect(nextFriday("2026-08-23")).toBe("2026-08-28");
    expect(nextFriday("2026-08-28")).toBe("2026-09-04");
  });

  it("arms the midnight timer for the coming midnight", () => {
    const late = new Date(2026, 7, 23, 23, 59, 0);
    expect(untilMidnight(late)).toBeGreaterThan(60_000);
    expect(untilMidnight(late)).toBeLessThan(62_000);
    const early = new Date(2026, 7, 23, 0, 0, 1);
    expect(untilMidnight(early)).toBeGreaterThan(23 * 3_600_000);
  });
});