import assert from 'node:assert/strict';
import { test } from 'node:test';
import {
  toLocalDate,
  toLocalTime,
  parseLocalDateTime,
  formatFriendlyDateTime,
} from './datetimeInput';

// All helpers work in the LOCAL timezone. We construct Dates with the local
// component constructor so the assertions hold regardless of where tests run.

test('toLocalDate: zero-pads month and day', () => {
  assert.equal(toLocalDate(new Date(2026, 0, 5, 9, 3)), '2026-01-05');
  assert.equal(toLocalDate(new Date(2026, 11, 25, 0, 0)), '2026-12-25');
});

test('toLocalTime: zero-pads hours and minutes (24h)', () => {
  assert.equal(toLocalTime(new Date(2026, 0, 5, 9, 3)), '09:03');
  assert.equal(toLocalTime(new Date(2026, 0, 5, 23, 59)), '23:59');
  assert.equal(toLocalTime(new Date(2026, 0, 5, 0, 0)), '00:00');
});

test('toLocalDate/toLocalTime round-trip through parseLocalDateTime', () => {
  const d = new Date(2026, 5, 15, 14, 30, 0, 0);
  const parsed = parseLocalDateTime(toLocalDate(d), toLocalTime(d));
  assert.ok(parsed);
  assert.equal(parsed.getTime(), d.getTime());
});

test('parseLocalDateTime: returns null for missing parts', () => {
  assert.equal(parseLocalDateTime('', '09:00'), null);
  assert.equal(parseLocalDateTime('2026-01-05', ''), null);
  assert.equal(parseLocalDateTime('', ''), null);
});

test('parseLocalDateTime: returns null for an invalid combination', () => {
  assert.equal(parseLocalDateTime('not-a-date', '09:00'), null);
  assert.equal(parseLocalDateTime('2026-13-40', '09:00'), null);
});

test('parseLocalDateTime: valid input yields the local wall-clock time', () => {
  const parsed = parseLocalDateTime('2026-01-05', '09:03');
  assert.ok(parsed);
  assert.equal(parsed.getFullYear(), 2026);
  assert.equal(parsed.getMonth(), 0);
  assert.equal(parsed.getDate(), 5);
  assert.equal(parsed.getHours(), 9);
  assert.equal(parsed.getMinutes(), 3);
});

test('formatFriendlyDateTime: uses Today/Tomorrow/date prefixes', () => {
  const now = new Date(2026, 0, 5, 10, 0).getTime();
  const laterToday = new Date(2026, 0, 5, 15, 30).getTime();
  const tomorrow = new Date(2026, 0, 6, 9, 0).getTime();
  const nextWeek = new Date(2026, 0, 12, 9, 0).getTime();

  assert.ok(formatFriendlyDateTime(laterToday, now).startsWith('Today at '));
  assert.ok(formatFriendlyDateTime(tomorrow, now).startsWith('Tomorrow at '));
  const other = formatFriendlyDateTime(nextWeek, now);
  assert.ok(!other.startsWith('Today'));
  assert.ok(!other.startsWith('Tomorrow'));
  assert.ok(other.includes(' at '));
});

test('formatFriendlyDateTime: Tomorrow rolls over month/year boundaries', () => {
  const nye = new Date(2026, 11, 31, 23, 0).getTime();
  const jan1 = new Date(2027, 0, 1, 9, 0).getTime();
  assert.ok(formatFriendlyDateTime(jan1, nye).startsWith('Tomorrow at '));
});
