import test from 'node:test';
import assert from 'node:assert/strict';

import { formatDisplayTime, DISPLAY_TIMEZONE } from '../utils/time.js';

test('DISPLAY_TIMEZONE defaults to America/New_York', () => {
  // If DISPLAY_TIMEZONE env is unset in test runner, we expect the default.
  const expected = process.env.DISPLAY_TIMEZONE || 'America/New_York';
  assert.equal(DISPLAY_TIMEZONE, expected);
});

test('formatDisplayTime: converts UTC instant to Eastern wall clock', () => {
  // 2026-07-21 18:13:45 UTC → 2:13:45 PM EDT (DST)
  const d = new Date('2026-07-21T18:13:45.000Z');
  const formatted = formatDisplayTime(d);
  assert.match(formatted, /2:13:45 PM/);
  assert.match(formatted, /EDT/);
});

test('formatDisplayTime: winter offset uses EST', () => {
  // 2026-01-15 18:00:00 UTC → 1:00:00 PM EST
  const d = new Date('2026-01-15T18:00:00.000Z');
  const formatted = formatDisplayTime(d);
  assert.match(formatted, /1:00:00 PM/);
  assert.match(formatted, /EST/);
});