import { expect, test, describe, beforeAll, afterAll } from "bun:test";
import { cn, getTodayInTimezone, getNow, getNowInMilliseconds, t2d, d2t, d2s, d2sDate, d2n, isSameDate } from './utils'
import { DateTime } from "luxon";

describe('cn utility', () => {
  test('should merge class names correctly', () => {
    expect(cn('foo', 'bar')).toBe('foo bar')
    expect(cn('foo', { bar: true })).toBe('foo bar')
    expect(cn('foo', { bar: false })).toBe('foo')
    expect(cn('foo', ['bar', 'baz'])).toBe('foo bar baz')
  })
})

describe('datetime utilities', () => {
  let fixedNow: DateTime;

  beforeAll(() => {
    // Fix the current time to 2024-01-01T00:00:00Z
    fixedNow = DateTime.fromISO('2024-01-01T00:00:00Z');
    DateTime.now = () => fixedNow;
  })

  describe('getTodayInTimezone', () => {
    test('should return today in YYYY-MM-DD format for timezone', () => {
      expect(getTodayInTimezone('America/New_York')).toBe('2023-12-31')
      expect(getTodayInTimezone('Asia/Tokyo')).toBe('2024-01-01')
    })
  })

  describe('getNow', () => {
    test('should return current datetime in specified timezone', () => {
      const nyNow = getNow({ timezone: 'America/New_York' });
      expect(nyNow.zoneName).toBe('America/New_York')
      expect(nyNow.year).toBe(2023)
      expect(nyNow.month).toBe(12)
      expect(nyNow.day).toBe(31)
    })

    test('should default to UTC', () => {
      const utcNow = getNow({});
      expect(utcNow.zoneName).toBe('UTC')
    })
  })

  describe('getNowInMilliseconds', () => {
    test('should return current time in milliseconds', () => {
      expect(getNowInMilliseconds()).toBe('1704067200000')
    })
  })

  describe('timestamp conversion utilities', () => {
    const testTimestamp = '2024-01-01T00:00:00.000Z';
    const testDateTime = DateTime.fromISO(testTimestamp);

    test('t2d should convert ISO timestamp to DateTime', () => {
      const result = t2d({ timestamp: testTimestamp, timezone: 'utc' });
      // Normalize both timestamps to handle different UTC offset formats (Z vs +00:00)
      expect(DateTime.fromISO(result.toISO()!).toMillis())
        .toBe(DateTime.fromISO(testTimestamp).toMillis())
    })

    test('d2t should convert DateTime to ISO timestamp', () => {
      const result = d2t({ dateTime: testDateTime });
      expect(result).toBe(testTimestamp)
    })

    test('d2s should format DateTime for display', () => {
      const result = d2s({ dateTime: testDateTime, timezone: 'utc' });
      expect(result).toBeString()

      const customFormat = d2s({ dateTime: testDateTime, format: 'yyyy-MM-dd', timezone: 'utc' });
      expect(customFormat).toBe('2024-01-01')
    })

    test('d2sDate should format DateTime as date string', () => {
      const result = d2sDate({ dateTime: testDateTime });
      expect(result).toBeString()
    })

    test('d2n should convert DateTime to milliseconds string', () => {
      const result = d2n({ dateTime: testDateTime });
      expect(result).toBe('1704067200000')
    })
  })

  describe('isSameDate', () => {
    test('should compare dates correctly', () => {
      const date1 = DateTime.fromISO('2024-01-01T12:00:00Z');
      const date2 = DateTime.fromISO('2024-01-01T15:00:00Z');
      const date3 = DateTime.fromISO('2024-01-02T12:00:00Z');

      expect(isSameDate(date1, date2)).toBe(true)
      expect(isSameDate(date1, date3)).toBe(false)
    })
  })
})