import { describe, expect, it } from 'bun:test'
import { flagEmoji, formatAgo, formatBytes } from './format.ts'

describe('流量数字', () => {
  it('零和不满 1KB 的按字节显示，不带小数', () => {
    expect(formatBytes(0)).toBe('0 B')
    expect(formatBytes(512)).toBe('512 B')
    expect(formatBytes(1023)).toBe('1023 B')
  })

  it('1024 的边界正好换档', () => {
    expect(formatBytes(1024)).toBe('1 KB')
    expect(formatBytes(1024 * 1024)).toBe('1 MB')
  })

  it('不满 100 保留一位小数，够 100 取整', () => {
    expect(formatBytes(23.4 * 1024 * 1024)).toBe('23.4 MB')
    expect(formatBytes(234.7 * 1024 * 1024)).toBe('235 MB')
  })

  it('超大数停在 TB 档', () => {
    expect(formatBytes(5 * 1024 ** 4)).toBe('5 TB')
    expect(formatBytes(5000 * 1024 ** 4)).toBe('5000 TB')
  })

  it('脏输入不炸', () => {
    expect(formatBytes(-1)).toBe('0 B')
    expect(formatBytes(Number.NaN)).toBe('0 B')
  })
})

describe('旗帜 emoji', () => {
  it('两位国家代码转成区域指示符对，大小写都认', () => {
    expect(flagEmoji('JP')).toBe('🇯🇵')
    expect(flagEmoji('us')).toBe('🇺🇸')
  })

  it('不像国家代码的输入原样返回', () => {
    expect(flagEmoji('')).toBe('')
    expect(flagEmoji('USA')).toBe('USA')
    expect(flagEmoji('1X')).toBe('1X')
  })
})

describe('相对时间', () => {
  const now = new Date('2026-08-12T12:00:00Z')
  const ago = (ms: number) => new Date(now.getTime() - ms)

  it('一分钟内是刚刚，之后按分、时、天换档', () => {
    expect(formatAgo(ago(30_000), now)).toBe('刚刚')
    expect(formatAgo(ago(21 * 60_000), now)).toBe('21 分钟前')
    expect(formatAgo(ago(3 * 3600_000), now)).toBe('3 小时前')
    expect(formatAgo(ago(5 * 86400_000), now)).toBe('5 天前')
  })

  it('超过 30 天给日期', () => {
    expect(formatAgo(new Date('2026-05-01T00:00:00'), now)).toBe('2026-05-01')
  })

  it('未来的时间当成刚刚，不出负数', () => {
    expect(formatAgo(ago(-60_000), now)).toBe('刚刚')
  })
})