import { describe, it, expect } from 'vitest'
import { formatDayCount, formatPercentage } from '@/utils/formatting'

describe('formatting.ts utilities', () => {
  describe('formatDayCount', () => {
    it('returns singular form for 1 day', () => {
      expect(formatDayCount(1)).toBe('1 dag')
    })

    it('returns plural form for 0 days', () => {
      expect(formatDayCount(0)).toBe('0 dagar')
    })

    it('returns plural form for 2 days', () => {
      expect(formatDayCount(2)).toBe('2 dagar')
    })

    it('returns plural form for many days', () => {
      expect(formatDayCount(25)).toBe('25 dagar')
      expect(formatDayCount(365)).toBe('365 dagar')
    })

    it('handles large numbers', () => {
      expect(formatDayCount(1000)).toBe('1000 dagar')
    })
  })

  describe('formatPercentage', () => {
    it('formats simple percentage', () => {
      expect(formatPercentage(1, 4)).toBe('25%')
    })

    it('rounds to nearest integer', () => {
      expect(formatPercentage(1, 3)).toBe('33%') // 33.333...%
      expect(formatPercentage(2, 3)).toBe('67%') // 66.666...%
    })

    it('handles 0% correctly', () => {
      expect(formatPercentage(0, 10)).toBe('0%')
    })

    it('handles 100% correctly', () => {
      expect(formatPercentage(10, 10)).toBe('100%')
    })

    it('returns 0% when denominator is 0', () => {
      expect(formatPercentage(5, 0)).toBe('0%')
    })

    it('handles fractional results with proper rounding', () => {
      expect(formatPercentage(1, 2)).toBe('50%')
      expect(formatPercentage(3, 4)).toBe('75%')
    })

    it('works with large numbers', () => {
      expect(formatPercentage(500, 1000)).toBe('50%')
    })
  })
})