import { describe, expect, it } from 'vitest'
import {
  formatTickLabel,
  generateTicks,
  isoToMinutes,
  minutesToIso,
  minutesToPx,
  pxToMinutes,
} from '@/lib/timetable/time-grid'

describe('time-grid coordinate conversions', () => {
  const gridStart = '2026-07-10T14:00:00.000Z'

  it('isoToMinutes returns 0 at the anchor', () => {
    expect(isoToMinutes(gridStart, gridStart)).toBe(0)
  })

  it('isoToMinutes computes minute offsets', () => {
    expect(isoToMinutes('2026-07-10T15:00:00.000Z', gridStart)).toBe(60)
    expect(isoToMinutes('2026-07-10T14:30:00.000Z', gridStart)).toBe(30)
    expect(isoToMinutes('2026-07-10T13:30:00.000Z', gridStart)).toBe(-30)
  })

  it('roundtrip isoToMinutes ↔ minutesToIso preserves the value', () => {
    const back = minutesToIso(isoToMinutes('2026-07-10T18:45:00.000Z', gridStart), gridStart)

    expect(back).toBe('2026-07-10T18:45:00.000Z')
  })

  it('minutesToPx and pxToMinutes are inverses', () => {
    expect(minutesToPx(30, 2)).toBe(60)
    expect(pxToMinutes(60, 2)).toBe(30)
    expect(pxToMinutes(60, 0)).toBe(0)
  })

  it('formatTickLabel returns nl-NL HH:MM', () => {
    const label = formatTickLabel(0, gridStart)

    expect(label).toMatch(/^\d{2}:\d{2}$/)
  })

  it('generateTicks produces inclusive endpoints', () => {
    const ticks = generateTicks(120, 30)

    expect(ticks).toEqual([0, 30, 60, 90, 120])
  })
})