import { describe, expect, it } from 'vitest'
import { groupPulse, lastMonths, type PulseEvent } from '../src/pulse'

describe('lastMonths', () => {
  it('returns 12 months ending at the given date, oldest first', () => {
    const m = lastMonths('2026-07-17')
    expect(m).toHaveLength(12)
    expect(m[0]).toBe('2025-08')
    expect(m[11]).toBe('2026-07')
  })
  it('crosses year boundaries correctly', () => {
    expect(lastMonths('2026-01-05', 3)).toEqual(['2025-11', '2025-12', '2026-01'])
  })
})

describe('groupPulse', () => {
  const ev = (lane: number, date: string, id: string): PulseEvent =>
    ({ id, lane, date, label: id, tone: 'accent' })
  const months = lastMonths('2026-07-17')

  it('buckets events by lane and month', () => {
    const g = groupPulse([ev(0, '2026-07-01', 'a'), ev(0, '2026-07-30', 'b'), ev(2, '2025-08-09', 'c')], months)
    expect(g.get('0:11')?.map((e) => e.id)).toEqual(['a', 'b'])
    expect(g.get('2:0')?.map((e) => e.id)).toEqual(['c'])
  })
  it('drops events outside the window', () => {
    const g = groupPulse([ev(1, '2024-01-01', 'old'), ev(1, '2027-01-01', 'future')], months)
    expect(g.size).toBe(0)
  })
})