import { describe, expect, it } from 'vitest'
import { settleWithConcurrency } from './useMapThemeSelectionInsights'

describe('settleWithConcurrency', () => {
  it('keeps result order and never exceeds the acquisition limit', async () => {
    let active = 0
    let maximumActive = 0

    const results = await settleWithConcurrency([0, 1, 2, 3, 4, 5], 3, async (value) => {
      active += 1
      maximumActive = Math.max(maximumActive, active)
      await new Promise((resolve) => setTimeout(resolve, (5 - value) * 2))
      active -= 1
      return value * 10
    })

    expect(maximumActive).toBe(3)
    expect(results).toEqual([
      { status: 'fulfilled', value: 0 },
      { status: 'fulfilled', value: 10 },
      { status: 'fulfilled', value: 20 },
      { status: 'fulfilled', value: 30 },
      { status: 'fulfilled', value: 40 },
      { status: 'fulfilled', value: 50 },
    ])
  })

  it('retains individual acquisition failures without stopping the queue', async () => {
    const results = await settleWithConcurrency(['ok', 'fail', 'later'], 2, async (value) => {
      if (value === 'fail') {
        throw new Error('provider unavailable')
      }
      return value.toUpperCase()
    })

    expect(results[0]).toEqual({ status: 'fulfilled', value: 'OK' })
    expect(results[1].status).toBe('rejected')
    expect(results[2]).toEqual({ status: 'fulfilled', value: 'LATER' })
  })
})