import { test } from 'node:test'
import assert from 'node:assert/strict'
import { MAX_RATE_DOMAIN, computeRateDomain } from './rateDomain.js'

test('computeRateDomain: covers the draws and the frequentist bounds', () => {
  const domain = computeRateDomain([[0, 1, 2, 3, 4]], [6])
  assert.ok(domain.niceMax >= 6, `niceMax ${domain.niceMax} should cover the AC upper bound`)
  assert.equal(domain.clipped, false)
})

test('computeRateDomain: ticks start at zero and end at niceMax', () => {
  const domain = computeRateDomain([[0, 1, 2]], [4])
  assert.equal(domain.ticks[0], 0)
  assert.equal(domain.ticks[domain.ticks.length - 1], domain.niceMax)
})

test('computeRateDomain: one extreme draw does not blow out the axis', () => {
  // A single 400-per-1,000 draw in a 53-student cell would otherwise squash
  // every other group into the leftmost pixel.
  const bulk = new Array(500).fill(2)
  bulk[0] = 400
  const domain = computeRateDomain([bulk], [3])
  assert.ok(domain.niceMax < 10, `niceMax was ${domain.niceMax}`)
})

test('computeRateDomain: caps the domain and reports the clip', () => {
  // The cap keeps a tiny-denominator group from flattening every other curve,
  // but the caller has to be able to say so on screen rather than silently
  // cropping data off the right edge.
  const wide = new Array(500).fill(0).map((_, i) => (i < 490 ? 60 : 0))
  const domain = computeRateDomain([wide], [80])
  assert.equal(domain.niceMax, MAX_RATE_DOMAIN)
  assert.equal(domain.clipped, true)
})

test('computeRateDomain: never returns a zero-width domain', () => {
  const domain = computeRateDomain([[0, 0, 0]], [0])
  assert.ok(domain.niceMax > 0)
  assert.equal(domain.clipped, false)
})

test('computeRateDomain: handles no data at all', () => {
  const domain = computeRateDomain([], [])
  assert.ok(domain.niceMax > 0)
  assert.ok(domain.ticks.length > 1)
})

test('computeRateDomain: ignores empty rate arrays', () => {
  const domain = computeRateDomain([[], [1, 2, 3]], [])
  assert.ok(domain.niceMax > 0 && domain.niceMax < MAX_RATE_DOMAIN)
})