import { describe, it, expect } from 'vitest'
import { toRelativeHistogramData } from './transforms'

describe('toRelativeHistogramData', () => {
  it('rewrites each bin count as its share of the series total in 0-100', () => {
    expect(toRelativeHistogramData([[10, 20, 70]])).toEqual([[10, 20, 70]])
  })

  it('handles non-100 totals (5/20 = 25%)', () => {
    expect(toRelativeHistogramData([[5, 15]])).toEqual([[25, 75]])
  })

  it('handles multiple series independently', () => {
    expect(
      toRelativeHistogramData([
        [3, 7],
        [50, 50],
      ]),
    ).toEqual([
      [30, 70],
      [50, 50],
    ])
  })

  it('returns a series unchanged when its total is zero', () => {
    expect(toRelativeHistogramData([[0, 0, 0]])).toEqual([[0, 0, 0]])
  })

  it('produces signed share-of-magnitude percentages for mixed-sign series', () => {
    // Denominator is 1000 + 990 = 1990
    const out = toRelativeHistogramData([[1000, -990]]) as number[][]
    expect(out[0]?.[0]).toBeCloseTo(50.25126, 4)
    expect(out[0]?.[1]).toBeCloseTo(-49.74874, 4)
  })

  it('returns the input unchanged when shape does not match number[][]', () => {
    expect(toRelativeHistogramData(null)).toBe(null)
    expect(toRelativeHistogramData('not an array')).toBe('not an array')
    // Series that isn't a flat number array (e.g. named-value or tuple)
    // is returned as-is — keeps the transform safe to attach to a
    // widget whose shape changes through other actions.
    expect(toRelativeHistogramData([[{ name: 'a', value: 10 }]])).toEqual([
      [{ name: 'a', value: 10 }],
    ])
  })
})