import { describe, it, expect, beforeEach, vi } from 'vitest'
import { createScatterplotDownloadConfig } from './download'
import type { ScatterplotWidgetData } from './types'

const data: ScatterplotWidgetData = [
  [
    [1, 10],
    [2, 20],
  ],
  [[3, 30]],
]

let csvText = ''

beforeEach(() => {
  csvText = ''
  vi.spyOn(URL, 'createObjectURL').mockReturnValue('blob:mock')
  vi.spyOn(URL, 'revokeObjectURL').mockImplementation(() => undefined)
  const RealBlob = global.Blob
  vi.stubGlobal(
    'Blob',
    class extends RealBlob {
      constructor(parts: BlobPart[], opts?: BlobPropertyBag) {
        csvText = typeof parts[0] === 'string' ? parts[0] : ''
        super(parts, opts)
      }
    },
  )
})

describe('createScatterplotDownloadConfig', () => {
  it('CSV-only by default', () => {
    expect(
      createScatterplotDownloadConfig({
        filename: 's',
        getData: () => data,
      }).map((i) => i.id),
    ).toEqual(['csv'])
  })

  it('prepends PNG when getCaptureEl is provided', () => {
    const items = createScatterplotDownloadConfig({
      filename: 's',
      getData: () => data,
      getCaptureEl: () => document.createElement('div'),
    })
    expect(items.map((i) => i.id)).toEqual(['png', 'csv'])
  })

  it('CSV resolve writes series × point rows with default names', async () => {
    const items = createScatterplotDownloadConfig({
      filename: 's',
      getData: () => data,
    })
    const handle = await items.find((i) => i.id === 'csv')!.resolve()
    expect(handle.filename).toBe('s.csv')
    expect(csvText).toBe(
      'series,x,y\nseries_1,1,10\nseries_1,2,20\nseries_2,3,30',
    )
  })

  it('CSV honours supplied seriesNames', async () => {
    const items = createScatterplotDownloadConfig({
      filename: 's',
      getData: () => data,
      seriesNames: ['A', 'B'],
    })
    await items.find((i) => i.id === 'csv')!.resolve()
    expect(csvText.split('\n')[1]).toBe('A,1,10')
  })
})