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

const single: PieWidgetData = [
  [
    { name: 'a', value: 1 },
    { name: 'b', value: 2 },
  ],
]
const multi: PieWidgetData = [
  [{ name: 'a', value: 1 }],
  [{ name: 'c', value: 3 }],
]

let csvText = ''

let revokeSpy: ReturnType<typeof vi.spyOn>

beforeEach(() => {
  csvText = ''
  vi.spyOn(URL, 'createObjectURL').mockReturnValue('blob:mock')
  revokeSpy = 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('createPieDownloadConfig', () => {
  it('returns CSV-only items by default', () => {
    const items = createPieDownloadConfig({
      filename: 'p',
      getData: () => single,
    })
    expect(items.map((i) => i.id)).toEqual(['csv'])
  })

  it('prepends PNG when getCaptureEl provided and rejects when null', async () => {
    const items = createPieDownloadConfig({
      filename: 'p',
      getData: () => single,
      getCaptureEl: () => null,
    })
    expect(items.map((i) => i.id)).toEqual(['png', 'csv'])
    await expect(items[0]!.resolve()).rejects.toThrow(/No PNG capture element/)
  })

  it('CSV resolve uses default series_<n> when seriesNames is absent', async () => {
    const items = createPieDownloadConfig({
      filename: 'p',
      getData: () => multi,
    })
    const handle = await items.find((i) => i.id === 'csv')!.resolve()
    expect(handle.filename).toBe('p.csv')
    expect(csvText).toBe('series,name,value\nseries_1,a,1\nseries_2,c,3')
    handle.revoke?.()
    expect(revokeSpy).toHaveBeenCalled()
  })

  it('CSV resolve uses provided seriesNames when supplied', async () => {
    const items = createPieDownloadConfig({
      filename: 'p',
      getData: () => multi,
      seriesNames: ['alpha', 'beta'],
    })
    await items.find((i) => i.id === 'csv')!.resolve()
    expect(csvText).toBe('series,name,value\nalpha,a,1\nbeta,c,3')
  })
})