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

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('createTimeseriesDownloadConfig', () => {
  it('CSV-only by default', () => {
    expect(
      createTimeseriesDownloadConfig({
        filename: 't',
        getData: () => [[{ name: '2024-01-01', value: 1 }]],
      }).map((i) => i.id),
    ).toEqual(['csv'])
  })

  it('prepends PNG when getCaptureEl is provided', () => {
    const items = createTimeseriesDownloadConfig({
      filename: 't',
      getData: () => [],
      getCaptureEl: () => document.createElement('div'),
    })
    expect(items.map((i) => i.id)).toEqual(['png', 'csv'])
  })

  it('emits ISO strings for Date keys and aligns rows across series', async () => {
    const d1 = new Date('2024-01-01T00:00:00.000Z')
    const d2 = new Date('2024-01-02T00:00:00.000Z')
    const data: TimeseriesWidgetData = [
      [
        { name: d1, value: 1 },
        { name: d2, value: 2 },
      ],
      [{ name: d2, value: 20 }],
    ]
    const items = createTimeseriesDownloadConfig({
      filename: 't',
      getData: () => data,
    })
    const handle = await items.find((i) => i.id === 'csv')!.resolve()
    expect(handle.filename).toBe('t.csv')
    expect(csvText).toBe(
      'time,series_1,series_2\n' +
        '2024-01-01T00:00:00.000Z,1,\n' +
        '2024-01-02T00:00:00.000Z,2,20',
    )
  })

  it('emits ISO strings for numeric ms-since-epoch keys', async () => {
    const ts = Date.UTC(2024, 0, 1)
    const data: TimeseriesWidgetData = [[{ name: ts, value: 7 }]]
    const items = createTimeseriesDownloadConfig({
      filename: 't',
      getData: () => data,
    })
    await items.find((i) => i.id === 'csv')!.resolve()
    expect(csvText).toContain('2024-01-01T00:00:00.000Z,7')
  })

  it('passes string time keys through verbatim', async () => {
    const data: TimeseriesWidgetData = [[{ name: '2024-Q1', value: 1 }]]
    const items = createTimeseriesDownloadConfig({
      filename: 't',
      getData: () => data,
    })
    await items.find((i) => i.id === 'csv')!.resolve()
    expect(csvText).toContain('2024-Q1,1')
  })

  it('uses supplied seriesNames in the header', async () => {
    const items = createTimeseriesDownloadConfig({
      filename: 't',
      getData: () => [[{ name: '2024', value: 1 }]],
      seriesNames: ['revenue'],
    })
    await items.find((i) => i.id === 'csv')!.resolve()
    expect(csvText.split('\n')[0]).toBe('time,revenue')
  })
})