import { describe, it, expect, beforeEach, vi } from 'vitest'
import { createMarkdownDownloadConfig } from './download'

let mdText = ''

let revokeSpy: ReturnType<typeof vi.spyOn>

beforeEach(() => {
  mdText = ''
  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) {
        mdText = typeof parts[0] === 'string' ? parts[0] : ''
        super(parts, opts)
      }
    },
  )
})

describe('createMarkdownDownloadConfig', () => {
  it('returns a single .md item by default', () => {
    const items = createMarkdownDownloadConfig({
      filename: 'doc',
      getData: () => ({ content: '# hi' }),
    })
    expect(items.map((i) => i.id)).toEqual(['md'])
  })

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

  it('md resolve writes the source verbatim with a .md filename', async () => {
    const items = createMarkdownDownloadConfig({
      filename: 'doc',
      getData: () => ({ content: '# title\n\nbody' }),
    })
    const handle = await items.find((i) => i.id === 'md')!.resolve()
    expect(handle.url).toBe('blob:mock')
    expect(handle.filename).toBe('doc.md')
    expect(mdText).toBe('# title\n\nbody')
    handle.revoke?.()
    expect(revokeSpy).toHaveBeenCalledWith('blob:mock')
  })

  it('md resolve falls back to empty content when data.content is missing', async () => {
    const items = createMarkdownDownloadConfig({
      filename: 'doc',
      // missing content field — exercise the `?? ''` branch
      getData: () => ({}) as { content: string },
    })
    await items.find((i) => i.id === 'md')!.resolve()
    expect(mdText).toBe('')
  })
})