import { describe, it, expect, vi, afterEach } from 'vitest'
import { mount } from '@vue/test-utils'
import ImageInput from '../ImageInput.vue'

function makeFile(name, type, size = 100) {
  return new File(['x'.repeat(size)], name, { type })
}

function setFiles(input, files) {
  Object.defineProperty(input.element, 'files', { value: files, configurable: true })
}

describe('ImageInput', () => {
  afterEach(() => vi.unstubAllGlobals())

  it('renders the drop zone and file input', () => {
    const wrapper = mount(ImageInput)
    expect(wrapper.find('label').exists()).toBe(true)
    expect(wrapper.find('input[type="file"]').exists()).toBe(true)
  })

  it('shows error for non-image file', async () => {
    const wrapper = mount(ImageInput)
    const input = wrapper.find('input[type="file"]')
    setFiles(input, [makeFile('doc.pdf', 'application/pdf')])
    await input.trigger('change')
    expect(wrapper.text()).toContain('Only image files are supported.')
  })

  it('shows error for file exceeding 20 MB', async () => {
    const wrapper = mount(ImageInput)
    const input = wrapper.find('input[type="file"]')
    setFiles(input, [makeFile('big.png', 'image/png', 21 * 1024 * 1024)])
    await input.trigger('change')
    expect(wrapper.text()).toContain('20 MB')
  })

  it('emits image-ready with correct shape on valid image', async () => {
    class MockFileReader {
      readAsDataURL() {
        this.onload({ target: { result: 'data:image/png;base64,abc' } })
      }
    }
    vi.stubGlobal('FileReader', MockFileReader)

    const wrapper = mount(ImageInput)
    const input = wrapper.find('input[type="file"]')
    setFiles(input, [makeFile('photo.png', 'image/png')])
    await input.trigger('change')

    const emitted = wrapper.emitted('image-ready')
    expect(emitted).toBeTruthy()
    expect(emitted[0][0]).toMatchObject({
      dataUrl: 'data:image/png;base64,abc',
      mimeType: 'image/png',
      filename: 'photo.png',
    })
  })

  it('attaches paste listener on mount and removes it on unmount', () => {
    const add = vi.spyOn(window, 'addEventListener')
    const remove = vi.spyOn(window, 'removeEventListener')

    const wrapper = mount(ImageInput)
    expect(add).toHaveBeenCalledWith('paste', expect.any(Function))

    wrapper.unmount()
    expect(remove).toHaveBeenCalledWith('paste', expect.any(Function))
  })
})