import {
  hasAllowedFileExtension,
  hasDragLeftDropZone,
  handleDropZoneKeyDown,
  isSupportedImageFile,
  prepareFileDrag,
  validateImageFiles,
} from '@/components/upload/drag-drop-utils'

function createDragEvent(
  currentTarget: HTMLElement,
  options: {
    clientX?: number
    clientY?: number
    relatedTarget?: EventTarget | null
    dropEffect?: DataTransfer['dropEffect']
  } = {},
): React.DragEvent<HTMLElement> {
  const dataTransfer = {
    dropEffect: options.dropEffect || 'none',
  }

  return {
    preventDefault: jest.fn(),
    stopPropagation: jest.fn(),
    currentTarget,
    relatedTarget: options.relatedTarget || null,
    clientX: options.clientX ?? 50,
    clientY: options.clientY ?? 50,
    dataTransfer,
  } as unknown as React.DragEvent<HTMLElement>
}

describe('drag-drop-utils', () => {
  test('经过上传区内部子元素时不应判定为离开', () => {
    const dropZone = document.createElement('div')
    const child = document.createElement('button')
    dropZone.appendChild(child)

    const event = createDragEvent(dropZone, { relatedTarget: child })

    expect(hasDragLeftDropZone(event)).toBe(false)
  })

  test('指针越过上传区边界时应判定为离开', () => {
    const dropZone = document.createElement('div')
    Object.defineProperty(dropZone, 'getBoundingClientRect', {
      configurable: true,
      value: () => ({
        left: 0,
        right: 100,
        top: 0,
        bottom: 100,
      }),
    })

    const event = createDragEvent(dropZone, { clientX: 120, clientY: 50 })

    expect(hasDragLeftDropZone(event)).toBe(true)
  })

  test('禁用状态应阻止默认拖放并显示禁止效果', () => {
    const dropZone = document.createElement('div')
    const event = createDragEvent(dropZone)

    prepareFileDrag(event, true)

    expect(event.preventDefault).toHaveBeenCalled()
    expect(event.stopPropagation).toHaveBeenCalled()
    expect(event.dataTransfer.dropEffect).toBe('none')
  })

  test('上传区获得焦点时按 Enter 或空格应打开文件选择器', () => {
    const dropZone = document.createElement('div')
    const openFilePicker = jest.fn()

    handleDropZoneKeyDown({
      key: 'Enter',
      preventDefault: jest.fn(),
      currentTarget: dropZone,
      target: dropZone,
    } as unknown as React.KeyboardEvent<HTMLElement>, openFilePicker)

    expect(openFilePicker).toHaveBeenCalledTimes(1)
  })

  test('上传区内的按钮按键不应再次打开文件选择器', () => {
    const dropZone = document.createElement('div')
    const child = document.createElement('button')
    const openFilePicker = jest.fn()

    handleDropZoneKeyDown({
      key: ' ',
      preventDefault: jest.fn(),
      currentTarget: dropZone,
      target: child,
    } as unknown as React.KeyboardEvent<HTMLElement>, openFilePicker)

    expect(openFilePicker).not.toHaveBeenCalled()
  })

  test('Windows 未提供 MIME 时应按常见图片扩展名识别', () => {
    const file = new File(['image'], 'preview.PNG', { type: '' })

    expect(isSupportedImageFile(file)).toBe(true)
  })

  test('应同时保留有效图片并返回非法及超大文件错误', () => {
    const valid = new File(['image'], 'valid.png', { type: 'image/png' })
    const invalid = new File(['text'], 'invalid.txt', { type: 'text/plain' })
    const oversized = new File([new Uint8Array(11)], 'large.jpg', { type: 'image/jpeg' })

    const result = validateImageFiles([valid, invalid, oversized], { maxBytes: 10 })

    expect(result.acceptedFiles).toEqual([valid])
    expect(result.errors.join('；')).toContain('invalid.txt')
    expect(result.errors.join('；')).toContain('large.jpg')
  })

  test('业务链路可按浏览器处理能力限制图片格式', () => {
    const jpg = new File(['image'], '1.jpg', { type: 'image/jpeg' })
    const heic = new File(['image'], 'phone.heic', { type: 'image/heic' })

    const result = validateImageFiles([jpg, heic], {
      allowedExtensions: ['jpg', 'jpeg', 'png', 'gif', 'webp'],
    })

    expect(result.acceptedFiles).toEqual([jpg])
    expect(result.errors.join('；')).toContain('phone.heic')
    expect(result.errors.join('；')).toContain('JPG、JPEG、PNG、GIF、WEBP')
  })

  test('图片数量限制应考虑已经选择的图片', () => {
    const files = [
      new File(['1'], '1.png', { type: 'image/png' }),
      new File(['2'], '2.png', { type: 'image/png' }),
      new File(['3'], '3.png', { type: 'image/png' }),
    ]

    const result = validateImageFiles(files, { maxCount: 5, existingCount: 4 })

    expect(result.acceptedFiles).toEqual([files[0]])
    expect(result.errors).toContain('最多只能选择 5 张图片，已忽略 2 张')
  })

  test('压缩包扩展名校验应忽略大小写和前导点', () => {
    const file = new File(['zip'], 'model.ZIP', { type: 'application/zip' })

    expect(hasAllowedFileExtension(file, ['.zip', '.rar', '.7z'])).toBe(true)
  })
})