WeFlow/src/components/ImagePreview.tsx

import React, { useState, useRef, useCallback, useEffect } from 'react'
import { X } from 'lucide-react'
import { createPortal } from 'react-dom'
import './ImagePreview.scss'

interface ImagePreviewProps {
  src: string
  onClose: () => void
}

export const ImagePreview: React.FC<ImagePreviewProps> = ({ src, onClose }) => {
  const [scale, setScale] = useState(1)
  const [position, setPosition] = useState({ x: 0, y: 0 })
  const [isDragging, setIsDragging] = useState(false)
  const dragStart = useRef({ x: 0, y: 0 })
  const positionStart = useRef({ x: 0, y: 0 })
  const containerRef = useRef<HTMLDivElement>(null)

  // 滚轮缩放
  const handleWheel = useCallback((e: React.WheelEvent) => {
    e.preventDefault()
    const delta = e.deltaY > 0 ? 0.9 : 1.1
    setScale(prev => Math.min(Math.max(prev * delta, 0.5), 5))
  }, [])

  // 开始拖动
  const handleMouseDown = useCallback((e: React.MouseEvent) => {
    if (scale <= 1) return
    e.preventDefault()
    setIsDragging(true)
    dragStart.current = { x: e.clientX, y: e.clientY }
    positionStart.current = { ...position }
  }, [scale, position])

  // 拖动中
  const handleMouseMove = useCallback((e: React.MouseEvent) => {
    if (!isDragging) return
    const dx = e.clientX - dragStart.current.x
    const dy = e.clientY - dragStart.current.y
    setPosition({
      x: positionStart.current.x + dx,
      y: positionStart.current.y + dy
    })
  }, [isDragging])

  // 结束拖动
  const handleMouseUp = useCallback(() => {
    setIsDragging(false)
  }, [])

  // 双击重置
  const handleDoubleClick = useCallback(() => {
    setScale(1)
    setPosition({ x: 0, y: 0 })
  }, [])

  // 点击背景关闭
  const handleOverlayClick = useCallback((e: React.MouseEvent) => {
    if (e.target === containerRef.current) {
      onClose()
    }
  }, [onClose])

  // ESC 关闭
  useEffect(() => {
    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key === 'Escape') onClose()
    }
    window.addEventListener('keydown', handleKeyDown)
    return () => window.removeEventListener('keydown', handleKeyDown)
  }, [onClose])

  return createPortal(
    <div
      ref={containerRef}
      className="image-preview-overlay"
      onClick={handleOverlayClick}
      onMouseMove={handleMouseMove}
      onMouseUp={handleMouseUp}
      onMouseLeave={handleMouseUp}
    >
      <img
        src={src}
        alt="图片预览"
        className={`preview-image ${isDragging ? 'dragging' : ''}`}
        style={{
          transform: `translate(${position.x}px, ${position.y}px) scale(${scale})`,
          cursor: scale > 1 ? (isDragging ? 'grabbing' : 'grab') : 'default'
        }}
        onWheel={handleWheel}
        onMouseDown={handleMouseDown}
        onDoubleClick={handleDoubleClick}
        draggable={false}
      />
      <button className="image-preview-close" onClick={onClose}>
        <X size={20} />
      </button>
    </div>,
    document.body
  )
}