/**
 * 图片预览模态框组件
 * 
 * 支持点击图片放大查看，带缩放、拖拽功能
 * 支持直接渲染 React 组件（用于显示 canvas 内容）
 */

import React, { useState, useRef, useEffect } from 'react';
import { X, RotateCw, Download } from 'lucide-react';

interface ImagePreviewModalProps {
  imageUrl?: string;
  isOpen: boolean;
  onClose: () => void;
  title?: string;
  downloadFileName?: string;
  renderContent?: () => React.ReactNode; // 自定义渲染内容
}

const ImagePreviewModal: React.FC<ImagePreviewModalProps> = ({
  imageUrl,
  isOpen,
  onClose,
  title = '图片预览',
  downloadFileName = 'image.png',
  renderContent
}) => {
  const [scale, setScale] = useState(1);
  const [rotation, setRotation] = useState(0);
  const [position, setPosition] = useState({ x: 0, y: 0 });
  const [isDragging, setIsDragging] = useState(false);
  const [dragStart, setDragStart] = useState({ x: 0, y: 0 });
  const imageRef = useRef<HTMLDivElement>(null);

  // 重置状态
  useEffect(() => {
    if (isOpen) {
      setScale(1);
      setRotation(0);
      setPosition({ x: 0, y: 0 });
    }
  }, [isOpen]);

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

  // 阻止背景滚动
  useEffect(() => {
    if (isOpen) {
      document.body.style.overflow = 'hidden';
    } else {
      document.body.style.overflow = '';
    }
    return () => {
      document.body.style.overflow = '';
    };
  }, [isOpen]);

  if (!isOpen) return null;

  // 缩放控制
  const handleZoomIn = () => setScale(prev => Math.min(prev + 0.25, 5));
  const handleZoomOut = () => setScale(prev => Math.max(prev - 0.25, 0.25));
  const handleResetZoom = () => {
    setScale(1);
    setPosition({ x: 0, y: 0 });
  };

  // 旋转控制
  const handleRotate = () => setRotation(prev => (prev + 90) % 360);

  // 下载图片
  const handleDownload = () => {
    if (!imageUrl) return;
    
    const link = document.createElement('a');
    link.href = imageUrl;
    link.download = downloadFileName;
    link.target = '_blank';
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
  };

  // 鼠标拖拽
  const handleMouseDown = (e: React.MouseEvent) => {
    if (scale > 1) {
      setIsDragging(true);
      setDragStart({
        x: e.clientX - position.x,
        y: e.clientY - position.y
      });
    }
  };

  const handleMouseMove = (e: React.MouseEvent) => {
    if (isDragging && scale > 1) {
      setPosition({
        x: e.clientX - dragStart.x,
        y: e.clientY - dragStart.y
      });
    }
  };

  const handleMouseUp = () => {
    setIsDragging(false);
  };

  // 鼠标滚轮缩放
  const handleWheel = (e: React.WheelEvent) => {
    e.preventDefault();
    if (e.deltaY < 0) {
      handleZoomIn();
    } else {
      handleZoomOut();
    }
  };

  return (
    <div
      className="fixed inset-0 z-50 flex items-center justify-center bg-black/90"
      onClick={onClose}
    >
      {/* 工具栏 */}
      <div className="absolute top-0 left-0 right-0 bg-black/50 backdrop-blur-sm p-4 flex items-center justify-between z-10">
        <h3 className="text-white font-medium">{title}</h3>
        
        <div className="flex items-center space-x-2">
          {/* 旋转 */}
          <button
            onClick={(e) => {
              e.stopPropagation();
              handleRotate();
            }}
            className="p-2 text-white hover:bg-white/20 rounded-lg transition-colors"
            title="旋转"
          >
            <RotateCw className="w-5 h-5" />
          </button>

          {/* 下载 */}
          {imageUrl && (
            <button
              onClick={(e) => {
                e.stopPropagation();
                handleDownload();
              }}
              className="p-2 text-white hover:bg-white/20 rounded-lg transition-colors"
              title="下载"
            >
              <Download className="w-5 h-5" />
            </button>
          )}

          {/* 关闭 */}
          <button
            onClick={(e) => {
              e.stopPropagation();
              onClose();
            }}
            className="p-2 text-white hover:bg-white/20 rounded-lg transition-colors"
            title="关闭 (ESC)"
          >
            <X className="w-5 h-5" />
          </button>
        </div>
      </div>

      {/* 图片容器 */}
      <div
        ref={imageRef}
        className="relative w-full h-full flex items-center justify-center overflow-hidden"
        onClick={(e) => e.stopPropagation()}
        onMouseDown={handleMouseDown}
        onMouseMove={handleMouseMove}
        onMouseUp={handleMouseUp}
        onMouseLeave={handleMouseUp}
        onWheel={handleWheel}
        style={{
          cursor: scale > 1 ? (isDragging ? 'grabbing' : 'grab') : 'default'
        }}
      >
        {renderContent ? (
          // 自定义内容渲染（用于 canvas 等）
          <div
            style={{
              transform: `translate(${position.x}px, ${position.y}px) scale(${scale}) rotate(${rotation}deg)`,
              transition: isDragging ? 'none' : 'transform 0.2s ease-out',
              maxHeight: '90vh',
              maxWidth: '90vw'
            }}
          >
            {renderContent()}
          </div>
        ) : imageUrl ? (
          // 普通图片渲染
          <img
            src={imageUrl}
            alt="预览"
            className="max-w-none select-none"
            draggable={false}
            style={{
              transform: `translate(${position.x}px, ${position.y}px) scale(${scale}) rotate(${rotation}deg)`,
              transition: isDragging ? 'none' : 'transform 0.2s ease-out',
              maxHeight: '90vh',
              maxWidth: '90vw'
            }}
          />
        ) : null}
      </div>
    </div>
  );
};

export default ImagePreviewModal;