import { useEffect, useState, useCallback } from "react";
import { createPortal } from "react-dom";
import { getBlockingDivs, type Rect } from "./utils";

interface SpotlightProps {
  /** 是否可见 */
  visible?: boolean;
  /** 目标元素选择器（支持单个或多个） */
  targetSelector?: string | string[] | null;
  /** 额外内边距 */
  padding?: number;
  /** 圆角 */
  borderRadius?: number;
}

const Spotlight: React.FC<SpotlightProps> = ({
  visible = false,
  targetSelector = null,
  padding = 8,
  borderRadius = 16,
}) => {
  const [rects, setRects] = useState<Rect[]>([]);

  const measure = useCallback(() => {
    if (!visible || !targetSelector) {
      setRects([]);
      return;
    }

    const selectors = Array.isArray(targetSelector)
      ? targetSelector
      : [targetSelector];
    const pad = Math.max(0, padding);
    const newRects: Rect[] = [];

    selectors.forEach((selector) => {
      const elements = document.querySelectorAll(selector);
      elements.forEach((el) => {
        const htmlEl = el as HTMLElement;
        const r = htmlEl.getBoundingClientRect();
        // 使用视口坐标（fixed层），不叠加滚动偏移
        newRects.push({
          top: r.top - pad,
          left: r.left - pad,
          width: r.width + pad * 2,
          height: r.height + pad * 2,
        });
      });
    });

    setRects(newRects);
  }, [visible, targetSelector, padding]);

  useEffect(() => {
    // 初始测量
    requestAnimationFrame(measure);
  }, [visible, targetSelector, padding, measure]);

  useEffect(() => {
    const onResize = () => measure();
    const onScroll = () => measure();

    window.addEventListener("resize", onResize);
    window.addEventListener("scroll", onScroll, {
      passive: true,
    } as AddEventListenerOptions);

    // 使用 ResizeObserver 监听目标元素尺寸变化
    const resizeObserver = new ResizeObserver(() => {
      measure();
    });

    // 观察所有目标元素
    if (visible && targetSelector) {
      const selectors = Array.isArray(targetSelector)
        ? targetSelector
        : [targetSelector];

      selectors.forEach((selector) => {
        const elements = document.querySelectorAll(selector);
        elements.forEach((el) => {
          resizeObserver.observe(el);
        });
      });
    }

    // 初始测量（延迟一帧确保 DOM 已渲染）
    requestAnimationFrame(measure);

    return () => {
      window.removeEventListener("resize", onResize);
      window.removeEventListener("scroll", onScroll);
      resizeObserver.disconnect();
    };
  }, [measure, visible, targetSelector]);

  if (!visible || rects.length === 0) return null;

  // 生成唯一ID用于SVG mask
  const maskId = `spotlight-mask-${Math.random().toString(36).substr(2, 9)}`;

  // 计算阻止点击的区域（使用共享工具函数）
  const viewportWidth = typeof window !== "undefined" ? window.innerWidth : 0;
  const viewportHeight = typeof window !== "undefined" ? window.innerHeight : 0;
  const blockingDivs = getBlockingDivs(rects, viewportWidth, viewportHeight);

  return createPortal(
    <div
      style={{
        position: "fixed",
        inset: 0,
        pointerEvents: "none",
        zIndex: 100000,
      }}
    >
      {/* SVG 视觉遮罩 */}
      <svg
        style={{
          position: "absolute",
          inset: 0,
          width: "100%",
          height: "100%",
          pointerEvents: "none",
        }}
      >
        <defs>
          <mask id={maskId}>
            <rect x="0" y="0" width="100%" height="100%" fill="white" />
            {rects.map((rect, index) => (
              <rect
                key={index}
                x={rect.left}
                y={rect.top}
                width={rect.width}
                height={rect.height}
                rx={borderRadius}
                ry={borderRadius}
                fill="black"
              />
            ))}
          </mask>
        </defs>
        <rect
          x="0"
          y="0"
          width="100%"
          height="100%"
          fill="rgba(0, 0, 0, 0.6)"
          mask={`url(#${maskId})`}
        />
      </svg>

      {/* 阻止点击层 - 使用多个div块覆盖非孔区域 */}
      {blockingDivs.map((block, index) => (
        <div
          key={`block-${index}`}
          style={{
            position: "absolute",
            top: `${block.top}px`,
            left:
              typeof block.left === "number" ? `${block.left}px` : block.left,
            width:
              typeof block.width === "number"
                ? `${block.width}px`
                : block.width,
            height:
              typeof block.height === "number"
                ? `${block.height}px`
                : block.height,
            pointerEvents: "auto",
            // backgroundColor: "rgba(255, 0, 0, 0.1)", // 调试用
          }}
        />
      ))}

      {/* 为每个孔添加高亮边框 */}
      {rects.map((rect, index) => (
        <div
          key={`border-${index}`}
          style={{
            position: "absolute",
            top: `${rect.top}px`,
            left: `${rect.left}px`,
            width: `${rect.width}px`,
            height: `${rect.height}px`,
            borderRadius: `${borderRadius}px`,
            border: "2px solid rgba(255, 255, 255, 0.3)",
            pointerEvents: "none",
          }}
        />
      ))}
    </div>,
    document.body
  );
};

export default Spotlight;