dros/src/components/measures/PolygonLengthMeasurementTool.ts

import { Point3, Point2, fromPoint3ToPoint2, decomposeVectorOnAxes } from './mathUtils';
import {
  utilities as csUtils,
  Types as CoreTypes,
  getEnabledElement,
} from '@cornerstonejs/core';

import {
  AnnotationTool,
  utilities,
  Types,
  annotation,
  drawing,
} from '@cornerstonejs/tools';

const {
  drawHandles,
  drawLinkedTextBox,
  drawLine: drawLineSvg,
  drawCircle: drawCircleSvg,
  drawPath: drawPathSvg,
} = drawing;

import {
  calculateMidpoint,
  vectorSubtract,
  vectorAdd,
  vectorScale,
  getAngleBetweenLines,
  degrees,
  getLineIntersection,
  fromPoint2ToPoint3,
} from './mathUtils';
import {
  PublicToolProps,
  ToolProps,
  EventTypes,
  SVGDrawingHelper,
} from '@cornerstonejs/tools/dist/esm/types';

// 十字准星光标
const cursorUrl = 'url("data:image/svg+xml;base64,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") 24 24, crosshair';

// 类型定义
type PolygonLengthMeasurementAnnotation = Types.Annotation & {
  data: {
    handles: {
      points: CoreTypes.Point3[];           // 多边形的所有顶点（世界坐标）
      activeHandleIndex: number | null;     // 当前激活的手柄索引
      textBox?: CoreTypes.Point2;           // 文本框位置
    };
    cachedStats?: {
      [targetId: string]: {
        totalLength: number;                // 总周长（像素）
        totalLengthMm: number;              // 总周长（mm）
        segmentLengths: number[];           // 各边长度（包括闭合边）
      };
    };
  };
};

// 导出的注解数据接口
export interface ExportedAnnotationData {
  points: CoreTypes.Point3[];               // 多边形的所有顶点
  totalLengthMm: number;                    // 总周长（mm）
  metadata: {
    viewPlaneNormal: CoreTypes.Point3;
    viewUp: CoreTypes.Point3;
    FrameOfReferenceUID: string;
    referencedImageId: string;
  };
}

export default class PolygonLengthMeasurementTool extends AnnotationTool {
  static toolName = 'PolygonLengthMeasurementTool';

  editData: {
    annotation: Types.Annotation;
    viewportIdsToRender: string[];
    handleIndex?: number;
    newAnnotation?: boolean;
    hasMoved?: boolean;
    textBoxBeingMoved?: boolean;            // 是否正在拖拽文本框
    textBoxOffset?: CoreTypes.Point2;       // 文本框拖拽偏移量
    movingWholeTool?: boolean;              // 是否移动整个工具
    wholeToolOffset?: CoreTypes.Point2;     // 整体移动偏移量
  } | null = null;

  currentAnnotation: PolygonLengthMeasurementAnnotation | null = null; // 当前正在绘制的注解

  isDrawing: boolean = false;

  drawingElement: HTMLDivElement | null = null; // 当前绘制模式的元素

  drawingCompleted: boolean = false; // 标记绘制是否已完成（双击后反激活）

  // 预览鼠标位置（canvas坐标）
  private previewMousePosition: CoreTypes.Point2 | null = null;

  constructor(
    toolProps: PublicToolProps = {},
    defaultToolProps: ToolProps = {
      supportedInteractionTypes: ['Mouse', 'Touch'],
      configuration: {
        shadow: true,
        preventHandleOutsideImage: false,
      },
    }
  ) {
    super(toolProps, defaultToolProps);
  }

  /**
   * 创建默认注解（用于预设模式）
   */
  static createDefaultAnnotation(
    element: HTMLDivElement,
    viewport: CoreTypes.IStackViewport | CoreTypes.IVolumeViewport,
    points: CoreTypes.Point3[] = []
  ): PolygonLengthMeasurementAnnotation {
    const enabledElement = getEnabledElement(element);
    if (!enabledElement) {
      throw new Error('Element is not enabled');
    }

    const camera = viewport.getCamera();
    const { viewPlaneNormal, viewUp } = camera;
    if (viewPlaneNormal === undefined) {
      throw new Error('viewPlaneNormal is undefined');
    }
    if (viewUp === undefined) {
      throw new Error('viewUp is undefined');
    }

    const annotationData = {
      invalidated: true,
      highlighted: false,
      metadata: {
        viewPlaneNormal: [...viewPlaneNormal] as CoreTypes.Point3,
        viewUp: [...viewUp] as CoreTypes.Point3,
        FrameOfReferenceUID: viewport.getFrameOfReferenceUID(),
        referencedImageId: viewport.getCurrentImageId?.() || '',
        toolName: PolygonLengthMeasurementTool.toolName,
      },
      data: {
        label: '',
        handles: {
          points: points,
          activeHandleIndex: null,
        },
        cachedStats: {},
      },
    } as PolygonLengthMeasurementAnnotation;

    return annotationData;
  }

  /**
   * 导出注解数据
   */
  static exportAnnotationData(
    annotation: PolygonLengthMeasurementAnnotation,
    viewport: CoreTypes.IStackViewport | CoreTypes.IVolumeViewport
  ): ExportedAnnotationData | null {
    const targetId = `imageId:${viewport.getCurrentImageId?.() || ''}`;
    const cachedStats = annotation.data.cachedStats?.[targetId];

    if (!cachedStats) {
      return null;
    }

    return {
      points: [...annotation.data.handles.points],
      totalLengthMm: cachedStats.totalLengthMm,
      metadata: {
        viewPlaneNormal: annotation.metadata?.viewPlaneNormal || [0, 0, 1],
        viewUp: annotation.metadata?.viewUp || [0, 1, 0],
        FrameOfReferenceUID: annotation.metadata?.FrameOfReferenceUID || '',
        referencedImageId: annotation.metadata?.referencedImageId || '',
      },
    };
  }

  /**
   * 添加新注解 - 创建空的闭合多边形注解用于绘制模式
   */
  addNewAnnotation(
    evt: EventTypes.InteractionEventType
  ): PolygonLengthMeasurementAnnotation {
    const eventDetail = evt.detail;
    const { element, currentPoints } = eventDetail;
    const worldPos = currentPoints.world;

    const enabledElement = getEnabledElement(element);
    if (!enabledElement) {
      throw new Error('Element is not enabled');
    }

    const camera = enabledElement.viewport.getCamera();
    const { viewPlaneNormal, viewUp } = camera;
    if (viewPlaneNormal === undefined) {
      throw new Error('viewPlaneNormal is undefined');
    }
    if (viewUp === undefined) {
      throw new Error('viewUp is undefined');
    }

    // 创建新的空注解
    const annotationData = {
      invalidated: true,
      highlighted: false,
      metadata: {
        viewPlaneNormal: [...viewPlaneNormal] as CoreTypes.Point3,
        viewUp: [...viewUp] as CoreTypes.Point3,
        FrameOfReferenceUID: enabledElement.viewport.getFrameOfReferenceUID(),
        referencedImageId: enabledElement.viewport.getCurrentImageId?.() || '',
        toolName: PolygonLengthMeasurementTool.toolName,
      },
      data: {
        label: '',
        handles: {
          points: [worldPos], // 添加第一个点
          activeHandleIndex: 0,
        },
        cachedStats: {},
      },
    } as PolygonLengthMeasurementAnnotation;

    // 设置编辑数据
    this.editData = {
      annotation: annotationData,
      viewportIdsToRender: [enabledElement.viewportId],
      newAnnotation: true,
      hasMoved: false,
    };

    // 激活绘制模式
    this._activateDraw(element);

    return annotationData;
  }

  /**
   * 取消操作
   */
  cancel(element: HTMLDivElement): string {
    if (this.isDrawing) {
      this.isDrawing = false;
      this._deactivateModify(element);

      const enabledElement = getEnabledElement(element);
      if (enabledElement) {
        const { renderingEngine } = enabledElement;
        const viewportIdsToRender =
          utilities.viewportFilters.getViewportIdsWithToolToRender(
            element,
            this.getToolName()
          );

        utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);
      }

      this.editData = null;
      return this.getToolName();
    }

    return '';
  }

  /**
   * 处理 控制点/端点 选中回调
   */
  handleSelectedCallback(
    evt: EventTypes.InteractionEventType,
    annotation: PolygonLengthMeasurementAnnotation
  ): void {
    // 实现控制点选中逻辑
    annotation.isSelected = true;
    annotation.highlighted = true;

    const { element } = evt.detail;
    const viewportIdsToRender =
      utilities.viewportFilters.getViewportIdsWithToolToRender(
        element,
        this.getToolName()
      );

    utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);
  }

  /**
   * 工具选中回调 - 当工具被激活时调用
   */
  toolSelectedCallback(
    evt: EventTypes.InteractionEventType,
    annotation: PolygonLengthMeasurementAnnotation
  ): void {
    const { element } = evt.detail;

    // 如果 annotation 不为空，说明是点击已有的注释，激活修改模式
    if (annotation) {
      console.log('PolygonLengthMeasurementTool selected existing annotation');
      this._activateModify(element);
      return;
    }

    // 工具被激活时，总是进入绘制模式，允许开始新的绘制
    // 完全重置所有绘制状态，确保全新的开始
    this._deactivateDraw(element); // 先清理之前的绘制状态
    this._deactivateModify(element); // 清理修改模式

    this.isDrawing = false; // 重置绘制状态
    this.drawingCompleted = false; // 允许新的点击操作
    this.currentAnnotation = null;
    this.drawingElement = null;

    // 激活绘制模式，等待用户开始绘制
    this._activateDraw(element);

    console.log('PolygonLengthMeasurementTool activated for new drawing');
  }

  /**
   * 激活时被调用
   */
  onSetToolActive(): void {
    // 示例：重置相关状态
    this.isDrawing = false;
    this.editData = null;
    this.drawingCompleted = false;//允许开始新的注解
    // 示例：添加工具特定的初始化
    // this.initializeCustomState();
  }

  /**
   * 检查点是否靠近工具
   */
  isPointNearTool(
    element: HTMLDivElement,
    annotation: PolygonLengthMeasurementAnnotation,
    canvasCoords: CoreTypes.Point2,
    proximity: number
  ): boolean {
    const enabledElement = getEnabledElement(element);
    if (!enabledElement) {
      return false;
    }
    const { viewport } = enabledElement;

    const points = annotation.data.handles.points;

    // 检查是否靠近文本框
    const textBox = annotation.data.handles.textBox;
    if (textBox && Array.isArray(textBox) && textBox.length >= 2) {
      if (this._isPointInTextBox(canvasCoords, textBox as CoreTypes.Point2)) {
        return true;
      }
    }

    // 检查是否靠近任意一个手柄点
    for (let i = 0; i < points.length; i++) {
      const point = points[i];
      const canvasPoint = viewport.worldToCanvas(point);
      const distance = Math.sqrt(
        Math.pow(canvasPoint[0] - canvasCoords[0], 2) +
        Math.pow(canvasPoint[1] - canvasCoords[1], 2)
      );

      if (distance < proximity) {
        return true;
      }
    }

    // 检查是否靠近线段（包括闭合线段）
    if (points.length >= 2) {
      for (let i = 0; i < points.length - 1; i++) {
        const p1Canvas = viewport.worldToCanvas(points[i]);
        const p2Canvas = viewport.worldToCanvas(points[i + 1]);

        const dist = this._distanceToSegment(canvasCoords, p1Canvas, p2Canvas);
        if (dist < proximity) {
          return true;
        }
      }
    }

    // 检查是否靠近闭合线段
    if (points.length >= 3) {
      if (this._isPointNearClosingSegment(canvasCoords, points, viewport, proximity)) {
        return true;
      }
    }

    return false;
  }

  /**
   * 检查是否靠近闭合线段
   */
  private _isPointNearClosingSegment(
    canvasCoords: CoreTypes.Point2,
    points: CoreTypes.Point3[],
    viewport: CoreTypes.IViewport,
    proximity: number
  ): boolean {
    if (points.length < 3) return false;

    const lastPoint = points[points.length - 1];
    const firstPoint = points[0];

    const lastCanvas = viewport.worldToCanvas(lastPoint);
    const firstCanvas = viewport.worldToCanvas(firstPoint);

    const dist = this._distanceToSegment(canvasCoords, lastCanvas, firstCanvas);
    return dist < proximity;
  }

  /**
   * 检查点击是否在文本框内
   */
  private _isPointInTextBox(
    canvasPoint: CoreTypes.Point2,
    textBoxPosition: CoreTypes.Point2,
    textWidth: number = 100,
    textHeight: number = 40
  ): boolean {
    // 确保参数有效
    if (!Array.isArray(canvasPoint) || canvasPoint.length < 2 ||
      !Array.isArray(textBoxPosition) || textBoxPosition.length < 2) {
      return false;
    }

    const [x, y] = canvasPoint;
    const [tx, ty] = textBoxPosition;

    const margin = 10;
    return (
      x >= tx - margin &&
      x <= tx + textWidth + margin &&
      y >= ty - margin &&
      y <= ty + textHeight + margin
    );
  }

  /**
   * 计算点到线段的距离
   */
  private _distanceToSegment(
    point: CoreTypes.Point2,
    lineStart: CoreTypes.Point2,
    lineEnd: CoreTypes.Point2
  ): number {
    const x = point[0];
    const y = point[1];
    const x1 = lineStart[0];
    const y1 = lineStart[1];
    const x2 = lineEnd[0];
    const y2 = lineEnd[1];

    const A = x - x1;
    const B = y - y1;
    const C = x2 - x1;
    const D = y2 - y1;

    const dot = A * C + B * D;
    const lenSq = C * C + D * D;
    let param = -1;

    if (lenSq !== 0) {
      param = dot / lenSq;
    }

    let xx, yy;

    if (param < 0) {
      xx = x1;
      yy = y1;
    } else if (param > 1) {
      xx = x2;
      yy = y2;
    } else {
      xx = x1 + param * C;
      yy = y1 + param * D;
    }

    const dx = x - xx;
    const dy = y - yy;

    return Math.sqrt(dx * dx + dy * dy);
  }

  /**
   * 计算两点间距离（像素）
   */
  private _calculateDistance(point1: CoreTypes.Point3, point2: CoreTypes.Point3, viewport: CoreTypes.IViewport): number {
    const canvas1 = viewport.worldToCanvas(point1);
    const canvas2 = viewport.worldToCanvas(point2);
    return Math.sqrt(
      Math.pow(canvas2[0] - canvas1[0], 2) + Math.pow(canvas2[1] - canvas1[1], 2)
    );
  }

  /**
   * 将像素距离转换为mm
   */
  private _convertPixelsToMm(pixels: number, viewport: CoreTypes.IViewport): number {
    // 这里需要根据DICOM元数据获取像素间距
    // 暂时使用固定值，实际应该从图像元数据中获取
    const pixelSpacing = 0.5; // mm per pixel，示例值
    return pixels * pixelSpacing;
  }

  /**
   * 更新缓存的统计数据（包含闭合边计算）
   */
  _updateCachedStats(
    annotation: PolygonLengthMeasurementAnnotation,
    enabledElement: CoreTypes.IEnabledElement
  ): void {
    const { viewport } = enabledElement;
    const { data } = annotation;
    const points = data.handles.points;

    const targetId = this.getTargetId(viewport);
    if (!targetId) {
      return;
    }

    if (!data.cachedStats) {
      data.cachedStats = {};
    }

    if (!data.cachedStats[targetId]) {
      data.cachedStats[targetId] = {
        totalLength: 0,
        totalLengthMm: 0,
        segmentLengths: []
      };
    }

    const stats = data.cachedStats[targetId];
    stats.segmentLengths = [];

    let totalPixels = 0;

    // 计算所有相邻顶点间的边长
    for (let i = 0; i < points.length - 1; i++) {
      const segmentLength = this._calculateDistance(points[i], points[i + 1], viewport);
      stats.segmentLengths.push(segmentLength);
      totalPixels += segmentLength;
    }

    // 计算闭合边（最后一个点到第一个点）
    if (points.length >= 3) {
      const closingSegmentLength = this._calculateDistance(points[points.length - 1], points[0], viewport);
      stats.segmentLengths.push(closingSegmentLength);
      totalPixels += closingSegmentLength;
    }

    stats.totalLength = totalPixels;
    stats.totalLengthMm = this._convertPixelsToMm(totalPixels, viewport);
  }

  /**
   * 激活绘制模式
   */
  _activateDraw(element: HTMLDivElement): void {
    this.drawingElement = element; // 存储当前绘制模式的元素
    this.isDrawing = true;
    element.addEventListener(
      'CORNERSTONE_TOOLS_MOUSE_CLICK',
      this._mouseClickDrawCallback as EventListener
    );
    element.addEventListener(
      'dblclick',
      this._mouseDoubleClickDrawCallback as EventListener
    );
    // 添加鼠标移动监听用于预览
    element.addEventListener(
      'CORNERSTONE_TOOLS_MOUSE_MOVE',
      this._mouseMoveDrawCallback as EventListener
    );
  }

  /**
   * 取消激活绘制模式
   */
  _deactivateDraw(element?: HTMLDivElement): void {
    const targetElement = element || this.drawingElement;
    if (!targetElement) return;

    this.isDrawing = false;
    targetElement.removeEventListener(
      'CORNERSTONE_TOOLS_MOUSE_CLICK',
      this._mouseClickDrawCallback as EventListener
    );
    targetElement.removeEventListener(
      'dblclick',
      this._mouseDoubleClickDrawCallback as EventListener
    );
    // 清理鼠标移动监听器
    targetElement.removeEventListener(
      'CORNERSTONE_TOOLS_MOUSE_MOVE',
      this._mouseMoveDrawCallback as EventListener
    );
    this.drawingElement = null; // 清理
    this.previewMousePosition = null; // 清理预览位置
  }

  /**
   * 激活修改模式
   */
  _activateModify(element: HTMLDivElement): void {
    element.addEventListener(
      'CORNERSTONE_TOOLS_MOUSE_DOWN',
      this._mouseDownModifyCallback as EventListener
    );
    element.addEventListener(
      'CORNERSTONE_TOOLS_MOUSE_DRAG',
      this._mouseDragModifyCallback as EventListener
    );
    element.addEventListener(
      'CORNERSTONE_TOOLS_MOUSE_UP',
      this._mouseUpModifyCallback as EventListener
    );
    element.addEventListener(
      'CORNERSTONE_TOOLS_MOUSE_MOVE',
      this._mouseMoveModifyCallback as EventListener
    );
    element.addEventListener(
      'keydown',
      this._keyDownCallback as EventListener
    );
  }

  /**
   * 取消激活修改模式
   */
  _deactivateModify(element: HTMLDivElement): void {
    element.removeEventListener(
      'CORNERSTONE_TOOLS_MOUSE_DOWN',
      this._mouseDownModifyCallback as EventListener
    );
    element.removeEventListener(
      'CORNERSTONE_TOOLS_MOUSE_DRAG',
      this._mouseDragModifyCallback as EventListener
    );
    element.removeEventListener(
      'CORNERSTONE_TOOLS_MOUSE_UP',
      this._mouseUpModifyCallback as EventListener
    );
    element.removeEventListener(
      'CORNERSTONE_TOOLS_MOUSE_MOVE',
      this._mouseMoveModifyCallback as EventListener
    );
    element.removeEventListener(
      'keydown',
      this._keyDownCallback as EventListener
    );
  }

  /**
   * 鼠标点击回调 - 用于绘制模式，添加新的点
   */
  _mouseClickDrawCallback = (evt: EventTypes.InteractionEventType): void => {
    if (!this.isDrawing || this.drawingCompleted) {
      return;
    }

    const eventDetail = evt.detail;
    const { element, currentPoints } = eventDetail;
    const worldPos = currentPoints.world;

    const enabledElement = getEnabledElement(element);
    if (!enabledElement) {
      return;
    }

    // 如果还没有当前注解，创建第一个
    if (!this.currentAnnotation) {
      // 创建新的注解
      const camera = enabledElement.viewport.getCamera();
      const { viewPlaneNormal, viewUp } = camera;
      if (viewPlaneNormal === undefined || viewUp === undefined) {
        return;
      }

      this.currentAnnotation = {
        invalidated: true,
        highlighted: false,
        metadata: {
          viewPlaneNormal: [...viewPlaneNormal] as CoreTypes.Point3,
          viewUp: [...viewUp] as CoreTypes.Point3,
          FrameOfReferenceUID: enabledElement.viewport.getFrameOfReferenceUID(),
          referencedImageId: enabledElement.viewport.getCurrentImageId?.() || '',
          toolName: PolygonLengthMeasurementTool.toolName,
        },
        data: {
          label: '',
          handles: {
            points: [worldPos],
            activeHandleIndex: 0,
          },
          cachedStats: {},
        },
      } as PolygonLengthMeasurementAnnotation;

      // 添加到临时状态以便渲染
      annotation.state.addAnnotation(this.currentAnnotation, element);

      console.log('Created first point for polygon');
    } else {
      // 添加新点到现有注解
      this.currentAnnotation.data.handles.points.push(worldPos);
      this.currentAnnotation.data.handles.activeHandleIndex = this.currentAnnotation.data.handles.points.length - 1;

      // 更新统计数据
      this._updateCachedStats(this.currentAnnotation, enabledElement);

      console.log(`Added point ${this.currentAnnotation.data.handles.points.length} to polygon`);
    }

    // 触发渲染更新
    const viewportIdsToRender = utilities.viewportFilters.getViewportIdsWithToolToRender(
      element,
      this.getToolName()
    );
    utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);

    evt.preventDefault();
    evt.stopPropagation();
  };

  /**
   * 鼠标移动回调 - 用于绘制模式，更新预览位置
   */
  _mouseMoveDrawCallback = (evt: EventTypes.InteractionEventType): void => {
    if (!this.isDrawing) {
      return;
    }

    const eventDetail = evt.detail;
    const canvasCoords = eventDetail.currentPoints?.canvas;

    if (canvasCoords) {
      this.previewMousePosition = [...canvasCoords];

      // 触发重新渲染以显示预览线
      const viewportIdsToRender = utilities.viewportFilters.getViewportIdsWithToolToRender(
        eventDetail.element,
        this.getToolName()
      );
      utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);
    }
  };

  /**
   * 鼠标双击回调 - 用于绘制模式，在双击位置添加最后一个点并结束绘制
   */
  _mouseDoubleClickDrawCallback = (evt: EventTypes.InteractionEventType): void => {
    if (!this.isDrawing || !this.currentAnnotation) {
      return;
    }

    const eventDetail = evt.detail;
    const element = eventDetail.element || this.drawingElement;
    const currentPoints = eventDetail.currentPoints;

    if (!element) {
      return;
    }

    // 获取双击位置，支持多种情况
    let worldPos: CoreTypes.Point3 | undefined;

    if (currentPoints?.world) {
      // 优先使用 world 坐标
      worldPos = currentPoints.world;
    } else if (currentPoints?.canvas) {
      // 如果没有 world 坐标但有 canvas 坐标，转换得到 world 坐标
      const enabledElement = getEnabledElement(element);
      if (enabledElement) {
        worldPos = enabledElement.viewport.canvasToWorld(currentPoints.canvas);
      }
    } else {
      // 如果 CornerstoneJS 没有提供坐标，使用原生 DOM 事件坐标
      // __类型转换__：将 `evt` 转换为 `MouseEvent`
      const mouseEvent = evt as unknown as MouseEvent;

      // __获取鼠标坐标__：使用 `clientX`, `clientY`
      const clientX = mouseEvent.clientX;
      const clientY = mouseEvent.clientY;

      // __计算 canvas 坐标__：减去 canvas 的偏移量
      const rect = element.getBoundingClientRect();
      const canvasX = clientX - rect.left;
      const canvasY = clientY - rect.top;

      const canvasPos: CoreTypes.Point2 = [canvasX, canvasY];

      // __转换为 world 坐标__：使用 `viewport.canvasToWorld()`
      const enabledElement = getEnabledElement(element);
      if (enabledElement) {
        worldPos = enabledElement.viewport.canvasToWorld(canvasPos);
      }
    }

    if (!worldPos) {
      // 如果仍然没有位置信息，记录警告但不中断流程
      console.warn('Unable to get double-click position for polygon');
      return;
    }

    // 先在双击位置添加最后一个点
    this.currentAnnotation.data.handles.points.push(worldPos);
    this.currentAnnotation.data.handles.activeHandleIndex = this.currentAnnotation.data.handles.points.length - 1;

    // 更新统计数据
    const enabledElement = getEnabledElement(element);
    if (enabledElement) {
      this._updateCachedStats(this.currentAnnotation, enabledElement);
    }

    // 然后检查点数决定是否结束绘制
    if (this.currentAnnotation.data.handles.points.length >= 3) {
      // 结束绘制模式，激活修改模式
      this._deactivateDraw(element);
      this._activateModify(element);
      this.isDrawing = false;
      this.drawingCompleted = true; // 标记绘制已完成，防止再次添加点
      this.currentAnnotation = null; // 完全清理当前注解引用，确保下次激活时全新的开始

      // 取消所有注解的选中状态，确保下次激活时 annotation 参数为 null
      const annotations = annotation.state.getAnnotations(this.getToolName(), element);
      if (annotations) {
        for (const ann of annotations) {
          const customAnn = ann as PolygonLengthMeasurementAnnotation;
          customAnn.isSelected = false;
          customAnn.highlighted = false;
        }
      }

      console.log('Finished drawing polygon');
    } else {
      // 如果点数仍然少于3个，删除这个注解
      annotation.state.removeAnnotation(this.currentAnnotation.annotationUID!);
      this.currentAnnotation = null;
    }

    // 触发渲染更新
    const viewportIdsToRender = utilities.viewportFilters.getViewportIdsWithToolToRender(
      element,
      this.getToolName()
    );
    utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);

    evt.preventDefault();
    evt.stopPropagation();
  };

  /**
   * 键盘按下回调 - 用于删除功能
   */
  _keyDownCallback = (evt: KeyboardEvent): void => {
    const element = evt.currentTarget as HTMLDivElement;

    if (evt.key === 'Delete' || evt.key === 'Backspace') {
      const enabledElement = getEnabledElement(element);
      if (!enabledElement) {
        return;
      }

      const annotations = annotation.state.getAnnotations(this.getToolName(), element);
      if (!annotations || annotations.length === 0) {
        return;
      }

      const selectedAnnotations = annotations.filter(
        (ann) => (ann as PolygonLengthMeasurementAnnotation).isSelected
      );

      if (selectedAnnotations.length === 0) {
        return;
      }

      for (const ann of selectedAnnotations) {
        annotation.state.removeAnnotation(ann.annotationUID!);
      }

      const viewportIdsToRender =
        utilities.viewportFilters.getViewportIdsWithToolToRender(
          element,
          this.getToolName()
        );

      utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);

      evt.preventDefault();
      evt.stopPropagation();
    }
  };

  /**
   * 鼠标移动回调 - 用于修改模式，处理悬停检测
   */
  _mouseMoveModifyCallback = (evt: EventTypes.InteractionEventType): void => {
    const eventDetail = evt.detail;
    const { element, currentPoints } = eventDetail;

    if (!currentPoints || !currentPoints.canvas) {
      return;
    }
    const canvasCoords = currentPoints.canvas;

    const enabledElement = getEnabledElement(element);
    if (!enabledElement) {
      return;
    }
    const { viewport } = enabledElement;

    const annotations = annotation.state.getAnnotations(this.getToolName(), element);
    if (!annotations || annotations.length === 0) {
      element.style.cursor = 'default';
      return;
    }

    let isHovering = false;

    // 检查是否悬停在文本框上
    for (const ann of annotations) {
      const customAnn = ann as PolygonLengthMeasurementAnnotation;
      const textBoxPosition = customAnn.data.handles.textBox;

      if (textBoxPosition && this._isPointInTextBox(canvasCoords, textBoxPosition)) {
        element.style.cursor = 'pointer';
        customAnn.highlighted = true;
        isHovering = true;
        break;
      }
    }

    // 如果没有悬停在文本框上，检查是否悬停在手柄或线段上
    if (!isHovering) {
      for (const ann of annotations) {
        const customAnn = ann as PolygonLengthMeasurementAnnotation;

        // 检查是否靠近手柄
        const handle = this.getHandleNearImagePoint(element, customAnn, canvasCoords, 6);
        if (handle) {
          element.style.cursor = cursorUrl;
          customAnn.highlighted = true;
          isHovering = true;
          break;
        }

        // 检查是否靠近线段（包括闭合线段）
        if (this.isPointNearTool(element, customAnn, canvasCoords, 10)) {
          element.style.cursor = cursorUrl;
          customAnn.highlighted = true;
          isHovering = true;
          break;
        }
      }
    }

    // 如果没有悬停在任何地方，重置高亮
    if (!isHovering) {
      for (const ann of annotations) {
        const customAnn = ann as PolygonLengthMeasurementAnnotation;
        if (!customAnn.isSelected) {
          customAnn.highlighted = false;
        }
      }
      element.style.cursor = 'default';
    }

    const viewportIdsToRender = utilities.viewportFilters.getViewportIdsWithToolToRender(
      element,
      this.getToolName()
    );
    utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);
  };

  /**
   * 鼠标按下回调 - 用于修改模式
   */
  _mouseDownModifyCallback = (evt: EventTypes.InteractionEventType): void => {
    const eventDetail = evt.detail;
    const { element, currentPoints } = eventDetail;
    const canvasCoords = currentPoints.canvas;

    const enabledElement = getEnabledElement(element);
    if (!enabledElement) {
      return;
    }
    const { viewport } = enabledElement;

    const annotations = annotation.state.getAnnotations(this.getToolName(), element);
    if (!annotations || annotations.length === 0) {
      return;
    }

    // 先检查是否点击在文本框上
    for (const ann of annotations) {
      const customAnn = ann as PolygonLengthMeasurementAnnotation;
      const textBoxPosition = customAnn.data.handles.textBox;

      if (textBoxPosition && this._isPointInTextBox(canvasCoords, textBoxPosition)) {
        const viewportIdsToRender =
          utilities.viewportFilters.getViewportIdsWithToolToRender(
            element,
            this.getToolName()
          );

        const textBoxOffset: CoreTypes.Point2 = [
          canvasCoords[0] - textBoxPosition[0],
          canvasCoords[1] - textBoxPosition[1],
        ];

        this.editData = {
          annotation: customAnn,
          viewportIdsToRender,
          hasMoved: false,
          textBoxBeingMoved: true,
          textBoxOffset: textBoxOffset,
        };

        customAnn.isSelected = true;
        customAnn.highlighted = true;
        utilities.triggerAnnotationRenderForViewportIds(viewportIdsToRender);

        evt.preventDefault();
        evt.stopPropagation();
        return;
      }
    }

    // 如果没有点击文本框，再查找最近的手柄
    for (const ann of annotations) {
      const customAnn = ann as PolygonLengthMeasurementAnnotation;
      const handle = this.getHandleNearImagePoint(
        element,
        customAnn,
        canvasCoords,
        6
      );

      if (handle) {
        const viewportIdsToRender =
          utilities.viewportFilters.getViewportIdsWithToolToRender(
            element,
            this.getToolName()
          );

        this.editData = {
          annotation: customAnn,
          viewportIdsToRender,
          handleIndex: customAnn.data.handles.activeHandleIndex || 0,
          hasMoved: false,
        };

        customAnn.isSelected = true;
        customAnn.highlighted = true;

        utilities.triggerAnnotationRenderForViewportIds(
          viewportIdsToRender
        );

        evt.preventDefault();
        evt.stopPropagation();
        return;
      }
    }

    // 如果没有找到手柄，检查是否点击在工具的其他位置（线段上，包括闭合线段）
    for (const ann of annotations) {
      const customAnn = ann as PolygonLengthMeasurementAnnotation;
      if (this.isPointNearTool(element, customAnn, canvasCoords, 10)) {
        const viewportIdsToRender =
          utilities.viewportFilters.getViewportIdsWithToolToRender(
            element,
            this.getToolName()
          );

        const points = customAnn.data.handles.points;
        if (points.length >= 2) {
          const midPoint = calculateMidpoint(points[0], points[1]);
          const midCanvas = viewport.worldToCanvas(midPoint);
          const wholeToolOffset: CoreTypes.Point2 = [
            canvasCoords[0] - midCanvas[0],
            canvasCoords[1] - midCanvas[1],
          ];

          this.editData = {
            annotation: customAnn,
            viewportIdsToRender,
            hasMoved: false,
            movingWholeTool: true,
            wholeToolOffset: wholeToolOffset,
          };

          customAnn.isSelected = true;
          customAnn.highlighted = true;

          utilities.triggerAnnotationRenderForViewportIds(
            viewportIdsToRender
          );

          evt.preventDefault();
          evt.stopPropagation();
          return;
        }
      }
    }

    // 如果没有点击在工具上，取消所有工具的选中状态
    for (const ann of annotations) {
      const customAnn = ann as PolygonLengthMeasurementAnnotation;
      customAnn.isSelected = false;
      customAnn.highlighted = false;
    }

    const viewportIdsToRender =
      utilities.viewportFilters.getViewportIdsWithToolToRender(
        element,
        this.getToolName()
      );

    utilities.triggerAnnotationRenderForViewportIds(
      viewportIdsToRender
    );
  };

  /**
   * 鼠标拖拽回调 - 用于修改模式
   */
  _mouseDragModifyCallback = (evt: EventTypes.InteractionEventType): void => {
    if (!this.editData) {
      return;
    }

    const eventDetail = evt.detail;
    const { currentPoints } = eventDetail;
    const canvasCoords = currentPoints.canvas;

    const enabledElement = getEnabledElement(eventDetail.element);
    if (!enabledElement) {
      return;
    }

    const { annotation: ann, viewportIdsToRender, textBoxBeingMoved, movingWholeTool } = this.editData;
    const customAnn = ann as PolygonLengthMeasurementAnnotation;
    const { data } = customAnn;

    // 如果正在拖拽文本框
    if (textBoxBeingMoved && this.editData.textBoxOffset) {
      const newTextBoxPosition: CoreTypes.Point2 = [
        canvasCoords[0] - this.editData.textBoxOffset[0],
        canvasCoords[1] - this.editData.textBoxOffset[1],
      ];

      data.handles.textBox = newTextBoxPosition;
      this.editData.hasMoved = true;

      utilities.triggerAnnotationRenderForViewportIds(
        viewportIdsToRender
      );

      evt.preventDefault();
      evt.stopPropagation();
      return;
    }

    // 如果正在移动整个工具
    if (movingWholeTool && this.editData.wholeToolOffset) {
      const newMidCanvas: CoreTypes.Point2 = [
        canvasCoords[0] - this.editData.wholeToolOffset[0],
        canvasCoords[1] - this.editData.wholeToolOffset[1],
      ];
      const newMidWorld = enabledElement.viewport.canvasToWorld(newMidCanvas);

      const points = data.handles.points;
      if (points.length >= 2) {
        const oldMid = calculateMidpoint(points[0], points[1]);
        const oldMidCanvas = enabledElement.viewport.worldToCanvas(oldMid);
        const offset = vectorSubtract(newMidWorld, oldMid);
        const canvasOffset: CoreTypes.Point2 = [
          newMidCanvas[0] - oldMidCanvas[0],
          newMidCanvas[1] - oldMidCanvas[1],
        ];

        // 移动所有点
        for (let i = 0; i < points.length; i++) {
          points[i] = vectorAdd(points[i], offset);
        }

        // 移动文本框位置 (使用canvas坐标偏移)
        if (data.handles.textBox && Array.isArray(data.handles.textBox) && data.handles.textBox.length >= 2) {
          data.handles.textBox[0] += canvasOffset[0];
          data.handles.textBox[1] += canvasOffset[1];
        }

        this._updateCachedStats(customAnn, enabledElement);
        this.editData.hasMoved = true;

        utilities.triggerAnnotationRenderForViewportIds(
          viewportIdsToRender
        );

        evt.preventDefault();
        evt.stopPropagation();
        return;
      }
    }

    // 否则处理手柄拖拽
    const worldPos = currentPoints.world;
    const activeHandleIndex = data.handles.activeHandleIndex;

    if (activeHandleIndex !== null && activeHandleIndex >= 0 && activeHandleIndex < data.handles.points.length) {
      data.handles.points[activeHandleIndex] = worldPos;
      this._updateCachedStats(customAnn, enabledElement);
      this.editData.hasMoved = true;

      utilities.triggerAnnotationRenderForViewportIds(
        viewportIdsToRender
      );

      evt.preventDefault();
      evt.stopPropagation();
    }
  };

  /**
   * 鼠标释放回调 - 用于修改模式
   */
  _mouseUpModifyCallback = (evt: EventTypes.InteractionEventType): void => {
    if (!this.editData) {
      return;
    }

    const { annotation: ann, hasMoved, movingWholeTool } = this.editData;
    const customAnn = ann as PolygonLengthMeasurementAnnotation;

    customAnn.data.handles.activeHandleIndex = null;

    if (!hasMoved && movingWholeTool) {
      customAnn.isSelected = true;
      customAnn.highlighted = true;
    }

    const eventDetail = evt.detail;
    const { element } = eventDetail;

    const viewportIdsToRender =
      utilities.viewportFilters.getViewportIdsWithToolToRender(
        element,
        this.getToolName()
      );

    utilities.triggerAnnotationRenderForViewportIds(
      viewportIdsToRender
    );

    this.editData = null;

    evt.preventDefault();
    evt.stopPropagation();
  };

  /**
   * 获取靠近图像点的手柄
   */
  getHandleNearImagePoint(
    element: HTMLDivElement,
    annotation: PolygonLengthMeasurementAnnotation,
    canvasCoords: CoreTypes.Point2,
    proximity: number
  ): Types.ToolHandle | undefined {
    const enabledElement = getEnabledElement(element);
    if (!enabledElement) {
      return undefined;
    }
    const { viewport } = enabledElement;

    const points = annotation.data.handles.points;
    const handleProximity = Math.max(proximity, 15);

    for (let i = 0; i < points.length; i++) {
      const point = points[i];
      const canvasPoint = viewport.worldToCanvas(point);
      const distance = Math.sqrt(
        Math.pow(canvasPoint[0] - canvasCoords[0], 2) +
        Math.pow(canvasPoint[1] - canvasCoords[1], 2)
      );

      if (distance < handleProximity) {
        annotation.data.handles.activeHandleIndex = i;
        return {
          worldPosition: point,
        } as Types.ToolHandle;
      }
    }

    annotation.data.handles.activeHandleIndex = null;
    return undefined;
  }

  /**
   * 渲染注解
   */
  renderAnnotation = (
    enabledElement: CoreTypes.IEnabledElement,
    svgDrawingHelper: SVGDrawingHelper
  ): boolean => {
    let renderStatus = false;
    const { viewport } = enabledElement;
    const { element } = viewport;

    let annotations = annotation.state.getAnnotations(this.getToolName(), element);

    if (!annotations?.length) {
      return renderStatus;
    }

    for (let i = 0; i < annotations.length; i++) {
      const annotation = annotations[i] as PolygonLengthMeasurementAnnotation;
      const { annotationUID, data } = annotation;
      const points = data.handles.points;

      // 如果点数为0，跳过
      if (points.length === 0) {
        continue;
      }

      const targetId = this.getTargetId(viewport);
      const cachedStats = targetId ? data.cachedStats?.[targetId] : undefined;

      // 转换所有点为 canvas 坐标
      const canvasPoints = points.map((p) => viewport.worldToCanvas(p));

      const lineOptions = {
        color: 'rgb(0, 255, 0)',
        width: 2,
      };
      // 绘制多边形线段（需要至少2个点）
      if (annotationUID && points.length >= 2) {
        for (let j = 0; j < canvasPoints.length - 1; j++) {
          const lineUID = `${annotationUID}-line-${j}`;
          drawLineSvg(
            svgDrawingHelper,
            annotationUID,
            lineUID,
            canvasPoints[j],
            canvasPoints[j + 1],
            lineOptions
          );
        }

        // 绘制闭合线段（从最后一个点到第一个点）
        if (points.length >= 3) {
          const closingLineUID = `${annotationUID}-closing-line`;
          drawLineSvg(
            svgDrawingHelper,
            annotationUID,
            closingLineUID,
            canvasPoints[canvasPoints.length - 1],
            canvasPoints[0],
            lineOptions
          );
        }
      }

      // 绘制周长文本（需要至少3个点且有统计数据）
      if (cachedStats?.totalLengthMm !== undefined && annotationUID && points.length >= 3) {
        const textLines = [`周长: ${cachedStats.totalLengthMm.toFixed(2)} mm`];
        const textUID = `${annotationUID}-length-text`;
        const textBoxPosition: CoreTypes.Point2 =
          (data.handles.textBox &&
            Array.isArray(data.handles.textBox) &&
            data.handles.textBox.length >= 2)
            ? data.handles.textBox
            : [
              canvasPoints[0][0] + 10,
              canvasPoints[0][1] - 10,
            ];

        console.log('textBoxPosition:', textBoxPosition);
        // 保存文本框位置到注解数据中
        data.handles.textBox = textBoxPosition;

        drawLinkedTextBox(
          svgDrawingHelper,
          annotationUID,
          textUID,
          textLines,
          textBoxPosition,
          [canvasPoints[0] as CoreTypes.Point2],
          {},
          {
            color: 'rgb(0, 255, 0)',
          }
        );
      }

      // 绘制手柄点（至少有1个点就绘制）
      if (annotationUID && points.length >= 1) {
        const handleGroupUID = '0';
        const isSelected = annotation.isSelected || annotation.highlighted;
        const handleRadius = isSelected ? 12 : 8;

        drawHandles(
          svgDrawingHelper,
          annotationUID,
          handleGroupUID,
          canvasPoints,
          {
            color: 'rgb(255, 255, 255)',
            handleRadius: handleRadius,
          }
        );
      }

      renderStatus = true;
    }

    // 绘制预览线（只在绘制模式且有鼠标位置时）
    if (this.isDrawing && this.previewMousePosition && this.currentAnnotation &&
      this.currentAnnotation.data.handles.points.length > 0) {

      const points = this.currentAnnotation.data.handles.points;
      const lastPoint = points[points.length - 1];
      const lastCanvasPoint = enabledElement.viewport.worldToCanvas(lastPoint);

      // 总是绘制从最后一个点到鼠标位置的预览线（用于显示即将添加的下一个线段）
      const previewLineUID = 'preview-line-to-mouse';
      drawLineSvg(
        svgDrawingHelper,
        'preview',  // 使用固定UID
        previewLineUID,
        lastCanvasPoint,
        this.previewMousePosition,
        {
          color: 'rgba(0, 255, 0, 0.7)',  // 半透明绿色
          width: 2,
          lineDash: [8, 4],  // 虚线样式：8px实线，4px空白
        }
      );

      // 当至少有两个点时，额外绘制从鼠标位置到起始点的预览线（用于预览闭合形状）
      if (points.length >= 2) {
        const firstPoint = points[0];
        const firstCanvasPoint = enabledElement.viewport.worldToCanvas(firstPoint);

        const closingPreviewLineUID = 'preview-line-closing';
        drawLineSvg(
          svgDrawingHelper,
          'preview',  // 使用固定UID
          closingPreviewLineUID,
          this.previewMousePosition,
          firstCanvasPoint,
          {
            color: 'rgba(255, 255, 0, 0.7)',  // 半透明黄色，用于区分
            width: 2,
            lineDash: [8, 4],  // 虚线样式：8px实线，4px空白
          }
        );
      }
    }

    return renderStatus;
  };
}