// 栅格化帮助
import { fabric } from "fabric-with-all";

/**
 * 创建栅格化图像 - 重构版本
 * 采用复制原对象+裁剪路径的方式，保持原始质量和准确位置
 * @returns {Promise<fabric.Image|fabric.Group|string>} 栅格化后的图像对象或DataURL
 * @private
 */
export const createRasterizedImage = async ({
  canvas, // 画布对象   必填
  fabricObjects = [], // 要栅格化的对象列表  -  按顺序  必填
  maskObject = null, // 用于裁剪的对象  -  可选
  clipPath = null, // 裁剪路径对象 - 可选，优先级高于maskObject
  trimWhitespace = true, // 是否裁剪空白区域
  trimPadding = 0, // 裁剪边距
  quality = 1.0, // 图像质量
  format = "png", // 图像格式
  scaleFactor = 1, //  高清倍数  - 默认是画布的高清倍数
  isReturenDataURL = false, // 是否返回DataURL而不是fabric.Image对象
  preserveOriginalQuality = true, // 是否保持原始质量（新增）
} = {}) => {
  try {
    console.log(`📊 开始栅格化 ${fabricObjects.length} 个对象`);

    // 确保有对象需要栅格化
    if (fabricObjects.length === 0) {
      console.warn("⚠️ 没有对象需要栅格化，返回空图像");
      return null;
    }

    // 处理裁剪对象，优先使用clipPath
    const clippingObject = clipPath || maskObject;
    // 如果保持原始质量且有裁剪对象，使用新的裁剪方法
    if (preserveOriginalQuality && clippingObject) {
      return await createClippedObjects({
        canvas,
        fabricObjects,
        clippingObject,
        isReturenDataURL,
      });
    }

    // 如果只是简单复制而不需要裁剪，直接克隆对象
    if (!clippingObject) {
      return await createSimpleClone({
        canvas,
        fabricObjects,
        isReturenDataURL,
        quality,
        format,
      });
    }

    // 兼容原有的离屏渲染方法（作为备选方案）
    return await createLegacyRasterization({
      canvas,
      fabricObjects,
      clippingObject,
      scaleFactor,
      quality,
      format,
      isReturenDataURL,
    });
  } catch (error) {
    console.error("创建栅格化图像失败:", error);
    throw new Error(`栅格化失败: ${error.message}`);
  }
};

/**
 * 创建带裁剪的对象 - 新方法
 * 直接复制原对象并应用裁剪路径，保持原始质量
 */
const createClippedObjects = async ({
  canvas,
  fabricObjects,
  clippingObject,
  isReturenDataURL,
}) => {
  try {
    console.log("🎯 使用新的裁剪方法创建对象");

    // 获取选区边界框
    const selectionBounds = clippingObject.getBoundingRect(true);
    console.log("📐 选区边界框:", selectionBounds);
    // 方法1：如果只需要返回DataURL，使用画布裁剪方法
    if (isReturenDataURL) {
      return await createClippedDataURLByCanvas({
        canvas,
        fabricObjects,
        clippingObject,
        selectionBounds,
      });
    }

    // 方法2：如果需要返回fabric对象，先生成DataURL再转换为fabric对象
    const clippedDataURL = await createClippedDataURLByCanvas({
      canvas,
      fabricObjects,
      clippingObject,
      selectionBounds,
    });

    // 将DataURL转换为fabric.Image对象
    const fabricImage = await createFabricImageFromDataURL(clippedDataURL);

    // 使用fabric原生方法恢复到选区的原始大小和位置
    fabricImage.scaleToWidth(selectionBounds.width);
    fabricImage.scaleToHeight(selectionBounds.height);

    // 设置到选区的原始位置（中心点）
    fabricImage.set({
      left: selectionBounds.left + selectionBounds.width / 2,
      top: selectionBounds.top + selectionBounds.height / 2,
      originX: "center",
      originY: "center",
      selectable: true,
      evented: true,
      hasControls: true,
      hasBorders: true,
      custom: {
        type: "clipped",
        clippedAt: new Date().toISOString(),
        hasClipping: true,
        preservedQuality: true,
        originalBounds: selectionBounds,
        restoredToOriginalSize: true,
      },
    });

    // 更新坐标
    fabricImage.setCoords();

    console.log("✅ 返回裁剪后的fabric对象，已恢复到原始大小和位置");
    return fabricImage;
  } catch (error) {
    console.error("创建裁剪对象失败:", error);
    throw error;
  }
};

/**
 * 通过画布裁剪生成DataURL
 * 裁剪掉选区以外的内容，保持和选区大小一致
 */
const createClippedDataURLByCanvas = async ({
  canvas,
  fabricObjects,
  clippingObject,
  selectionBounds,
}) => {
  try {
    console.log("🖼️ 使用画布裁剪方法生成DataURL");

    // 创建临时画布，尺寸与选区完全一致
    const tempCanvas = new fabric.StaticCanvas();

    // 使用高分辨率以保证质量
    const pixelRatio = window.devicePixelRatio || 1;
    const qualityMultiplier = Math.max(2, pixelRatio);

    const canvasWidth = Math.ceil(selectionBounds.width * qualityMultiplier);
    const canvasHeight = Math.ceil(selectionBounds.height * qualityMultiplier);

    tempCanvas.setDimensions({
      width: canvasWidth,
      height: canvasHeight,
    });

    console.log(
      `📏 临时画布尺寸: ${canvasWidth}x${canvasHeight} (质量倍数: ${qualityMultiplier})`
    );

    // 克隆并添加所有需要裁剪的对象
    for (const obj of fabricObjects) {
      const clonedObj = await cloneObjectAsync(obj);

      // 调整对象位置：将选区左上角作为新的原点(0,0)
      // 同时应用质量倍数缩放
      clonedObj.set({
        left: (clonedObj.left - selectionBounds.left) * qualityMultiplier,
        top: (clonedObj.top - selectionBounds.top) * qualityMultiplier,
        scaleX: (clonedObj.scaleX || 1) * qualityMultiplier,
        scaleY: (clonedObj.scaleY || 1) * qualityMultiplier,
      });

      tempCanvas.add(clonedObj);
    }

    // 克隆裁剪路径并调整位置
    const clipPath = await cloneObjectAsync(clippingObject);
    clipPath.set({
      left: (clipPath.left - selectionBounds.left) * qualityMultiplier,
      top: (clipPath.top - selectionBounds.top) * qualityMultiplier,
      scaleX: (clipPath.scaleX || 1) * qualityMultiplier,
      scaleY: (clipPath.scaleY || 1) * qualityMultiplier,
      fill: "transparent",
      stroke: "",
      strokeWidth: 0,
      absolutePositioned: true,
    });

    // 为整个画布设置裁剪路径
    tempCanvas.clipPath = clipPath;

    // 渲染画布
    tempCanvas.renderAll();

    // 生成高质量DataURL
    const dataURL = tempCanvas.toDataURL({
      format: "png",
      quality: 1.0,
      multiplier: 1, // 已经通过尺寸处理了缩放
    });

    // 清理临时画布
    tempCanvas.dispose();

    console.log("✅ 画布裁剪完成，生成DataURL");
    return dataURL;
  } catch (error) {
    console.error("画布裁剪失败:", error);
    throw error;
  }
};

/**
 * 创建简单克隆对象
 * 当不需要裁剪时，直接克隆原对象
 */
const createSimpleClone = async ({
  canvas,
  fabricObjects,
  isReturenDataURL,
  quality,
  format,
}) => {
  try {
    console.log("📋 创建简单克隆对象");

    const clonedObjects = [];

    // 克隆所有对象
    for (const obj of fabricObjects) {
      const clonedObj = await cloneObjectAsync(obj);

      clonedObj.set({
        selectable: true,
        evented: true,
        hasControls: true,
        hasBorders: true,
        custom: {
          ...clonedObj.custom,
          type: "cloned",
          clonedAt: new Date().toISOString(),
          preservedQuality: true,
        },
      });

      clonedObjects.push(clonedObj);
    }

    // 如果需要返回DataURL，需要渲染
    if (isReturenDataURL) {
      return await renderObjectsToDataURL(clonedObjects, quality, format);
    }

    // 如果只有一个对象，直接返回
    if (clonedObjects.length === 1) {
      return clonedObjects[0];
    }

    // 创建组合
    const group = new fabric.Group(clonedObjects, {
      selectable: true,
      evented: true,
      hasControls: true,
      hasBorders: true,
      custom: {
        type: "clonedGroup",
        clonedAt: new Date().toISOString(),
        objectCount: clonedObjects.length,
        preservedQuality: true,
      },
    });

    return group;
  } catch (error) {
    console.error("创建简单克隆失败:", error);
    throw error;
  }
};

/**
 * 将对象渲染为DataURL
 */
const renderObjectsToDataURL = async (objects, quality, format) => {
  try {
    // 计算对象边界框
    const bounds = calculateBounds(objects);
    if (!bounds.absoluteBounds) {
      throw new Error("无法计算对象边界框");
    }

    // 创建临时画布用于渲染
    const tempCanvas = new fabric.StaticCanvas();
    const { absoluteBounds } = bounds;

    tempCanvas.setDimensions({
      width: Math.ceil(absoluteBounds.width),
      height: Math.ceil(absoluteBounds.height),
    });

    // 调整对象位置并添加到临时画布
    for (const obj of objects) {
      const tempObj = await cloneObjectAsync(obj);
      tempObj.set({
        left: tempObj.left - absoluteBounds.left,
        top: tempObj.top - absoluteBounds.top,
      });
      tempCanvas.add(tempObj);
    }

    // 渲染并获取DataURL
    tempCanvas.renderAll();
    const dataURL = tempCanvas.toDataURL({
      format,
      quality,
    });

    // 清理临时画布
    tempCanvas.dispose();

    return dataURL;
  } catch (error) {
    console.error("渲染对象为DataURL失败:", error);
    throw error;
  }
};

/**
 * 渲染裁剪后的对象为DataURL
 * 专门处理带有裁剪路径的对象渲染（备用方法）
 */
const renderClippedObjectsToDataURL = async (clippedObjects) => {
  try {
    console.log("🖼️ 渲染裁剪对象为DataURL");

    // 计算所有裁剪对象的总边界框
    let totalBounds = null;

    for (const obj of clippedObjects) {
      const objBounds = obj.getBoundingRect(true, true);

      if (!totalBounds) {
        totalBounds = { ...objBounds };
      } else {
        const right = Math.max(
          totalBounds.left + totalBounds.width,
          objBounds.left + objBounds.width
        );
        const bottom = Math.max(
          totalBounds.top + totalBounds.height,
          objBounds.top + objBounds.height
        );

        totalBounds.left = Math.min(totalBounds.left, objBounds.left);
        totalBounds.top = Math.min(totalBounds.top, objBounds.top);
        totalBounds.width = right - totalBounds.left;
        totalBounds.height = bottom - totalBounds.top;
      }
    }

    if (!totalBounds) {
      throw new Error("无法计算对象边界框");
    }

    // 创建临时画布，使用高分辨率
    const tempCanvas = new fabric.StaticCanvas();
    const pixelRatio = window.devicePixelRatio || 1;
    const scaleFactor = Math.max(2, pixelRatio);

    const canvasWidth = Math.ceil(totalBounds.width * scaleFactor);
    const canvasHeight = Math.ceil(totalBounds.height * scaleFactor);

    tempCanvas.setDimensions({
      width: canvasWidth,
      height: canvasHeight,
    });

    // 调整对象位置并添加到临时画布
    for (const obj of clippedObjects) {
      const tempObj = await cloneObjectAsync(obj);

      // 调整位置到画布坐标系
      tempObj.set({
        left: (tempObj.left - totalBounds.left) * scaleFactor,
        top: (tempObj.top - totalBounds.top) * scaleFactor,
        scaleX: (tempObj.scaleX || 1) * scaleFactor,
        scaleY: (tempObj.scaleY || 1) * scaleFactor,
      });

      // 如果有裁剪路径，也需要调整裁剪路径
      if (tempObj.clipPath) {
        tempObj.clipPath.set({
          scaleX: (tempObj.clipPath.scaleX || 1) * scaleFactor,
          scaleY: (tempObj.clipPath.scaleY || 1) * scaleFactor,
        });
      }

      tempCanvas.add(tempObj);
    }

    // 渲染画布
    tempCanvas.renderAll();

    // 获取DataURL
    const dataURL = tempCanvas.toDataURL({
      format: "png",
      quality: 1.0,
      multiplier: 1, // 已经通过尺寸处理了缩放
    });

    // 清理临时画布
    tempCanvas.dispose();

    console.log("✅ 裁剪对象渲染完成");
    return dataURL;
  } catch (error) {
    console.error("渲染裁剪对象失败:", error);
    throw error;
  }
};

/**
 * 兼容的离屏渲染方法（原有逻辑，作为备选）
 */
const createLegacyRasterization = async ({
  canvas,
  fabricObjects,
  clippingObject,
  scaleFactor,
  quality,
  format,
  isReturenDataURL,
}) => {
  console.log("⚠️ 使用兼容的离屏渲染方法");

  // 这里保留原有的离屏渲染逻辑作为备选方案
  const currentZoom = canvas.getZoom?.() || 1;
  scaleFactor = Math.max(
    scaleFactor || canvas?.getRetinaScaling?.(),
    currentZoom
  );
  scaleFactor = Math.min(scaleFactor, 3);

  const { absoluteBounds, relativeBounds } = calculateBounds(fabricObjects);

  return await createOffscreenRasterization({
    canvas,
    objects: fabricObjects,
    absoluteBounds,
    relativeBounds,
    scaleFactor,
    clippingObject,
    trimWhitespace: true,
    trimPadding: 1,
    quality,
    format,
    currentZoom,
    isReturenDataURL,
  });
};

/**
 * 计算对象的绝对边界框和相对边界框
 * @param {Array} fabricObjects fabric对象数组
 * @returns {Object} 包含绝对边界框和相对边界框的对象
 */
const calculateBounds = (fabricObjects) => {
  if (fabricObjects.length === 0) {
    console.warn("⚠️ 没有对象，无法计算边界框");
    return { absoluteBounds: null, relativeBounds: null };
  }

  let absoluteBounds = null;
  let relativeBounds = null;

  fabricObjects.forEach((obj, index) => {
    // 获取相对边界框（考虑画布缩放和平移）
    const relativeBound = obj.getBoundingRect();
    // 获取绝对边界框（原始大小和位置）
    const absoluteBound = obj.getBoundingRect(true, true);

    console.log(`对象 ${obj.id || index} 边界框比较:`, {
      relative: relativeBound,
      absolute: absoluteBound,
      scaleX: obj.scaleX,
      scaleY: obj.scaleY,
    });

    // 计算绝对边界框的累积范围
    if (!absoluteBounds) {
      absoluteBounds = { ...absoluteBound };
    } else {
      const right = Math.max(
        absoluteBounds.left + absoluteBounds.width,
        absoluteBound.left + absoluteBound.width
      );
      const bottom = Math.max(
        absoluteBounds.top + absoluteBounds.height,
        absoluteBound.top + absoluteBound.height
      );

      absoluteBounds.left = Math.min(absoluteBounds.left, absoluteBound.left);
      absoluteBounds.top = Math.min(absoluteBounds.top, absoluteBound.top);
      absoluteBounds.width = right - absoluteBounds.left;
      absoluteBounds.height = bottom - absoluteBounds.top;
    }

    // 计算相对边界框的累积范围
    if (!relativeBounds) {
      relativeBounds = { ...relativeBound };
    } else {
      const right = Math.max(
        relativeBounds.left + relativeBounds.width,
        relativeBound.left + relativeBound.width
      );
      const bottom = Math.max(
        relativeBounds.top + relativeBounds.height,
        relativeBound.top + relativeBound.height
      );

      relativeBounds.left = Math.min(relativeBounds.left, relativeBound.left);
      relativeBounds.top = Math.min(relativeBounds.top, relativeBound.top);
      relativeBounds.width = right - relativeBounds.left;
      relativeBounds.height = bottom - relativeBounds.top;
    }
  });

  return { absoluteBounds, relativeBounds };
};

/**
 * 创建离屏栅格化渲染
 * @param {Object} options 渲染选项
 * @returns {Promise<fabric.Image>} 栅格化后的图像对象
 */
const createOffscreenRasterization = async ({
  canvas,
  objects,
  absoluteBounds,
  relativeBounds,
  scaleFactor,
  clippingObject,
  trimWhitespace,
  trimPadding,
  quality,
  format,
  currentZoom,
  isReturenDataURL,
}) => {
  try {
    // 创建离屏画布，使用绝对尺寸以保证高质量
    const offscreenCanvas = new fabric.StaticCanvas();

    // 如果有裁剪对象，使用裁剪对象的边界框
    let renderBounds = absoluteBounds;
    if (clippingObject) {
      const clippingBounds = clippingObject.getBoundingRect(true, true);
      console.log("🎯 使用裁剪对象边界框:", clippingBounds);
      renderBounds = clippingBounds;
    }

    // 设置离屏画布尺寸，并应用高清倍数
    const canvasWidth = Math.ceil(renderBounds.width);
    const canvasHeight = Math.ceil(renderBounds.height);

    offscreenCanvas.setDimensions({
      width: canvasWidth,
      height: canvasHeight,
    });

    console.log(
      `🎨 离屏画布尺寸: ${canvasWidth}x${canvasHeight}, 缩放: ${scaleFactor}`
    );

    // 克隆对象到离屏画布
    const clonedObjects = [];
    for (const obj of objects) {
      const clonedObj = await cloneObjectAsync(obj);

      // 调整对象位置，相对于渲染边界框的左上角
      clonedObj.set({
        left: clonedObj.left - renderBounds.left,
        top: clonedObj.top - renderBounds.top,
      });

      // 如果有裁剪对象，为每个对象设置裁剪路径
      if (clippingObject) {
        const clippingPath = await cloneObjectAsync(clippingObject);
        clippingPath.set({
          left: clippingPath.left - renderBounds.left,
          top: clippingPath.top - renderBounds.top,
          fill: "",
          stroke: "",
          absolutePositioned: true,
        });
        clonedObj.set({
          clipPath: clippingPath,
        });
      }

      clonedObjects.push(clonedObj);
      offscreenCanvas.add(clonedObj);
    }

    // 渲染离屏画布
    offscreenCanvas.renderAll();

    // 生成图像数据
    const dataURL = offscreenCanvas.toDataURL({
      format,
      quality,
      multiplier: 1, // 已经通过画布尺寸处理了高清倍数
    });

    if (isReturenDataURL) {
      return dataURL; // 如果需要返回DataURL
    }

    // 清理离屏画布
    offscreenCanvas.dispose();

    // 创建fabric.Image对象
    const fabricImage = await createFabricImageFromDataURL(dataURL);

    // 设置图像位置为裁剪区域的位置
    fabricImage.set({
      left: renderBounds.left + renderBounds.width / 2,
      top: renderBounds.top + renderBounds.height / 2,
      originX: "center",
      originY: "center",
    });

    return fabricImage;
  } catch (error) {
    console.error("离屏栅格化失败:", error);
    throw error;
  }
};

/**
 * 异步克隆fabric对象
 * @param {fabric.Object} obj 要克隆的对象
 * @returns {Promise<fabric.Object>} 克隆的对象
 */
const cloneObjectAsync = (obj) => {
  return new Promise((resolve, reject) => {
    obj.clone((cloned) => {
      if (cloned) {
        resolve(cloned);
      } else {
        reject(new Error("对象克隆失败"));
      }
    });
  });
};

/**
 * 从DataURL创建fabric.Image对象
 * @param {string} dataURL 图像数据URL
 * @returns {Promise<fabric.Image>} fabric图像对象
 */
const createFabricImageFromDataURL = (dataURL) => {
  return new Promise((resolve, reject) => {
    fabric.Image.fromURL(dataURL, (img) => {
      if (img) {
        resolve(img);
      } else {
        reject(new Error("无法从DataURL创建图像"));
      }
    });
  });
};

/**
 * 计算栅格化图像在当前画布上的正确变换
 * @param {Object} params 计算参数
 * @returns {Object} 变换属性对象
 */
const calculateImageTransform = ({
  absoluteBounds,
  relativeBounds,
  currentZoom,
  scaleFactor,
  imageWidth,
  imageHeight,
}) => {
  // 计算缩放比例：相对尺寸 / 绝对尺寸
  const scaleX = relativeBounds.width / absoluteBounds.width;
  const scaleY = relativeBounds.height / absoluteBounds.height;

  // 由于我们生成的图像是基于绝对尺寸的高清版本，需要考虑scaleFactor
  const finalScaleX = scaleX / scaleFactor;
  const finalScaleY = scaleY / scaleFactor;

  return {
    left: relativeBounds.left + relativeBounds.width / 2, // 设置为中心点
    top: relativeBounds.top + relativeBounds.height / 2, // 设置为中心点
    // scaleX: finalScaleX,
    // scaleY: finalScaleY,
    originX: "center",
    originY: "center",
  };
};

/**
 * 应用遮罩到画布（已弃用，使用clipPath方式）
 * @param {fabric.Canvas} canvas 目标画布
 * @param {fabric.Object} maskObject 遮罩对象
 * @param {Object} bounds 边界框
 */
const applyMaskToCanvas = async (canvas, maskObject, bounds) => {
  // 此方法已被clipPath方式替代
  console.log("⚠️ applyMaskToCanvas已被clipPath方式替代");
};

export const getObjectsBounds = (fabricObjects) => {
  const { absoluteBounds } = calculateBounds(fabricObjects);
  return absoluteBounds;
};