import JSZipUtils from 'jszip-utils';
import docxtemplater from 'docxtemplater';
import ImageModule from 'docxtemplater-image-module-free';
import Pizzip from 'pizzip';
import FileSaver from 'file-saver';

/**
 * 将base64格式图片转换为ArrayBuffer
 * @param {string} base64Str - base64格式图片字符串（可包含data URL前缀）
 * @returns {ArrayBuffer} 转换后的ArrayBuffer对象
 */
function base64ToArrayBuffer(base64Str) {
  // 移除data URL前缀（如果存在）
  const base64Content = base64Str.replace(/^data:image\/\w+;base64,/, '');

  // 处理URL安全的base64字符
  const safeBase64 = base64Content.replace(/-/g, '+').replace(/_/g, '/');

  // 解码base64字符串
  const binaryStr = atob(safeBase64);

  // 转换为Uint8Array
  const byteLength = binaryStr.length;
  const uint8Array = new Uint8Array(byteLength);

  for (let i = 0; i < byteLength; i++) {
    uint8Array[i] = binaryStr.charCodeAt(i);
  }

  // 返回ArrayBuffer
  return uint8Array.buffer;
}

/**
 * 等比例缩放图片
 * 根据图片的长宽比进行不同方式的缩放
 * 如果宽度大于高度（横拍图片），则按照设定高度等比缩放；
 * 如果宽度小于高度（竖拍图片），则按照设定宽度等比缩放；
 * @param {Number} horizontalHeight 设定高度
 * @param {Number} verticalWidth 设定宽度
 * @param {*} img
 * @param {*} tagValue
 * @param {*} tagName
 * @returns
 */
function getSizeProportional(
  horizontalHeight,
  verticalWidth,
  img,
  tagValue,
  tagName
) {
  return new Promise(function (resolve, reject) {
    const image = new Image();
    image.src = tagValue;
    image.onload = function () {
      let width = image.width;
      let height = image.height;
      // console.log('width height', width, height);

      if (width > height && horizontalHeight && height > horizontalHeight) {
        const scale = image.height / horizontalHeight;
        height = horizontalHeight;
        width = image.width / scale;
      } else if (width <= height && verticalWidth && width > verticalWidth) {
        const scale = image.width / verticalWidth;
        width = verticalWidth;
        height = image.height / scale;
      }
      // console.log('scale', width, height);

      resolve([width, height]);
    };
    image.onerror = function (e) {
      console.log('img, tagValue, tagName : ', img, tagValue, tagName);
      alert('An error occured while loading ' + tagValue);
      reject(e);
    };
  });
}

/**
 * 固定大小缩放图片
 * 根据图片的长宽比进行不同方式的缩放
 * 如果宽度大于高度（横拍图片），则按照设定高度和宽高比缩放；
 * 如果宽度小于高度（竖拍图片），则按照设定宽度和宽高比缩放；
 * @param {*} horizontalHeight 设定高度
 * @param {*} verticalWidth 设定宽度
 * @param {*} scale 缩放比例，长边除短边的比例系数
 * @param {*} img
 * @param {*} tagValue
 * @param {*} tagName
 * @returns
 */
function getSizeFixed(
  horizontalHeight,
  verticalWidth,
  scale,
  img,
  tagValue,
  tagName
) {
  return new Promise(function (resolve, reject) {
    const image = new Image();
    image.src = tagValue;
    image.onload = function () {
      let width = image.width;
      let height = image.height;

      if (
        width > height &&
        horizontalHeight &&
        height > horizontalHeight &&
        scale
      ) {
        height = horizontalHeight;
        width = horizontalHeight * scale;
      } else if (
        width <= height &&
        verticalWidth &&
        width > verticalWidth &&
        scale
      ) {
        width = verticalWidth;
        height = verticalWidth * scale;
      }
      resolve([width, height]);
    };
    image.onerror = function (e) {
      console.log('img, tagValue, tagName : ', img, tagValue, tagName);
      alert('An error occured while loading ' + tagValue);
      reject(e);
    };
  });
}

/**
 * 获取图片配置信息
 * @param {Number} horizontalHeight 图片宽度大于高度时，限制其高度
 * @param {Number} verticalWidth 图片宽度小于高度时，限制其宽度
 * @returns
 */
function getImageOptions(options) {
  const horizontalHeight = options ? options.horizontalHeight : undefined;
  const verticalWidth = options ? options.verticalWidth : undefined;
  return {
    centered: false,
    fileType: 'docx',
    getImage(tagValue) {
      // In this case tagValue will be a URL tagValue = "https://docxtemplater.com/puffin.png"
      return new Promise(function (resolve, reject) {
        if (tagValue.indexOf('http') == 0) {
          JSZipUtils.getBinaryContent(tagValue, function (error, content) {
            if (error) {
              return reject(error);
            }
            return resolve(content);
          });
        } else if (tagValue.indexOf('data:image') == 0) {
          const buffer = base64ToArrayBuffer(tagValue);
          return resolve(buffer);
        }
      });
    },

    getSize(img, tagValue, tagName) {
      // return getSizeProportional(horizontalHeight, verticalWidth, img, tagValue, tagName)
      return getSizeFixed(
        horizontalHeight,
        verticalWidth,
        options.scale,
        img,
        tagValue,
        tagName
      );
    }
  };
}

export const exportDocx = (tempDocpath, data, zipName, imageSize) => {
  return new Promise((resolve, reject) => {
    JSZipUtils.getBinaryContent(tempDocpath, (error, content) => {
      if (error) {
        reject(error);
        throw error;
      }
      const zip = new Pizzip(content);
      let doc = new docxtemplater()
        .setOptions({ paragraphLoop: true })
        .loadZip(zip);

      if (imageSize) {
        const imageOptions = getImageOptions(imageSize);
        doc.attachModule(new ImageModule(imageOptions));
      }
      doc.compile();
      doc.resolveData(data).then(() => {
        try {
          doc.render();
        } catch (error) {
          console.log(error);
          throw error;
        }
        const out = doc.getZip().generate({
          type: 'blob',
          mimeType:
            'application/vnd.openxmlformats-officedocumnet.wordprocessingml.document'
        });
        FileSaver.saveAs(out, zipName);
        resolve();
      });
    });
  });
};