import path from 'path'
import sharp from 'sharp'
import { CheckFileOrDirExist, CheckFolderExistsOrCreate } from './file'
import fs from 'fs'
import https from 'https'

/**
 * 将指定的图片的尺寸修改，返回修改后的图片数据(base64或buffer)
 * @param {*} image_path
 * @param {*} width
 * @param {*} height
 * @param {*} type
 * @returns 返回修改后的图片数据(base64或buffer)
 */
export async function ResizeImage(image_path: string, width: number | sharp.ResizeOptions, height: number, type: string) {
  try {
    // 检查 type 参数
    if (type !== 'base64' && type !== 'buffer') {
      throw new Error('type 参数必须是 "base64" 或 "buffer"')
    }

    // 判断是不是图片文件
    if (!image_path.match(/\.(jpg|jpeg|png)$/)) {
      throw new Error('输入的文件地址不是图片文件地址')
    }

    // 判断文件是否存在
    if (!(await CheckFileOrDirExist(image_path))) {
      throw new Error('文件不存在')
    }

    // 修改图片尺寸
    const image = sharp(image_path)
    image.resize(width, height)
    let data = await image.toBuffer()
    if (type === 'base64') {
      return data.toString('base64')
    } else {
      return data
    }
  } catch (error) {
    throw error
  }
}

/**
 * 获取指定图片文件的宽高
 * @param {*} image_path 图片文件的路径
 * @returns 返回以一个对象，包含width和height属性
 */

export async function GetImageSize(image_path: string) {
  try {
    // 判断文件是否存在
    if (!(await CheckFileOrDirExist(image_path))) {
      throw new Error('文件不存在')
    }

    // 判断是不是图片文件
    if (!image_path.match(/\.(jpg|jpeg|png)$/)) {
      throw new Error('输入的文件地址不是图片文件地址')
    }

    // 获取图片的宽高
    const metadata = await sharp(image_path).metadata()
    return {
      width: metadata.width,
      height: metadata.height
    }
  } catch (error) {
    throw error
  }
}

/**
 * 根据文件扩展名获取MIME类型
 * @param filePath 文件路径
 * @returns MIME类型字符串
 */
export function GetMimeType(filePath: string): string {
  const extension = path.extname(filePath).toLowerCase();
  const mimeTypes: { [key: string]: string } = {
    '.jpg': 'image/jpeg',
    '.jpeg': 'image/jpeg',
    '.png': 'image/png',
    '.gif': 'image/gif',
    '.webp': 'image/webp',
    // 添加更多文件类型和对应的MIME类型
  };
  return mimeTypes[extension] || 'application/octet-stream';
}

/**
 * 将本地文件地址或网络图片地址转换为包含MIME类型的base64字符串
 * @param url 本地文件路径或网络图片URL
 * @returns Promise<string> 返回一个Promise，解析为包含MIME类型的base64字符串
 */
export function GetImageBase64(url: string): Promise<string> {
  if (!url) {
    return Promise.reject('URL不能为空');
  }
  if (url.startsWith('http://') || url.startsWith('https://')) {
    return new Promise((resolve, reject) => {
      https.get(url, (response) => {
        const mimeType = response.headers['content-type'] || 'application/octet-stream';
        const data: any[] = [];
        response.on('data', (chunk) => data.push(chunk));
        response.on('end', () => {
          const buffer = Buffer.concat(data);
          const base64Data = `data:${mimeType};base64,${buffer.toString('base64')}`;
          resolve(base64Data);
        });
      }).on('error', (err) => reject(err));
    });
  } else {
    return new Promise((resolve, reject) => {
      fs.readFile(url, (err, data) => {
        if (err) {
          reject(err);
        } else {
          const mimeType = GetMimeType(url);
          const base64Data = `data:${mimeType};base64,${data.toString('base64')}`;
          resolve(base64Data);
        }
      });
    });
  }
}

/**
 * 压缩图片到指定的大小
 * @param base64 图片的Blob对象
 * @param maxSizeInBytes 最大文件大小，单位字节
 * @returns 返回一个Promise，解析为压缩后的Blob对象
 */
export async function CompressImageToSize(filePath: string, maxSizeInBytes: number): Promise<Buffer> {
  let quality = 100; // 初始质量设置
  let outputBuffer;

  const image = sharp(filePath);
  // 输出图片的大小
  const metadata = await image.metadata();

  // 迭代压缩过程
  while (true) {
    outputBuffer = await image.jpeg({ quality }).toBuffer();
    if (outputBuffer.length <= maxSizeInBytes || quality === 20) {
      break;
    }
    quality -= 5; // 每次迭代降低质量
  }

  return outputBuffer;
}

/**
 * 生成图片蒙板
 * 将选中的区域涂白，其他区域涂黑（这个颜色可以变）
 * @param inputPath 输入的文件路径
 * @param outputPath  输出的文件路径
 * @param regions 范围对象，包含x, y, width, height属性
 * @param markColor 标记颜色，默认为白色 { r: 255, g: 255, b: 255 } 
 * @param backColor 背景颜色，默认为黑色  { r: 0, g: 0, b: 0 }
 */
export async function ProcessImage(inputPath: string,
  outputPath: string,
  regions: { width: any; height: any; x: any; y: any, imageWidth?: any, imageHeight?: any }[],
  markColor: { r: number; g: number; b: number } = { r: 255, g: 255, b: 255 },
  backColor: { r: number; g: number; b: number } = { r: 0, g: 0, b: 0 },
): Promise<void> {
  try {
    // 读取图片并进行处理
    const image = sharp(inputPath);

    // 获取图片的元数据
    const { width, height } = await image.metadata();

    // 创建一个新的黑色图片，背景为白色
    const whiteBackground = await sharp({
      create: {
        width,
        height,
        channels: 3, // RGB channels
        background: backColor // White color
      }
    }).png().toBuffer();

    // 创建多个白色的矩形，并进行合成
    const composites = await Promise.all(regions.map(async (region) => {

      let rateW = undefined;
      let rateY = undefined;
      let rate = undefined;
      if (region.imageWidth != null && region.imageHeight != null) {
        rateY = height / region.imageHeight;
        rateW = width / region.imageWidth;
        rate = rateY;
      }
      if (rate == null) {
        rate = 1;
      }

      const regionBuffer = await sharp({
        create: {
          width: Math.ceil(region.width * rate),
          height: Math.ceil(region.height * rate),
          channels: 3, // RGB channels
          background: markColor // 标记颜色
        }
      }).png().toBuffer();

      return {
        input: regionBuffer,
        left: Math.ceil(region.x * rate),
        top: Math.ceil(region.y * rate),
      };

    }));

    // 在背景上叠加所有的矩形区域
    await sharp(whiteBackground)
      .composite(composites)
      .toFile(outputPath);

  } catch (err) {
    throw err;
  }
}

/**
 * 将图片的base64写到本地文件
 * @param base64 base64字符串
 * @param outFilePath 写出的文件路径
 */
export async function Base64ToFile(base64: string, outFilePath: string): Promise<void> {
  try {
    let base64Data = base64.replace(/^data:image\/\w+;base64,/, '')
    let dataBuffer = Buffer.from(base64Data, 'base64')
    let out_folder = path.dirname(outFilePath)
    await CheckFolderExistsOrCreate(out_folder)
    await fs.promises.writeFile(outFilePath, dataBuffer)
    // await this.tools.writeArrayToFile(dataBuffer, out_file);
  } catch (error) {
    throw new Error('将base64转换为文件失败，失败信息如下：' + error.toString())
  }
}

/**
 * 将图片分割为4份
 * @param inputPath 输入的文件路径 
 * @param reName 重命名的名字，用做新文件名的前缀
 * @param outputDir 输出的文件夹路径
 * @returns 
 */
export async function ImageSplit(inputPath: string, reName: string, outputDir: string) {
  try {
    const metadata = await sharp(inputPath).metadata()
    const smallWidth = metadata.width / 2
    const smallHeight = metadata.height / 2
    let times = new Date().getTime()
    let imgs = []

    for (let i = 0; i < 4; i++) {
      const xOffset = i % 2 === 0 ? 0 : smallWidth
      const yOffset = Math.floor(i / 2) * smallHeight
      let out_file = path.join(outputDir, `/${reName}_${times}_${i}.png`)
      await sharp(inputPath)
        .extract({
          left: xOffset,
          top: yOffset,
          width: smallWidth,
          height: smallHeight
        })
        .resize(smallWidth, smallHeight)
        .toFile(out_file)

      imgs.push(out_file)
    }
    return imgs
  } catch (err) {
    throw err
  }
}