import md5 from "@/utils/uploadMD5";  //见上一篇文章封装MD5
import { taskInfoService, initTaskService, mergeUploadService } from "@/api/chunkUploadFile";
const FILE_CHUNKSIZE = 5 * 1024 * 1024;
const BlobSlice =
  File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice;
let failCount = 0;

//定义data
data() {
  return {
    file: null,
    fileMd5: "",
    uploadId: "",
    fileName: "",
    simultaneousUploads: 3,  //并发数
    uploadPercentage: 0,  //上传进度
    uploadFail: false,  //上传失败
  };
}

async fileUpload() {
  this.file.chunkList = [];
  this.fileMd5 = await md5(this.file, FILE_CHUNKSIZE);

  const checkRes = await taskInfoService(this.fileMd5); //检查是否已上传
  if (checkRes.code === 100000) {
    // 已上传
    this.uploadPercentage = 100;
    return;
  }
  if (checkRes.code === 300000) {
    // 上传失败
    this.uploadFail = false;
    return;
  }
  let fileChunks = this.createFileChunk();
  const initTaskData = {
    fileMd5: this.fileMd5,
    fileName: this.file.name,
    fileSize: this.file.size,
    chunkSize: FILE_CHUNKSIZE,
    partCount: Math.ceil(this.file.size / FILE_CHUNKSIZE),
    rtspUrl: this.fileInfo.rtspUrl,
    beginTime: this.fileInfo.beginTime,
    endTime: this.fileInfo.endTime,
    fileType: this.fileInfo.type,
  };
  if (checkRes.code === 2000000) {
    // 断点续传
    const uploadedList = checkRes.urlList;  //已上传成功的切片列表
    uploadedList.forEach((uploaded) => {
      let index = this.fileChunks.findIndex((item) => item === uploaded);
      if (index !== -1) {
        this.fileChunks.splice(index, 1);
      }
    });
  }
  // 文件未上传
  const initRes = await initTaskService(initTaskData);  //获取各切片上传地址
  let uploadUrls = initRes.data.urlList;
  this.uploadId = initRes.data.uploadId;
  this.fileName = initRes.data.fileName;
  fileChunks.map((chunkItem, index) => {
    this.file.chunkList.push({
      chunkNumber: index + 1,
      chunk: chunkItem,
      uploadUrl: uploadUrls[index],
    });
  });
  // 上传
  await this.uploadChunkBase(this.file.chunkList);
  // 合并文件
  await mergeUploadService({
    uploadId: this.uploadId,
    fileName: this.fileName,
    fileMd5: this.fileMd5,
    rtspUrl: this.fileInfo.rtspUrl,
    beginTime: this.fileInfo.beginTime,
    endTime: this.fileInfo.endTime,
    fileType: this.fileInfo.type,
  });
}

//各切片上传
uploadChunkBase(chunkList) {
  let successCount = 0;
  let totalChunks = chunkList.length;
  return new Promise((resolve, reject) => {
    const handler = () => {
      if (chunkList.length) {
        const chunkItem = chunkList.shift();
        // 直接上传二进制，不需要构造 FormData，否则上传后文件损坏
        axios
          .put(chunkItem.uploadUrl, chunkItem.chunk.file, {
            // 上传进度处理
            headers: {
              "Content-Type": "application/octet-stream",
            },
          })
          .then((response) => {
            if (response.status === 200) {
              console.log("分片：" + chunkItem.chunkNumber + " 上传成功");
              successCount++;
              this.uploadPercentage = (successCount / totalChunks) * 100;
              // 继续上传下一个分片
              handler();
            } else {
              console.log(
                "上传失败：" + response.status + "，" + response.statusText
              );
            }
          })
          .catch((error) => {
            // 失败后只上传五次，防止卡死
            failCount++;
            if (failCount < 5) {
              // 更新状态
              console.log(
                "分片：" + chunkItem.chunkNumber + " 上传失败，" + error
              );
              // 重新添加到队列中
              chunkList.push(chunkItem);
              handler();
            } else {
              this.$message.error(
                "分片：" + chunkItem.chunkNumber + " 上传失败"
              );
            }
          });
      }
      if (successCount >= totalChunks) {
        resolve();
      }
    };
    // 并发  import Queue from 'promise-queue-plus';
    for (let i = 0; i < this.simultaneousUploads; i++) {
      handler();
    }
  });
}

// 文件分片
createFileChunk() {
  const fileChunkList = [];
  let count = 0;
  while (count < this.file.size) {
    fileChunkList.push({
      file: BlobSlice.call(this.file, count, count + FILE_CHUNKSIZE),
    });
    count += FILE_CHUNKSIZE;
  }
  return fileChunkList;
}