import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class ObjectsService {

  static readonly c_apiRoot = "/api/";//普通上传的API根路径
  static readonly c_apiRoot_Multipart = "/api/";//分块上传的API根路径

  // static testPath = "f1/f2";//测试路径

  constructor(private http: HttpClient) { }



  //普通上传，单个文件上限5M
  static baseUrl = ObjectsService.c_apiRoot + 'Objects/WebPlan/';
  postFile(extensionPath: string, file: File): Observable<Object> {
    let formData = new FormData()
    //console.log(file.name + file.type);
    formData.append("file", file, file.name)

    let data = { keepOriginalName: 'true' }
    return this.http.post(ObjectsService.baseUrl + extensionPath, formData, { params: data });
  }




  //分块上传
  static baseUrl_MultipartUpload = ObjectsService.c_apiRoot_Multipart + 'NewMultipartUpload/WebPlan/';
  //   {
  //   "objectName": "string",
  //     "uploadId": "string"
  // }
  postFile_MultipartUpload(extensionPath: string, file: File): Promise<Object> {
    // let formData = new FormData()
    // formData.append("file", file, file.name)
    // return this.http.post(ObjectsService.baseUrl + extensionPath, formData);
    let data = { keepOriginalName: 'true', filename: file.name }
    return new Promise((resolve, reject) => {
      this.http.post(ObjectsService.baseUrl_MultipartUpload + extensionPath, {}, { params: data }).subscribe(async (data: any) => { //初始化分段上传
        let objectName = data.objectName
        let uploadId = data.uploadId
        let PartNumberETag = []; //每次返回需要保存的信息
        //分块 处理
        let fileSize = file.size || null //上传文件的总大小
        let shardSize = 5 * 1024 * 1024 //5MB一个分片
        let allSlice = Math.ceil(fileSize / shardSize) //总文件/5MB===共分多少段

        for (let i = 0; i < allSlice; i++) { //循环分段上传
          let start = i * shardSize //切割文件开始位置
          let end = Math.min(fileSize, start + shardSize); //切割文件结束位置
          let formData = new FormData()
          formData.append("file", file.slice(start, end))

          //同步写法实现异步调用
          let result = await new Promise((resolve, reject) => {
            // await 需要后面返回一个 promise 对象
            this.http.post(ObjectsService.c_apiRoot_Multipart + `MultipartUpload/WebPlan/${objectName}?uploadId=${uploadId}&partNumber=${i + 1}`, formData).subscribe((data: any) => {
              let msg = { "partNumber": data.partNumber || null, "eTag": data.eTag || null }
              resolve(msg) // 调用 promise 内置方法处理成功
            })
          });
          PartNumberETag.push(result)

          if (PartNumberETag.length === allSlice) { //分块上传完成
            let data = PartNumberETag
            let paramsData = { uploadId: uploadId };
            let path = ObjectsService.c_apiRoot_Multipart + 'CompleteMultipartUpload/WebPlan/' + objectName;
            this.http.post(path, data, { params: paramsData }).subscribe(data => {
              let objData: any = new Object();
              objData.fileName = file.name;
              objData.filePath = (ObjectsService.baseUrl + objectName).replace(file.name, "");
              resolve(objData)
            })
          }
        }//for循环

        //分块 处理
      })
    })
  }
}