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

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

    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 = ObjectsSimpleService.c_apiRoot + 'Objects/sinochemweb/';
    postFile(extensionPath: string, file: File): Observable<Object> {
        let formData = new FormData()
        formData.append("file", file, file.name)
        let data = { keepOriginalName: 'true' }
        return this.http.post(ObjectsSimpleService.baseUrl + extensionPath, formData, { params: data });
    }




    //分块上传
    static baseUrl_MultipartUpload = ObjectsSimpleService.c_apiRoot_Multipart + 'NewMultipartUpload/sinochemweb/';
    //   {
    //   "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(ObjectsSimpleService.baseUrl + extensionPath, formData);
        let data = { keepOriginalName: 'true', filename: file.name }
        return new Promise((resolve, reject) => {
            this.http.post(ObjectsSimpleService.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(ObjectsSimpleService.c_apiRoot_Multipart + `MultipartUpload/sinochemweb/${objectName}?uploadId=${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 = ObjectsSimpleService.c_apiRoot_Multipart + 'CompleteMultipartUpload/sinochemweb/' + objectName;
                        this.http.post(path, data, { params: paramsData }).subscribe(data => {
                            let objData: any = new Object();
                            objData.fileName = file.name;
                            objData.filePath = (ObjectsSimpleService.baseUrl + objectName).replace(file.name, "");
                            resolve(objData)
                        })
                    }
                }//for循环

                //分块 处理
            })
        })
    }
}