/**文件打包
  * arrImages:文件list:[{fileUrl:文件url,renameFileName:文件名}]
  * filename 壓縮包名
  * */
  filesToRar(arrImages, filename) {
  let _this = this;
  let zip = new JSZip();
  let cache = {};
  let promises = [];
  _this.title = '正在加載壓縮文件';
  for (let item of arrImages) {
   const promise= _this.getImgArrayBuffer(item.fileUrl).then(data => {
   // 下載文件, 并存成ArrayBuffer對象(blob)
   zip.file(item.renameFileName, data, { binary: true }); // 逐個添加文件
   cache[item.renameFileName] = data;
   });
   promises.push(promise);
  }
  Promise.all(promises).then(() => {
   zip.generateAsync({ type: "blob" }).then(content => {
   _this.title = '正在壓縮';
   // 生成二進制流
   FileSaver.saveAs(content, filename); // 利用file-saver保存文件 自定義文件名
   _this.title = '壓縮完成';
   });
  }).catch(res=>{
   _this.$message.error('文件壓縮失敗');
  });
  },
 //獲取文件blob
  getImgArrayBuffer(url){
  let _this=this;
  return new Promise((resolve, reject) => {
   //通過請求獲取文件blob格式
   let xmlhttp = new XMLHttpRequest();
   xmlhttp.open("GET", url, true);
   xmlhttp.responseType = "blob";
   xmlhttp.onload = function () {
   if (this.status == 200) {
    resolve(this.response);
   }else{
    reject(this.status);
   }
   }
   xmlhttp.send();
  });
  },

<template>
	<div>
		<div v-show="codeId" ref="QrcodePage" style="z-index:-1111;position:absolute;left:-99999;width: 450px;height: 475px;background-size: cover;">
			<div id="qrCode" v-if="codeId">
				<QrcodeVue :logoSrc="imageUrl" :key="random" :callback="texte" :text="codeValue" :logoScale="50" :size="750"></QrcodeVue>
				<p style="text-align: center; font-size: 1.5625rem;">{{ codeNumber }}</p>
			</div>
		</div>
	</div>
</template>
<script>
let loadingInstance = '';
import QrcodeVue from 'vue-qr';
import html2canvas from 'html2canvas';
import JSZip from 'jszip';
import FileSaver from 'file-saver';
export default {
	name: 'qrcode',
	components: {
		QrcodeVue
	},
	data() {
		return {
			random: '1',
			codeId: '',
			qrcodeUrl: '',
			imageUrl: '',
			// imageUrl: 'https://shop.mmdddd.com/workShopWeb/static/img/72.png',//logo
			qrContentImage: '',
			codeValue: '',
			initCodeVal: 'http://xcx.nmte.net/tips/index.html',
			codeNumber: '',
			arr: [],
			qrcodeArr: [],
			index: 0
		};
	},
	watch: {
		index(newName, oldName){
			if(newName != oldName && newName <= this.arr.length-1){
				setTimeout(_ => {
					this.setarr(this.arr);
				}, 0);
			}else {
				this.$nextTick(_ => {
					loadingInstance.close();
				});
			}
		}
	},
	created() {
	},
	mounted() {},
	methods: {
		texte(url,qid) {
			setTimeout(_ => {
				this.createImgs();
			}, 100);
		},
		setarr(arr) {
			this.arr = arr;
			if(this.index > this.arr.length -1) {
				this.index = 0;
			}
			let index=this.index||0;
			loadingInstance = this.$Loading.service({
				lock: true, 
				text: '二維碼碼批量下載中，請稍后...', 
				spinner: 'el-icon-loading', 
				background: 'rgba(0, 0, 0, 0.7)'
			});
			this.codeNumber = this.arr[index].codeNumber; 
			this.arr[index].codeId ? (this.codeId = this.arr[index].codeId) : this.$Message.warn('獲取信息失敗，請刷新重試');
			this.codeValue = this.initCodeVal + '?codeId=' + this.arr[index].codeId + '&codeNumber=' + this.arr[index].codeNumber;
			this.random = Math.random(); 
		},
		createImgs() {
			var that = this;
			if(that.index <= that.arr.length -1 && that.codeId){
				let shareContent = that.$refs.QrcodePage, 
					width = shareContent.offsetWidth, 
					height = shareContent.offsetHeight,
					canvas = document.createElement('canvas'), 
					scale = 1; 
				canvas.width = width * scale; 
				canvas.height = height * scale; 
				canvas.style.width = (shareContent.clientWidth * scale) / 100 + 'rem';
				canvas.style.height = (shareContent.clientHeight * scale) / 100 + 'rem';
				canvas.getContext('2d').scale(scale, scale); 
				let opts = {
					scale: scale, 
					canvas: canvas,
					logging: false,
					width: width, 
					height: height,
					useCORS: true
				};
				html2canvas(shareContent, opts)
					.then(function(canvas) {	
						const qrContentImage = canvas.toDataURL('image/jpeg', 1.0);
						if(that.index <= that.arr.length -1 && that.codeId){
							that.qrcodeArr.push({
								url: qrContentImage,
								name: that.arr[that.index].codeNumber
							});
						}
						if(that.codeId){
							that.index ++;
						}
						if(that.qrcodeArr.length == that.arr.length){
							that.packageImages();
							that.codeId = null;
						}
					})
					.catch(function(reason) {
						console.log(reason);
					});
			}
		},
		packageImages() {
			let that = this;
			const zip = new JSZip();
			const cache = {};
			setTimeout(_ => {
				let arr = that.qrcodeArr;
				arr.forEach((item,index)=>{
					let fileName = item.name;
					zip.file(fileName + '.png',item.url.substring(22),{base64:true})
					cache[fileName] = item.url
				})
				zip.generateAsync({type:"blob"}).then(content => { 
					FileSaver.saveAs(content, "二維碼.zip") 
				})
			},0)
		}
	}
};
</script>
<style lang="less" scoped="scoped">
#qrCode {
	width: 375px;
	height: 375px;
	position: absolute;
	top: 52%;
	left: 50%;
	transform: translate(-50%, -50%);
	img {
		display: block;
		width: 100%;
		height: 100%;
	}
}
</style>