const AliOss = (function (){
    const downloadFile = function (url, filename) {
        axios.get(url, {responseType: 'blob' }).then(res => {
            saveAs(res.data, filename);
        });
    };

    const downloadFileSync = function(url) {
        return new Promise((resolve, reject) => {
            axios.get(url, {responseType: 'blob'}).then(res => {
                resolve(res.data);
            }).catch(err => {
                reject(err);
            });
        })
    };

    const zipFiles = function (files, filename = '打包.zip', successCallback, errorCallback) {
        const zip = new JSZip();
        const download = [], fails = [];
        files.forEach(f => {
            download.push(downloadFileSync(f.filepath).then(data => {
                zip.file(f.filename + f.fileext, data, {binary: true});
            }).catch(err => {
                fails.push(f);
            }));
        });
        Promise.all(download).then(() => {
            if (fails.length < files.length) {
                zip.generateAsync({ type: "blob" }).then(content => {
                    saveAs(content, filename);
                    successCallback && successCallback(fails);
                });
            } else {
                errorCallback && errorCallback(fails);
            }
        })
    };

    return { downloadFile, downloadFileSync, zipFiles}
})();