let utils = {
    guid:function() {
        function S4() {
            return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1)
        }
        return S4() + S4() + S4() + S4() + S4() + S4() + S4() + S4()
    },

    getStorage:function(name) {
        let value = window.localStorage.getItem(name);

        try {
            const temp = JSON.parse(value);

            let nowDate = new Date();
            let expireDate = new Date(temp.expire);
            if (temp) {
                if (temp.expire) {
                    if (nowDate < expireDate) {
                        return temp.token
                    } else {
                        return null;
                    }
                } else {
                    return temp
                }
            } else {
                return null;
            }
        } catch (e) {
            return value;
        }


    },
    setStorage:function(name, value) {
        if (value.expire) {
            value.expire = new Date().getTime() + value.expire * 1000;
        }
        window.localStorage.setItem(name, JSON.stringify(value));
    },

    //格式化日期
    formatDate:function(str) {
        let date = new Date(str * 1000);
        const year = date.getFullYear();
        const month = date.getMonth() + 1;
        const day = date.getDate();
        return [year, month, day].map(formatNumber).join('-');
    },

    //格式化时间
    formatTime:function(str) {
        let date = new Date(str * 1000);
        const year = date.getFullYear();
        const month = date.getMonth() + 1;
        const day = date.getDate();
        const hour = date.getHours();
        const minute = date.getMinutes();
        const second = date.getSeconds();
        return [year, month, day].map(formatNumber).join('-') + ' ' + [hour, minute, second].map(formatNumber).join(':');
    },

    //加0
    formatNumber:function(n) {
        n = n.toString();
        return n[1] ? n : '0' + n;
    },

    getBase64Image:function(img) {
        var canvas = document.createElement("canvas");
        canvas.width = img.width;
        canvas.height = img.height;
        var ctx = canvas.getContext("2d");
        ctx.drawImage(img, 0, 0, img.width, img.height);
        var dataURL = canvas.toDataURL("image/png");  // 可选其他值 image/jpeg
        return dataURL;
    },

    main:function(src, cb) {
        var image = new Image();
        image.src = src + '?v=' + Math.random(); // 处理缓存
        image.crossOrigin = "*";  // 支持跨域图片
        image.onload = function () {
            var base64 = getBase64Image(image);
            cb && cb(base64);
        }
    },

    // 处理文件大小
    handleSize:function(size) {
        if ((size / 1024 / 1024) < 1) {
            return (size / 1024).toFixed(2) + 'KB';
        } else {
            return (size / 1024 / 1024).toFixed(2) + 'MB';
        }
    }
}