refactor: refactor for modern layout

- split frontend and backend.
- update backend with modern Python dev strategies.

frontend/static/js/utils.js

@@ -0,0 +1,70 @@
+/*
+function ComputPasswordWithSalt(password, salt) {
+    return ComputeSHA256(ComputeSHA256(password) + salt.toString());
+}
+
+function ComputeSHA256(strl) {
+    var tempstr = new TextEncoder().encode(strl);
+    var hashedStrl = undefined
+    var shitpromise = crypto.subtle.digest('SHA-256', tempstr);
+    Promise.all(shitpromise).then(function(result) {
+        hashedStrl = result;
+    });
+    var hashArray = Array.from(new Uint8Array(hashedStrl));
+    var hashHex = hashArray.map(b => ('00' + b.toString(16)).slice(-2)).join('');
+    return hashHex.toLowerCase();
+}
+*/
+var DefaultColor = '#536dfe';
+
+function IsResponseOK(data) {
+    if (typeof (data) == 'undefined') {
+        console.log("Fail to execute an api!");
+        return false;
+    }
+    if (!data['success']) {
+        console.log("Fail to execute an api! Reason:");
+        console.log(data['error']);
+        return false;
+    }
+    return true;
+}
+
+function LineBreaker2Br(strl) {
+    return $('<div>').text(strl).html().replace(/\n/g, '<br />');
+}
+
+function IsUndefinedOrEmpty(data) {
+    return (typeof (data) == 'undefined' || data == "");
+}
+
+function SmarterShowHide(boolean, element) {
+    if (typeof (element) == 'undefined') return;
+    if (boolean) element.show();
+    else element.hide();
+}
+
+function GCD(a, b) {
+    if (b == 0) return a;
+    return GCD(b, a % b);
+}
+
+function LCM(a, b) {
+    return a / GCD(a, b) * b;
+}
+
+String.prototype.format = function() { 
+    var e = arguments; 
+    return !!this && this.replace(
+        /\{(\d+)\}/g, 
+        function (t, n) { 
+            return e[n].toString() ? e[n].toString() : t;
+        }
+    );
+};
+
+Date.prototype.getWeekday = function() {
+    var temp = this.getDay();
+    if (temp == 0) return 6;
+    else return temp - 1;
+};