[Client] LS to JS and some Clean up ✌️

src/web/app/common/scripts/api.js

@@ -0,0 +1,44 @@
+/**
+ * API Request
+ */
+
+let spinner = null;
+let pending = 0;
+
+/**
+ * Send a request to API
+ * @param  {string|Object} i  Credential
+ * @param  {string} endpoint  Endpoint
+ * @param  {Object} [data={}] Data
+ * @return {Promise<Object>} Response
+ */
+module.exports = (i, endpoint, data = {}) => {
+	if (++pending === 1) {
+		spinner = document.createElement('div');
+		spinner.setAttribute('id', 'wait');
+		document.body.appendChild(spinner);
+	}
+
+	// Append the credential
+	if (i != null) data.i = typeof i === 'object' ? i.token : i;
+
+	return new Promise((resolve, reject) => {
+		// Send request
+		fetch(endpoint.indexOf('://') > -1 ? endpoint : `${CONFIG.api.url}/${endpoint}`, {
+			method: 'POST',
+			body: JSON.stringify(data),
+			credentials: endpoint === 'signin' ? 'include' : 'omit'
+		}).then(res => {
+			if (--pending === 0) spinner.parentNode.removeChild(spinner);
+			if (res.status === 200) {
+				res.json().then(resolve);
+			} else if (res.status === 204) {
+				resolve();
+			} else {
+				res.json().then(err => {
+					reject(err.error);
+				});
+			}
+		}).catch(reject);
+	});
+};