WIP: Add axios lib file

frontend/src/lib/axios.ts

@@ -0,0 +1,50 @@
+import axios from 'axios';
+import { dev } from '$app/environment';
+import { goto } from '$app/navigation';
+
+if (dev) {
+  axios.defaults.baseURL = "http://localhost:8000/api/v1"
+} else {
+  axios.defaults.baseURL = "/api/v1"
+}
+
+function createTokenRefreshInterceptor() {
+  const interceptor = axios.interceptors.response.use(
+    (response) => response,
+    (error) => {
+      // Reject promise if usual error
+      if (error.response.status !== 401) {
+        return Promise.reject(error);
+      }
+
+      /*
+      * When response code is 401, try to refresh the token.
+      * Eject the interceptor so it doesn't loop in case
+      * token refresh causes the 401 response.
+      *
+      * Must be re-attached later on or the token refresh will only happen once
+      */
+      axios.interceptors.response.eject(interceptor);
+
+      return axios
+        .post("/auth/refresh", {
+          refresh_token: "",
+        })
+        .then((response) => {
+          // TODO: Save token
+          error.response.config.headers["Authorization"] = "Bearer " + response.data.access_token;
+          // Retry initial request with new token
+          return axios(error.response.config);
+        })
+        .catch((retryError) => {
+          // Retry failed, clean up and reject the promise
+          // TODO: Remove invalid token
+          goto('/login?reauth')
+          return Promise.reject(retryError);
+        })
+        .finally(createTokenRefreshInterceptor); // Re-attach interceptor for future requests
+      }
+  );
+}
+
+createTokenRefreshInterceptor();