From b69f4e6ef1e5889f398e00705565a501cb0800a1 Mon Sep 17 00:00:00 2001
From: Stefano Pigozzi <256895@studenti.unimore.it>
Date: Mon, 26 Apr 2021 16:35:00 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=94=A7=20Add=20`working`=20and=20`error`?=
 =?UTF-8?q?=20to=20useSavedLogin?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 code/frontend/src/contexts/ContextLogin.js |  2 +
 code/frontend/src/hooks/useSavedLogin.js   | 73 +++++++++++++---------
 code/frontend/src/routes/PageLogin.js      |  5 +-
 3 files changed, 48 insertions(+), 32 deletions(-)

diff --git a/code/frontend/src/contexts/ContextLogin.js b/code/frontend/src/contexts/ContextLogin.js
index 0d8ea8d..69fe044 100644
--- a/code/frontend/src/contexts/ContextLogin.js
+++ b/code/frontend/src/contexts/ContextLogin.js
@@ -7,6 +7,8 @@ import {createContext} from "react";
  *   - `server`: The base url of the N.E.S.T. backend
  *   - `email`: The email of the account the user is logged in as
  *   - `token`: The bearer token to use in authenticated API requests
+ * - `working`: `true` if the login procedure is running, `false` otherwise
+ * - `error`: `null` if no login error happened, an instance of {@link Error} otherwise.
  * - `login`: an async function which logs in the user if given the following parameters: `server, email, password`
  * - `logout`: a function which logs out the user
  * - `fetch_unauth`: a variant of {@link fetch} which uses `state.server` as the base url, allowing only the API path
diff --git a/code/frontend/src/hooks/useSavedLogin.js b/code/frontend/src/hooks/useSavedLogin.js
index 89e65c6..76788ed 100644
--- a/code/frontend/src/hooks/useSavedLogin.js
+++ b/code/frontend/src/hooks/useSavedLogin.js
@@ -1,3 +1,4 @@
+import {useState} from "react"
 import useLocalStorageState from "./useLocalStorageState"
 
 
@@ -6,41 +7,53 @@ import useLocalStorageState from "./useLocalStorageState"
  */
 export default function useSavedLogin() {
     const [state, setState] = useLocalStorageState("login", null)
+    const [working, setWorking] = useState(false)
+    const [error, setError] = useState(null)
 
     const login = async (server, email, password) => {
-        console.debug("Contacting server to login...")
-        const response = await fetch(`${server}/api/login`, {
-            method: "POST",
-            cache: "no-cache",
-            headers: {
-                "Content-Type": "application/json",
-            },
-            body: JSON.stringify({
-                "email": email,
-                "password": password,
+        setWorking(true)
+        try {
+            console.debug("Contacting server to login...")
+            const response = await fetch(`${server}/api/login`, {
+                method: "POST",
+                cache: "no-cache",
+                headers: {
+                    "Content-Type": "application/json",
+                },
+                body: JSON.stringify({
+                    "email": email,
+                    "password": password,
+                })
             })
-        })
 
-        console.debug("Decoding server response...")
-        const data = await response.json()
+            console.debug("Decoding server response...")
+            const data = await response.json()
 
-        console.debug("Ensuring the request was a success...")
-        if(data["result"] !== "success") {
-            console.error(`Login failed: ${data["msg"]}`)
-            return
+            console.debug("Ensuring the request was a success...")
+            if(data["result"] !== "success") {
+                // noinspection ExceptionCaughtLocallyJS
+                throw new Error(data["msg"])
+            }
+
+            console.debug("Storing login state...")
+            setState({
+                server: server,
+                email: data["user"]["email"],
+                isAdmin: data["user"]["isAdmin"],
+                username: data["user"]["username"],
+                token: data["access_token"],
+            })
+
+            console.debug("Clearing error...")
+            setError(null)
+
+            console.info("Login successful!")
+        } catch(e) {
+            console.error(`Caught error while trying to login: ${e}`)
+            setError(e)
+        } finally {
+            setWorking(false)
         }
-
-        console.debug("Storing login state...")
-        setState({
-            server: server,
-            email: data["user"]["email"],
-            isAdmin: data["user"]["isAdmin"],
-            username: data["user"]["username"],
-            token: data["access_token"],
-        })
-        console.debug("Stored login state!")
-
-        console.info("Login successful!")
     }
 
     const logout = () => {
@@ -65,5 +78,5 @@ export default function useSavedLogin() {
         return await fetch_unauth(path, init)
     }
 
-    return {state, login, logout, fetch_unauth, fetch_auth}
+    return {state, working, error, login, logout, fetch_unauth, fetch_auth}
 }
\ No newline at end of file
diff --git a/code/frontend/src/routes/PageLogin.js b/code/frontend/src/routes/PageLogin.js
index 2274e5f..d88b26e 100644
--- a/code/frontend/src/routes/PageLogin.js
+++ b/code/frontend/src/routes/PageLogin.js
@@ -16,7 +16,7 @@ export default function PageLogin({ className, ...props }) {
     const [server, setServer] = useState("http://localhost:5000")
     const [email, setEmail] = useState("admin@admin.com")
     const [password, setPassword] = useState("password")
-    const {login} = useContext(ContextLogin)
+    const {login, working, error} = useContext(ContextLogin)
     const history = useHistory()
 
     return (
@@ -60,7 +60,8 @@ export default function PageLogin({ className, ...props }) {
                             history.push("/dashboard")
                         }}
                         icon={faArrowRight}
-                        color={"Green"}
+                        color={error ? "Green" : "Red"}
+                        disabled={working}
                     >
                         Login
                     </Button>