added alert for multiple account

src/context/AuthContext.js

@@ -1,7 +1,6 @@
-// src/context/AuthContext.js
-import { onAuthStateChanged, signOut } from "firebase/auth";
+import { onAuthStateChanged, signOut, fetchSignInMethodsForEmail, signInWithPopup } from "firebase/auth";
 import React, { useContext, useEffect, useState } from "react";
-import { GithubAuthProvider, GoogleAuthProvider, auth, signInWithPopup } from "../components/firebase";
+import { GithubAuthProvider, GoogleAuthProvider, auth } from "../components/firebase";
 
 const AuthContext = React.createContext();
 
@@ -12,15 +11,36 @@ export function useAuth() {
 export function AuthProvider({ children }) {
   const [currentUser, setCurrentUser] = useState(null);
 
-  const googleSignIn = ()=>{
+  const googleSignIn = async () => {
     const provider = new GoogleAuthProvider();
-    signInWithPopup(auth, provider);
-  }
-  
-  const githubSignIn = ()=>{
+    await signInWithPopup(auth, provider);
+  };
+
+  const githubSignIn = async () => {
     const provider = new GithubAuthProvider();
-    signInWithPopup(auth, provider);
-  }
+
+    try {
+      // Attempt to sign in with GitHub
+      const result = await signInWithPopup(auth, provider);
+      return result.user;
+    } catch (error) {
+      // Check if the error is for an existing account
+      if (error.code === "auth/account-exists-with-different-credential") {
+        const email = error.customData.email;
+        const signInMethods = await fetchSignInMethodsForEmail(auth, email);
+        if (signInMethods.includes("google.com")) {
+          // If the existing account is Google, sign in with Google instead
+          alert("You already have an account with this email using Google. Signing you in with Google now.");
+          const googleProvider = new GoogleAuthProvider();
+          const googleResult = await signInWithPopup(auth, googleProvider);
+          return googleResult.user;
+        } else {
+          alert("An account already exists with this email. Please sign in using one of the other method");
+        }
+      }
+      throw error;
+    }
+  };
 
   function logOut() {
     signOut(auth);
@@ -32,8 +52,7 @@ export function AuthProvider({ children }) {
     });
 
     return () => unsubscribe();
-  }, [currentUser]);
-
+  }, []);
 
   return <AuthContext.Provider value={{ currentUser, googleSignIn, githubSignIn, logOut }}>{children}</AuthContext.Provider>;
 }