feat: enhance login and registration pages with session handling

- Added `useEffect` to redirect authenticated users to the home page in both `LoginPage` and `RegisterPage`.
- Integrated `useSession` from `next-auth/react` to manage session state and loading indicators.
- Implemented loading state display while checking session status, improving user experience during authentication.
- Prevented form display for authenticated users, streamlining the login and registration process.

src/app/login/page.tsx

@@ -1,7 +1,7 @@
 'use client'
 
-import { useState } from 'react'
-import { signIn, getSession } from 'next-auth/react'
+import { useState, useEffect } from 'react'
+import { signIn, getSession, useSession } from 'next-auth/react'
 import { useRouter } from 'next/navigation'
 import Link from 'next/link'
 import { Button } from '@/components/ui/Button'
@@ -15,6 +15,14 @@ export default function LoginPage() {
   const [error, setError] = useState('')
   const [isLoading, setIsLoading] = useState(false)
   const router = useRouter()
+  const { data: session, status } = useSession()
+
+  // Redirection si l'utilisateur est déjà connecté
+  useEffect(() => {
+    if (status === 'authenticated' && session) {
+      router.push('/')
+    }
+  }, [status, session, router])
 
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault()
@@ -44,6 +52,23 @@ export default function LoginPage() {
     }
   }
 
+  // Afficher un loader pendant la vérification de session
+  if (status === 'loading') {
+    return (
+      <div className="min-h-screen relative overflow-hidden">
+        <TowerBackground />
+        <div className="relative z-10 min-h-screen flex items-center justify-center">
+          <div className="text-[var(--foreground)]">Chargement...</div>
+        </div>
+      </div>
+    )
+  }
+
+  // Ne pas afficher le formulaire si l'utilisateur est connecté
+  if (status === 'authenticated') {
+    return null
+  }
+
   return (
     <div className="min-h-screen relative overflow-hidden">
       <TowerBackground />

src/app/register/page.tsx

@@ -1,7 +1,8 @@
 'use client'
 
-import { useState } from 'react'
+import { useState, useEffect } from 'react'
 import { useRouter } from 'next/navigation'
+import { useSession } from 'next-auth/react'
 import { Button } from '@/components/ui/Button'
 import { Input } from '@/components/ui/Input'
 import Link from 'next/link'
@@ -18,6 +19,14 @@ export default function RegisterPage() {
   const [error, setError] = useState('')
   const [isLoading, setIsLoading] = useState(false)
   const router = useRouter()
+  const { data: session, status } = useSession()
+
+  // Redirection si l'utilisateur est déjà connecté
+  useEffect(() => {
+    if (status === 'authenticated' && session) {
+      router.push('/')
+    }
+  }, [status, session, router])
 
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault()
@@ -67,6 +76,23 @@ export default function RegisterPage() {
     }
   }
 
+  // Afficher un loader pendant la vérification de session
+  if (status === 'loading') {
+    return (
+      <div className="min-h-screen relative overflow-hidden">
+        <TowerBackground />
+        <div className="relative z-10 min-h-screen flex items-center justify-center">
+          <div className="text-[var(--foreground)]">Chargement...</div>
+        </div>
+      </div>
+    )
+  }
+
+  // Ne pas afficher le formulaire si l'utilisateur est connecté
+  if (status === 'authenticated') {
+    return null
+  }
+
   return (
     <div className="min-h-screen relative overflow-hidden">
       <TowerBackground />