feat: integrate NextAuth.js for authentication, update database service to use better-sqlite3 adapter, and enhance header component with user session management

src/lib/auth.config.ts

@@ -0,0 +1,29 @@
+import type { NextAuthConfig } from 'next-auth';
+
+export const authConfig: NextAuthConfig = {
+  pages: {
+    signIn: '/login',
+  },
+  callbacks: {
+    authorized({ auth, request: { nextUrl } }) {
+      const isLoggedIn = !!auth?.user;
+      const isOnProtectedPage =
+        nextUrl.pathname.startsWith('/sessions') || nextUrl.pathname.startsWith('/api/sessions');
+      const isOnAuthPage =
+        nextUrl.pathname.startsWith('/login') || nextUrl.pathname.startsWith('/register');
+
+      if (isOnProtectedPage) {
+        if (isLoggedIn) return true;
+        return false; // Redirect to login
+      }
+
+      if (isOnAuthPage && isLoggedIn) {
+        return Response.redirect(new URL('/sessions', nextUrl));
+      }
+
+      return true;
+    },
+  },
+  providers: [], // Configured in auth.ts
+};
+

src/lib/auth.ts

@@ -0,0 +1,62 @@
+import NextAuth from 'next-auth';
+import Credentials from 'next-auth/providers/credentials';
+import { compare } from 'bcryptjs';
+import { prisma } from '@/services/database';
+
+export const { handlers, signIn, signOut, auth } = NextAuth({
+  providers: [
+    Credentials({
+      name: 'credentials',
+      credentials: {
+        email: { label: 'Email', type: 'email' },
+        password: { label: 'Password', type: 'password' },
+      },
+      async authorize(credentials) {
+        if (!credentials?.email || !credentials?.password) {
+          return null;
+        }
+
+        const user = await prisma.user.findUnique({
+          where: { email: credentials.email as string },
+        });
+
+        if (!user) {
+          return null;
+        }
+
+        const isPasswordValid = await compare(credentials.password as string, user.password);
+
+        if (!isPasswordValid) {
+          return null;
+        }
+
+        return {
+          id: user.id,
+          email: user.email,
+          name: user.name,
+        };
+      },
+    }),
+  ],
+  session: {
+    strategy: 'jwt',
+  },
+  pages: {
+    signIn: '/login',
+  },
+  callbacks: {
+    async jwt({ token, user }) {
+      if (user) {
+        token.id = user.id;
+      }
+      return token;
+    },
+    async session({ session, token }) {
+      if (session.user) {
+        session.user.id = token.id as string;
+      }
+      return session;
+    },
+  },
+});
+