test_sample.diff

diff --git a/src/auth/LoginService.ts b/src/auth/LoginService.ts
new file mode 100644
index 0000000..a1b2c3d
--- /dev/null
+++ b/src/auth/LoginService.ts
@@ -0,0 +1,35 @@
+import jwt from 'jsonwebtoken';
+import bcrypt from 'bcrypt';
+
+export class LoginService {
+  private secretKey: string;
+
+  constructor(secretKey: string) {
+    this.secretKey = secretKey;
+  }
+
+  async login(username: string, password: string): Promise<string> {
+    // Validate credentials
+    const user = await this.validateCredentials(username, password);
+
+    if (!user) {
+      throw new Error('Invalid credentials');
+    }
+
+    // Generate JWT token
+    const token = jwt.sign(
+      { userId: user.id, username: user.username, role: user.role },
+      this.secretKey,
+      { expiresIn: '24h' }
+    );
+
+    return token;
+  }
+
+  private async validateCredentials(username: string, password: string) {
+    // Query user from database
+    const user = await db.users.findOne({ username });
+    if (!user) return null;
+
+    // Verify password
+    const isValid = await bcrypt.compare(password, user.passwordHash);
+    return isValid ? user : null;
+  }
+}