added client RA bill wise download report

app/services/user_service.py

@@ -0,0 +1,27 @@
+from app.models.user_model import User
+from app.services.db_service import db
+
+class UserService:
+
+    @staticmethod
+    def register_user(name, email, password):
+        if User.query.filter_by(email=email).first():
+            return None
+
+        user = User(name=name, email=email)
+        user.set_password(password)
+
+        db.session.add(user)
+        db.session.commit()
+        return user
+
+    @staticmethod
+    def validate_login(email, password):
+        user = User.query.filter_by(email=email).first()
+        if user and user.check_password(password):
+            return user
+        return None
+
+    @staticmethod
+    def get_all_users():
+        return User.query.all()