import uuid

class LocalDB:
    def __init__(self):
        self.users = {}
        self.categories = {}
        self.records = {}

    def get_users(self):
        return self.users

    def get_user(self, uid):
        if uid in self.users:
            return {
                'uuid': uid,
                'name': self.users[uid]
            }
        else:
            return {}

    def add_user(self, name):
        if not name:
            return {}

        if name in set(self.users.values()):
            return {}

        new_uuid = uuid.uuid4().hex
        self.users[new_uuid] = name
        return {
            'uuid': new_uuid,
            'name': name
        }

    def del_user(self, uid):
        if uid in self.users:
            name = self.users[uid]
            del self.users[uid]
            return {
                'uuid': uid,
                'name': name
            }
        else:
            return {}