export interface User {
    id: number;
    username: string;
    password: string;
    created_at: Date;
}
export interface Session {
    id: string;
    user_id: number;
    expires_at: number;
    created_at: number;
}
export declare function createUser(username: string, password: string): Promise<User>;
export declare function findUserByUsername(username: string): Promise<User | undefined>;
export declare function validateUserCredentials(username: string, password: string): Promise<User | null>;
export declare function createSession(userId: number): Promise<Session>;
export declare function validateSession(sessionId: string): Promise<User | null>;
export declare function removeSession(sessionId: string): Promise<void>;
export declare function hasUsers(): Promise<boolean>;
export declare function createInitialUserIfNeeded(username: string, password: string): Promise<User | null>;
export declare function resetUsers(): Promise<string>;
