/**
 * Base query interface that all queries must implement
 * @see /docs/query-mediator.md
 */
export interface Query<TResult = unknown> {
    readonly queryId: string;
    readonly cacheKey?: string;
    readonly cacheTtl?: number;
    readonly projection?: string[];
    readonly timeout?: number;
}
/**
 * Interface for a handler that processes a specific query type
 */
export interface QueryHandler<TQuery extends Query<TResult>, TResult> {
    handle(query: TQuery): Promise<TResult>;
}
export interface QueryResult<T> {
    data: T;
    metadata: {
        cached: boolean;
        executionTime: number;
        cacheKey?: string;
        projectedFields?: string[];
        source: "cache" | "database" | "api";
    };
}
export interface QueryCache {
    get<T>(key: string): Promise<T | null>;
    set<T>(key: string, value: T, ttlSeconds?: number): Promise<void>;
    invalidate(pattern: string): Promise<void>;
    clear(): Promise<void>;
}
export interface QueryMiddleware {
    execute<TResult>(query: Query<TResult>, next: () => Promise<TResult>): Promise<TResult>;
}
export interface QueryMediator {
    registerHandler<TQuery extends Query<TResult>, TResult>(queryId: string, handler: QueryHandler<TQuery, TResult>): void;
    registerMiddleware(middleware: QueryMiddleware): void;
    query<TResult>(query: Query<TResult>): Promise<TResult>;
}