/**
 * Cache dependency interface - similar to Yii2 cache dependency system
 *
 * A cache dependency represents a dependency relationship between cached data
 * and some external state. When the external state changes, the cached data
 * becomes invalid.
 *
 * @example
 * ```typescript
 * // Tag-based dependency
 * new TagDependency(['user-list'])
 *
 * // Database-based dependency
 * new DbDependency('SELECT MAX(updated_at) FROM users WHERE id = ?', [userId])
 *
 * // Callback-based dependency
 * new CallbackDependency(() => ConfigService.get('app.version'))
 * ```
 */
export interface CacheDependency {
    /**
     * Get a unique key that identifies this dependency
     * This key is used to store the dependency state
     *
     * @returns Unique dependency key
     */
    getKey(): string;
    /**
     * Get the current state/value of this dependency
     * This value will be compared with stored state to detect changes
     *
     * @returns Current dependency data/state
     */
    getData(): Promise<any>;
    /**
     * Check if the dependency has changed by comparing old data with current data
     *
     * @param oldData - Previously stored dependency data
     * @returns true if dependency has changed, false otherwise
     */
    isChanged(oldData: any): Promise<boolean>;
    /**
     * Reset/clear the dependency state
     * Used when manually invalidating dependencies
     */
    reset?(): Promise<void>;
}
/**
 * Serialized dependency data stored alongside cached values
 */
export interface DependencyData {
    /**
     * Dependency key
     */
    key: string;
    /**
     * Dependency state snapshot at cache time
     */
    data: any;
    /**
     * Timestamp when dependency was captured
     */
    timestamp: number;
}