export type SecretProvider = 'GCP' | 'FILE' | 'VAULT' | 'ENV';
export interface VaultConfig {
    endpoint: string;
    token?: string;
    mount?: string;
    namespace?: string;
}
export interface SecretServiceConfig {
    provider: SecretProvider;
    location: string;
    encryptionKey?: string;
    vaultConfig?: VaultConfig;
    cacheTTL?: number;
}
export declare class SecretService<SecretType> {
    provider: SecretProvider;
    location: string;
    encryptionKey?: string;
    vaultConfig?: VaultConfig;
    cacheTTL: number;
    protected preloadedSecrets?: SecretType;
    protected isPreloaded: boolean;
    private fileWatcher?;
    constructor(config: SecretServiceConfig);
    /**
     * Preload secrets asynchronously for synchronous access later
     * This method loads secrets once and stores them in the instance
     */
    preload(): Promise<void>;
    /**
     * Invalidate preloaded secrets and stop file watching
     */
    invalidate(): Promise<void>;
    /**
     * Set up file watching for automatic invalidation
     */
    private setupFileWatcher;
    /**
     * Load secrets asynchronously with decryption for all providers
     */
    private loadSecretsAsync;
    private isCacheValid;
    private setCache;
    private getCache;
    loadSecretsFromFileAsync(): Promise<SecretType>;
    loadSecretsFromFile(): SecretType;
    loadSecretsFromGCP(): SecretType;
    loadEncryptionKeyFromGCP(): string;
    loadSecretsFromEnv(): SecretType;
    loadSecretsFromVault(): Promise<SecretType>;
    storeSecretsToVault(secrets: Partial<SecretType>): Promise<void>;
    loadSecrets(): SecretType | Promise<SecretType>;
    loadEncryptionKey(): string;
    getSecretAsync(secretName: keyof SecretType): Promise<string>;
    getSecretJsonAsync<T = any>(secretName: keyof SecretType): Promise<T>;
    getSecret(secretName: keyof SecretType): Promise<string>;
    getSecretJson<T = any>(secretName: keyof SecretType): Promise<T>;
    /**
     * Get a secret synchronously (requires preload() to be called first)
     */
    getSecretSync(secretName: keyof SecretType): string;
    /**
     * Get a JSON secret synchronously (requires preload() to be called first)
     */
    getSecretJsonSync<T = any>(secretName: keyof SecretType): T;
    static clearCache(): void;
    static cleanupExpiredCache(): void;
    /**
     * Clean up resources (file watchers, etc.) when service is no longer needed
     */
    dispose(): void;
}