/**
 * Settings persistence for Photon instances.
 *
 * Owns the load → merge → expose-as-Proxy → persist-on-change lifecycle for
 * `protected settings` declared by photons. Extracted from PhotonLoader so
 * the loader doesn't have to know about settings paths, the read-only Proxy,
 * or the auto-generated MCP tool surface.
 */
import { PhotonTool, type SettingsSchema, type InputProvider, type OutputHandler } from '@portel/photon-core';
type LogFn = (message: string, meta?: Record<string, any>) => void;
interface SettingsToolOptions {
    outputHandler?: OutputHandler;
    inputProvider?: InputProvider;
}
export declare class SettingsPersistence {
    private readonly baseDir;
    private readonly log;
    /** Per-(photon, instance) write chains — see queuePersist. */
    private persistTails;
    constructor(baseDir: string | undefined, log: LogFn);
    /**
     * Get the settings persistence path for a photon instance.
     * Co-located with state: settings.json sits next to state.json inside
     * the per-instance directory.
     */
    getPath(photonName: string, instanceName: string): string;
    /** Load persisted settings from disk. Returns {} if the file is missing. */
    load(photonName: string, instanceName: string): Promise<Record<string, any>>;
    /** Persist settings to disk, creating parent directories as needed. */
    persist(photonName: string, instanceName: string, values: Record<string, any>): Promise<void>;
    /**
     * Serialize persists per (photon, instance). settings.json is written
     * non-atomically, so concurrent writes for the same instance can interleave
     * or land out of order; chaining them guarantees the last change wins.
     */
    private queuePersist;
    /** Wait for all queued settings writes for an instance to reach disk. */
    flush(photonName: string, instanceName: string): Promise<void>;
    /**
     * Inject settings into a photon instance:
     * - Load persisted values (persisted wins over in-source defaults)
     * - Replace `instance.settings` with a read-only Proxy
     * - Stamp the writable backing object plus identity on the instance so the
     *   auto-generated `settings` tool can update it later.
     */
    inject(instance: Record<string, unknown>, photonName: string, instanceName: string, schema: SettingsSchema): Promise<void>;
    /** Generate an MCP tool definition from a SettingsSchema. */
    generateTool(schema: SettingsSchema): PhotonTool;
    /**
     * Execute the auto-generated settings tool:
     * - No params → return current settings (eliciting any required-but-unset values)
     * - Params with values → update those settings, persist, emit change
     * - Params with explicit undefined on a required prop → trigger elicitation
     */
    execute(instance: Record<string, unknown>, parameters: Record<string, any> | undefined, options?: SettingsToolOptions): Promise<Record<string, any>>;
    /** Emit a `settings:changed` event through the photon's emit system. */
    private emitChange;
}
export {};
//# sourceMappingURL=settings-persistence.d.ts.map