/**
 * Core estimator contract shared by every model in the library.
 *
 * Every estimator must:
 *  - accept a single props object in its constructor (positional overloads may
 *    be kept for backwards compatibility, but the props form is canonical);
 *  - implement `getParams()` returning exactly the props-object shape;
 *  - be registered via `registerEstimator()` so it can be revived by
 *    `loadModel()`.
 *
 * `setParams`, `clone`, `toJSON` and `loadModel` are then provided generically
 * by `BaseEstimator`.
 *
 * Serialization format: a versioned, JSON-safe envelope. Values that plain
 * JSON cannot express are wrapped in single-key tag objects ("$num", "$map",
 * "$set", "$typed", "$cls", "$undef", "$obj"). Class instances held in fitted
 * state (tree nodes, KD-trees, nested estimators, ...) must be registered with
 * `registerSerializableClass()` (estimators are registered automatically).
 */
export type Params = Record<string, unknown>;
export declare const MODEL_FORMAT = "@kanaries/ml-model";
export declare const MODEL_FORMAT_VERSION = 1;
export interface SerializedModel {
    format: typeof MODEL_FORMAT;
    formatVersion: number;
    estimator: string;
    params: unknown;
    state: unknown;
}
type AnyCtor = new (...args: never[]) => object;
export declare function registerSerializableClass(name: string, ctor: AnyCtor): void;
export declare function registerEstimator(name: string, ctor: AnyCtor): void;
export declare function getRegisteredEstimators(): ReadonlyMap<string, AnyCtor>;
export declare function encodeValue(value: unknown): unknown;
export declare function decodeValue(value: unknown): unknown;
export declare abstract class BaseEstimator {
    /**
     * Return the constructor parameters of this estimator, using exactly the
     * key names accepted by the props-object constructor. Must reflect current
     * values (after any setParams), not the values passed at construction.
     */
    abstract getParams(): Params;
    /**
     * Merge `params` into the estimator's parameters and reset it to the
     * unfitted state (the estimator is rebuilt through its constructor so all
     * validation logic reruns). Unknown keys throw.
     */
    setParams(params: Params): this;
    /**
     * A new unfitted estimator with identical parameters. Nested estimators
     * inside params (meta-estimators: pipelines, search, ensembles) are
     * themselves cloned, so the copy shares no mutable estimator state.
     */
    clone(): this;
    /**
     * Serialize the estimator (parameters + fitted state) to a JSON-safe
     * object. `JSON.stringify(model)` therefore produces a portable model
     * file; revive it with `loadModel()`.
     */
    toJSON(): SerializedModel;
    /** Typed convenience wrapper around `loadModel` for a known class. */
    static fromJSON<T extends BaseEstimator>(this: new (...args: never[]) => T, json: SerializedModel | string): T;
}
/** Revive any serialized estimator produced by `estimator.toJSON()`. */
export declare function loadModel(json: SerializedModel | string): BaseEstimator;
export {};