import { EventEmitter } from "events";
import { ModelBase } from "../../models/ModelBase";
import { Logger } from "../../utils/Logger";
import { GameState } from '../gamestate/GameState';
import { EventMap } from "../../constants/events";
export type EmitterContext = EventEmitter<EventMap>;
export interface DiffOptions {
    previously?: GameState;
    added?: GameState;
}
export declare abstract class DifferBase<T extends ModelBase> {
    protected previously: GameState | null;
    protected added: GameState | null;
    protected abstract logger: Logger | Console;
    constructor(previously?: GameState, added?: GameState);
    emitWithContext(emitter: EventEmitter<EventMap>, eventName: keyof EventMap, ...data: EventMap[typeof eventName]): void;
    /**
     * 🔥 Safely obtains a field from `curr`, or if it doesn't exist, from `fallback`.
     * @param {string} path E.g.: 'player.state.hp'
     * @param {Object} curr Current snapshot
     * @param {Object} fallback Fallback snapshot (added or previously)
     * @returns {any} Value found or null */
    getFieldSafe(path: string, curr: GameState, fallback: GameState | null): any;
    abstract diff(previousState: GameState, currentState: GameState, emitterContext: EmitterContext, options: DiffOptions): any;
}