import { DeepPartial } from './types';
export type LogMode = 'off' | 'minimal' | 'full';
/**
 * Configuration options for downtimer object.
 */
export type DowntimerOptions = {
    /**
     * Use colours in log output. Defaults to `true`, can also be disabled using `NO_COLOR`
     * environment variable.
     */
    useColor: boolean;
    /** Configuration for event logging */
    logConfig: {
        /** Log when a new timer is scheduled */
        schedule: LogMode;
        /** Log options when executing a timer */
        execute: {
            /** Log just before a timer callback is executed */
            before: LogMode;
            /** Log when an error occurs in a timer callback */
            onError: LogMode;
        };
        /** Log options when clearing a timer */
        clear: {
            /**
             * Log when an attempt is made to clear a timer with an unknown ID.
             *
             * This happens if the timer has already been cleared or has already executed.
             */
            notFound: LogMode;
            /** Log when a timer is cleared successfully */
            success: LogMode;
            /** Log when all outstanding timers are cleared */
            allOutstanding: LogMode;
        };
        /** Log when the server exits with outstanding timers */
        exitWithOutstandingTimers: LogMode;
    };
};
/** Default options for Downtimer */
export declare const defaultOptions: DowntimerOptions;
/**
 * Merge a `DeepPartial<T>` object with a collection of defaults of type `T`
 *
 * If `T extends object`, then all properties are optional, and any value that is `undefined` in the
 * `options` will be replaced with the corresponding value in `defaults`.
 *
 * Otherwise, the object is considered to be a complete type, and so is only checked for
 * undefined-ness.
 */
export declare function mergeDeepPartial<T>(defaults: T, options?: DeepPartial<T>): T;