import { ReadonlyJsonCompatibleObject } from '@croct/json';
/**
 * Additional information about the log message.
 */
export type LogDetails = ReadonlyJsonCompatibleObject;
/**
 * The severity of the log message.
 */
export declare enum LogLevel {
    /**
     * Fine-grained messages that provide context to understand the steps leading
     * to errors and warnings.
     */
    DEBUG = "debug",
    /**
     * Informational messages that highlight the system state and progress.
     */
    INFO = "info",
    /**
     * Potential issues that might be problems or might not.
     */
    WARNING = "warning",
    /**
     * Errors that prevent the system from working as intended.
     */
    ERROR = "error"
}
/**
 * A log message.
 *
 * Specifying a structured additional information type makes providing details required.
 *
 * @template D The structure of the log details.
 */
export type Log<D extends LogDetails = LogDetails> = {
    /**
     * The severity of the log message.
     */
    level: LogLevel;
    /**
     * The log message.
     */
    message: string;
} & (LogDetails extends D ? {
    details?: D;
} : {
    details: D;
});
/**
 * A common interface for loggers.
 */
export interface Logger<L extends Log = Log> {
    /**
     * Logs a message.
     *
     * @param log The log message.
     */
    log(log: L): void;
}