export type LogLevel = 'debug' | 'info' | 'warn' | 'error' | 'fatal';
export type LogContext = Record<string, unknown>;
export type ErrorInfo = {
    name: string;
    message: string;
    stack?: string;
    cause?: ErrorInfo;
};
export type TraceContext = {
    traceId: string;
    spanId: string;
    traceFlags?: number;
};
export type LogRecord = {
    level: LogLevel;
    message: string;
    timestamp: string;
    context: LogContext;
    error?: ErrorInfo;
    trace?: TraceContext;
};
export type Formatter = {
    format: (record: LogRecord) => Record<string, unknown>;
    messageKey: string;
};
export type LabelStyle = 'icon' | 'none' | 'text';
export declare const defaultLabelStyle: LabelStyle;
export type TimeStyle = 'datetime' | 'iso' | 'time';
/**
 * Resolve the plain-text timestamp style.
 * Precedence: LOG_TIME > stdout TTY detection.
 * Interactive terminals get time only — the date is invariant across a session
 * and the line stays narrow. Piped or redirected output gets the full date,
 * since captured lines are read back long after they were written.
 * Unrecognized `LOG_TIME` values fall through to TTY detection.
 */
export declare function detectTimeStyle(): TimeStyle;
export declare const defaultTimeStyle: TimeStyle;
export type LoggerOptions = {
    colors?: boolean;
    formatter?: Formatter;
    json?: boolean;
    labels?: LabelStyle;
    level?: LogLevel;
    time?: TimeStyle;
    traceContext?: () => TraceContext | undefined;
};
export type FormatterName = 'datadog' | 'ecs' | 'google-cloud-logging' | 'pino' | 'victoria-logs';
export declare const defaultFormat: FormatterName | undefined;
export declare const isJsonMode: boolean;
/**
 * Resolve whether colored plain-text output should be used.
 * Precedence: FORCE_COLOR > NO_COLOR > stdout TTY detection.
 * `FORCE_COLOR=0`/`false` disables; any other value (incl. empty) enables.
 * `NO_COLOR` (https://no-color.org) disables when present, regardless of value.
 */
export declare function detectColors(): boolean;
export declare const defaultColors: boolean;
export type InterceptOptions = {
    formatter?: Formatter;
    filter?: (level: LogLevel, message: string) => boolean;
    level?: LogLevel;
    traceContext?: () => TraceContext | undefined;
};
export declare const logLevelValues: Record<LogLevel, number>;
export declare function stripAnsi(str: string): string;
export declare function flattenError(entry: Record<string, unknown>, error: ErrorInfo, prefix?: string): void;
export declare function write(data: string, isError: boolean): void;