/**
 * Logging types.
 */
/**
 * Valid log level values, ordered from most verbose to least verbose.
 *
 * - `trace`: Most verbose, detailed debugging information
 * - `debug`: Debugging information
 * - `info`: General informational messages (default)
 * - `warn`: Warning messages
 * - `error`: Error messages
 * - `fatal`: Fatal errors
 * - `silent`: Suppress all output
 */
export type LogLevel = 'trace' | 'debug' | 'info' | 'warn' | 'error' | 'fatal' | 'silent';
/**
 * Context object for structured logging entries.
 *
 * A dictionary where any string key can hold any value,
 * used to attach contextual metadata to log messages.
 */
export interface LogContext {
    [key: string]: unknown;
}
/** Writable stream interface for custom log destinations (Node.js Writable compatible) */
export interface LogDestination {
    write(chunk: string | Buffer, encoding?: BufferEncoding, callback?: (error?: Error | null) => void): boolean;
    on?(event: string, listener: (...args: unknown[]) => void): this;
    once?(event: string, listener: (...args: unknown[]) => void): this;
    emit?(event: string, ...args: unknown[]): boolean;
}
/**
 * Configuration options for creating or configuring a logger.
 *
 * All options are optional and have sensible defaults.
 * Options provided to {@link createLogger} merge with global defaults set via {@link configureLogger}.
 */
export interface LoggerOptions {
    /** Log level. Default: 'info' */
    level?: LogLevel;
    /** File descriptor to write to (1=stdout, 2=stderr). Default: 2 */
    fd?: number;
    /** Custom destination stream. Overrides fd when provided. Useful for testing. */
    destination?: LogDestination;
    /** Base context included in all log entries */
    baseContext?: LogContext;
    /** Enable secret redaction. Default: true */
    redact?: boolean;
    /** Output JSON lines instead of pretty print. Default: false */
    json?: boolean;
    /** Enable colors in pretty print mode. Default: true */
    colorize?: boolean;
}
/**
 * Logger interface for structured logging with support for multiple log levels.
 *
 * Each log method supports two overloads:
 * - `method(message: string, context?: LogContext)` - message-first format
 * - `method(context: LogContext, message: string)` - context-first format for structured logging
 *
 * Use {@link Logger.child} to create a child logger with bound context that will be included in all subsequent log entries.
 */
export interface Logger {
    trace(message: string, context?: LogContext): void;
    trace(context: LogContext, message: string): void;
    debug(message: string, context?: LogContext): void;
    debug(context: LogContext, message: string): void;
    info(message: string, context?: LogContext): void;
    info(context: LogContext, message: string): void;
    warn(message: string, context?: LogContext): void;
    warn(context: LogContext, message: string): void;
    error(message: string, context?: LogContext): void;
    error(context: LogContext, message: string): void;
    fatal(message: string, context?: LogContext): void;
    fatal(context: LogContext, message: string): void;
    child(context: LogContext): Logger;
}