/**
 * Logger interfaces and implementations
 *
 * Why: Replaces console.error with structured, level-based logging.
 * Enables production-ready logging with context and proper error handling.
 *
 * Security: Profile-aware token redaction prevents sensitive data leakage.
 */
import type { AuthInterceptor } from '../types/profile.js';
/**
 * Sanitize log message to prevent log injection
 * Strips ANSI codes and escapes control characters
 */
export declare function sanitizeLogMessage(message: string): string;
export declare enum LogLevel {
    DEBUG = 0,
    INFO = 1,
    WARN = 2,
    ERROR = 3,
    SILENT = 4
}
export interface Logger {
    debug(message: string, context?: Record<string, unknown>): void;
    info(message: string, context?: Record<string, unknown>): void;
    warn(message: string, context?: Record<string, unknown>): void;
    error(message: string, error?: Error, context?: Record<string, unknown>): void;
}
/**
 * Default logger - writes to stderr, respects MCP4_LOG_LEVEL env var
 *
 * Security: Redacts auth tokens based on profile configuration
 */
export declare class ConsoleLogger implements Logger {
    private level;
    private authConfig?;
    constructor(level?: LogLevel, authConfig?: AuthInterceptor);
    debug(message: string, context?: Record<string, unknown>): void;
    info(message: string, context?: Record<string, unknown>): void;
    warn(message: string, context?: Record<string, unknown>): void;
    error(message: string, error?: Error, context?: Record<string, unknown>): void;
    private write;
}
/**
 * Structured JSON logger for production
 *
 * Why: Machine-readable logs for log aggregation systems (ELK, Splunk, etc.)
 * Security: Redacts auth tokens based on profile configuration
 */
export declare class JsonLogger implements Logger {
    private level;
    private authConfig?;
    constructor(level?: LogLevel, authConfig?: AuthInterceptor);
    debug(message: string, context?: Record<string, unknown>): void;
    info(message: string, context?: Record<string, unknown>): void;
    warn(message: string, context?: Record<string, unknown>): void;
    error(message: string, error?: Error, context?: Record<string, unknown>): void;
    private write;
}
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