/**
 * Represents log levels in ascending order of severity.
 *
 * Log levels follow standard severity conventions.
 *
 * - TRACE: Finest-grained informational events for detailed debugging.
 * - DEBUG: Detailed informational events useful for debugging.
 * - INFO: Informational messages highlighting application progress.
 * - WARN: Potentially harmful situations that warrant attention.
 * - ERROR: Error events that might still allow the application to continue.
 *
 * @category Logging
 */
export declare enum LogLevel {
    /**
     * Finest-grained informational events, typically used for detailed debugging.
     */
    TRACE = 0,
    /**
     * Detailed informational events useful for debugging an application.
     */
    DEBUG = 1,
    /**
     * Informational messages that highlight the progress of the application.
     */
    INFO = 2,
    /**
     * Potentially harmful situations that warrant attention.
     */
    WARN = 3,
    /**
     * Error events that might still allow the application to continue running.
     */
    ERROR = 4
}
/**
 * Parses a log level from either a string or LogLevel enum value.
 *
 * When a string is provided, the parsing is case-insensitive.
 *
 * @param level - The log level as a string or LogLevel enum value.
 * @returns {LogLevel | undefined} The corresponding LogLevel enum value, or undefined if invalid.
 *
 * @category Logging
 */
export declare function parseLogLevel(level: LogLevel | string): LogLevel | undefined;
/**
 * Interface for logging operations within the Couchbase SDK.
 *
 * All logging methods are optional, allowing implementers to choose which
 * log levels to support.
 *
 * @category Logging
 */
export interface Logger {
    /**
     * Logs a message at the TRACE level.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    trace?(message: string, ...args: any[]): void;
    /**
     * Logs a message at the DEBUG level.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    debug?(message: string, ...args: any[]): void;
    /**
     * Logs a message at the INFO level.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    info?(message: string, ...args: any[]): void;
    /**
     * Logs a message at the WARN level.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    warn?(message: string, ...args: any[]): void;
    /**
     * Logs a message at the ERROR level.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    error?(message: string, ...args: any[]): void;
}
/**
 * A no-operation logger implementation that discards all log messages.
 *
 * @category Logging
 */
export declare class NoOpLogger implements Logger {
    /**
     * No-op implementation of trace logging.
     */
    trace(): void;
    /**
     * No-op implementation of debug logging.
     */
    debug(): void;
    /**
     * No-op implementation of info logging.
     */
    info(): void;
    /**
     * No-op implementation of warn logging.
     */
    warn(): void;
    /**
     * No-op implementation of error logging.
     */
    error(): void;
}
/**
 * A safe wrapper around user-provided Logger implementations.
 *
 * This wrapper ensures that calling any logging method is always safe, even if the
 * underlying logger is undefined or the underlying logger only implements a subset
 * of methods.
 *
 * @category Logging
 */
export declare class CouchbaseLogger implements Logger {
    private readonly _logger?;
    /**
     * Creates a new CouchbaseLogger wrapper.
     *
     * @param logger - Optional user-provided logger implementation.
     *                 Can be undefined or implement only a subset of methods.
     */
    constructor(logger?: Logger);
    /**
     * Logs a message at the TRACE level if the underlying logger implements it.
     *
     * If the logger is undefined or doesn't implement trace, this is a no-op.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    trace(message: string, ...args: any[]): void;
    /**
     * Logs a message at the DEBUG level if the underlying logger implements it.
     *
     * If the logger is undefined or doesn't implement debug, this is a no-op.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    debug(message: string, ...args: any[]): void;
    /**
     * Logs a message at the INFO level if the underlying logger implements it.
     *
     * If the logger is undefined or doesn't implement info, this is a no-op.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    info(message: string, ...args: any[]): void;
    /**
     * Logs a message at the WARN level if the underlying logger implements it.
     *
     * If the logger is undefined or doesn't implement warn, this is a no-op.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    warn(message: string, ...args: any[]): void;
    /**
     * Logs a message at the ERROR level if the underlying logger implements it.
     *
     * If the logger is undefined or doesn't implement error, this is a no-op.
     *
     * @param message - The message to log.
     * @param args - Optional additional arguments for formatting or context.
     */
    error(message: string, ...args: any[]): void;
}
/**
 * Creates a CouchbaseLogger that outputs to the console up to the specified log level.
 *
 * @param logLevel - The log level to output to the console.
 * @param prefix - Optional prefix to prepend to all log messages.
 * @returns {CouchbaseLogger} A CouchbaseLogger configured for console output.
 *
 * @category Logging
 */
export declare function createConsoleLogger(logLevel: LogLevel, prefix?: string): CouchbaseLogger;