import type { Meta, Processor } from "../types.d.ts";
/**
 * Configuration options for the OpenTelemetry processor.
 */
export interface OpenTelemetryProcessorOptions {
    /**
     * Field name for the span ID. Defaults to 'span_id'
     */
    spanIdFieldName?: string;
    /**
     * If specified, all trace fields will be nested under this key
     */
    traceFieldName?: string;
    /**
     * Field name for the trace flags. Defaults to 'trace_flags'
     */
    traceFlagsFieldName?: string;
    /**
     * Field name for the trace ID. Defaults to 'trace_id'
     */
    traceIdFieldName?: string;
}
/**
 * OpenTelemetry Processor.
 *
 * A processor that adds OpenTelemetry trace context to log metadata.
 * Extracts trace ID, span ID, and trace flags from the active OpenTelemetry span
 * and adds them to the log context for distributed tracing correlation.
 * @template L - The log level type
 * @example
 * ```typescript
 * import { createPail } from "@visulima/pail";
 * import { OpenTelemetryProcessor } from "@visulima/pail/processor/opentelemetry";
 *
 * const logger = createPail({
 *   processors: [new OpenTelemetryProcessor()]
 * });
 *
 * logger.info("Processing request");
 * // Context includes: { trace_id: "...", span_id: "...", trace_flags: "01" }
 * ```
 * @example
 * ```typescript
 * // With custom field names
 * const logger = createPail({
 *   processors: [new OpenTelemetryProcessor({
 *     traceFieldName: "trace",
 *     traceIdFieldName: "traceId",
 *     spanIdFieldName: "spanId"
 *   })]
 * });
 * ```
 */
export declare class OpenTelemetryProcessor<L extends string = string> implements Processor<L> {
    #private;
    /**
     * Creates a new OpenTelemetryProcessor instance.
     * @param options Configuration options for field names and nesting
     */
    constructor(options?: OpenTelemetryProcessorOptions);
    /**
     * Processes log metadata to add OpenTelemetry trace context.
     *
     * Extracts trace information from the active OpenTelemetry span and adds it
     * to the log context. If no valid span is found, the metadata is returned unchanged.
     * @param meta The log metadata to process
     * @returns The processed metadata with trace context added
     */
    process(meta: Meta<L>): Meta<L>;
}