/**
 * Tool Discovery Service
 * Automatically discovers and registers tools from external MCP servers
 * Handles tool validation, transformation, and lifecycle management
 */
import { EventEmitter } from "events";
import type { Client } from "@modelcontextprotocol/sdk/client/index.js";
import type { ExternalMCPToolInfo, ExternalMCPToolResult, ToolDiscoveryResult, ExternalToolExecutionOptions, JsonObject } from "../types/index.js";
import type { McpOutputNormalizer } from "./mcpOutputNormalizer.js";
/**
 * ToolDiscoveryService
 * Handles automatic tool discovery and registration from external MCP servers
 */
export declare class ToolDiscoveryService extends EventEmitter {
    private serverToolStorage;
    private toolRegistry;
    private serverTools;
    private discoveryInProgress;
    /** Optional normalizer applied to every tool output before it is returned. */
    private outputNormalizer?;
    constructor();
    /**
     * Attach a McpOutputNormalizer.
     * When set, every raw callTool() result is passed through the normalizer
     * before being returned. Oversized outputs are replaced with compact
     * surrogates according to the configured strategy.
     */
    setOutputNormalizer(normalizer: McpOutputNormalizer): void;
    /**
     * Discover tools from an external MCP server
     */
    discoverTools(serverId: string, client: Client, timeout?: number): Promise<ToolDiscoveryResult>;
    /**
     * Perform the actual tool discovery
     */
    private performToolDiscovery;
    /**
     * Register discovered tools
     */
    private registerDiscoveredTools;
    /**
     * Create tool info from MCP tool definition
     */
    private createToolInfo;
    /**
     * Infer tool category from tool definition
     */
    private inferToolCategory;
    /**
     * Validate a tool
     */
    private validateTool;
    /**
     * Infer tool complexity
     */
    private inferComplexity;
    /**
     * Infer if tool requires authentication
     */
    private inferAuthRequirement;
    /**
     * Execute a tool
     */
    executeTool(toolName: string, serverId: string, client: Client, parameters: JsonObject, options?: ExternalToolExecutionOptions): Promise<ExternalMCPToolResult>;
    /**
     * Validate tool parameters
     */
    private validateToolParameters;
    /**
     * Validate parameter type
     */
    private validateParameterType;
    /**
     * Validate tool output with enhanced type safety
     */
    private validateToolOutput;
    /**
     * Update tool statistics
     */
    private updateToolStats;
    /**
     * Get tool by name and server
     */
    getTool(toolName: string, serverId: string): ExternalMCPToolInfo | undefined;
    /**
     * Get all tools for a server
     */
    getServerTools(serverId: string): ExternalMCPToolInfo[];
    /**
     * Get all registered tools
     */
    getAllTools(): ExternalMCPToolInfo[];
    /**
     * Clear tools for a server
     */
    clearServerTools(serverId: string): void;
    /**
     * Update tool availability
     */
    updateToolAvailability(toolName: string, serverId: string, isAvailable: boolean): void;
    /**
     * Create tool key for registry
     */
    private createToolKey;
    /**
     * Create timeout promise
     */
    private createTimeoutPromise;
    /**
     * Destroy the tool discovery service and clean up all resources
     * This method should be called when the service is no longer needed
     * to prevent memory leaks from accumulated event listeners
     *
     * @example
     * ```typescript
     * const service = new ToolDiscoveryService();
     * // ... use the service ...
     * service.destroy(); // Clean up when done
     * ```
     */
    destroy(): void;
    /**
     * Reset statistics for all tools
     * This clears execution counts, timing data, and other statistics
     * while preserving the tool registrations themselves
     */
    resetStatistics(): void;
    /**
     * Get the count of active event listeners
     * Useful for monitoring potential memory leaks
     */
    getListenerCount(): number;
    /**
     * Get discovery statistics
     */
    getStatistics(): {
        totalTools: number;
        availableTools: number;
        unavailableTools: number;
        totalServers: number;
        toolsByServer: Record<string, number>;
        toolsByCategory: Record<string, number>;
    };
}