import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { Inject, Injectable, Logger, Optional, Scope } from '@nestjs/common';
import { ModuleRef, Reflector } from '@nestjs/core';
import { McpRegistryDiscoveryService } from './mcp-registry-discovery.service';
import { McpToolsHandler } from './handlers/mcp-tools.handler';
import { McpResourcesHandler } from './handlers/mcp-resources.handler';
import { McpPromptsHandler } from './handlers/mcp-prompts.handler';
import { HttpRequest } from '../interfaces/http-adapter.interface';
import { ToolAuthorizationService } from './tool-authorization.service';
import type { McpOptions } from '../interfaces/mcp-options.interface';
import { createMcpLogger } from '../utils/mcp-logger.factory';

/**
 * Request-scoped service for executing MCP tools
 */
@Injectable({ scope: Scope.REQUEST })
export class McpExecutorService {
  private logger: Logger;
  private toolsHandler: McpToolsHandler;
  private resourcesHandler: McpResourcesHandler;
  private promptsHandler: McpPromptsHandler;

  constructor(
    moduleRef: ModuleRef,
    registry: McpRegistryDiscoveryService,
    @Inject('MCP_MODULE_ID') mcpModuleId: string,
    @Inject('MCP_OPTIONS') options: McpOptions,
    authService: ToolAuthorizationService,
    reflector: Reflector,
  ) {
    this.logger = createMcpLogger(McpExecutorService.name, options);
    this.toolsHandler = new McpToolsHandler(
      moduleRef,
      registry,
      reflector,
      mcpModuleId,
      options,
      authService,
    );
    this.resourcesHandler = new McpResourcesHandler(
      moduleRef,
      registry,
      reflector,
      mcpModuleId,
    );
    this.promptsHandler = new McpPromptsHandler(
      moduleRef,
      registry,
      reflector,
      mcpModuleId,
    );
  }

  /**
   * Register tool-related request handlers with the MCP server
   * @param mcpServer - The MCP server instance
   * @param request - The current HTTP request object
   */
  registerRequestHandlers(mcpServer: McpServer, httpRequest: HttpRequest) {
    this.toolsHandler.registerHandlers(mcpServer, httpRequest);
    this.resourcesHandler.registerHandlers(mcpServer, httpRequest);
    this.promptsHandler.registerHandlers(mcpServer, httpRequest);
  }
}