/**
 * Copyright (c) 2026, Salesforce, Inc.,
 * All rights reserved.
 * For full license text, see the LICENSE.txt file
 */

import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";

/**
 * Transport/dispatch bring-up stub: returns caller input verbatim, deliberately
 * bypassing the runTool/sanitizePaths/neutralizeControlChars chokepoint. Because
 * it reflects raw bytes it is registered only when GRAPHITI_ENABLE_ECHO === "1"
 * (see createServer) and is absent from the default published surface, pending
 * removal now that the sf_gql_* tools provide real coverage (W-23148363).
 */
export function registerEchoTool(server: McpServer): void {
	server.registerTool(
		"echo",
		{
			description:
				"Echo the input message back verbatim. Used to verify MCP transport and dispatch end-to-end before the typed sf_gql_* tools are wired in.",
			inputSchema: {
				message: z.string().describe("The message to echo back."),
			},
		},
		async ({ message }) => ({
			content: [{ type: "text", text: message }],
		}),
	);
}