import { createInterface } from "node:readline";

// A minimal legacy stdio fixture. No third-party SDK or external service.
for await (const line of createInterface({ input: process.stdin })) {
  const request = JSON.parse(line);
  if (request.id === undefined) continue;
  let result: unknown;
  if (request.method === "initialize") result = { protocolVersion: request.params.protocolVersion, capabilities: { tools: {} }, serverInfo: { name: "tjwater-mcp-fixture", version: "1" } };
  else if (request.method === "tools/list") result = { tools: [{ name: "echo", description: "Read-only fixture echo", inputSchema: { type: "object", properties: { value: { type: "string" } }, required: ["value"] }, annotations: { readOnlyHint: true } }] };
  else if (request.method === "tools/call") result = { content: [{ type: "text", text: JSON.stringify({ value: request.params.arguments.value, internal_token_empty: !process.env.AGENT_INTERNAL_TOKEN, model_key_empty: !process.env.DEEPSEEK_API_KEY, own_token_present: process.env.MCP_FIXTURE_TOKEN === "MCP_ONLY" }) }] };
  else if (request.method === "ping") result = {};
  else {
    process.stdout.write(`${JSON.stringify({ jsonrpc: "2.0", id: request.id, error: { code: -32601, message: "Method not found" } })}\n`);
    continue;
  }
  process.stdout.write(`${JSON.stringify({ jsonrpc: "2.0", id: request.id, result })}\n`);
}