Agent 执行循环、工具调用与 MCP / Skills 协议

interface Message {
  role: 'system' | 'user' | 'assistant' | 'tool';
  content?: string;
  tool_calls?: ToolCall[];
  tool_call_id?: string;
}

async function runAgentLoop(userPrompt: string, tools: ToolDefinition[], maxIterations = 10) {
  const messages: Message[] = [
    { role: 'system', content: 'You are an autonomous AI Agent with Tool Use capability.' },
    { role: 'user', content: userPrompt }
  ];

  let iterations = 0;
  while (iterations < maxIterations) {
    iterations++;
    console.log(`[Harness Loop] 第 ${iterations} 轮推理...`);

    // 1. 调用模型获取回复
    const response = await callLLM({ messages, tools });
    messages.push(response.message);

    // 2. 检查模型是否决定调用工具
    if (!response.message.tool_calls || response.message.tool_calls.length === 0) {
      // 模型没有调用工具，说明已推理完毕，输出最终答案
      console.log("[Harness Loop] 任务完成，返回最终结果。");
      return response.message.content;
    }

    // 3. Harness 依次执行工具调用 (防御性执行与安全沙盒)
    for (const toolCall of response.message.tool_calls) {
      console.log(`[Tool Dispatch] 执行工具: ${toolCall.function.name}`);
      const result = await executeToolSafely(toolCall.function.name, toolCall.function.arguments);
      
      // 4. 将执行观测结果回传给上下文，供模型下一步决策
      messages.push({
        role: 'tool',
        tool_call_id: toolCall.id,
        content: JSON.stringify(result)
      });
    }
  }

  throw new Error("超出最大安全循环轮数 (Max Iterations Exceeded)，防止死循环消耗 Token！");
}