A2A通信框架

// A2A客户端实现
class A2AClient {
  constructor(remoteAgentUrl) {
    this.remoteAgentUrl = remoteAgentUrl;
  }

  // 获取远程智能体能力
  async discoverAgent() {
    try {
      const response = await fetch(`${this.remoteAgentUrl}/.well-known/agent.json`);
      
      if (!response.ok) {
        throw new Error(`Failed to discover agent: ${response.statusText}`);
      }
      
      return await response.json();
    } catch (error) {
      console.error("Agent discovery failed:", error);
      throw error;
    }
  }

  // 创建新任务
  async createTask(description, parameters) {
    try {
      const agentCard = await this.discoverAgent();
      const endpoint = `${this.remoteAgentUrl}${agentCard.endpoint}/tasks`;
      
      const response = await fetch(endpoint, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          description,
          parameters
        })
      });
      
      if (!response.ok) {
        throw new Error(`Failed to create task: ${response.statusText}`);
      }
      
      return await response.json();
    } catch (error) {
      console.error("Task creation failed:", error);
      throw error;
    }
  }

  // 获取任务状态
  async getTaskStatus(taskId) {
    try {
      const agentCard = await this.discoverAgent();
      const endpoint = `${this.remoteAgentUrl}${agentCard.endpoint}/tasks/${taskId}`;
      
      const response = await fetch(endpoint);
      
      if (!response.ok) {
        throw new Error(`Failed to get task status: ${response.statusText}`);
      }
      
      return await response.json();
    } catch (error) {
      console.error("Get task status failed:", error);
      throw error;
    }
  }

  // 使用示例
  async findCandidates(skills, experience, location) {
    try {
      // 创建任务
      const task = await this.createTask(
        "寻找匹配的软件工程师候选人", 
        { skills, experience, location }
      );
      
      console.log(`Task created with ID: ${task.task_id}`);
      
      // 轮询任务状态
      return new Promise((resolve, reject) => {
        const checkStatus = async () => {
          const status = await this.getTaskStatus(task.task_id);
          
          console.log(`Current task status: ${status.status}`);
          
          if (status.status === "completed") {
            resolve(status.result);
          } else if (status.status === "failed") {
            reject(new Error("Task failed"));
          } else {
            // 继续轮询
            setTimeout(checkStatus, 2000);
          }
        };
        
        checkStatus();
      });
    } catch (error) {
      console.error("Find candidates operation failed:", error);
      throw error;
    }
  }
}

// 使用示例
async function runExample() {
  const client = new A2AClient("https://recruitment-agent.example.com");
  
  try {
    const candidates = await client.findCandidates(
      ["Python", "JavaScript", "React"], 
      "3+ years",
      "Remote"
    );
    
    console.log("Found candidates:", candidates);
  } catch (error) {
    console.error("Example failed:", error);
  }
}

runExample();