import { Workflow, RunResult, ApiResponse, HealthStatus } from '../types/types';

// 默认超时时间（毫秒）
const DEFAULT_TIMEOUT = 30000;

// 后端API基础URL
const API_BASE_URL = '/api'; // 如果是代理模式，前缀为/api

/**
 * 带超时的fetch请求
 */
async function fetchWithTimeout(
  url: string, 
  options: RequestInit = {}, 
  timeout = DEFAULT_TIMEOUT
): Promise<Response> {
  const controller = new AbortController();
  const id = setTimeout(() => controller.abort(), timeout);
  
  const response = await fetch(url, {
    ...options,
    signal: controller.signal
  });
  
  clearTimeout(id);
  return response;
}

/**
 * 统一处理API响应
 */
async function handleResponse<T>(response: Response): Promise<ApiResponse<T>> {
  try {
    const data = await response.json();
    
    if (!response.ok) {
      return {
        success: false,
        error: data.error || `请求失败: ${response.status}`,
        status_code: response.status
      };
    }
    
    return {
      success: true,
      data,
      status_code: response.status
    };
  } catch (error) {
    return {
      success: false,
      error: error instanceof Error ? error.message : '未知错误',
      status_code: response.status
    };
  }
}

/**
 * API客户端
 */
const apiClient = {
  /**
   * 运行实验工作流
   */
  runExperiment: async (workflow: Workflow): Promise<ApiResponse<RunResult>> => {
    try {
      const response = await fetchWithTimeout(
        `${API_BASE_URL}/run_experiment`,
        {
          method: 'POST',
          headers: {
            'Content-Type': 'application/json',
          },
          body: JSON.stringify(workflow),
        }
      );
      
      return handleResponse<RunResult>(response);
    } catch (error) {
      return {
        success: false,
        error: error instanceof Error ? error.message : '未知错误',
      };
    }
  },
  
  /**
   * 检查后端健康状态
   */
  checkHealth: async (): Promise<ApiResponse<HealthStatus>> => {
    try {
      const startTime = Date.now();
      const response = await fetchWithTimeout(
        `${API_BASE_URL}/health`,
        {
          method: 'GET',
        },
        5000 // 健康检查使用较短的超时时间
      );
      
      const latency = Date.now() - startTime;
      const result = await handleResponse<any>(response);
      
      if (result.success) {
        return {
          success: true,
          data: {
            status: 'online',
            message: 'Lab服务器在线',
            latency
          },
          status_code: result.status_code
        };
      } else {
        return {
          success: true,
          data: {
            status: 'offline',
            message: result.error || 'Lab服务器异常',
            latency
          },
          status_code: result.status_code
        };
      }
    } catch (error) {
      return {
        success: false,
        data: {
          status: 'offline',
          message: error instanceof Error ? error.message : '连接失败'
        },
        error: error instanceof Error ? error.message : '未知错误',
      };
    }
  },
  
  /**
   * 获取工作流执行状态
   */
  getRunStatus: async (runId: string): Promise<ApiResponse<RunResult>> => {
    try {
      const response = await fetchWithTimeout(
        `${API_BASE_URL}/run_status/${runId}`,
        {
          method: 'GET',
        }
      );
      
      return handleResponse<RunResult>(response);
    } catch (error) {
      return {
        success: false,
        error: error instanceof Error ? error.message : '未知错误',
      };
    }
  },
};

export default apiClient;