// app/api/client.ts
import { mockData, type MockApiResponse } from './mock';

/**
 * API响应类型
 */
export type ApiResponse<T> = {
  data?: T;
  error?: string;
  status: number;
  headers?: Record<string, string>; // 添加对响应头的支持
};

export type QueryParams = Record<string, string | number | boolean | undefined>;

// 获取 API 基础 URL
const API_BASE_URL = '172.16.0.119:9000/admin';

// 是否使用模拟数据（开发环境使用）
const USE_MOCK_DATA = false; // 设置为true使用模拟数据，避免API连接问题

/**
 * 构建完整的 API URL
 */
function buildUrl(endpoint: string, params?: QueryParams): string {
  // 创建 URL 字符串
  const url = new URL(
    endpoint.startsWith('http') ? endpoint : `http://${API_BASE_URL}${endpoint.startsWith('/') ? endpoint : `/${endpoint}`}`, 
    typeof window !== 'undefined' ? window.location.origin : 'http://localhost:3000'
  );
  
  // 添加查询参数
  if (params) {
    Object.entries(params).forEach(([key, value]) => {
      if (value !== undefined) {
        url.searchParams.append(key, String(value));
      }
    });
  }
  
  return url.toString();
}

// 超时控制
const fetchWithTimeout = async (url: string, options: RequestInit, timeout = 5000) => {
  const controller = new AbortController();
  const id = setTimeout(() => controller.abort(), timeout);
  
  try {
    const response = await fetch(url, {
      ...options,
      signal: controller.signal
    });
    clearTimeout(id);
    return response;
  } catch (error) {
    clearTimeout(id);
    throw error;
  }
};

/**
 * 获取模拟响应数据
 */
function getMockResponse<T>(endpoint: string): ApiResponse<T> {
  console.log(`[开发模式] 使用模拟数据: ${endpoint}`);
  
  // 移除开头的斜杠以便于匹配
  const path = endpoint.startsWith('/') ? endpoint.substring(1) : endpoint;
  
  // 查找匹配的模拟数据
  for (const mockPath in mockData) {
    const normalizedMockPath = mockPath.startsWith('/') ? mockPath.substring(1) : mockPath;
    if (path === normalizedMockPath || path.startsWith(normalizedMockPath + '/')) {
      // 如果是详情查询 (如 /evaluation_points/1)
      if (path.includes('/') && path !== normalizedMockPath) {
        const id = parseInt(path.split('/')[1]);
        const mockDataItem = mockData[mockPath as keyof typeof mockData] as MockApiResponse<unknown>;
        
        if (Array.isArray(mockDataItem.data)) {
          const item = mockDataItem.data.find((item: {id: number}) => item.id === id);
          
          if (item) {
            return {
              data: {
                code: 0,
                msg: "成功",
                data: item
              } as unknown as T,
              status: 200
            };
          }
        }
        
        return { error: '未找到数据', status: 404 };
      }
      
      // 返回列表数据
      return { 
        data: mockData[mockPath as keyof typeof mockData] as unknown as T, 
        status: 200 
      };
    }
  }
  
  return { error: '没有匹配的模拟数据', status: 404 };
}

/**
 * 通用 API 请求函数
 */
export async function apiRequest<T>(
  endpoint: string, 
  options: RequestInit = {}, 
  params?: QueryParams
): Promise<ApiResponse<T>> {
  // 如果使用模拟数据，直接返回模拟响应
  if (USE_MOCK_DATA) {
    return getMockResponse<T>(endpoint);
  }
  
  try {
    // 构建 URL
    const url = buildUrl(endpoint, params);
    
    // 设置默认请求头
    const headers = new Headers(options.headers || {});
    if (!headers.has('Content-Type') && options.method !== 'GET') {
      headers.set('Content-Type', 'application/json');
    }
    if (!headers.has('Accept')) {
      headers.set('Accept', 'application/json');
    }
    
    // 发送请求，5秒超时
    const response = await fetchWithTimeout(url, {
      ...options,
      headers
    }, 10000);
    
    // 解析响应
    let data = null;
    const contentType = response.headers.get('content-type');
    if (contentType && contentType.includes('application/json') && response.status !== 204) {
      data = await response.json();
    }
    
    // 收集响应头信息
    const responseHeaders: Record<string, string> = {};
    response.headers.forEach((value, key) => {
      responseHeaders[key] = value;
    });
    
    // 检查API返回的状态码
    if (data && 'code' in data && data.code !== 0) {
      console.error(`API请求失败: ${data.msg || '未知错误'} - ${url}`);
      return {
        error: data.msg || '请求失败',
        status: response.status,
        headers: responseHeaders
      };
    }
    
    if (!response.ok) {
      console.error(`HTTP请求失败: ${response.status} - ${url}`);
      return {
        error: data?.msg || `请求失败: ${response.status}`,
        status: response.status,
        headers: responseHeaders
      };
    }
    
    return {
      data,
      status: response.status,
      headers: responseHeaders
    };
  } catch (error) {
    console.error('API请求失败:', error);
    
    // 如果超时或网络错误，使用模拟数据（仅开发环境）
    if (process.env.NODE_ENV !== 'production') {
      console.warn('自动使用模拟数据作为回退');
      return getMockResponse<T>(endpoint);
    }
    
    return {
      error: error instanceof Error ? error.message : '未知错误',
      status: 500
    };
  }
}