/**
 * API工具类 - 统一封装后端API请求
 */

import type {
  ApiResponse,
  TotalAssetsResponse,
  GetPortfoliosResponse,
  PortfolioDetailResponse,
  CreatePortfolioRequest,
  CreatePortfolioResponse,
  UpdatePortfolioRequest,
  GetTransactionsResponse,
  CreateTransactionRequest,
  CreateTransactionResponse,
  NavHistoryResponse,
  BackfillNavResponse,
  StrategyListResponse,
  StrategyDetailResponse,
  CreateStrategyRequest,
  UpdateStrategyRequest,
  StrategyResponse,
  DeleteStrategyResponse,
  StrategySignalResponse,
  UserInfoResponse,
  UserStatsResponse,
  UpdateUserRequest,
  UpdateUserResponse,
} from '@/types';

// API基础URL
const BASE_URL: string = import.meta.env.VITE_API_BASE_URL || 'https://localhost:7040/';

// 请求超时时间
const TIMEOUT = 10000;

// 登录锁，防止并发登录
let loginLock: Promise<any> | null = null;

// 全局loading计数
let loadingCount = 0;

const showLoading = (): void => {
  if (loadingCount === 0) {
    uni.showLoading({ title: '加载中...', mask: true });
  }
  loadingCount++;
};

const hideLoading = (): void => {
  loadingCount--;
  if (loadingCount <= 0) {
    loadingCount = 0;
    uni.hideLoading();
  }
};

/**
 * 获取微信登录码
 */
const getWechatCode = (): Promise<string> => {
  return new Promise((resolve, reject) => {
    uni.login({
      provider: 'weixin',
      success: (res) => {
        if (res.code) {
          resolve(res.code);
        } else {
          reject(new Error(`微信登录码获取失败: ${res.errMsg}`));
        }
      },
      fail: (err) => {
        reject(new Error(`微信登录失败: ${err.errMsg}`));
      }
    });
  });
};

/**
 * 执行微信登录
 */
const doWechatLogin = async (): Promise<ApiResponse<{ token: string; userId: string }>> => {
  const code = await getWechatCode();
  
  const res = await new Promise<any>((resolve, reject) => {
    uni.request({
      url: `${BASE_URL}api/auth/wechat-login`,
      method: 'POST',
      data: { code },
      header: { 'Content-Type': 'application/json' },
      timeout: TIMEOUT,
      success: resolve,
      fail: reject
    });
  });
  
  if (res.statusCode === 200 && res.data?.code === 200 && res.data?.data?.token) {
    uni.setStorageSync('token', res.data.data.token);
    return res.data;
  } else {
    throw new Error(res.data?.message || '微信登录失败');
  }
};

/**
 * 带重试机制的请求方法
 */
const requestWithRetry = async <T = any>(
  url: string,
  method: 'GET' | 'POST' | 'PUT' | 'DELETE' = 'GET',
  data: Record<string, any> = {},
  headers: Record<string, string> = {},
  retryCount: number = 0
): Promise<T> => {
  try {
    let token = uni.getStorageSync('token') as string | undefined;
    
    // 如果没有token，先执行微信登录
    if (!token) {
      if (loginLock) {
        await loginLock;
        token = uni.getStorageSync('token');
      } else {
        loginLock = doWechatLogin();
        await loginLock;
        loginLock = null;
        token = uni.getStorageSync('token');
      }
    }
    
    // 处理URL拼接
    let fullUrl: string;
    if (BASE_URL.endsWith('/') && url.startsWith('/')) {
      fullUrl = BASE_URL + url.substring(1);
    } else if (!BASE_URL.endsWith('/') && !url.startsWith('/')) {
      fullUrl = BASE_URL + '/' + url;
    } else {
      fullUrl = BASE_URL + url;
    }
    
    showLoading();
    
    const res = await new Promise<any>((resolve, reject) => {
      uni.request({
        url: fullUrl,
        method,
        data,
        header: {
          'Content-Type': 'application/json',
          'Authorization': token ? `Bearer ${token}` : '',
          ...headers
        },
        timeout: TIMEOUT,
        success: resolve,
        fail: reject
      });
    });
    
    hideLoading();
    
    if (res.statusCode === 200) {
      return res.data as T;
    } else if (res.statusCode === 401) {
      uni.removeStorageSync('token');
      
      if (retryCount < 3) {
        if (loginLock) {
          await loginLock;
        } else {
          loginLock = doWechatLogin();
          await loginLock;
          loginLock = null;
        }
        return requestWithRetry<T>(url, method, data, headers, retryCount + 1);
      } else {
        uni.showToast({ title: '系统异常，请稍后重试', icon: 'none' });
        throw new Error('登录已过期，重试次数超限');
      }
    } else {
      throw new Error(`请求失败: ${res.statusCode}`);
    }
  } catch (error: any) {
    hideLoading();
    
    if (retryCount < 3 && error.message?.includes('网络请求失败')) {
      return requestWithRetry<T>(url, method, data, headers, retryCount + 1);
    }
    
    if (retryCount >= 2) {
      uni.showToast({ title: '系统异常，请稍后重试', icon: 'none', duration: 2000 });
    }
    
    throw error;
  }
};

/**
 * 基础请求方法
 */
const request = <T = any>(
  url: string,
  method: 'GET' | 'POST' | 'PUT' | 'DELETE' = 'GET',
  data: Record<string, any> = {},
  headers: Record<string, string> = {}
): Promise<T> => {
  return requestWithRetry<T>(url, method, data, headers);
};

/**
 * GET请求
 */
export const get = <T = any>(
  url: string,
  params: Record<string, any> = {},
  headers: Record<string, string> = {}
): Promise<T> => {
  const queryString = Object.keys(params)
    .map(key => `${key}=${encodeURIComponent(params[key])}`)
    .join('&');
  const fullUrl = queryString ? `${url}?${queryString}` : url;
  return request<T>(fullUrl, 'GET', {}, headers);
};

/**
 * POST请求
 */
export const post = <T = any>(
  url: string,
  data: Record<string, any> = {},
  headers: Record<string, string> = {}
): Promise<T> => {
  return request<T>(url, 'POST', data, headers);
};

/**
 * PUT请求
 */
export const put = <T = any>(
  url: string,
  data: Record<string, any> = {},
  headers: Record<string, string> = {}
): Promise<T> => {
  return request<T>(url, 'PUT', data, headers);
};

/**
 * DELETE请求
 */
export const del = <T = any>(
  url: string,
  headers: Record<string, string> = {}
): Promise<T> => {
  return request<T>(url, 'DELETE', {}, headers);
};

/**
 * API接口封装
 */
export const api = {
  assets: {
    getAssetData: (): Promise<ApiResponse<TotalAssetsResponse>> => 
      get('/api/v1/portfolio/assets'),
    
    getHoldings: (): Promise<ApiResponse<GetPortfoliosResponse>> => 
      get('/api/v1/portfolio'),
    
    getPortfolio: (id: string | number): Promise<ApiResponse<PortfolioDetailResponse>> => 
      get(`/api/v1/portfolio/${id}`),
    
    getTransactions: (params: { portfolioId?: string; limit: number; offset: number }): Promise<ApiResponse<GetTransactionsResponse>> => 
      get('/api/v1/portfolio/transactions', params),
    
    createTransaction: (data: CreateTransactionRequest): Promise<ApiResponse<CreateTransactionResponse>> => 
      post('/api/v1/portfolio/transactions', data),
    
    createPortfolio: (data: CreatePortfolioRequest): Promise<ApiResponse<CreatePortfolioResponse>> => 
      post('/api/v1/portfolio', data),
    
    updatePortfolio: (id: string | number, data: UpdatePortfolioRequest): Promise<ApiResponse<void>> => 
      put(`/api/v1/portfolio/${id}`, data),
    
    getPortfolioSignal: (id: string | number): Promise<ApiResponse<StrategySignalResponse>> => 
      get(`/api/v1/portfolio/${id}/signal`),
    
    getNavHistory: (id: string | number, params?: { startDate?: string; endDate?: string; interval?: string }): Promise<ApiResponse<NavHistoryResponse>> => 
      get(`/api/v1/portfolio/${id}/nav-history`, params),
    
    backfillNavHistory: (id: string | number, force: boolean = false): Promise<ApiResponse<BackfillNavResponse>> => 
      post(`/api/v1/portfolio/${id}/nav-history/backfill`, { force }),
  },
  
  strategies: {
    getStrategies: (): Promise<ApiResponse<StrategyListResponse>> => 
      get('/api/v1/strategy/strategies'),
    
    getStrategy: (id: string | number): Promise<ApiResponse<StrategyDetailResponse>> => 
      get(`/api/v1/strategy/${id}`),
    
    createStrategy: (data: CreateStrategyRequest): Promise<ApiResponse<StrategyResponse>> => 
      post('/api/v1/strategy', data),
    
    updateStrategy: (id: string | number, data: UpdateStrategyRequest): Promise<ApiResponse<StrategyResponse>> => 
      put(`/api/v1/strategy/${id}`, data),
    
    deleteStrategy: (id: string | number): Promise<ApiResponse<DeleteStrategyResponse>> => 
      del(`/api/v1/strategy/${id}`),
  },
  
  user: {
    getUserInfo: (): Promise<ApiResponse<UserInfoResponse>> => 
      get('/api/v1/user/info'),
    
    getUserStats: (): Promise<ApiResponse<UserStatsResponse>> => 
      get('/api/v1/user/stats'),
    
    updateUserInfo: (data: UpdateUserRequest): Promise<ApiResponse<UpdateUserResponse>> => 
      put('/api/v1/user/info', data),
  },

  ticker: {
    search: (keyword: string, limit: number = 20): Promise<ApiResponse<{ items: { symbol: string; name: string }[] }>> => 
      get('/api/v1/ticker/search', { keyword, limit }),
  }
};

export default api;