import api from './api';

export interface User {
  id: string;
  firstName: string;
  lastName: string;
  email: string;
  mobile: string | null;
  role: string;
  walletBalance: number;
  charityDonationTotal: number;
  hasPassword?: boolean;
  password?: string;
  currentPassword?: string;
  createdAt: string;
  updatedAt: string;
  pets?: unknown[];
  orders?: unknown[];
}

export interface AuthResponse {
  success: boolean;
  data: {
    user: User;
    accessToken: string;
    refreshToken?: string;
  };
}

interface ApiErr {
  response?: {
    status?: number;
    data?: {
      message?: string | string[];
    };
  };
}

export class AuthService {
  private static instance: AuthService;

  private constructor() {}

  public static getInstance(): AuthService {
    if (!AuthService.instance) {
      AuthService.instance = new AuthService();
    }
    return AuthService.instance;
  }

  /**
   * Send SMS verification code (OTP)
   */
  public async sendOtp(phoneNumber: string): Promise<{ success: boolean; message: string }> {
    try {
      const response = await api.post('/auth/send-otp', { phoneNumber });
      return response.data;
    } catch (error) {
      const err = error as ApiErr;
      const message = err.response?.data?.message || 'خطا در ارسال کد تایید';
      throw new Error(Array.isArray(message) ? message[0] : message);
    }
  }

  /**
   * Verify SMS verification code and login/register
   */
  public async verifyOtp(phoneNumber: string, code: string): Promise<AuthResponse> {
    try {
      const response = await api.post('/auth/verify-otp', { phoneNumber, code });
      const { data } = response.data;
      if (data?.accessToken) {
        localStorage.setItem('accessToken', data.accessToken);
      }
      if (data?.refreshToken) {
        localStorage.setItem('refreshToken', data.refreshToken);
      }
      return response.data;
    } catch (error) {
      const err = error as ApiErr;
      const message = err.response?.data?.message || 'کد تایید نامعتبر است';
      throw new Error(Array.isArray(message) ? message[0] : message);
    }
  }

  /**
   * Register with email/mobile and password
   */
  public async register(data: Record<string, unknown>): Promise<AuthResponse> {
    try {
      const response = await api.post('/auth/register', data);
      const { data: resData } = response.data;
      if (resData?.accessToken) {
        localStorage.setItem('accessToken', resData.accessToken);
      }
      if (resData?.refreshToken) {
        localStorage.setItem('refreshToken', resData.refreshToken);
      }
      return response.data;
    } catch (error) {
      const err = error as ApiErr;
      const message = err.response?.data?.message || 'خطا در ثبت‌نام';
      throw new Error(Array.isArray(message) ? message[0] : message);
    }
  }

  /**
   * Login with mobile and password
   */
  public async login(mobile: string, password: string): Promise<AuthResponse> {
    try {
      const response = await api.post('/auth/login', { mobile, password });
      const { data } = response.data;
      if (data?.accessToken) {
        localStorage.setItem('accessToken', data.accessToken);
      }
      if (data?.refreshToken) {
        localStorage.setItem('refreshToken', data.refreshToken);
      }
      return response.data;
    } catch (error) {
      const err = error as ApiErr;
      const message = err.response?.data?.message || 'نام کاربری یا رمز عبور اشتباه است';
      throw new Error(Array.isArray(message) ? message[0] : message);
    }
  }

  /**
   * Refresh auth tokens using the stored refresh token
   */
  public async refreshAuthToken(): Promise<string | null> {
    try {
      const refreshToken = typeof window !== 'undefined' ? localStorage.getItem('refreshToken') : null;
      if (!refreshToken) return null;

      const response = await api.post('/auth/refresh-token', { refreshToken }, { hideErrorToast: true } as unknown as import('axios').AxiosRequestConfig);
      const { data } = response.data;
      if (data?.accessToken) {
        localStorage.setItem('accessToken', data.accessToken);
      }
      if (data?.refreshToken) {
        localStorage.setItem('refreshToken', data.refreshToken);
      }
      return data?.accessToken || null;
    } catch {
      this.logout();
      return null;
    }
  }

  /**
   * Get current user profile
   */
  public async getProfile(): Promise<User | null> {
    try {
      const response = await api.get('/users/profile', { hideErrorToast: true } as unknown as import('axios').AxiosRequestConfig);
      return response.data;
    } catch (error) {
      const err = error as ApiErr;
      if (err.response?.status === 401 || err.response?.status === 403) {
        return null;
      }
      const message = err.response?.data?.message || 'خطا در دریافت اطلاعات کاربری';
      throw new Error(Array.isArray(message) ? message[0] : message);
    }
  }

  /**
   * Update current user profile
   */
  public async updateProfile(profileData: Partial<User>): Promise<User> {
    try {
      const response = await api.patch('/users/profile', profileData);
      return response.data;
    } catch (error) {
      const err = error as ApiErr;
      const message = err.response?.data?.message || 'خطا در ویرایش اطلاعات کاربری';
      throw new Error(Array.isArray(message) ? message[0] : message);
    }
  }

  /**
   * Logout user and clear tokens
   */
  public logout(): void {
    if (typeof window !== 'undefined') {
      try {
        const token = localStorage.getItem('accessToken');
        if (token) {
          api.post('/auth/logout').catch(() => {});
        }
      } catch {}
      localStorage.removeItem('accessToken');
      localStorage.removeItem('refreshToken');
    }
  }
}

export const authService = AuthService.getInstance();