import axios, { AxiosError, InternalAxiosRequestConfig } from 'axios';
import type { TokenResponse, User, CompanyAnalysis, BatchAnalysisResult, JobStatus, Analytics } from '../types';

const API_BASE_URL = import.meta.env.VITE_API_URL || '/api';

const api = axios.create({
  baseURL: API_BASE_URL,
  headers: {
    'Content-Type': 'application/json',
  },
});

// Token management
let accessToken: string | null = localStorage.getItem('access_token');
let refreshToken: string | null = localStorage.getItem('refresh_token');

export const setTokens = (tokens: TokenResponse) => {
  accessToken = tokens.access_token;
  refreshToken = tokens.refresh_token;
  localStorage.setItem('access_token', tokens.access_token);
  localStorage.setItem('refresh_token', tokens.refresh_token);
};

export const clearTokens = () => {
  accessToken = null;
  refreshToken = null;
  localStorage.removeItem('access_token');
  localStorage.removeItem('refresh_token');
};

export const getAccessToken = () => accessToken;

// Request interceptor to add auth header
api.interceptors.request.use((config: InternalAxiosRequestConfig) => {
  if (accessToken) {
    config.headers.Authorization = `Bearer ${accessToken}`;
  }
  return config;
});

// Response interceptor to handle token refresh
api.interceptors.response.use(
  (response) => response,
  async (error: AxiosError) => {
    const originalRequest = error.config as InternalAxiosRequestConfig & { _retry?: boolean };

    if (error.response?.status === 401 && !originalRequest._retry && refreshToken) {
      originalRequest._retry = true;

      try {
        const response = await axios.post<TokenResponse>(`${API_BASE_URL}/auth/refresh`, {
          refresh_token: refreshToken,
        });

        setTokens(response.data);
        originalRequest.headers.Authorization = `Bearer ${response.data.access_token}`;

        return api(originalRequest);
      } catch {
        clearTokens();
        window.location.href = '/login';
      }
    }

    return Promise.reject(error);
  }
);

// Auth API
export const authApi = {
  register: async (email: string, password: string): Promise<User> => {
    const response = await api.post<User>('/auth/register', { email, password });
    return response.data;
  },

  login: async (email: string, password: string): Promise<TokenResponse> => {
    const response = await api.post<TokenResponse>('/auth/login', { email, password });
    setTokens(response.data);
    return response.data;
  },

  getMe: async (): Promise<User> => {
    const response = await api.get<User>('/auth/me');
    return response.data;
  },

  logout: () => {
    clearTokens();
  },
};

// Analysis API
export const analysisApi = {
  analyzeCompany: async (companyName: string): Promise<CompanyAnalysis> => {
    const response = await api.get<CompanyAnalysis>(`/analyze/${encodeURIComponent(companyName)}`);
    return response.data;
  },

  analyzeBatch: async (companies: string[], maxWorkers = 3): Promise<BatchAnalysisResult> => {
    const response = await api.post<BatchAnalysisResult>('/analyze/batch', {
      companies,
      max_workers: maxWorkers,
    });
    return response.data;
  },

  analyzeBatchAsync: async (companies: string[], maxWorkers = 3): Promise<JobStatus> => {
    const response = await api.post<JobStatus>('/analyze/batch/async', {
      companies,
      max_workers: maxWorkers,
    });
    return response.data;
  },

  getJobStatus: async (jobId: string): Promise<JobStatus> => {
    const response = await api.get<JobStatus>(`/jobs/${jobId}`);
    return response.data;
  },

  listJobs: async (status?: string, limit = 10): Promise<JobStatus[]> => {
    const params = new URLSearchParams();
    if (status) params.append('status', status);
    params.append('limit', limit.toString());
    const response = await api.get<JobStatus[]>(`/jobs?${params}`);
    return response.data;
  },
};

// Analytics API
export const analyticsApi = {
  getAnalytics: async (days = 30): Promise<Analytics> => {
    const response = await api.get<Analytics>(`/analytics?days=${days}`);
    return response.data;
  },
};

// Admin API
export const adminApi = {
  listUsers: async (limit = 100, offset = 0): Promise<User[]> => {
    const response = await api.get<User[]>(`/admin/users?limit=${limit}&offset=${offset}`);
    return response.data;
  },

  updateUserRole: async (userId: number, role: 'admin' | 'user'): Promise<User> => {
    const response = await api.patch<User>(`/admin/users/${userId}/role`, { role });
    return response.data;
  },

  deleteUser: async (userId: number): Promise<void> => {
    await api.delete(`/admin/users/${userId}`);
  },
};

export default api;