import axios, { AxiosInstance, AxiosRequestConfig, AxiosError } from 'axios'

const API_BASE_URL = process.env.NEXT_PUBLIC_API_BASE_URL || 'http://localhost:8000/api/v1'

// Create axios instance
export const apiClient: AxiosInstance = axios.create({
  baseURL: API_BASE_URL,
  headers: {
    'Content-Type': 'application/json',
  },
  timeout: 30000, // 30 seconds
})

// Request interceptor to add auth token
apiClient.interceptors.request.use(
  (config) => {
    // Get token from localStorage (will be replaced with proper auth context)
    if (typeof window !== 'undefined') {
      const token = localStorage.getItem('access_token')
      if (token && config.headers) {
        config.headers.Authorization = `Bearer ${token}`
      }
    }
    return config
  },
  (error) => {
    return Promise.reject(error)
  }
)

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

    // If 401 and we haven't retried yet, try to refresh token
    if (error.response?.status === 401 && !originalRequest._retry) {
      originalRequest._retry = true

      try {
        const refreshToken = localStorage.getItem('refresh_token')
        if (!refreshToken) {
          throw new Error('No refresh token available')
        }

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

        const { access_token } = response.data
        localStorage.setItem('access_token', access_token)

        // Retry original request with new token
        if (originalRequest.headers) {
          originalRequest.headers.Authorization = `Bearer ${access_token}`
        }

        return apiClient(originalRequest)
      } catch (refreshError) {
        // Refresh failed, clear tokens and redirect to login
        localStorage.removeItem('access_token')
        localStorage.removeItem('refresh_token')

        if (typeof window !== 'undefined') {
          window.location.href = '/login'
        }

        return Promise.reject(refreshError)
      }
    }

    return Promise.reject(error)
  }
)

export default apiClient