import axios from 'axios'
import { setCurrentRequestId } from './lib/logger.js'

const api = axios.create({
  baseURL: '',
  timeout: 30000,
})

// Generate a request id per outgoing call (for cross-correlation)
function newRequestId() {
  // RFC4122-ish: use crypto if available
  if (typeof crypto !== 'undefined' && crypto.randomUUID) {
    return crypto.randomUUID()
  }
  return 'req-' + Math.random().toString(36).slice(2) + Date.now().toString(36)
}

// Request interceptor: auth + X-Request-ID
api.interceptors.request.use(
  config => {
    const token = localStorage.getItem('aars_token')
    if (token) {
      config.headers.Authorization = `Bearer ${token}`
    }
    config.headers['X-Request-ID'] = newRequestId()
    return config
  },
  error => Promise.reject(error)
)

// Response interceptor: capture server's X-Request-ID for log correlation + 401 handling
api.interceptors.response.use(
  response => {
    const rid = response.headers['x-request-id']
    if (rid) setCurrentRequestId(rid)
    return response
  },
  error => {
    const rid = error.response?.headers?.['x-request-id']
    if (rid) setCurrentRequestId(rid)

    if (error.response?.status === 401) {
      localStorage.removeItem('aars_token')
      // Avoid loop if already on /login
      if (!window.location.pathname.startsWith('/login')) {
        window.location.href = '/login'
      }
    }
    return Promise.reject(error)
  }
)

export default api