import axios, { type AxiosError } from 'axios'

export const api = axios.create({
  baseURL: process.env.NEXT_PUBLIC_API_URL ?? 'http://localhost:5089/api',
  headers: { 'Content-Type': 'application/json' },
  withCredentials: true,
})

type UnauthorizedHandler = () => void
let unauthorizedHandler: UnauthorizedHandler | null = null

export function registerUnauthorizedHandler(fn: UnauthorizedHandler): () => void {
  unauthorizedHandler = fn
  return () => { unauthorizedHandler = null }
}

api.interceptors.response.use(
  (res) => res,
  (error: AxiosError<{ error: string }>) => {
    const status = error.response?.status
    if (status === 401 && typeof window !== 'undefined' && window.location.pathname !== '/login') {
      unauthorizedHandler?.()
      return new Promise(() => {})
    }
    return Promise.reject(error)
  }
)

export function getApiError(error: unknown): string {
  if (axios.isAxiosError(error)) {
    return error.response?.data?.error ?? error.message
  }
  return 'An unexpected error occurred'
}