import { AxiosHeaders, type InternalAxiosRequestConfig } from 'axios'

/** Matches the end-to-end upload timeout policy at the Nginx boundary. */
export const FORM_DATA_UPLOAD_TIMEOUT_MS = 60_000

/**
 * Keep FormData intact through Axios transformRequest. Axios' browser adapter
 * already lets the browser generate the multipart boundary; deleting a stale
 * JSON or manually supplied content type here ensures FormData is not
 * serialized as JSON before the adapter gets it.
 */
export function applyFormDataRequestDefaults(config: InternalAxiosRequestConfig): InternalAxiosRequestConfig {
  if (typeof FormData === 'undefined' || !(config.data instanceof FormData)) {
    return config
  }

  const headers = AxiosHeaders.from(config.headers)

  headers.delete('Content-Type')
  config.headers = headers
  if (config.timeout === undefined || config.timeout === 0) {
    config.timeout = FORM_DATA_UPLOAD_TIMEOUT_MS
  }

  return config
}