import { API_BASE_URL } from "../config/constants";

export const authFetch = async (endpoint: string, options: RequestInit = {}) => {
  const token = localStorage.getItem("accessToken");
  const isFormData = options.body instanceof FormData;
  
  const headers: HeadersInit = {
    ...(!isFormData && { "Content-Type": "application/json" }),
    ...(token ? { Authorization: `Bearer ${token}` } : {}),
    ...options.headers,
  };

  // Safely join URLs preventing double slashes (e.g., "http://api.com//api/..." -> "http://api.com/api/...")
  const cleanBaseUrl = API_BASE_URL.replace(/\/+$/, "");
  const cleanEndpoint = endpoint.startsWith("/") ? endpoint : `/${endpoint}`;
  const url = `${cleanBaseUrl}${cleanEndpoint}`;

  const response = await fetch(url, {
    ...options,
    headers,
  });

  if (response.status === 401) {
    localStorage.removeItem("accessToken");
    localStorage.removeItem("refreshToken");
    window.location.href = "/login";
  }

  return response;
};