const API_URL = import.meta.env.VITE_API_URL || '/api';

let onUnauthorized = () => {};
export function setUnauthorizedHandler(fn) {
  onUnauthorized = fn;
}

function getToken() {
  return localStorage.getItem('plc_token');
}

async function request(method, path, { body, isForm, extraHeaders } = {}) {
  const headers = { ...extraHeaders };
  const token = getToken();
  if (token) headers.Authorization = `Bearer ${token}`;
  if (!isForm && body !== undefined) headers['Content-Type'] = 'application/json';

  const res = await fetch(`${API_URL}${path}`, {
    method,
    headers,
    body: isForm ? body : body !== undefined ? JSON.stringify(body) : undefined,
  });

  if (res.status === 401) {
    onUnauthorized();
  }

  if (res.status === 204) return null;

  const isJson = (res.headers.get('content-type') || '').includes('application/json');
  const payload = isJson ? await res.json() : null;

  if (!res.ok) {
    const message = payload?.error || `Error ${res.status}`;
    throw new Error(message);
  }
  return payload?.data;
}

export const api = {
  get: (path, extraHeaders) => request('GET', path, { extraHeaders }),
  post: (path, body, extraHeaders) => request('POST', path, { body, extraHeaders }),
  put: (path, body, extraHeaders) => request('PUT', path, { body, extraHeaders }),
  patch: (path, body) => request('PATCH', path, { body }),
  delete: (path, extraHeaders) => request('DELETE', path, { extraHeaders }),
  postForm: (path, formData) => request('POST', path, { body: formData, isForm: true }),
  putForm: (path, formData) => request('PUT', path, { body: formData, isForm: true }),
  setToken: (token) => {
    if (token) localStorage.setItem('plc_token', token);
    else localStorage.removeItem('plc_token');
  },
  downloadUrl: (path) => `${API_URL}${path}`,
};