// 클라이언트 API wrapper. JWT 는 localStorage 에 보관.
const TOKEN_KEY = 'jm_token';

export function getToken(): string | null {
  if (typeof window === 'undefined') return null;
  return localStorage.getItem(TOKEN_KEY);
}
export function setToken(t: string) { localStorage.setItem(TOKEN_KEY, t); }
export function clearToken() { localStorage.removeItem(TOKEN_KEY); }

async function request<T = any>(path: string, opts: RequestInit = {}): Promise<T> {
  const token = getToken();
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
    ...(opts.headers as any),
  };
  if (token) headers['Authorization'] = `Bearer ${token}`;
  const res = await fetch(path, { ...opts, headers });
  if (res.status === 401) {
    clearToken();
    if (typeof window !== 'undefined' && window.location.pathname !== '/login') {
      window.location.href = '/login';
    }
    throw new Error('unauthorized');
  }
  if (!res.ok) {
    const text = await res.text();
    let msg = text;
    try {
      const j = JSON.parse(text);
      const d = j.detail;
      if (typeof d === 'string') msg = d;
      else if (Array.isArray(d)) msg = d.map((e: any) => e?.msg || e?.detail || JSON.stringify(e)).join(', ');
      else if (d && typeof d === 'object') msg = d.msg || JSON.stringify(d);
      else msg = text;
    } catch {}
    if (typeof msg !== 'string') msg = String(msg);
    throw new Error(msg || `${res.status}`);
  }
  if (res.status === 204) return undefined as any;
  return res.json();
}

export const api = {
  get:    <T = any>(p: string)            => request<T>(p),
  post:   <T = any>(p: string, body: any) => request<T>(p, { method: 'POST', body: JSON.stringify(body) }),
  put:    <T = any>(p: string, body: any) => request<T>(p, { method: 'PUT',  body: JSON.stringify(body) }),
  delete: <T = any>(p: string)            => request<T>(p, { method: 'DELETE' }),
};