const API = {
  base: '/api',
  _key: window.__API_KEY__ || '',

  async req(method, path, data) {
    const token = Auth.token();
    const headers = {};
    if (token) headers['Authorization'] = `Bearer ${token}`;
    if (this._key) headers['x-api-key'] = this._key;
    const opts = { method, headers };
    if (data instanceof FormData) opts.body = data;
    else if (data && method !== 'GET') { headers['Content-Type'] = 'application/json'; opts.body = JSON.stringify(data); }
    opts.headers = headers;
    const res = await fetch(this.base + path, opts);
    const ct = res.headers.get('content-type');
    if (ct && ct.includes('application/json')) {
      const json = await res.json();
      if (!res.ok) throw new Error(json.error || '请求失败');
      return json;
    }
    if (!res.ok) throw new Error('请求失败');
    return res;
  },

  get(p) { return this.req('GET', p); },
  post(p, d) { return this.req('POST', p, d); },
  put(p, d) { return this.req('PUT', p, d); },

  async download(path) {
    const token = Auth.token();
    const h = {};
    if (token) h['Authorization'] = `Bearer ${token}`;
    if (this._key) h['x-api-key'] = this._key;
    const res = await fetch(this.base + path, { headers: h });
    if (!res.ok) throw new Error('下载失败');
    const blob = await res.blob();
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    const disp = res.headers.get('content-disposition');
    a.download = disp?.match(/filename=(.+)/)?.[1] || 'export.csv';
    a.click();
    URL.revokeObjectURL(url);
  }
};