export function validateSitePayload(payload, site) {
  const data = payload?.data;
  if (!data || data.site !== site || !Array.isArray(data.list)) throw new Error('库区数据不匹配');
  if (data.list.some(row => row.site !== site)) throw new Error('仓库归属不匹配');
  return data;
}

export async function fetchSiteData(site, fetcher = fetch) {
  const path = `/api/index/granaryList?site=${encodeURIComponent(site)}`;
  const endpoints = [path, `https://grain.gynhc.com${path}`];
  for (const url of endpoints) {
    try {
      const response = await fetcher(url, { cache: 'no-store', signal: AbortSignal.timeout(8000) });
      if (!response.ok) continue;
      return validateSitePayload(await response.json(), site);
    } catch (_) { /* Try the configured service if this origin is unavailable. */ }
  }
  throw new Error('暂时无法读取库区数据');
}

export function showSiteDataState(site, state, count, hasDemo = false) {
  const wrapper = document.getElementById('screen-wrapper');
  if (!wrapper) return;
  let badge = document.getElementById('site-data-state');
  if (!badge) {
    badge = document.createElement('div');
    badge.id = 'site-data-state';
    badge.setAttribute('role', 'status');
    badge.style.cssText = 'position:absolute;top:83px;left:50%;transform:translateX(-50%);z-index:100;padding:5px 14px;border:1px solid #35536a;border-radius:4px;background:#0b1828;color:#bcd4e8;font-size:13px;pointer-events:none;white-space:nowrap';
    wrapper.appendChild(badge);
  }
  const name = site === 'xishui' ? '习水库' : '遵义中心库';
  badge.dataset.state = state;
  badge.hidden = state === 'live';
  badge.textContent = state === 'live' ? `${name} · 后台数据 · ${count} 座仓储设施${hasDemo ? ' · 含 DEMO 演示化验，非实测' : ''}`
    : state === 'empty' ? `${name} · 暂无仓库资料` : `${name} · 数据连接失败，请稍后重试`;
  let empty = document.getElementById('site-empty-state');
  if (!empty) {
    empty = document.createElement('div');
    empty.id = 'site-empty-state';
    empty.style.cssText = 'position:absolute;inset:120px 0 50px;z-index:99;display:none;align-items:center;justify-content:center;background:rgba(6,16,29,.97);color:#bcd4e8;font-size:24px';
    wrapper.appendChild(empty);
  }
  empty.style.display = state === 'live' ? 'none' : 'flex';
  empty.textContent = state === 'empty' ? '当前库区暂无仓库资料，请在后台录入' : '暂时无法读取库区数据，请检查网络后刷新';
}