let state = {
  gpus: [],
  liveAgents: { ok: false, agents: [] },
  expandedGpuHosts: new Set(),
  settings: { gpuHosts: [] },
  errors: {}
};

const $ = (id) => document.getElementById(id);

function percent(value, total) {
  if (!Number.isFinite(value) || !Number.isFinite(total) || total <= 0) return 0;
  return Math.max(0, Math.min(100, Math.round((value / total) * 100)));
}

function escapeHtml(value) {
  return String(value ?? '').replace(/[&<>"']/g, (char) => ({
    '&': '&amp;',
    '<': '&lt;',
    '>': '&gt;',
    '"': '&quot;',
    "'": '&#39;'
  }[char]));
}

function isGpuIdle(gpu) {
  const memoryPercent = percent(gpu.memoryUsedMiB, gpu.memoryTotalMiB);
  return memoryPercent < 5 || gpu.gpuUtilizationPercent < 5;
}

function isGpuAbnormal(gpu) {
  const memoryPercent = percent(gpu.memoryUsedMiB, gpu.memoryTotalMiB);
  return memoryPercent >= 5 && gpu.gpuUtilizationPercent < 5;
}

function toast(message, tone = '') {
  if (!message) return;
  const host = $('toastHost');
  if (!host) return;
  const node = document.createElement('div');
  node.className = `toast ${tone}`.trim();
  node.textContent = message;
  host.appendChild(node);
  setTimeout(() => {
    node.style.transition = 'opacity 200ms ease';
    node.style.opacity = '0';
    setTimeout(() => node.remove(), 220);
  }, 4500);
}

async function request(path, options) {
  const response = await fetch(path, options);
  if (response.status === 401) {
    window.location.href = '/login';
    throw new Error('未登录');
  }
  if (!response.ok) {
    const text = await response.text().catch(() => '');
    throw new Error(text || `${response.status} ${response.statusText}`);
  }
  return response.json();
}

const ERROR_LABELS = {
  settings: '设置',
  gpus: 'GPU',
  liveAgents: 'Live Agents'
};

function renderErrorBanner() {
  const banner = $('errorBanner');
  if (!banner) return;
  const entries = Object.entries(state.errors || {}).filter(([key]) => ERROR_LABELS[key]);
  if (!entries.length) {
    banner.hidden = true;
    banner.innerHTML = '';
    return;
  }
  banner.hidden = false;
  banner.innerHTML = `
    <div><strong>部分数据加载失败</strong></div>
    <ul>${entries.map(([key, message]) => (
      `<li><strong>${escapeHtml(ERROR_LABELS[key] || key)}</strong> · ${escapeHtml(message)}</li>`
    )).join('')}</ul>
  `;
}

function renderGpuHostsChips() {
  const chips = $('gpuHostsChips');
  if (!chips) return;
  const hosts = state.settings?.gpuHosts || [];
  if (!hosts.length) {
    chips.innerHTML = '<span class="host-chip-empty">未配置任何机器</span>';
    return;
  }
  const statusByHost = new Map(state.gpus.map((host) => [host.host, host.ok]));
  chips.innerHTML = hosts.map((host) => {
    const ok = statusByHost.get(host);
    const cls = ok === true ? 'ok' : ok === false ? 'bad' : '';
    const safe = escapeHtml(host);
    return `<span class="host-chip ${cls}">
      <span class="host-chip-dot" aria-hidden="true"></span>
      <span class="host-chip-label">${safe}</span>
      <button type="button" class="host-chip-remove" data-remove-host="${safe}" aria-label="删除 ${safe}" title="删除">
        <svg viewBox="0 0 10 10" aria-hidden="true"><path d="M2.5 2.5l5 5M7.5 2.5l-5 5" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" fill="none"/></svg>
      </button>
    </span>`;
  }).join('');
}

function renderGpus() {
  const okHosts = state.gpus.filter((host) => host.ok).length;
  $('gpuSummary').textContent = state.gpus.length ? `${okHosts}/${state.gpus.length} 在线` : '尚未配置';
  renderGpuHostsChips();
  $('gpuBoard').innerHTML = state.gpus.length ? state.gpus.map((host) => {
    if (!host.ok) {
      return `<article class="host-card">
        <div class="host-title"><span>${escapeHtml(host.host)}</span><span class="status-bad">离线</span></div>
        <div class="repo-meta">${escapeHtml(host.error || '无法获取 GPU 状态')}</div>
      </article>`;
    }
    const idleCount = host.gpus.filter(isGpuIdle).length;
    const totalCount = host.gpus.length;
    const expanded = state.expandedGpuHosts.has(host.host);
    const thumbRows = host.gpus.map((gpu) => {
      const memoryPercent = percent(gpu.memoryUsedMiB, gpu.memoryTotalMiB);
      const thumbClass = isGpuAbnormal(gpu) ? 'abnormal' : isGpuIdle(gpu) ? 'idle' : 'busy';
      return `<span class="gpu-thumb ${thumbClass}" title="#${gpu.index} GPU ${gpu.gpuUtilizationPercent}% · MEM ${memoryPercent}%"></span>`;
    }).join('');
    const gpuRows = host.gpus.map((gpu) => {
      const memoryPercent = percent(gpu.memoryUsedMiB, gpu.memoryTotalMiB);
      return `<article class="gpu-detail-card">
        <div class="metric-row">
          <strong>#${gpu.index} ${escapeHtml(gpu.name)}</strong>
          <span>${gpu.gpuUtilizationPercent}% GPU</span>
        </div>
        <meter class="meter" min="0" max="100" low="50" high="85" optimum="10" value="${gpu.gpuUtilizationPercent}" title="GPU Util"></meter>
        <div class="metric-row muted">
          <span>${gpu.memoryUsedMiB} / ${gpu.memoryTotalMiB} MiB</span>
          <span>${memoryPercent}% 显存</span>
        </div>
        <meter class="meter" min="0" max="100" low="50" high="85" optimum="10" value="${memoryPercent}" title="Memory"></meter>
      </article>`;
    }).join('');
    return `<article class="host-card ${expanded ? 'expanded' : ''}">
      <button class="host-summary" type="button" data-host="${escapeHtml(host.host)}" aria-expanded="${expanded}">
        <span>
          <strong>${escapeHtml(host.host)}</strong>
          <span class="muted">${idleCount}/${totalCount} 空闲</span>
        </span>
        <span class="gpu-thumbs">${thumbRows}</span>
        <span class="chip">${expanded ? '收起' : '展开'}</span>
      </button>
      ${expanded ? `<div class="gpu-list">${gpuRows || '<span class="muted">未发现 GPU</span>'}</div>` : ''}
    </article>`;
  }).join('') : '<div class="empty-state">还没有配置 GPU 机器</div>';
}

function renderLiveAgents() {
  const agents = state.liveAgents?.agents || [];
  $('liveAgentSummary').textContent = agents.length ? `${agents.length} 个运行中` : '无运行中';
  if (!agents.length) {
    $('liveAgentBoard').innerHTML = '<div class="empty-state">tmux 中没有正在运行的 agent</div>';
    return;
  }
  const groups = new Map();
  for (const agent of agents) {
    if (!groups.has(agent.session)) groups.set(agent.session, []);
    groups.get(agent.session).push(agent);
  }
  $('liveAgentBoard').innerHTML = [...groups.entries()].map(([session, members]) => {
    const rows = members.map((agent) => {
      const termUrl = `/term/?arg=${encodeURIComponent(agent.session)}&arg=${encodeURIComponent(agent.windowIndex)}`;
      return `<article class="agent-card">
        <span class="agent-chip ${escapeHtml(agent.engine)}">${escapeHtml(agent.engine)}</span>
        <span class="agent-card-main">
          <strong>:${agent.windowIndex}</strong>
          <span class="muted">${escapeHtml(agent.windowName)}</span>
        </span>
        <span class="agent-card-cwd muted" title="${escapeHtml(agent.cwd)}">${escapeHtml(agent.cwd)}</span>
        <a class="secondary-button small" href="${escapeHtml(termUrl)}" target="_blank" rel="noopener">打开终端</a>
      </article>`;
    }).join('');
    return `<section class="agent-group">
      <div class="agent-group-heading">
        <strong>${escapeHtml(session)}</strong>
      </div>
      <div class="agent-group-list">${rows}</div>
    </section>`;
  }).join('');
}

function render() {
  renderErrorBanner();
  renderGpus();
  renderLiveAgents();
}

async function refresh() {
  const button = $('refreshButton');
  button.disabled = true;
  button.classList.add('loading');
  try {
    const [settings, gpus, liveAgents] = await Promise.allSettled([
      request('/api/settings'),
      request('/api/gpus'),
      request('/api/tmux/agents')
    ]);
    const errors = {};
    const value = (result, fallback, key) => {
      if (result.status === 'fulfilled') return result.value;
      errors[key] = String(result.reason?.message || result.reason || 'unknown error');
      return fallback;
    };
    state = {
      ...state,
      settings: value(settings, state.settings, 'settings'),
      gpus: value(gpus, [], 'gpus'),
      liveAgents: value(liveAgents, { ok: false, agents: [] }, 'liveAgents'),
      errors
    };
    render();
  } catch (error) {
    toast(`刷新失败: ${error.message}`, 'error');
  } finally {
    button.disabled = false;
    button.classList.remove('loading');
  }
}

$('refreshButton').addEventListener('click', refresh);

$('logoutButton').addEventListener('click', async () => {
  try {
    await fetch('/api/auth/logout', { method: 'POST' });
  } finally {
    window.location.href = '/login';
  }
});

$('gpuBoard').addEventListener('click', (event) => {
  const button = event.target.closest('.host-summary');
  if (!button) return;
  const host = button.dataset.host;
  if (state.expandedGpuHosts.has(host)) state.expandedGpuHosts.delete(host);
  else state.expandedGpuHosts.add(host);
  renderGpus();
});

async function saveGpuHosts(gpuHosts, successMessage) {
  try {
    const settings = await request('/api/settings/gpu-hosts', {
      method: 'PUT',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify({ gpuHosts })
    });
    state.settings = settings;
    renderGpuHostsChips();
    if (successMessage) toast(successMessage, 'success');
    await refresh();
    return true;
  } catch (error) {
    toast(`保存失败: ${error.message}`, 'error');
    return false;
  }
}

function setHostAdding(adding) {
  const trigger = $('hostAddTrigger');
  const form = $('hostAddForm');
  const input = $('hostAddInput');
  if (!trigger || !form) return;
  form.hidden = !adding;
  trigger.hidden = adding;
  if (adding && input) {
    input.value = '';
    input.focus();
  }
}

$('hostAddTrigger').addEventListener('click', () => setHostAdding(true));
$('hostAddCancel').addEventListener('click', () => setHostAdding(false));
$('hostAddInput').addEventListener('keydown', (event) => {
  if (event.key === 'Escape') {
    event.preventDefault();
    setHostAdding(false);
  }
});

$('hostAddForm').addEventListener('submit', async (event) => {
  event.preventDefault();
  const name = $('hostAddInput').value.trim();
  if (!name) {
    toast('请输入主机名', 'warn');
    return;
  }
  const current = state.settings?.gpuHosts || [];
  if (current.includes(name)) {
    toast(`${name} 已存在`, 'warn');
    return;
  }
  const ok = await saveGpuHosts([...current, name], `已添加 ${name}`);
  if (ok) setHostAdding(false);
});

$('gpuHostsChips').addEventListener('click', async (event) => {
  const button = event.target.closest('[data-remove-host]');
  if (!button) return;
  const host = button.dataset.removeHost;
  const current = state.settings?.gpuHosts || [];
  if (!current.includes(host)) return;
  await saveGpuHosts(current.filter((item) => item !== host), `已移除 ${host}`);
});

$('liveAgentForm').addEventListener('submit', async (event) => {
  event.preventDefault();
  const payload = {
    engine: $('liveAgentEngine').value,
    session: $('liveAgentSession').value.trim(),
    cwd: $('liveAgentCwd').value.trim(),
    windowName: $('liveAgentWindowName').value.trim()
  };
  if (!payload.session || !payload.cwd) {
    toast('请填写 session 和工作目录', 'warn');
    return;
  }
  const button = $('liveAgentLaunchButton');
  button.disabled = true;
  try {
    const result = await request('/api/tmux/agents', {
      method: 'POST',
      headers: { 'content-type': 'application/json' },
      body: JSON.stringify(payload)
    });
    toast(`已在 ${result.session} 启动 ${result.engine}`, 'success');
    $('liveAgentWindowName').value = '';
    await refresh();
  } catch (error) {
    toast(`启动 agent 失败: ${error.message}`, 'error');
  } finally {
    button.disabled = false;
  }
});

refresh();
setInterval(refresh, 60000);