const API_BASE = import.meta.env.VITE_API_BASE ?? '';
const REFRESH_MS = 3000;

const SAMPLE_IMAGE_URL =
  'https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/coco_sample.png';

interface HostInfo {
  id: string;
  model: string;
  online: boolean;
  registeredAt: number;
  lastHeartbeat: number;
}

const brokerStatusEl = document.getElementById('broker-status')!;
const onlineCountEl = document.getElementById('online-count')!;
const totalCountEl = document.getElementById('total-count')!;
const hostsEl = document.getElementById('hosts')!;
const errorEl = document.getElementById('error')!;
const refreshNoteEl = document.getElementById('refresh-note')!;

const expandedCurlHosts = new Set<string>();

function syncExpandedCurlFromDom(): void {
  hostsEl.querySelectorAll<HTMLDetailsElement>('details.curl-details').forEach((details) => {
    const id = details.closest('[data-host-id]')?.getAttribute('data-host-id');
    if (!id) {
      return;
    }
    if (details.open) {
      expandedCurlHosts.add(id);
    } else {
      expandedCurlHosts.delete(id);
    }
  });
}

function detectOrigin(): string {
  return window.location.origin;
}

function buildCurlExample(hostId: string, modelId: string): string {
  const origin = detectOrigin();

  if (modelId === 'smolvlm-500m') {
    return `curl -X POST '${origin}/v1/describe' \\
  -H 'Content-Type: application/json' \\
  -d '{
    "host": "${hostId}",
    "image_url": "${SAMPLE_IMAGE_URL}",
    "instruction": "What do you see?",
    "max_new_tokens": 100
  }'`;
  }

  return `curl -X POST '${origin}/v1/detect' \\
  -H 'Content-Type: application/json' \\
  -d '{
    "host": "${hostId}",
    "image_url": "${SAMPLE_IMAGE_URL}",
    "threshold": 0.5
  }'`;
}

function formatTime(ms: number): string {
  return new Date(ms).toLocaleString();
}

function relativeTime(ms: number): string {
  const seconds = Math.floor((Date.now() - ms) / 1000);
  if (seconds < 60) {
    return `${seconds}s ago`;
  }
  const minutes = Math.floor(seconds / 60);
  if (minutes < 60) {
    return `${minutes}m ago`;
  }
  const hours = Math.floor(minutes / 60);
  return `${hours}h ago`;
}

function showError(message: string): void {
  errorEl.textContent = message;
  errorEl.style.display = 'block';
}

function clearError(): void {
  errorEl.style.display = 'none';
}

async function fetchBrokerHealth(): Promise<boolean> {
  const res = await fetch(`${API_BASE}/health`);
  if (!res.ok) {
    return false;
  }
  const json = (await res.json()) as {status?: string};
  return json.status === 'ok';
}

async function fetchHosts(): Promise<HostInfo[]> {
  const res = await fetch(`${API_BASE}/v1/hosts`);
  if (!res.ok) {
    throw new Error(`GET /v1/hosts failed (${res.status})`);
  }
  const json = (await res.json()) as {hosts: HostInfo[]};
  return json.hosts ?? [];
}

function renderHosts(hosts: HostInfo[]): void {
  const online = hosts.filter((h) => h.online).length;
  onlineCountEl.textContent = String(online);
  onlineCountEl.className = `stat-value ${online > 0 ? 'ok' : 'warn'}`;
  totalCountEl.textContent = String(hosts.length);

  if (hosts.length === 0) {
    hostsEl.innerHTML = `
      <div class="empty">
        <p>No hosts registered yet.</p>
        <p><a href="/public">Open the host page</a>, pick an id, and click “Start hosting”.</p>
      </div>`;
    return;
  }

  const sorted = [...hosts].sort((a, b) => {
    if (a.online !== b.online) {
      return a.online ? -1 : 1;
    }
    return b.lastHeartbeat - a.lastHeartbeat;
  });

  syncExpandedCurlFromDom();

  hostsEl.innerHTML = sorted
    .map((host) => {
      const curl = buildCurlExample(host.id, host.model);
      const escapedCurl = curl.replace(/'/g, '&#39;');
      return `
        <article class="host-card" data-host-id="${escapeHtml(host.id)}">
          <div class="host-header">
            <span class="host-id">${escapeHtml(host.id)}</span>
            <span class="badge ${host.online ? 'online' : 'offline'}">
              ${host.online ? 'Online' : 'Offline'}
            </span>
          </div>
          <div class="host-meta">
            <span>Model: ${escapeHtml(host.model)}</span>
            <span>Registered: ${formatTime(host.registeredAt)}</span>
            <span>Last heartbeat: ${relativeTime(host.lastHeartbeat)}</span>
          </div>
          <details class="curl-details"${expandedCurlHosts.has(host.id) ? ' open' : ''}>
            <summary>
              <span class="summary-show">Show curl example</span>
              <span class="summary-hide">Hide curl example</span>
            </summary>
            <div class="curl-body">
              <button type="button" class="copy" data-curl="${escapedCurl}">Copy curl</button>
              <pre>${escapeHtml(curl)}</pre>
            </div>
          </details>
        </article>`;
    })
    .join('');

  hostsEl.querySelectorAll('button.copy').forEach((btn) => {
    btn.addEventListener('click', async () => {
      const curl = btn.getAttribute('data-curl')?.replace(/&#39;/g, "'") ?? '';
      await navigator.clipboard.writeText(curl);
      const label = btn.textContent;
      btn.textContent = 'Copied!';
      setTimeout(() => {
        btn.textContent = label;
      }, 1500);
    });
  });
}

function escapeHtml(text: string): string {
  return text
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}

async function refresh(): Promise<void> {
  try {
    const healthy = await fetchBrokerHealth();
    brokerStatusEl.textContent = healthy ? 'Healthy' : 'Unreachable';
    brokerStatusEl.className = `stat-value ${healthy ? 'ok' : 'err'}`;

    if (!healthy) {
      showError(
        `Broker at ${detectOrigin()} is not responding. Run \`npm run dev\` or \`npm run dev:api\`.`,
      );
      hostsEl.innerHTML = '';
      onlineCountEl.textContent = '—';
      totalCountEl.textContent = '—';
      return;
    }

    clearError();
    const hosts = await fetchHosts();
    renderHosts(hosts);
    refreshNoteEl.textContent = `Last updated ${new Date().toLocaleTimeString()} · refreshing every ${REFRESH_MS / 1000}s`;
  } catch (error) {
    const message = error instanceof Error ? error.message : String(error);
    showError(message);
    brokerStatusEl.textContent = 'Error';
    brokerStatusEl.className = 'stat-value err';
  }
}

hostsEl.addEventListener('toggle', (event) => {
  const details = event.target;
  if (!(details instanceof HTMLDetailsElement) || !details.classList.contains('curl-details')) {
    return;
  }
  const id = details.closest('[data-host-id]')?.getAttribute('data-host-id');
  if (!id) {
    return;
  }
  if (details.open) {
    expandedCurlHosts.add(id);
  } else {
    expandedCurlHosts.delete(id);
  }
});

void refresh();
setInterval(() => {
  void refresh();
}, REFRESH_MS);