(() => {
  const NODE_CONTROL_ID = 'myelin-fleet-control';
  const EXECUTION_CONTROL_ID = 'myelin-contextual-execution';
  const BULK_CONTROL_ID = 'myelin-fleet-bulk-control';
  const CONFIRM_ID = 'myelin-confirm-dialog';
  const STYLE_ID = 'myelin-fleet-control-style';
  const selectedNodes = new Set();
  let lastModel = null;
  let syncing = false;
  let executionPoll = null;
  const page = document.getElementById('page');
  if (!page) return;

  function installUi() {
    if (document.getElementById(STYLE_ID)) return;
    const style = document.createElement('style');
    style.id = STYLE_ID;
    style.textContent = `
      .myelin-control { display:flex;align-items:center;flex-wrap:wrap;gap:10px;margin:0 0 12px }
      .myelin-control button { border:1px solid var(--cyan);background:transparent;color:var(--cyan);border-radius:var(--r);padding:6px 10px;font:600 12px var(--mono);cursor:pointer }
      .myelin-control button.danger { border-color:var(--bad);color:var(--bad) }
      .myelin-control button:disabled { cursor:not-allowed;opacity:.55 }
      .myelin-control-message { color:var(--muted);font:12px var(--mono) }
      .myelin-bulk-control { width:fit-content;margin:0 0 12px auto;padding:6px 8px;border:1px solid var(--divider);background:transparent;border-radius:var(--r) }
      .node-card[data-bulk-selected="true"] { border-color:var(--bad);background:var(--selected);box-shadow:inset 3px 0 0 var(--bad) }
      .node-card[data-bulk-killable="true"] { user-select:none }
      .myelin-execution { display:grid;gap:8px;width:min(720px,100%);padding:10px 12px;border:1px solid var(--divider);border-radius:var(--r);background:var(--ghost) }
      .myelin-execution-row { display:flex;align-items:center;flex-wrap:wrap;gap:8px }
      .myelin-execution input[type="file"] { max-width:100%;color:var(--text);font:12px var(--mono) }
      .myelin-execution-output { display:none;max-height:260px;overflow:auto;margin:0;padding:9px;background:var(--inset);border:1px solid var(--divider);white-space:pre-wrap;word-break:break-word;color:var(--text);font:12px/1.45 var(--mono) }
      .myelin-execution-output[data-active="true"] { display:block }
      .myelin-confirm { width:min(440px,calc(100vw - 32px));padding:0;color:var(--text);background:var(--panel);border:1px solid var(--bad);border-radius:var(--r);box-shadow:0 18px 60px rgba(0,0,0,.55) }
      .myelin-confirm::backdrop { background:rgba(0,6,12,.78) }
      .myelin-confirm form { display:grid;gap:14px;padding:18px }
      .myelin-confirm h2,.myelin-confirm p { margin:0 }
      .myelin-confirm h2 { color:var(--bad) }
      .myelin-confirm-actions { display:flex;justify-content:flex-end;gap:8px }
      .myelin-confirm button { padding:6px 12px;background:transparent;color:var(--text);border:1px solid var(--border);border-radius:var(--r);cursor:pointer;font:600 13px var(--mono) }
      .myelin-confirm button[value="confirm"] { color:var(--danger-ink);background:var(--danger-fill);border-color:var(--danger-border) }
    `;
    document.head.append(style);
  }

  function confirmTermination(title, message, action) {
    let dialog = document.getElementById(CONFIRM_ID);
    if (!dialog) {
      dialog = document.createElement('dialog');
      dialog.id = CONFIRM_ID;
      dialog.className = 'myelin-confirm';
      dialog.setAttribute('aria-labelledby', 'myelin-confirm-title');
      dialog.setAttribute('aria-describedby', 'myelin-confirm-message');
      dialog.innerHTML = `<form method="dialog">
        <h2 id="myelin-confirm-title"></h2>
        <p id="myelin-confirm-message"></p>
        <div class="myelin-confirm-actions">
          <button value="cancel" autofocus>Cancel</button>
          <button value="confirm"></button>
        </div>
      </form>`;
      document.body.append(dialog);
    }
    dialog.querySelector('#myelin-confirm-title').textContent = title;
    dialog.querySelector('#myelin-confirm-message').textContent = message;
    dialog.querySelector('[value="confirm"]').textContent = action;
    dialog.returnValue = 'cancel';
    return new Promise(resolve => {
      dialog.addEventListener('close', () => resolve(dialog.returnValue === 'confirm'), { once: true });
      dialog.showModal();
    });
  }

  function killable(node) {
    return node && !['kill_requested', 'stopping', 'stopped', 'orphan'].includes(node.phase);
  }

  function managedNodes(model) {
    return Array.isArray(model?.nodes) ? model.nodes : [];
  }

  function commandId(logicalNodeId) {
    return `fleet-kill-${logicalNodeId}-${globalThis.crypto?.randomUUID?.() || Date.now()}`;
  }

  async function submitKills(logicalNodeIds) {
    return Promise.all(logicalNodeIds.map(async logicalNodeId => {
      try {
        const response = await fetch(`/api/control/nodes/${logicalNodeId}/kill`, {
          method: 'POST',
          headers: { 'content-type': 'application/json' },
          body: JSON.stringify({ command_id: commandId(logicalNodeId) }),
        });
        if (!response.ok) {
          const body = await response.json().catch(() => ({}));
          throw new Error(body.error || `HTTP ${response.status}`);
        }
        return { logicalNodeId, error: null };
      } catch (error) {
        return { logicalNodeId, error: error.message };
      }
    }));
  }

  function resultMessage(results) {
    const failed = results.filter(result => result.error);
    if (!failed.length) return `Termination accepted for ${results.length} node${results.length === 1 ? '' : 's'}`;
    const accepted = results.length - failed.length;
    const failures = failed.map(result => `${result.logicalNodeId}: ${result.error}`).join('; ');
    return `${accepted} accepted; ${failed.length} failed — ${failures}`;
  }

  function syncFleetControl(model) {
    const page = document.getElementById('page');
    const cards = [...page.querySelectorAll('a.node-card[data-node]')];
    if (!cards.length) {
      document.getElementById(BULK_CONTROL_ID)?.remove();
      return;
    }
    const byId = new Map(managedNodes(model).map(node => [node.logical_node_id, node]));
    for (const logicalNodeId of [...selectedNodes]) {
      if (!killable(byId.get(logicalNodeId))) selectedNodes.delete(logicalNodeId);
    }
    for (const card of cards) {
      const logicalNodeId = Number(card.dataset.node);
      const selectable = card.dataset.origin !== 'orchestrator'
        && Number.isSafeInteger(logicalNodeId)
        && killable(byId.get(logicalNodeId));
      card.dataset.bulkKillable = String(selectable);
      card.dataset.bulkSelected = String(selectable && selectedNodes.has(logicalNodeId));
      card.setAttribute('aria-selected', String(selectable && selectedNodes.has(logicalNodeId)));
      card.title = selectable ? 'Open node; Shift+click to select for termination' : '';
    }

    const count = selectedNodes.size;
    let control = document.getElementById(BULK_CONTROL_ID);
    if (!count) {
      control?.remove();
      return;
    }
    if (!control) {
      control = document.createElement('div');
      control.id = BULK_CONTROL_ID;
      control.className = 'myelin-control myelin-bulk-control';
      control.innerHTML = `<span data-selection></span>
        <button type="button" class="danger" data-action="kill-selected">Terminate selected</button>
        <span class="myelin-control-message" data-message role="status"></span>`;
      page.querySelector('.grid').before(control);
      control.querySelector('[data-action="kill-selected"]').onclick = killSelected;
    }
    control.querySelector('[data-selection]').textContent =
      `${count} worker node${count === 1 ? '' : 's'} selected`;
    const button = control.querySelector('[data-action="kill-selected"]');
    button.disabled = false;
    button.textContent = `Terminate ${count} selected`;
  }


  async function killSelected() {
    const control = document.getElementById(BULK_CONTROL_ID);
    const button = control?.querySelector('[data-action="kill-selected"]');
    const message = control?.querySelector('[data-message]');
    const byId = new Map(managedNodes(lastModel).map(node => [node.logical_node_id, node]));
    const ids = [...selectedNodes].filter(logicalNodeId => killable(byId.get(logicalNodeId)));
    if (!ids.length) return;
    const label = ids.join(', ');
    if (!await confirmTermination(
      `Terminate ${ids.length} managed node${ids.length === 1 ? '' : 's'}?`,
      `Terminate managed node${ids.length === 1 ? '' : 's'} ${label}? Vast.ai contracts are destroyed and billing stops.`,
      `Terminate ${ids.length}`,
    )) return;
    button.disabled = true;
    message.textContent = 'Submitting termination requests…';
    const results = await submitKills(ids);
    for (const result of results) {
      if (!result.error) selectedNodes.delete(result.logicalNodeId);
    }
    message.textContent = resultMessage(results);
    syncFleetControl(lastModel);
  }

  function ensureOrchestratorControl(nodeView, model) {
    const heading = nodeView.querySelector('section.panel > h2');
    if (!heading) return;
    let control = document.getElementById(NODE_CONTROL_ID);
    if (!control) {
      control = document.createElement('div');
      control.id = NODE_CONTROL_ID;
      control.className = 'myelin-control';
      control.innerHTML = `<button type="button" class="danger" data-action="shutdown-all">Shutdown all</button>
        <span class="myelin-control-message" data-message role="status"></span>`;
      heading.after(control);
      control.querySelector('[data-action="shutdown-all"]').onclick = shutdownAll;
    }
    const count = managedNodes(model).filter(killable).length;
    const button = control.querySelector('[data-action="shutdown-all"]');
    button.disabled = count === 0;
    button.textContent = count ? `Shutdown all (${count})` : 'No managed nodes to shut down';
  }

  async function shutdownAll() {
    const control = document.getElementById(NODE_CONTROL_ID);
    const button = control?.querySelector('[data-action="shutdown-all"]');
    const message = control?.querySelector('[data-message]');
    const ids = managedNodes(lastModel).filter(killable).map(node => node.logical_node_id);
    if (!ids.length) return;
    if (!await confirmTermination(
      `Shut down all ${ids.length} managed node${ids.length === 1 ? '' : 's'}?`,
      `This terminates managed nodes ${ids.join(', ')}. Vast.ai contracts are destroyed and billing stops.`,
      'Shutdown all',
    )) return;
    button.disabled = true;
    message.textContent = 'Submitting termination requests…';
    const results = await submitKills(ids);
    message.textContent = resultMessage(results);
  }

  function stopExecutionPoll() {
    if (executionPoll?.timer) clearTimeout(executionPoll.timer);
    executionPoll = null;
  }

  function appendExecutionEvent(panel, observation) {
    const event = observation?.event || {};
    const type = event.type || 'unknown';
    const status = panel.querySelector('[data-execution-status]');
    const output = panel.querySelector('[data-execution-output]');
    if (type === 'stdout' || type === 'stderr') {
      const bytes = Array.isArray(event.bytes) ? new Uint8Array(event.bytes) : new Uint8Array();
      output.dataset.active = 'true';
      output.textContent += new TextDecoder().decode(bytes);
      output.scrollTop = output.scrollHeight;
    } else if (type === 'context_ready') {
      status.textContent = 'Swactor context ready';
    } else if (type === 'process_started') {
      status.textContent = `Python started · pid ${event.pid}`;
    } else if (type === 'spawned') {
      status.textContent = 'Program transferred; starting Python…';
    } else if (type === 'exited') {
      status.textContent = `Exited · ${JSON.stringify(event.status)}`;
    } else if (event.error) {
      status.textContent = event.error;
    }
    return ['spawn_rejected', 'spawn_failed', 'bootstrap_failed', 'exited', 'process_error'].includes(type);
  }

  async function pollExecution(panel, requestId, afterSequence) {
    if (!panel.isConnected || executionPoll?.requestId !== requestId) return;
    try {
      const response = await fetch(
        `/api/control/contextual/${encodeURIComponent(requestId)}/events?after_sequence=${afterSequence}`,
        { cache: 'no-store' },
      );
      const body = await response.json().catch(() => ({}));
      if (!response.ok) throw new Error(body.error || `HTTP ${response.status}`);
      const execution = body.execution;
      let terminal = Boolean(execution?.terminal);
      for (const record of execution?.events || []) {
        terminal = appendExecutionEvent(panel, record.observation) || terminal;
      }
      if (terminal) {
        stopExecutionPoll();
        panel.querySelector('[data-run]').disabled = false;
        return;
      }
      executionPoll.afterSequence = Number(execution?.next_sequence || afterSequence);
      executionPoll.timer = setTimeout(
        () => pollExecution(panel, requestId, executionPoll.afterSequence),
        300,
      );
    } catch (error) {
      panel.querySelector('[data-execution-status]').textContent = error.message;
      panel.querySelector('[data-run]').disabled = false;
      stopExecutionPoll();
    }
  }

  function ensureExecutionControl(nodeView, logicalNodeId, disabled) {
    let panel = document.getElementById(EXECUTION_CONTROL_ID);
    if (!panel) {
      panel = document.createElement('div');
      panel.id = EXECUTION_CONTROL_ID;
      panel.className = 'myelin-control myelin-execution';
      panel.innerHTML = `<div class="myelin-execution-row">
          <input type="file" accept=".py,text/x-python" data-file aria-label="Python file">
          <button type="button" data-run disabled>Run with Swactor context</button>
          <span class="myelin-control-message" data-execution-status role="status">Select one Python file</span>
        </div>
        <pre class="myelin-execution-output" data-execution-output data-active="false"></pre>`;
      const control = document.getElementById(NODE_CONTROL_ID);
      control.after(panel);
      const input = panel.querySelector('[data-file]');
      const run = panel.querySelector('[data-run]');
      input.onchange = () => {
        const file = input.files?.[0];
        run.disabled = !file || disabled;
        panel.querySelector('[data-execution-status]').textContent =
          file ? `${file.name} · ${file.size} bytes` : 'Select one Python file';
      };
      run.onclick = async () => {
        const file = input.files?.[0];
        if (!file) return;
        stopExecutionPoll();
        run.disabled = true;
        const status = panel.querySelector('[data-execution-status]');
        const output = panel.querySelector('[data-execution-output]');
        output.textContent = '';
        output.dataset.active = 'false';
        status.textContent = 'Uploading program…';
        try {
          const response = await fetch(
            `/api/control/contextual/nodes/${logicalNodeId}/python?filename=${encodeURIComponent(file.name)}`,
            {
              method: 'POST',
              headers: { 'content-type': 'application/octet-stream' },
              body: file,
            },
          );
          const body = await response.json().catch(() => ({}));
          if (!response.ok) throw new Error(body.error || `HTTP ${response.status}`);
          const observation = body.observation;
          const requestId = observation?.request_id;
          if (!requestId) throw new Error('spawn response did not include a request ID');
          const terminal = appendExecutionEvent(panel, observation);
          if (terminal) {
            run.disabled = false;
            return;
          }
          executionPoll = { requestId, afterSequence: 0, timer: null };
          pollExecution(panel, requestId, 0);
        } catch (error) {
          status.textContent = error.message;
          run.disabled = false;
        }
      };
    }
    const input = panel.querySelector('[data-file]');
    input.disabled = disabled;
    if (disabled) panel.querySelector('[data-run]').disabled = true;
  }

  async function syncManagedNodeControl(nodeView, model, logicalNodeId) {
    const node = managedNodes(model).find(candidate => candidate.logical_node_id === logicalNodeId);
    if (!node) return;

    const heading = nodeView.querySelector('section.panel > h2');
    if (!heading) return;
    let control = document.getElementById(NODE_CONTROL_ID);
    if (!control) {
      control = document.createElement('div');
      control.id = NODE_CONTROL_ID;
      control.className = 'myelin-control';
      control.innerHTML = `<button type="button" class="danger" data-action="kill">Kill</button>
        <span class="myelin-control-message" data-message role="status"></span>`;
      heading.after(control);
    }

    const killButton = control.querySelector('[data-action="kill"]');
    const message = control.querySelector('[data-message]');
    const terminal = node.phase === 'stopped' || node.phase === 'orphan';
    const pending = node.phase === 'kill_requested' || node.phase === 'stopping';
    killButton.hidden = terminal;
    killButton.disabled = pending;
    killButton.textContent = pending ? 'Kill requested' : 'Kill';
    message.textContent = `managed node ${logicalNodeId}: ${node.phase}`;
    ensureExecutionControl(nodeView, logicalNodeId, terminal || pending);

    killButton.onclick = async () => {
      if (!await confirmTermination(
        'Terminate managed node?',
        `Terminate managed node ${logicalNodeId}? Vast.ai contracts are destroyed and billing stops.`,
        'Terminate node',
      )) return;
      killButton.disabled = true;
      message.textContent = 'Submitting kill…';
      const [result] = await submitKills([logicalNodeId]);
      message.textContent = result.error ? result.error : 'Kill accepted';
      if (result.error) killButton.disabled = false;
    };
  }

  async function syncControl() {
    if (syncing) return;
    syncing = true;
    try {
      let model;
      try {
        const response = await fetch('/api/control/fleet', { cache: 'no-store' });
        if (!response.ok) return;
        model = (await response.json()).FleetStatus;
      } catch (_) {
        return;
      }
      lastModel = model;
      window.dispatchEvent(new CustomEvent('dashboard-hardware-source', {
        detail: { source: model?.provider?.provisioning_mode === 'mock' ? 'orchestrator' : 'node' },
      }));

      const nodeView = document.querySelector('.node-view[data-node]');
      if (!nodeView) {
        syncFleetControl(model);
        return;
      }
      if (nodeView.dataset.origin === 'orchestrator') {
        ensureOrchestratorControl(nodeView, model);
        return;
      }
      const rawNodeId = nodeView.dataset.node || '';
      if (/^\d+$/.test(rawNodeId)) await syncManagedNodeControl(nodeView, model, Number(rawNodeId));
    } finally {
      syncing = false;
    }
  }

  installUi();
  page.addEventListener('click', event => {
    const card = event.target.closest('a.node-card[data-node]');
    if (!card || !page.contains(card) || !event.shiftKey) return;
    const logicalNodeId = Number(card.dataset.node);
    const node = managedNodes(lastModel).find(candidate => candidate.logical_node_id === logicalNodeId);
    const selectable = card.dataset.origin !== 'orchestrator'
      && Number.isSafeInteger(logicalNodeId)
      && killable(node);
    if (!selectable) return;
    event.preventDefault();
    if (selectedNodes.has(logicalNodeId)) selectedNodes.delete(logicalNodeId);
    else selectedNodes.add(logicalNodeId);
    syncFleetControl(lastModel);
  });
  new MutationObserver(mutations => {
    const dashboardChanged = mutations.some(mutation => {
      const element = mutation.target.nodeType === Node.ELEMENT_NODE
        ? mutation.target
        : mutation.target.parentElement;
      return !element?.closest(
        `#${NODE_CONTROL_ID}, #${EXECUTION_CONTROL_ID}, #${BULK_CONTROL_ID}`,
      );
    });
    if (dashboardChanged) syncControl();
  }).observe(page, { childList: true, subtree: true });
  syncControl();
  setInterval(syncControl, 1000);
})();