// ── Session State ──

let currentSessionId = null;

function getCurrentSessionId() {
  return currentSessionId;
}

async function initSession() {
  // SessionId aus localStorage oder neue erstellen
  const stored = localStorage.getItem('sessionId');
  if (stored) {
    currentSessionId = stored;
  } else {
    const session = await apiCreateSession();
    currentSessionId = session.sessionId;
    localStorage.setItem('sessionId', currentSessionId);
  }

  await refreshSessionList();
}

async function createNewSession() {
  const session = await apiCreateSession();
  currentSessionId = session.sessionId;
  localStorage.setItem('sessionId', currentSessionId);

  // Chat leeren und neu laden
  messages.length = 0;
  chatEl().innerHTML = '';
  lastKnownMessageId = 0;
  loadedArchiveCount = 0;
  setMeta('');

  await refreshSessionList();
  await loadHistory();
}

async function switchSession(sessionId) {
  if (sessionId === currentSessionId) return;

  currentSessionId = sessionId;
  localStorage.setItem('sessionId', currentSessionId);

  // Chat leeren und Session laden
  messages.length = 0;
  chatEl().innerHTML = '';
  lastKnownMessageId = 0;
  loadedArchiveCount = 0;
  setMeta('');

  await refreshSessionList();
  await loadHistory();
}

async function refreshSessionList() {
  const sessions = await apiGetSessions();
  const list = $('#sessionList');
  list.innerHTML = '';

  for (const s of sessions) {
    const div = document.createElement('div');
    div.className = 'session-item' + (s.sessionId === currentSessionId ? ' active' : '');
    div.dataset.sessionId = s.sessionId;

    const name = document.createElement('span');
    name.className = 'session-name';
    name.textContent = s.name || 'Unbenannt';
    name.addEventListener('dblclick', () => renameSession(s.sessionId, name));

    const date = document.createElement('span');
    date.className = 'session-date';
    date.textContent = new Date(s.updatedAt).toLocaleString('de-AT', {
      day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit'
    });

    div.appendChild(name);
    div.appendChild(date);
    div.addEventListener('click', () => switchSession(s.sessionId));

    list.appendChild(div);
  }
}

async function renameSession(sessionId, nameEl) {
  const input = document.createElement('input');
  input.type = 'text';
  input.className = 'session-rename';
  input.value = nameEl.textContent;

  nameEl.replaceWith(input);
  input.focus();
  input.select();

  const save = async () => {
    const newName = input.value.trim();
    if (newName) {
      await apiUpdateSession(sessionId, { name: newName });
    }
    await refreshSessionList();
  };

  input.addEventListener('blur', save);
  input.addEventListener('keydown', (e) => {
    if (e.key === 'Enter') input.blur();
    if (e.key === 'Escape') { input.value = nameEl.textContent; input.blur(); }
  });
}