// Everything that talks to OUR OWN backend: party REST endpoints, and the
// realtime WebSocket. Same origin as this page, so no CORS concerns here -
// contrast with embyApi.js.
import { session } from './embyApi.js';

async function apiFetch(path, options = {}) {
  const res = await fetch(path, {
    ...options,
    headers: {
      'Content-Type': 'application/json',
      'X-Emby-Token': session.token,
      'X-Emby-UserId': session.userId,
      ...(options.headers || {})
    }
  });
  if (!res.ok) {
    const body = await res.json().catch(() => ({}));
    throw new Error(body.error || `Request failed: ${res.status}`);
  }
  return res.json();
}

export function createParty(itemId) {
  return apiFetch('/api/parties', { method: 'POST', body: JSON.stringify({ itemId }) });
}

export function joinParty(joinCode) {
  return apiFetch(`/api/parties/${encodeURIComponent(joinCode)}/join`, { method: 'POST' });
}

export function leaveParty(partyId) {
  return apiFetch(`/api/parties/${partyId}/leave`, { method: 'POST' });
}

export function getParty(partyId) {
  return apiFetch(`/api/parties/${partyId}`);
}

/**
 * Opens the realtime connection for a party. The Emby token is sent as the
 * FIRST WebSocket message, not a query string - tokens don't belong in URLs
 * (they'd end up in server logs, browser history, etc.).
 */
export function connectParty(partyId, { onMembers, onPlaystate, onError, onClose } = {}) {
  const proto = location.protocol === 'https:' ? 'wss://' : 'ws://';
  const ws = new WebSocket(proto + location.host + '/ws');

  ws.addEventListener('open', () => {
    ws.send(JSON.stringify({ type: 'auth', token: session.token, userId: session.userId, partyId }));
  });

  ws.addEventListener('message', (evt) => {
    let msg;
    try { msg = JSON.parse(evt.data); } catch (err) { return; }
    if (msg.type === 'members' && onMembers) onMembers(msg.members);
    if (msg.type === 'playstate' && onPlaystate) onPlaystate(msg);
    if (msg.type === 'error' && onError) onError(msg.message);
  });

  ws.addEventListener('close', () => { if (onClose) onClose(); });

  return {
    sendPlaystate(isPaused, positionTicks) {
      if (ws.readyState === WebSocket.OPEN) {
        ws.send(JSON.stringify({ type: 'playstate', isPaused, positionTicks }));
      }
    },
    leave() {
      if (ws.readyState === WebSocket.OPEN) {
        ws.send(JSON.stringify({ type: 'leave' }));
      }
      ws.close();
    }
  };
}