import * as Y from 'yjs';
import { WebrtcProvider } from 'y-webrtc';

// --- Peer ID (stable across reloads) ---

function getOrCreatePeerId() {
  let id = localStorage.getItem('peer-id');
  if (!id) {
    id = crypto.randomUUID();
    localStorage.setItem('peer-id', id);
  }
  return id;
}

const peerId = getOrCreatePeerId();

// --- Room name from URL ---

function getRoomName() {
  const params = new URLSearchParams(window.location.search);
  return params.get('room') || 'default-poll';
}

const roomName = getRoomName();

// --- Yjs setup ---

const ydoc = new Y.Doc();
const provider = new WebrtcProvider(roomName, ydoc);
const yOptions = ydoc.getMap('poll-options');

// --- Data operations ---

function addOption(name) {
  const id = crypto.randomUUID();
  const optionMap = new Y.Map();
  optionMap.set('name', name);
  optionMap.set('votes', new Y.Map());
  yOptions.set(id, optionMap);
}

function toggleVote(optionId) {
  const optionMap = yOptions.get(optionId);
  if (!optionMap) return;
  const votes = optionMap.get('votes');
  if (votes.has(peerId)) {
    votes.delete(peerId);
  } else {
    votes.set(peerId, true);
  }
}

// --- UI rendering ---

const container = document.getElementById('poll-options');
const emptyState = document.getElementById('empty-state');

function render() {
  container.innerHTML = '';

  const entries = [];
  yOptions.forEach((optionMap, id) => {
    entries.push({
      id,
      name: optionMap.get('name'),
      votes: optionMap.get('votes').size,
      voted: optionMap.get('votes').has(peerId),
    });
  });

  entries.sort((a, b) => b.votes - a.votes || a.name.localeCompare(b.name));

  emptyState.className = entries.length > 0 ? 'hidden' : '';

  for (const entry of entries) {
    const div = document.createElement('div');
    div.className = 'poll-option';

    const nameSpan = document.createElement('span');
    nameSpan.className = 'option-name';
    nameSpan.textContent = entry.name;

    const voteCount = document.createElement('span');
    voteCount.className = 'vote-count';
    voteCount.textContent = entry.votes;

    const voteBtn = document.createElement('button');
    voteBtn.className = entry.voted ? 'vote-btn voted' : 'vote-btn';
    voteBtn.textContent = entry.voted ? 'Unvote' : 'Vote';
    voteBtn.addEventListener('click', () => toggleVote(entry.id));

    div.append(nameSpan, voteCount, voteBtn);
    container.appendChild(div);
  }
}

// Re-render on any change in the shared state
yOptions.observeDeep(() => render());

// --- Add option handlers ---

const input = document.getElementById('option-input');
const addBtn = document.getElementById('add-btn');

addBtn.addEventListener('click', () => {
  const name = input.value.trim();
  if (name) {
    addOption(name);
    input.value = '';
  }
});

input.addEventListener('keydown', (e) => {
  if (e.key === 'Enter') addBtn.click();
});

// --- Connection status & peer count ---

const statusEl = document.getElementById('connection-status');
const peerCountEl = document.getElementById('peer-count');

provider.on('synced', ({ synced }) => {
  statusEl.textContent = synced ? 'Connected' : 'Connecting...';
  statusEl.className = synced ? 'connected' : 'connecting';
});

function updatePeerCount() {
  const count = provider.awareness.getStates().size;
  peerCountEl.textContent = `${count} peer${count !== 1 ? 's' : ''}`;
}

provider.awareness.on('change', updatePeerCount);
updatePeerCount();

// --- Initial render ---
render();