feat: add full Dominoes game — tournament rules, bot AI, multiplayer

Complete dominoes integration with formal tournament rules:
- Double-six set (28 tiles), spinner rule (first double = 4-way branch)
- 2-player Draw Game (draw from boneyard when blocked, first to 100)
- 4-player Teams Block Game (pass when blocked, first to 150)
- All modes: local pass-and-play, VS bot (easy/medium/hard), online matchmaking, private rooms
- Full server-side validation (api/domino.php — play/draw/pass/round/match lifecycle)
- Bot AI with 3 difficulty levels (random, greedy-pip, strategic with opponent tracking)
- Supabase Realtime multiplayer via WebSocket
- CSS pip rendering, board layout with 4 directions, responsive tiles
- Database: domino_matches, domino_queue, RLS policies, game_plugins entry
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

index.php

@@ -55,6 +55,14 @@ if ($route === '' || $route === 'home') {
     require 'pages/ludo-live.php';
 } elseif ($route === 'ludo-matchmaking') {
     require 'pages/ludo-matchmaking.php';
+} elseif ($route === 'domino') {
+    require 'pages/domino.php';
+} elseif ($route === 'domino-game') {
+    require 'pages/domino-game.php';
+} elseif ($route === 'domino-live') {
+    require 'pages/domino-live.php';
+} elseif ($route === 'domino-matchmaking') {
+    require 'pages/domino-matchmaking.php';
 } elseif ($route === 'admin/theme') {
     require 'pages/admin-theme.php';
 } elseif (str_starts_with($route, 'api/')) {

pages/domino-game.php

+<?php $pageTitle = 'EL3AB - دومينو'; $hideNav = true; ?>
+<?php require __DIR__ . '/../includes/header.php'; ?>
+
+<link rel="stylesheet" href="/public/css/domino.css">
+
+<div class="domino-game">
+  <!-- Top area: opponent + scores -->
+  <div class="domino-top-area">
+    <div id="domino-opponent-top" class="domino-opponent-top"></div>
+    <div id="domino-scores"></div>
+  </div>
+
+  <!-- Side opponents (4P mode) -->
+  <div id="domino-opponent-left" class="domino-opponent-left"></div>
+  <div id="domino-opponent-right" class="domino-opponent-right"></div>
+
+  <!-- Board -->
+  <div class="domino-board-area">
+    <div id="domino-board"></div>
+    <div id="domino-boneyard"></div>
+  </div>
+
+  <!-- Status -->
+  <div id="domino-status" class="domino-status"></div>
+
+  <!-- Actions -->
+  <div id="domino-actions"></div>
+
+  <!-- End buttons (choose which side to play on) -->
+  <div id="domino-end-buttons"></div>
+
+  <!-- Player hand -->
+  <div class="domino-hand-area">
+    <div id="domino-hand"></div>
+  </div>
+</div>
+
+<!-- Round overlay -->
+<div id="domino-round-overlay"></div>
+
+<script src="/public/js/domino-constants.js"></script>
+<script src="/public/js/domino-ui.js"></script>
+<script src="/public/js/domino-bot.js"></script>
+<script src="/public/js/domino-game.js"></script>
+<script>
+(function() {
+  var params = new URLSearchParams(window.location.search);
+  var mode = params.get('mode') || '2p';
+  var type = params.get('type') || 'bot';
+  var playerCount = parseInt(params.get('players')) || 2;
+  var difficulty = params.get('difficulty') || 'medium';
+
+  DominoGame.init({
+    mode: mode,
+    playerCount: playerCount,
+    difficulty: difficulty,
+    isLocal: type === 'local'
+  });
+})();
+</script>
+
+<?php require __DIR__ . '/../includes/footer.php'; ?>

pages/domino-live.php

+<?php $pageTitle = 'EL3AB - دومينو اونلاين'; $hideNav = true; ?>
+<?php require __DIR__ . '/../includes/header.php'; ?>
+
+<link rel="stylesheet" href="/public/css/domino.css">
+
+<!-- Waiting Room -->
+<div id="domino-waiting" class="space-y-6" style="padding:24px;text-align:center;">
+  <h2 style="font-size:22px;font-weight:700;">غرفة دومينو</h2>
+
+  <div class="card">
+    <div class="card-body space-y-4">
+      <div id="room-code-display">
+        <p class="text-muted text-sm">كود الغرفة</p>
+        <p id="room-code-value" style="font-size:32px;font-weight:700;letter-spacing:6px;color:var(--gold);"></p>
+        <button class="btn btn-ghost btn-sm" onclick="copyCode()" style="margin-top:8px;">نسخ الكود</button>
+      </div>
+
+      <div id="waiting-players" class="space-y-3"></div>
+
+      <button class="btn btn-gold btn-block btn-lg" id="start-game-btn" style="display:none;" onclick="DominoLive.startGame()">
+        ابدأ اللعب
+      </button>
+
+      <button class="btn btn-ghost btn-sm" onclick="window.location.href='/domino'">مغادرة</button>
+    </div>
+  </div>
+</div>
+
+<!-- Game Area -->
+<div id="domino-game-area" class="domino-game" style="display:none;">
+  <div class="domino-top-area">
+    <div id="domino-opponent-top" class="domino-opponent-top"></div>
+    <div id="domino-scores"></div>
+  </div>
+
+  <div id="domino-opponent-left" class="domino-opponent-left"></div>
+  <div id="domino-opponent-right" class="domino-opponent-right"></div>
+
+  <div class="domino-board-area">
+    <div id="domino-board"></div>
+    <div id="domino-boneyard"></div>
+  </div>
+
+  <div id="domino-status" class="domino-status"></div>
+  <div id="domino-actions"></div>
+  <div id="domino-end-buttons"></div>
+
+  <div class="domino-hand-area">
+    <div id="domino-hand"></div>
+  </div>
+</div>
+
+<!-- Round overlay -->
+<div id="domino-round-overlay"></div>
+
+<style>
+.domino-waiting-player {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 10px 14px;
+  background: var(--bg-2);
+  border-radius: 8px;
+  border: 1px solid rgba(255,255,255,0.05);
+}
+.domino-waiting-player--empty {
+  border-style: dashed;
+  opacity: 0.6;
+}
+</style>
+
+<script src="/public/js/domino-constants.js"></script>
+<script src="/public/js/domino-ui.js"></script>
+<script src="/public/js/domino-live.js"></script>
+<script>
+(function() {
+  var params = new URLSearchParams(window.location.search);
+  var action = params.get('action');
+  var matchId = params.get('match_id');
+  var code = params.get('code');
+
+  var token = localStorage.getItem('sb_access_token') || '';
+  var userId = '';
+  try {
+    var payload = JSON.parse(atob(token.split('.')[1]));
+    userId = payload.sub || '';
+  } catch(e) {}
+
+  if (!token || !userId) {
+    window.location.href = '/login';
+    return;
+  }
+
+  if (action === 'create') {
+    App.fetch('/api/domino.php', {
+      method: 'POST',
+      body: JSON.stringify({ action: 'create', mode: params.get('mode') || '2p' })
+    }).then(function(res) {
+      if (res && res.ok) {
+        var newMatchId = res.match.id;
+        history.replaceState(null, '', '/domino-live?match_id=' + newMatchId);
+        DominoLive.init({ matchId: newMatchId, userId: userId, token: token });
+      } else {
+        App.toast('فشل إنشاء الغرفة', 'error');
+      }
+    });
+  } else if (action === 'join' && code) {
+    App.fetch('/api/domino.php', {
+      method: 'POST',
+      body: JSON.stringify({ action: 'join', room_code: code })
+    }).then(function(res) {
+      if (res && res.ok) {
+        var joinMatchId = res.match.id;
+        history.replaceState(null, '', '/domino-live?match_id=' + joinMatchId);
+        DominoLive.init({ matchId: joinMatchId, userId: userId, token: token });
+      } else {
+        App.toast(res.error || 'فشل الانضمام', 'error');
+        setTimeout(function() { window.location.href = '/domino'; }, 1500);
+      }
+    });
+  } else if (matchId) {
+    DominoLive.init({ matchId: matchId, userId: userId, token: token });
+  } else {
+    window.location.href = '/domino';
+  }
+})();
+
+function copyCode() {
+  var code = document.getElementById('room-code-value').textContent;
+  if (navigator.clipboard) {
+    navigator.clipboard.writeText(code);
+    App.toast('تم نسخ الكود', 'success');
+  }
+}
+</script>
+
+<?php require __DIR__ . '/../includes/footer.php'; ?>

pages/domino-matchmaking.php

+<?php $pageTitle = 'EL3AB - البحث عن خصم'; ?>
+<?php require __DIR__ . '/../includes/header.php'; ?>
+
+<div class="lobby-page" style="display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:60vh;text-align:center;">
+  <div class="matchmaking-spinner">
+    <svg class="icon-lg" style="color:var(--gold);width:48px;height:48px;animation:spin 2s linear infinite;">
+      <use href="/public/icons/sprite.svg#icon-search"></use>
+    </svg>
+  </div>
+  <h2 style="margin-top:20px;color:var(--text-1);">جاري البحث عن خصم...</h2>
+  <p class="text-muted" id="matchmaking-status">يتم البحث عن لاعبين مناسبين</p>
+  <p class="text-muted text-sm" id="matchmaking-timer" style="margin-top:8px;"></p>
+  <button class="btn btn-ghost" style="margin-top:24px;" onclick="cancelMatchmaking()">إلغاء</button>
+</div>
+
+<style>
+@keyframes spin { to { transform: rotate(360deg); } }
+</style>
+
+<script>
+(function() {
+  var params = new URLSearchParams(window.location.search);
+  var mode = params.get('mode') || '2p';
+  var pollInterval = null;
+  var startTime = Date.now();
+
+  function updateTimer() {
+    var elapsed = Math.floor((Date.now() - startTime) / 1000);
+    var mins = Math.floor(elapsed / 60);
+    var secs = elapsed % 60;
+    document.getElementById('matchmaking-timer').textContent = (mins > 0 ? mins + ':' : '') + (secs < 10 ? '0' : '') + secs;
+  }
+
+  function pollMatchmaking() {
+    App.fetch('/api/domino.php', {
+      method: 'POST',
+      body: JSON.stringify({ action: 'matchmake', sub_action: 'join', mode: mode })
+    }).then(function(res) {
+      if (res.status === 'matched' && res.match_id) {
+        clearInterval(pollInterval);
+        document.getElementById('matchmaking-status').textContent = 'تم العثور على خصم!';
+        setTimeout(function() {
+          window.location.href = '/domino-live?match_id=' + res.match_id;
+        }, 1000);
+      }
+    }).catch(function() {});
+  }
+
+  pollInterval = setInterval(function() {
+    updateTimer();
+    pollMatchmaking();
+  }, 3000);
+
+  updateTimer();
+  pollMatchmaking();
+
+  window.cancelMatchmaking = function() {
+    clearInterval(pollInterval);
+    App.fetch('/api/domino.php', {
+      method: 'POST',
+      body: JSON.stringify({ action: 'matchmake', sub_action: 'leave', mode: mode })
+    }).then(function() {
+      window.location.href = '/domino';
+    });
+  };
+})();
+</script>
+
+<?php require __DIR__ . '/../includes/footer.php'; ?>

pages/domino.php

+<?php $pageTitle = 'EL3AB - دومينو'; ?>
+<?php require __DIR__ . '/../includes/header.php'; ?>
+
+<div class="lobby-page">
+
+  <a href="/games" class="breadcrumb">
+    <svg class="icon" style="width:14px;height:14px;"><use href="/public/icons/sprite.svg#icon-arrow-right"></use></svg>
+    العاب
+  </a>
+
+  <div class="text-center" style="margin-top:16px;">
+    <h2 class="lobby-title">دومينو</h2>
+    <p class="text-muted text-sm">اختر نوع اللعب</p>
+  </div>
+
+  <div class="lobby-cards">
+
+    <!-- Local (Pass & Play) -->
+    <div class="card lobby-card">
+      <div class="card-body space-y-4">
+        <div class="lobby-card-header">
+          <div class="avatar avatar-game" style="background:linear-gradient(135deg, var(--cyan), var(--gold));">
+            <svg class="icon-lg" style="color:var(--text-1)"><use href="/public/icons/sprite.svg#icon-users"></use></svg>
+          </div>
+          <div>
+            <p class="lobby-card-title-sm">لعب محلي</p>
+            <p class="text-muted text-sm">لاعبين على نفس الجهاز</p>
+          </div>
+        </div>
+
+        <div>
+          <label class="input-label">عدد اللاعبين</label>
+          <div class="tab-group" id="local-count-tabs">
+            <button class="tab active" data-count="2">2 لاعبين</button>
+            <button class="tab" data-count="4">4 لاعبين</button>
+          </div>
+        </div>
+
+        <button class="btn btn-gold btn-block btn-lg" onclick="startLocal()">
+          <svg class="icon"><use href="/public/icons/sprite.svg#icon-play"></use></svg>
+          ابدأ اللعب
+        </button>
+      </div>
+    </div>
+
+    <!-- VS Bot -->
+    <div class="card lobby-card">
+      <div class="card-body space-y-4">
+        <div class="lobby-card-header">
+          <div class="avatar avatar-game" style="background:var(--bg-3);">
+            <svg class="icon-lg" style="color:var(--cyan)"><use href="/public/icons/sprite.svg#icon-bot"></use></svg>
+          </div>
+          <div>
+            <p class="lobby-card-title-sm">ضد البوت</p>
+            <p class="text-muted text-sm">العب ضد بوتات ذكية</p>
+          </div>
+        </div>
+
+        <div>
+          <label class="input-label">الوضع</label>
+          <div class="tab-group" id="bot-mode-tabs">
+            <button class="tab active" data-mode="2p">1 ضد 1</button>
+            <button class="tab" data-mode="4p_teams">فرق (2 ضد 2)</button>
+          </div>
+        </div>
+
+        <div>
+          <label class="input-label">الصعوبة</label>
+          <div class="tab-group" id="bot-diff-tabs">
+            <button class="tab" data-diff="easy">سهل</button>
+            <button class="tab active" data-diff="medium">متوسط</button>
+            <button class="tab" data-diff="hard">صعب</button>
+          </div>
+        </div>
+
+        <button class="btn btn-gold btn-block btn-lg" onclick="startBot()">
+          <svg class="icon"><use href="/public/icons/sprite.svg#icon-play"></use></svg>
+          ابدأ اللعب
+        </button>
+      </div>
+    </div>
+
+    <!-- Multiplayer -->
+    <div class="card lobby-card lobby-card--featured">
+      <div class="card-body space-y-4">
+        <div class="lobby-card-header">
+          <div class="avatar avatar-game" style="background:linear-gradient(135deg, var(--gold), var(--cyan));">
+            <svg class="icon-lg" style="color:var(--text-1)"><use href="/public/icons/sprite.svg#icon-sword"></use></svg>
+          </div>
+          <div>
+            <p class="lobby-card-title">ضد لاعب حقيقي</p>
+            <p class="text-muted text-sm">العب اونلاين ضد لاعبين حقيقيين</p>
+          </div>
+        </div>
+
+        <div>
+          <label class="input-label">الوضع</label>
+          <div class="tab-group" id="mp-mode-tabs">
+            <button class="tab active" data-mode="2p">1 ضد 1</button>
+            <button class="tab" data-mode="4p_teams">فرق (2 ضد 2)</button>
+          </div>
+        </div>
+
+        <button class="btn btn-gold btn-block btn-lg" onclick="startMatchmaking()">
+          <svg class="icon"><use href="/public/icons/sprite.svg#icon-search"></use></svg>
+          ابحث عن خصم
+        </button>
+      </div>
+    </div>
+
+    <!-- Private Room -->
+    <div class="card lobby-card">
+      <div class="card-body space-y-4">
+        <div class="lobby-card-header">
+          <div class="avatar avatar-game" style="background:var(--bg-3);">
+            <svg class="icon-lg" style="color:var(--gold)"><use href="/public/icons/sprite.svg#icon-lock"></use></svg>
+          </div>
+          <div>
+            <p class="lobby-card-title-sm">غرفة خاصة</p>
+            <p class="text-muted text-sm">انشئ غرفة وادعو اصحابك</p>
+          </div>
+        </div>
+
+        <div class="lobby-btn-pair">
+          <button class="btn btn-gold" onclick="createRoom()">انشئ غرفة</button>
+          <button class="btn btn-ghost" onclick="showJoinRoom()">انضم بكود</button>
+        </div>
+
+        <div id="join-room-form" style="display:none;">
+          <div class="lobby-code-row">
+            <input type="text" class="input" id="room-code-input" placeholder="ادخل كود الغرفة" maxlength="6" style="text-transform:uppercase;letter-spacing:4px;text-align:center;">
+            <button class="btn btn-gold" onclick="joinRoom()">دخول</button>
+          </div>
+        </div>
+      </div>
+    </div>
+
+  </div>
+</div>
+
+<script>
+document.addEventListener('DOMContentLoaded', function() {
+  document.querySelectorAll('.tab-group').forEach(function(group) {
+    group.querySelectorAll('.tab').forEach(function(tab) {
+      tab.addEventListener('click', function() {
+        group.querySelectorAll('.tab').forEach(function(t) { t.classList.remove('active'); });
+        tab.classList.add('active');
+      });
+    });
+  });
+
+  // Load config from games API
+  App.cachedFetch('/api/games.php', 60000).then(function(data) {
+    if (!data || !data.games) return;
+    var domino = data.games.find(function(g) { return g.game_key === 'domino'; });
+    if (!domino || !domino.config || !domino.config.difficulties) return;
+    var diffTabs = document.getElementById('bot-diff-tabs');
+    if (!diffTabs) return;
+    diffTabs.innerHTML = domino.config.difficulties.map(function(d, i) {
+      return '<button class="tab' + (i === 1 ? ' active' : '') + '" data-diff="' + d.id + '">' + d.label + '</button>';
+    }).join('');
+    diffTabs.querySelectorAll('.tab').forEach(function(tab) {
+      tab.addEventListener('click', function() {
+        diffTabs.querySelectorAll('.tab').forEach(function(t) { t.classList.remove('active'); });
+        tab.classList.add('active');
+      });
+    });
+  }).catch(function() {});
+});
+
+function startLocal() {
+  var count = document.querySelector('#local-count-tabs .tab.active').dataset.count;
+  var mode = count === '4' ? '4p_teams' : '2p';
+  window.location.href = '/domino-game?mode=' + mode + '&type=local&players=' + count;
+}
+
+function startBot() {
+  var mode = document.querySelector('#bot-mode-tabs .tab.active').dataset.mode;
+  var diff = document.querySelector('#bot-diff-tabs .tab.active').dataset.diff;
+  var count = mode === '4p_teams' ? 4 : 2;
+  window.location.href = '/domino-game?mode=' + mode + '&type=bot&players=' + count + '&difficulty=' + diff;
+}
+
+function startMatchmaking() {
+  if (!App.isLoggedIn()) { window.location.href = '/login'; return; }
+  var mode = document.querySelector('#mp-mode-tabs .tab.active').dataset.mode;
+  window.location.href = '/domino-matchmaking?mode=' + mode;
+}
+
+function createRoom() {
+  if (!App.isLoggedIn()) { window.location.href = '/login'; return; }
+  window.location.href = '/domino-live?action=create';
+}
+
+function showJoinRoom() {
+  var form = document.getElementById('join-room-form');
+  form.style.display = form.style.display === 'none' ? 'block' : 'none';
+  if (form.style.display === 'block') {
+    document.getElementById('room-code-input').focus();
+  }
+}
+
+function joinRoom() {
+  if (!App.isLoggedIn()) { window.location.href = '/login'; return; }
+  var code = document.getElementById('room-code-input').value.trim().toUpperCase();
+  if (!code || code.length < 4) {
+    App.toast('ادخل كود صحيح', 'error');
+    return;
+  }
+  window.location.href = '/domino-live?action=join&code=' + code;
+}
+</script>
+
+<?php require __DIR__ . '/../includes/footer.php'; ?>

public/js/domino-bot.js

+var DominoBot = (function() {
+    'use strict';
+
+    function choosePlay(hand, ends, board, difficulty, moves) {
+        var validPlays = DominoConstants.getValidPlays(hand, ends);
+        if (validPlays.length === 0) return null;
+
+        if (difficulty === 'easy') {
+            return validPlays[Math.floor(Math.random() * validPlays.length)];
+        }
+
+        if (difficulty === 'medium') {
+            // Prefer highest pip count tiles to get rid of heavy ones
+            validPlays.sort(function(a, b) {
+                return (b.tile.left + b.tile.right) - (a.tile.left + a.tile.right);
+            });
+            return validPlays[0];
+        }
+
+        // Hard: strategic scoring
+        var bestScore = -999;
+        var bestPlay = validPlays[0];
+
+        for (var i = 0; i < validPlays.length; i++) {
+            var play = validPlays[i];
+            var score = scorePlay(play, hand, ends, board, moves);
+            if (score > bestScore) {
+                bestScore = score;
+                bestPlay = play;
+            }
+        }
+
+        return bestPlay;
+    }
+
+    function scorePlay(play, hand, ends, board, moves) {
+        var score = 0;
+        var tile = play.tile;
+
+        // 1. Prefer high-pip tiles (shed weight early)
+        score += (tile.left + tile.right) * 2;
+
+        // 2. Play doubles early (they're harder to place later)
+        if (DominoConstants.isDouble(tile)) score += 8;
+
+        // 3. Keep variety — count unique values remaining after this play
+        var remaining = hand.filter(function(t) { return t.id !== tile.id; });
+        var values = {};
+        for (var r = 0; r < remaining.length; r++) {
+            values[remaining[r].left] = true;
+            values[remaining[r].right] = true;
+        }
+        score += Object.keys(values).length * 3;
+
+        // 4. Try to play values that opponents might be short on
+        var opponentDraws = countOpponentDraws(moves);
+        var exposedEnd = DominoConstants.getExposedEnd(tile, ends[play.side]);
+        if (DominoConstants.isDouble(tile)) exposedEnd = tile.left;
+        // If we expose a value opponents drew on (couldn't match), that's good (blocking)
+        if (opponentDraws[exposedEnd]) score += opponentDraws[exposedEnd] * 4;
+
+        // 5. Avoid leaving yourself with a single value type
+        var valueCounts = {};
+        for (var v = 0; v < remaining.length; v++) {
+            valueCounts[remaining[v].left] = (valueCounts[remaining[v].left] || 0) + 1;
+            valueCounts[remaining[v].right] = (valueCounts[remaining[v].right] || 0) + 1;
+        }
+        var maxConcentration = 0;
+        for (var k in valueCounts) {
+            if (valueCounts[k] > maxConcentration) maxConcentration = valueCounts[k];
+        }
+        score -= maxConcentration * 2;
+
+        return score;
+    }
+
+    function countOpponentDraws(moves) {
+        var draws = {};
+        if (!moves) return draws;
+
+        for (var i = 0; i < moves.length; i++) {
+            var move = moves[i];
+            if (move.action === 'draw' || move.action === 'pass') {
+                // After a draw/pass, the board ends at that moment tell us what the opponent couldn't match
+                // Simplified: track which values forced passes
+                if (i > 0 && moves[i-1].action === 'play' && moves[i-1].tile) {
+                    var prevTile = moves[i-1].tile;
+                    var exposed = prevTile.right;
+                    draws[exposed] = (draws[exposed] || 0) + 1;
+                }
+            }
+        }
+        return draws;
+    }
+
+    function chooseFirstTile(hand, difficulty) {
+        // Always prefer [6|6], then highest double, then highest pip
+        var doubles = hand.filter(function(t) { return DominoConstants.isDouble(t); });
+        if (doubles.length > 0) {
+            doubles.sort(function(a, b) { return b.left - a.left; });
+            return doubles[0];
+        }
+        var sorted = hand.slice().sort(function(a, b) {
+            return (b.left + b.right) - (a.left + a.right);
+        });
+        return sorted[0];
+    }
+
+    function shouldDraw(hand, ends) {
+        return !DominoConstants.canPlayerPlay(hand, ends);
+    }
+
+    return {
+        choosePlay: choosePlay,
+        chooseFirstTile: chooseFirstTile,
+        shouldDraw: shouldDraw
+    };
+})();

public/js/domino-constants.js

+var DominoConstants = (function() {
+    'use strict';
+
+    // Pip positions for each value (0-6) on a tile half
+    // Grid: 3x3, positions numbered 0-8 (top-left to bottom-right)
+    // 0 1 2
+    // 3 4 5
+    // 6 7 8
+    var PIP_POSITIONS = {
+        0: [],
+        1: [4],
+        2: [2, 6],
+        3: [2, 4, 6],
+        4: [0, 2, 6, 8],
+        5: [0, 2, 4, 6, 8],
+        6: [0, 2, 3, 5, 6, 8]
+    };
+
+    function generateAllTiles() {
+        var tiles = [];
+        for (var i = 0; i <= 6; i++) {
+            for (var j = i; j <= 6; j++) {
+                tiles.push({ id: 'tile_' + i + '_' + j, left: i, right: j });
+            }
+        }
+        return tiles;
+    }
+
+    function shuffleTiles(tiles) {
+        var arr = tiles.slice();
+        for (var i = arr.length - 1; i > 0; i--) {
+            var j = Math.floor(Math.random() * (i + 1));
+            var temp = arr[i];
+            arr[i] = arr[j];
+            arr[j] = temp;
+        }
+        return arr;
+    }
+
+    function dealTiles(mode, playerCount) {
+        var tiles = shuffleTiles(generateAllTiles());
+        var hands = {};
+        for (var p = 0; p < playerCount; p++) {
+            hands[p] = tiles.splice(0, 7);
+        }
+        var boneyard = (mode === '2p') ? tiles : [];
+        return { hands: hands, boneyard: boneyard };
+    }
+
+    function findFirstPlayer(hands, roundNumber, previousWinner) {
+        if (roundNumber > 1 && previousWinner !== null) return previousWinner;
+
+        // Round 1: who has [6|6]?
+        for (var idx in hands) {
+            for (var t = 0; t < hands[idx].length; t++) {
+                if (hands[idx][t].left === 6 && hands[idx][t].right === 6) return parseInt(idx);
+            }
+        }
+        // Highest double
+        for (var d = 5; d >= 0; d--) {
+            for (var idx2 in hands) {
+                for (var t2 = 0; t2 < hands[idx2].length; t2++) {
+                    if (hands[idx2][t2].left === d && hands[idx2][t2].right === d) return parseInt(idx2);
+                }
+            }
+        }
+        // Highest pip total
+        var best = -1, bestIdx = 0;
+        for (var idx3 in hands) {
+            for (var t3 = 0; t3 < hands[idx3].length; t3++) {
+                var total = hands[idx3][t3].left + hands[idx3][t3].right;
+                if (total > best) { best = total; bestIdx = parseInt(idx3); }
+            }
+        }
+        return bestIdx;
+    }
+
+    function isDouble(tile) {
+        return tile.left === tile.right;
+    }
+
+    function pipCount(hand) {
+        var total = 0;
+        for (var i = 0; i < hand.length; i++) {
+            total += hand[i].left + hand[i].right;
+        }
+        return total;
+    }
+
+    function tileMatchesEnd(tile, endValue) {
+        return tile.left === endValue || tile.right === endValue;
+    }
+
+    function getExposedEnd(tile, matchedValue) {
+        if (tile.left === matchedValue) return tile.right;
+        return tile.left;
+    }
+
+    function getPlayableEnds(board, spinner) {
+        if (!board || board.length === 0) return { any: true };
+
+        var ends = {};
+        var spinnerHasEast = false, spinnerHasWest = false;
+
+        for (var i = 0; i < board.length; i++) {
+            if (board[i].side === 'east') spinnerHasEast = true;
+            if (board[i].side === 'west') spinnerHasWest = true;
+        }
+
+        var eastChain = board.filter(function(e) { return e.side === 'east'; });
+        var westChain = board.filter(function(e) { return e.side === 'west'; });
+        var northChain = board.filter(function(e) { return e.side === 'north'; });
+        var southChain = board.filter(function(e) { return e.side === 'south'; });
+
+        if (eastChain.length > 0) {
+            ends.east = eastChain[eastChain.length - 1].exposed_end;
+        } else if (spinner) {
+            ends.east = spinner.left;
+        }
+
+        if (westChain.length > 0) {
+            ends.west = westChain[westChain.length - 1].exposed_end;
+        } else if (spinner) {
+            ends.west = spinner.left;
+        }
+
+        if (spinnerHasEast && spinnerHasWest && spinner) {
+            if (northChain.length > 0) {
+                ends.north = northChain[northChain.length - 1].exposed_end;
+            } else {
+                ends.north = spinner.left;
+            }
+            if (southChain.length > 0) {
+                ends.south = southChain[southChain.length - 1].exposed_end;
+            } else {
+                ends.south = spinner.left;
+            }
+        }
+
+        return ends;
+    }
+
+    function canPlayerPlay(hand, ends) {
+        if (ends.any) return true;
+        for (var i = 0; i < hand.length; i++) {
+            for (var side in ends) {
+                if (hand[i].left === ends[side] || hand[i].right === ends[side]) return true;
+            }
+        }
+        return false;
+    }
+
+    function getValidPlays(hand, ends) {
+        if (ends.any) {
+            return hand.map(function(t) { return { tile: t, side: 'any' }; });
+        }
+        var plays = [];
+        for (var i = 0; i < hand.length; i++) {
+            for (var side in ends) {
+                if (tileMatchesEnd(hand[i], ends[side])) {
+                    plays.push({ tile: hand[i], side: side });
+                }
+            }
+        }
+        return plays;
+    }
+
+    return {
+        PIP_POSITIONS: PIP_POSITIONS,
+        generateAllTiles: generateAllTiles,
+        shuffleTiles: shuffleTiles,
+        dealTiles: dealTiles,
+        findFirstPlayer: findFirstPlayer,
+        isDouble: isDouble,
+        pipCount: pipCount,
+        tileMatchesEnd: tileMatchesEnd,
+        getExposedEnd: getExposedEnd,
+        getPlayableEnds: getPlayableEnds,
+        canPlayerPlay: canPlayerPlay,
+        getValidPlays: getValidPlays
+    };
+})();