<?php
session_start();
$msgFile = 'messages.json';
$usersFile = 'registered_users.json';
$cookieName = 'chat_username';
$cookieExpire = time() + (365 * 24 * 60 * 60);

// ایجاد فایل‌ها
if (!file_exists($msgFile)) {
    file_put_contents($msgFile, json_encode([]));
}
if (!file_exists($usersFile)) {
    file_put_contents($usersFile, json_encode([]));
}

// ----- توابع مدیریت کاربران با ID -----
function getRegisteredUsers() {
    global $usersFile;
    $data = file_get_contents($usersFile);
    return json_decode($data, true) ?: [];
}

function saveRegisteredUsers($users) {
    global $usersFile;
    $fp = fopen($usersFile, 'w');
    if (flock($fp, LOCK_EX)) {
        fwrite($fp, json_encode($users));
        flock($fp, LOCK_UN);
    }
    fclose($fp);
}

function findUserByName($name) {
    $users = getRegisteredUsers();
    foreach ($users as $user) {
        if ($user['name'] === $name) {
            return $user; // ['id' => ..., 'name' => ...]
        }
    }
    return null;
}

function isUserRegistered($name) {
    return findUserByName($name) !== null;
}

function registerUser($name) {
    $users = getRegisteredUsers();
    // پیدا کردن بیشترین ID برای تولید ID جدید
    $maxId = 0;
    foreach ($users as $user) {
        if ($user['id'] > $maxId) $maxId = $user['id'];
    }
    $newId = $maxId + 1;
    $users[] = ['id' => $newId, 'name' => $name];
    saveRegisteredUsers($users);
    return $newId;
}

// ----- تابع تولید رنگ بر اساس ID (نه نام) -----
function getUserColorById($id) {
    $hash = md5((string)$id);
    $hue = hexdec(substr($hash, 0, 2)) % 360;
    return "hsl($hue, 75%, 60%)";
}

// ----- دریافت پیام‌های جدید (با رنگ) -----
if (isset($_GET['get'])) {
    $last = isset($_GET['last']) ? (int)$_GET['last'] : 0;
    $data = file_get_contents($msgFile);
    $msgs = json_decode($data, true) ?: [];
    $new = [];
    foreach ($msgs as $m) {
        if ($m['time'] > $last) {
            // پیدا کردن کاربر بر اساس نام
            $user = findUserByName($m['user']);
            $color = $user ? getUserColorById($user['id']) : '#f7c948';
            $m['color'] = $color;
            $new[] = $m;
        }
    }
    header('Content-Type: application/json');
    echo json_encode($new);
    exit;
}

// ----- ارسال پیام جدید -----
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['send'])) {
    if (!isset($_SESSION['username'])) exit;
    if (isset($_SESSION['last_send']) && time() - $_SESSION['last_send'] < 2) {
        http_response_code(429);
        exit;
    }
    $_SESSION['last_send'] = time();

    $user = $_SESSION['username'];
    $text = trim($_POST['text']);
    if ($text === '') exit;

    $data = file_get_contents($msgFile);
    $msgs = json_decode($data, true) ?: [];
    $msgs[] = [
        'user' => $user,
        'text' => htmlspecialchars($text),
        'time' => time()
    ];

    if (count($msgs) >= 200) {
        $msgs = array_slice($msgs, 100);
    }

    $fp = fopen($msgFile, 'w');
    if (flock($fp, LOCK_EX)) {
        fwrite($fp, json_encode($msgs));
        flock($fp, LOCK_UN);
    }
    fclose($fp);
    exit;
}

// ----- ورود خودکار با کوکی -----
if (!isset($_SESSION['username']) && isset($_COOKIE[$cookieName])) {
    $cachedName = $_COOKIE[$cookieName];
    if (isUserRegistered($cachedName)) {
        $_SESSION['username'] = htmlspecialchars($cachedName);
        setcookie($cookieName, $cachedName, $cookieExpire, '/');
    }
}

// ----- ورود کاربر جدید -----
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['username'])) {
    $name = trim($_POST['username']);
    $error = '';
    if ($name === '') {
        $error = 'لطفاً نام خود را وارد کنید.';
    } elseif (isUserRegistered($name)) {
        $error = 'این نام قبلاً ثبت شده است. لطفاً نام دیگری انتخاب کنید.';
    } else {
        registerUser($name);
        $_SESSION['username'] = htmlspecialchars($name);
        setcookie($cookieName, $name, $cookieExpire, '/');
        header('Location: ' . $_SERVER['PHP_SELF']);
        exit;
    }
    $logged_in = false;
    $login_error = $error;
} else {
    $logged_in = isset($_SESSION['username']);
    $login_error = '';
}

$currentUser = $logged_in ? $_SESSION['username'] : '';
?>
<!DOCTYPE html>
<html dir="rtl" lang="fa">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
    <title>چت‌روم</title>
    <style>
        * { margin:0; padding:0; box-sizing:border-box; font-family:Tahoma,sans-serif; }
        html, body { width:100%; height:100%; background:#1a1a2e; overflow:hidden; }
        .container {
            width:100%; height:100%;
            display:flex; flex-direction:column;
            background:#16213e; padding:10px;
        }
        #login {
            flex:1; display:flex; flex-direction:column;
            justify-content:center; align-items:center;
            text-align:center; color:#eee;
        }
        #login h2 { margin-bottom:20px; font-weight:normal; }
        #login input {
            width:80%; max-width:300px; padding:14px 20px;
            border-radius:40px; border:none; background:#0f3460;
            color:#fff; font-size:16px; outline:none; margin-bottom:12px;
        }
        #login button {
            padding:12px 40px; border-radius:40px; border:none;
            background:#e94560; color:#fff; font-size:16px; font-weight:bold; cursor:pointer;
        }
        .error-msg {
            color:#ff6b6b;
            background:#2d1a1a;
            padding:8px 16px;
            border-radius:30px;
            margin-bottom:12px;
            font-size:14px;
            display:inline-block;
        }
        #chat {
            flex:1; display:none; flex-direction:column; height:100%;
        }
        .header {
            display:flex; justify-content:flex-start; align-items:center;
            color:#aaa; background:#0f3460; padding:8px 16px;
            border-radius:30px; margin-bottom:8px; flex-shrink:0;
        }
        .header .username {
            color:#f7c948; font-weight:bold;
        }
        #messages {
            flex:1; overflow-y:auto; background:#0f3460;
            border-radius:16px; padding:12px; display:flex;
            flex-direction:column; gap:6px; margin-bottom:8px; min-height:0;
        }
        .msg {
            padding:8px 14px; border-radius:16px;
            max-width:85%; word-wrap:break-word; font-size:15px; line-height:1.5;
            align-self:flex-start; background:#2a2a4a; color:#eee;
        }
        .msg .user {
            font-weight:bold; font-size:13px; display:block; margin-bottom:2px;
        }
        .msg .time { font-size:10px; color:#aaa; margin-right:8px; }
        .msg.self {
            background:#1e88e5; align-self:flex-end; color:#fff;
        }
        .msg.self .user { color:#bbdefb; }
        .msg.self .time { color:#e3f2fd; }
        .msg.other { background:#2d2d4a; }
        .msg.other .user { color:#f7c948; }
        .system {
            background:transparent !important; text-align:center;
            color:#888; font-size:13px; align-self:center !important; max-width:100%;
        }
        #input-area {
            display:flex; gap:8px; flex-shrink:0; padding:4px 0;
        }
        #input-area input {
            flex:1; padding:12px 18px; border-radius:40px; border:none;
            background:#0f3460; color:#fff; font-size:15px; outline:none; min-width:0;
        }
        #input-area button {
            padding:12px 20px; border-radius:40px; border:none;
            background:#e94560; color:#fff; font-weight:bold; font-size:15px;
            cursor:pointer; white-space:nowrap;
        }
        @media (max-width:480px) {
            .container { padding:6px; }
            .msg { font-size:14px; padding:6px 12px; }
            #input-area input { padding:10px 14px; font-size:14px; }
            #input-area button { padding:10px 16px; font-size:14px; }
        }
        #messages::-webkit-scrollbar { width:5px; }
        #messages::-webkit-scrollbar-track { background:#0f3460; }
        #messages::-webkit-scrollbar-thumb { background:#4a6fa5; border-radius:10px; }
    </style>
</head>
<body>
<div class="container">
    <?php if (!$logged_in): ?>
        <div id="login">
            <h2>👋 به چت خوش آمدید</h2>
            <?php if (!empty($login_error)): ?>
                <div class="error-msg">⚠️ <?= htmlspecialchars($login_error) ?></div>
            <?php endif; ?>
            <form method="POST" style="width:100%; display:flex; flex-direction:column; align-items:center;">
                <input type="text" name="username" placeholder="نام خود را وارد کنید..." required>
                <button type="submit">ثبت نام و ورود</button>
            </form>
            <p style="color:#666; font-size:13px; margin-top:15px;">نام شما فقط یک بار ثبت می‌شود و دفعات بعد به‌طور خودکار وارد می‌شوید</p>
        </div>
    <?php else: ?>
        <div id="chat" style="display:flex;">
            <div class="header">
                <span class="username">👤 <?= htmlspecialchars($currentUser) ?></span>
            </div>
            <div id="messages"></div>
            <div id="input-area">
                <input type="text" id="msgInput" placeholder="پیام خود را بنویسید..." autofocus>
                <button id="sendBtn">ارسال</button>
            </div>
        </div>
        <script>
            const currentUser = "<?= addslashes($currentUser) ?>";
        </script>
    <?php endif; ?>
</div>

<?php if ($logged_in): ?>
<script>
    const msgsDiv = document.getElementById('messages');
    const msgInput = document.getElementById('msgInput');
    const sendBtn = document.getElementById('sendBtn');

    let lastTime = 0;

    function fetchMessages() {
        fetch('?get=1&last=' + lastTime)
            .then(res => res.json())
            .then(data => {
                if (data.length === 0) return;
                data.forEach(msg => {
                    const isSelf = (msg.user === currentUser);
                    const time = new Date(msg.time * 1000).toLocaleTimeString('fa-IR', { hour:'2-digit', minute:'2-digit' });
                    const div = document.createElement('div');
                    div.className = 'msg ' + (isSelf ? 'self' : 'other');
                    const color = msg.color || '#f7c948';
                    div.innerHTML = `
                        <span class="user" style="color:${color};">${msg.user}</span>
                        <span class="time">${time}</span>
                        <div>${msg.text}</div>
                    `;
                    msgsDiv.appendChild(div);
                    if (msg.time > lastTime) lastTime = msg.time;
                });
                msgsDiv.scrollTop = msgsDiv.scrollHeight;
            });
    }

    function sendMessage() {
        const text = msgInput.value.trim();
        if (!text) return;
        fetch('', {
            method: 'POST',
            headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
            body: 'send=1&text=' + encodeURIComponent(text)
        })
        .then(res => {
            if (res.status === 429) {
                alert('لطفاً کمی صبر کنید.');
                return;
            }
            msgInput.value = '';
            fetchMessages();
        });
    }

    sendBtn.addEventListener('click', sendMessage);
    msgInput.addEventListener('keypress', e => {
        if (e.key === 'Enter') sendMessage();
    });

    setInterval(fetchMessages, 3000);
    fetchMessages();
    msgInput.focus();
</script>
<?php endif; ?>

            <link href="https://fonts.googleapis.com/css2?family=Beiruti:wght@200..900&display=swap" rel="stylesheet">
            <div style="position: fixed; bottom: 0; left: 0; width: 100%; background-color: #0a0a0a; color: #ffffff; text-align: center; padding: 5px; font-size: 10px; font-family: 'Beiruti', serif; z-index: 9999; box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);">
                <span>This page was created by Litebase Page Builder and has no affiliation with other sites</span>
            </div>
        </body>
</html>