<?php
session_start();

// ===== KIỂM TRA ĐĂNG NHẬP =====
function isUserLoggedIn() {
    return isset($_SESSION['user_id']) && isset($_SESSION['username']);
}

function requireLogin() {
    if (!isUserLoggedIn()) {
        header('Location: login.php');
        exit;
    }
}

function getCurrentUserId() {
    return $_SESSION['user_id'] ?? null;
}

function getCurrentUsername() {
    return $_SESSION['username'] ?? null;
}

// Kiểm tra đăng nhập
requireLogin();

// ===== KẾT NỐI DATABASE =====
require_once __DIR__ . '/Database.php';

try {
    $db = Database::getInstance();
    $pdo = $db->getPDO();
} catch(Exception $e) {
    error_log('DATABASE_CONNECTION_ERROR: ' . $e->getMessage());
    die('❌ Lỗi kết nối hệ thống.');
}

$current_user_id = getCurrentUserId();
$message = '';
$message_type = '';

// ===== TẠO BẢNG NẾU CHƯA TỒN TẠI =====
try {
    $pdo->exec("
        CREATE TABLE IF NOT EXISTS youtube_links (
            id INT AUTO_INCREMENT PRIMARY KEY,
            user_id INT NOT NULL,
            title VARCHAR(255) NOT NULL,
            youtube_url TEXT NOT NULL,
            description TEXT,
            position INT NOT NULL,
            is_active TINYINT(1) DEFAULT 1,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
            INDEX idx_user_id (user_id),
            INDEX idx_position (position)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
    ");
} catch(Exception $e) {
    error_log('CREATE_TABLE_ERROR: ' . $e->getMessage());
}

// ===== XỬ LÝ THÊM/SỬA LINK =====
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['action'])) {
    try {
        if ($_POST['action'] === 'save') {
            $id = $_POST['id'] ?? null;
            $title = trim($_POST['title']);
            $youtube_url = trim($_POST['youtube_url']);
            $description = trim($_POST['description']);
            $position = (int)$_POST['position'];
            
            if (empty($title) || empty($youtube_url)) {
                throw new Exception('Vui lòng điền đầy đủ tiêu đề và link YouTube!');
            }
            
            // Validate YouTube URL
            if (!empty($youtube_url) && !preg_match('/^(https?:\/\/)?(www\.)?(youtube\.com|youtu\.be)\/.+$/', $youtube_url)) {
                throw new Exception('Link YouTube không hợp lệ!');
            }
            
            if ($id) {
                // Cập nhật
                $stmt = $pdo->prepare("
                    UPDATE youtube_links 
                    SET title = ?, youtube_url = ?, description = ?, position = ?, updated_at = NOW()
                    WHERE id = ? AND user_id = ?
                ");
                $stmt->execute([$title, $youtube_url, $description, $position, $id, $current_user_id]);
                $message = '✅ Cập nhật link thành công!';
            } else {
                // Thêm mới
                $stmt = $pdo->prepare("
                    INSERT INTO youtube_links (user_id, title, youtube_url, description, position)
                    VALUES (?, ?, ?, ?, ?)
                ");
                $stmt->execute([$current_user_id, $title, $youtube_url, $description, $position]);
                $message = '✅ Thêm link mới thành công!';
            }
            
            $message_type = 'success';
        }
        
        if ($_POST['action'] === 'delete') {
            $id = (int)$_POST['id'];
            $stmt = $pdo->prepare("DELETE FROM youtube_links WHERE id = ? AND user_id = ?");
            $stmt->execute([$id, $current_user_id]);
            $message = '✅ Xóa link thành công!';
            $message_type = 'success';
        }
        
        if ($_POST['action'] === 'toggle') {
            $id = (int)$_POST['id'];
            $stmt = $pdo->prepare("
                UPDATE youtube_links 
                SET is_active = NOT is_active 
                WHERE id = ? AND user_id = ?
            ");
            $stmt->execute([$id, $current_user_id]);
            $message = '✅ Cập nhật trạng thái thành công!';
            $message_type = 'success';
        }
        
    } catch(Exception $e) {
        $message = '❌ ' . $e->getMessage();
        $message_type = 'danger';
    }
}

// ===== LẤY DANH SÁCH LINK =====
try {
    $stmt = $pdo->prepare("
        SELECT * FROM youtube_links 
        WHERE user_id = ? 
        ORDER BY position ASC, id ASC
    ");
    $stmt->execute([$current_user_id]);
    $links = $stmt->fetchAll(PDO::FETCH_ASSOC);
    
    // Nếu chưa có link nào, tạo 6 placeholder
    if (empty($links)) {
        for ($i = 1; $i <= 6; $i++) {
            $stmt = $pdo->prepare("
                INSERT INTO youtube_links (user_id, title, youtube_url, description, position, is_active)
                VALUES (?, ?, ?, ?, ?, 0)
            ");
            $stmt->execute([
                $current_user_id,
                "Video {$i} - Chưa cập nhật",
                "",
                "Mô tả cho video {$i}",
                $i
            ]);
        }
        
        // Lấy lại danh sách
        $stmt = $pdo->prepare("
            SELECT * FROM youtube_links 
            WHERE user_id = ? 
            ORDER BY position ASC, id ASC
        ");
        $stmt->execute([$current_user_id]);
        $links = $stmt->fetchAll(PDO::FETCH_ASSOC);
    }
    
} catch(Exception $e) {
    error_log('GET_LINKS_ERROR: ' . $e->getMessage());
    $links = [];
}

// ===== FUNCTION: EXTRACT YOUTUBE VIDEO ID =====
function getYouTubeVideoId($url) {
    if (empty($url)) return null;
    
    preg_match('/(?:youtube\.com\/(?:[^\/]+\/.+\/|(?:v|e(?:mbed)?)\/|.*[?&]v=)|youtu\.be\/)([^"&?\/ ]{11})/', $url, $matches);
    return $matches[1] ?? null;
}

?>
<!DOCTYPE html>
<html lang="vi">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Quản Lý YouTube Links - DTD Agency</title>
    <link href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.1.3/css/bootstrap.min.css" rel="stylesheet">
    <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0/css/all.min.css" rel="stylesheet">
    <style>
        :root {
            --primary-color: #FF0000;
            --secondary-color: #282828;
            --accent-color: #065fd4;
        }
        
        body {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            padding: 20px 0;
        }
        
        .main-container {
            max-width: 1400px;
            margin: 0 auto;
        }
        
        .page-header {
            background: white;
            border-radius: 15px;
            padding: 30px;
            margin-bottom: 30px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.2);
        }
        
        .page-header h1 {
            color: var(--primary-color);
            margin: 0;
        }
        
        .video-card {
            background: white;
            border-radius: 15px;
            padding: 20px;
            margin-bottom: 20px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: 3px solid transparent;
        }
        
        .video-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.2);
        }
        
        .video-card.active {
            border-color: #28a745;
        }
        
        .video-card.inactive {
            opacity: 0.6;
            border-color: #dc3545;
        }
        
        .video-thumbnail {
            width: 100%;
            border-radius: 10px;
            margin-bottom: 15px;
            aspect-ratio: 16/9;
            object-fit: cover;
        }
        
        .placeholder-thumbnail {
            width: 100%;
            aspect-ratio: 16/9;
            background: linear-gradient(135deg, #e0e0e0 0%, #bdbdbd 100%);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #757575;
            font-size: 3rem;
            margin-bottom: 15px;
        }
        
        .video-title {
            font-size: 1.2rem;
            font-weight: bold;
            color: var(--secondary-color);
            margin-bottom: 10px;
        }
        
        .video-description {
            color: #606060;
            font-size: 0.9rem;
            margin-bottom: 15px;
        }
        
        .btn-youtube {
            background: var(--primary-color);
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 8px;
            font-weight: bold;
            transition: all 0.3s ease;
        }
        
        .btn-youtube:hover {
            background: #cc0000;
            color: white;
            transform: scale(1.05);
        }
        
        .position-badge {
            position: absolute;
            top: 10px;
            left: 10px;
            background: var(--primary-color);
            color: white;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            font-size: 1.2rem;
            box-shadow: 0 3px 10px rgba(0,0,0,0.3);
        }
        
        .status-badge {
            position: absolute;
            top: 10px;
            right: 10px;
            padding: 5px 15px;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: bold;
        }
        
        .modal-header {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
        }
        
        .back-button {
            background: white;
            border: 2px solid var(--primary-color);
            color: var(--primary-color);
            padding: 10px 25px;
            border-radius: 25px;
            font-weight: bold;
            transition: all 0.3s ease;
        }
        
        .back-button:hover {
            background: var(--primary-color);
            color: white;
        }
    </style>
</head>
<body>

<div class="main-container">
    <!-- Header -->
    <div class="page-header">
        <div class="d-flex justify-content-between align-items-center">
            <div>
                <h1>
                    <i class="fab fa-youtube" style="color: var(--primary-color);"></i>
                    Quản Lý YouTube Links
                </h1>
                <p class="text-muted mb-0">
                    <i class="fas fa-user"></i> <?php echo htmlspecialchars(getCurrentUsername()); ?>
                    | <i class="fas fa-fingerprint"></i> ID: <?php echo getCurrentUserId(); ?>
                </p>
            </div>
            <div>
                <a href="facebook_bot.php" class="back-button">
                    <i class="fas fa-arrow-left"></i> Quay lại Dashboard
                </a>
            </div>
        </div>
    </div>
    
    <!-- Thông báo -->
    <?php if ($message): ?>
    <div class="alert alert-<?php echo $message_type; ?> alert-dismissible fade show" role="alert">
        <?php echo $message; ?>
        <button type="button" class="btn-close" data-bs-dismiss="alert"></button>
    </div>
    <?php endif; ?>
    
    <!-- Danh sách Video -->
    <div class="row">
        <?php foreach ($links as $link): 
            $videoId = getYouTubeVideoId($link['youtube_url']);
            $thumbnailUrl = $videoId 
                ? "https://img.youtube.com/vi/{$videoId}/maxresdefault.jpg" 
                : null;
        ?>
        <div class="col-md-4 mb-4">
            <div class="video-card <?php echo $link['is_active'] ? 'active' : 'inactive'; ?> position-relative">
                
                <!-- Position Badge -->
                <div class="position-badge"><?php echo $link['position']; ?></div>
                
                <!-- Status Badge -->
                <div class="status-badge <?php echo $link['is_active'] ? 'bg-success' : 'bg-danger'; ?>">
                    <?php echo $link['is_active'] ? '✓ Kích hoạt' : '✗ Tắt'; ?>
                </div>
                
                <!-- Thumbnail -->
                <?php if ($thumbnailUrl): ?>
                    <img src="<?php echo htmlspecialchars($thumbnailUrl); ?>" 
                         class="video-thumbnail" 
                         alt="<?php echo htmlspecialchars($link['title']); ?>">
                <?php else: ?>
                    <div class="placeholder-thumbnail">
                        <i class="fab fa-youtube"></i>
                    </div>
                <?php endif; ?>
                
                <!-- Title -->
                <div class="video-title">
                    <?php echo htmlspecialchars($link['title']); ?>
                </div>
                
                <!-- Description -->
                <?php if (!empty($link['description'])): ?>
                <div class="video-description">
                    <?php echo nl2br(htmlspecialchars($link['description'])); ?>
                </div>
                <?php endif; ?>
                
                <!-- Buttons -->
                <div class="d-grid gap-2">
                    <?php if (!empty($link['youtube_url'])): ?>
                    <a href="<?php echo htmlspecialchars($link['youtube_url']); ?>" 
                       target="_blank" 
                       class="btn btn-youtube">
                        <i class="fab fa-youtube"></i> Xem Video
                    </a>
                    <?php endif; ?>
                    
                    <button class="btn btn-primary" 
                            onclick="editLink(<?php echo htmlspecialchars(json_encode($link)); ?>)">
                        <i class="fas fa-edit"></i> Chỉnh sửa
                    </button>
                    
                    <form method="POST" style="display: inline;" 
                          onsubmit="return confirm('Bạn có chắc muốn <?php echo $link['is_active'] ? 'TẮT' : 'BẬT'; ?> link này?')">
                        <input type="hidden" name="action" value="toggle">
                        <input type="hidden" name="id" value="<?php echo $link['id']; ?>">
                        <button type="submit" class="btn btn-warning w-100">
                            <i class="fas fa-power-off"></i> 
                            <?php echo $link['is_active'] ? 'Tắt' : 'Bật'; ?>
                        </button>
                    </form>
                    
                    <form method="POST" style="display: inline;" 
                          onsubmit="return confirm('Bạn có chắc muốn XÓA link này?')">
                        <input type="hidden" name="action" value="delete">
                        <input type="hidden" name="id" value="<?php echo $link['id']; ?>">
                        <button type="submit" class="btn btn-danger w-100">
                            <i class="fas fa-trash"></i> Xóa
                        </button>
                    </form>
                </div>
            </div>
        </div>
        <?php endforeach; ?>
    </div>
    
    <!-- Thêm link mới -->
    <?php if (count($links) < 6): ?>
    <div class="text-center mb-4">
        <button class="btn btn-success btn-lg" onclick="addNewLink()">
            <i class="fas fa-plus-circle"></i> Thêm Link Mới (Còn <?php echo 6 - count($links); ?> slot)
        </button>
    </div>
    <?php endif; ?>
</div>

<!-- Modal Chỉnh sửa -->
<div class="modal fade" id="editModal" tabindex="-1">
    <div class="modal-dialog modal-lg">
        <div class="modal-content">
            <form method="POST">
                <input type="hidden" name="action" value="save">
                <input type="hidden" name="id" id="edit_id">
                
                <div class="modal-header">
                    <h5 class="modal-title">
                        <i class="fab fa-youtube"></i> <span id="modal_title">Chỉnh sửa Link</span>
                    </h5>
                    <button type="button" class="btn-close btn-close-white" data-bs-dismiss="modal"></button>
                </div>
                
                <div class="modal-body">
                    <div class="mb-3">
                        <label class="form-label">
                            <i class="fas fa-sort-numeric-up"></i> Vị trí (1-6) <span class="text-danger">*</span>
                        </label>
                        <input type="number" class="form-control" name="position" id="edit_position" 
                               min="1" max="6" required>
                    </div>
                    
                    <div class="mb-3">
                        <label class="form-label">
                            <i class="fas fa-heading"></i> Tiêu đề <span class="text-danger">*</span>
                        </label>
                        <input type="text" class="form-control" name="title" id="edit_title" 
                               placeholder="VD: Hướng dẫn sử dụng Chatbot AI" required>
                    </div>
                    
                    <div class="mb-3">
                        <label class="form-label">
                            <i class="fab fa-youtube"></i> Link YouTube <span class="text-danger">*</span>
                        </label>
                        <input type="url" class="form-control" name="youtube_url" id="edit_youtube_url" 
                               placeholder="https://www.youtube.com/watch?v=..." required>
                        <small class="text-muted">
                            Hỗ trợ: youtube.com/watch?v=... hoặc youtu.be/...
                        </small>
                    </div>
                    
                    <div class="mb-3">
                        <label class="form-label">
                            <i class="fas fa-align-left"></i> Mô tả
                        </label>
                        <textarea class="form-control" name="description" id="edit_description" 
                                  rows="3" placeholder="Mô tả ngắn về video..."></textarea>
                    </div>
                    
                    <div class="alert alert-info">
                        <i class="fas fa-info-circle"></i>
                        <strong>Lưu ý:</strong> Sau khi lưu, thumbnail sẽ tự động hiển thị từ YouTube.
                    </div>
                </div>
                
                <div class="modal-footer">
                    <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">
                        <i class="fas fa-times"></i> Hủy
                    </button>
                    <button type="submit" class="btn btn-primary">
                        <i class="fas fa-save"></i> Lưu
                    </button>
                </div>
            </form>
        </div>
    </div>
</div>

<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap/5.1.3/js/bootstrap.bundle.min.js"></script>
<script>
const editModal = new bootstrap.Modal(document.getElementById('editModal'));

function editLink(link) {
    document.getElementById('modal_title').textContent = 'Chỉnh sửa Link';
    document.getElementById('edit_id').value = link.id;
    document.getElementById('edit_position').value = link.position;
    document.getElementById('edit_title').value = link.title;
    document.getElementById('edit_youtube_url').value = link.youtube_url;
    document.getElementById('edit_description').value = link.description || '';
    editModal.show();
}

function addNewLink() {
    document.getElementById('modal_title').textContent = 'Thêm Link Mới';
    document.getElementById('edit_id').value = '';
    document.getElementById('edit_position').value = <?php echo count($links) + 1; ?>;
    document.getElementById('edit_title').value = '';
    document.getElementById('edit_youtube_url').value = '';
    document.getElementById('edit_description').value = '';
    editModal.show();
}

// Auto dismiss alert
setTimeout(function() {
    const alert = document.querySelector('.alert');
    if (alert) {
        const bsAlert = new bootstrap.Alert(alert);
        bsAlert.close();
    }
}, 5000);

console.log('✅ YouTube Links Manager V1.0.0 - Loaded');
console.log('👤 User ID:', <?php echo getCurrentUserId(); ?>);
</script>

</body>
</html>