<?php
// config.php - Database configuration
class Database {
    private $host = "202.46.28.160";
    private $port = "45432";
    private $db_name = "tgs01_5803024013";
    private $username = "5803024013";
    private $password = "pw5803024013";
    public $conn;

    public function getConnection() {
        $this->conn = null;
        try {
            $this->conn = new PDO(
                "pgsql:host=" . $this->host . ";port=" . $this->port . ";dbname=" . $this->db_name,
                $this->username,
                $this->password
            );
            $this->conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        } catch(PDOException $exception) {
            echo "Connection error: " . $exception->getMessage();
        }
        return $this->conn;
    }
}

// Initialize database and create tables if they don't exist
function initializeDatabase() {
    $database = new Database();
    $conn = $database->getConnection();
    
    try {
        // Create groups table
        $query = "CREATE TABLE IF NOT EXISTS groups (
            group_id SERIAL PRIMARY KEY,
            group_name VARCHAR(255) NOT NULL UNIQUE,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )";
        $conn->exec($query);
        
        // Create tasks table
        $query = "CREATE TABLE IF NOT EXISTS tasks (
            task_id SERIAL PRIMARY KEY,
            task_name VARCHAR(255) NOT NULL,
            task_description TEXT,
            group_id INTEGER REFERENCES groups(group_id) ON DELETE CASCADE,
            is_done BOOLEAN DEFAULT FALSE,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        )";
        $conn->exec($query);
        
        // Insert default groups if none exist
        $stmt = $conn->prepare("SELECT COUNT(*) FROM groups");
        $stmt->execute();
        $count = $stmt->fetchColumn();
        
        if ($count == 0) {
            $defaultGroups = ['Personal', 'Work', 'Urgent'];
            foreach ($defaultGroups as $group) {
                $stmt = $conn->prepare("INSERT INTO groups (group_name) VALUES (?)");
                $stmt->execute([$group]);
            }
        }
        
    } catch(PDOException $exception) {
        echo "Error creating tables: " . $exception->getMessage();
    }
}

// Handle AJAX requests and form submissions
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $database = new Database();
    $conn = $database->getConnection();
    
    $action = $_POST['action'] ?? '';
    
    try {
        switch ($action) {
            case 'add_group':
                $groupName = trim($_POST['group_name']);
                if (!empty($groupName)) {
                    $stmt = $conn->prepare("INSERT INTO groups (group_name) VALUES (?)");
                    $stmt->execute([$groupName]);
                    echo json_encode(['success' => true, 'message' => 'Group added successfully']);
                } else {
                    echo json_encode(['success' => false, 'message' => 'Group name cannot be empty']);
                }
                exit;
                
            case 'add_task':
                $taskName = trim($_POST['task_name']);
                $taskDesc = trim($_POST['task_description']);
                $groupId = $_POST['group_id'];
                
                if (!empty($taskName) && !empty($groupId)) {
                    $stmt = $conn->prepare("INSERT INTO tasks (task_name, task_description, group_id) VALUES (?, ?, ?)");
                    $stmt->execute([$taskName, $taskDesc, $groupId]);
                    echo json_encode(['success' => true, 'message' => 'Task added successfully']);
                } else {
                    echo json_encode(['success' => false, 'message' => 'Task name and group are required']);
                }
                exit;
                
            case 'toggle_task':
                $taskId = $_POST['task_id'];
                $isDone = $_POST['is_done'] === 'true' ? 'TRUE' : 'FALSE';
                
                $stmt = $conn->prepare("UPDATE tasks SET is_done = $isDone WHERE task_id = ?");
                $stmt->execute([$taskId]);
                echo json_encode(['success' => true]);
                exit;
                
            case 'delete_task':
                $taskId = $_POST['task_id'];
                $stmt = $conn->prepare("DELETE FROM tasks WHERE task_id = ?");
                $stmt->execute([$taskId]);
                echo json_encode(['success' => true, 'message' => 'Task deleted successfully']);
                exit;
                
            case 'delete_group':
                $groupId = $_POST['group_id'];
                $stmt = $conn->prepare("DELETE FROM groups WHERE group_id = ?");
                $stmt->execute([$groupId]);
                echo json_encode(['success' => true, 'message' => 'Group and all associated tasks deleted successfully']);
                exit;
                
            case 'update_task':
                $taskId = $_POST['task_id'];
                $taskName = trim($_POST['task_name']);
                $taskDesc = trim($_POST['task_description']);
                $groupId = $_POST['group_id'];
                
                if (!empty($taskName) && !empty($groupId)) {
                    $stmt = $conn->prepare("UPDATE tasks SET task_name = ?, task_description = ?, group_id = ? WHERE task_id = ?");
                    $stmt->execute([$taskName, $taskDesc, $groupId, $taskId]);
                    echo json_encode(['success' => true, 'message' => 'Task updated successfully']);
                } else {
                    echo json_encode(['success' => false, 'message' => 'Task name and group are required']);
                }
                exit;
        }
    } catch(PDOException $exception) {
        echo json_encode(['success' => false, 'message' => 'Database error: ' . $exception->getMessage()]);
        exit;
    }
}

// Initialize database
initializeDatabase();

// Fetch data for display
$database = new Database();
$conn = $database->getConnection();

// Get all groups with their tasks
$query = "SELECT g.group_id, g.group_name, 
                 t.task_id, t.task_name, t.task_description, t.is_done, t.created_at as task_created
          FROM groups g
          LEFT JOIN tasks t ON g.group_id = t.group_id
          ORDER BY g.group_name, t.created_at DESC";
$stmt = $conn->prepare($query);
$stmt->execute();
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);

// Organize data by groups
$groupsData = [];
foreach ($results as $row) {
    $groupId = $row['group_id'];
    if (!isset($groupsData[$groupId])) {
        $groupsData[$groupId] = [
            'group_id' => $row['group_id'],
            'group_name' => $row['group_name'],
            'tasks' => []
        ];
    }
    
    if ($row['task_id']) {
        $groupsData[$groupId]['tasks'][] = [
            'task_id' => $row['task_id'],
            'task_name' => $row['task_name'],
            'task_description' => $row['task_description'],
            'is_done' => $row['is_done'],
            'task_created' => $row['task_created']
        ];
    }
}

// Get all groups for the dropdown
$stmt = $conn->prepare("SELECT group_id, group_name FROM groups ORDER BY group_name");
$stmt->execute();
$allGroups = $stmt->fetchAll(PDO::FETCH_ASSOC);
?>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Advanced To-Do List Manager</title>
    <style>
        * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', 'SF Pro Display', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 25%, #f093fb 50%, #f5576c 75%, #4facfe 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    min-height: 100vh;
    padding: 20px;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: 25px;
    padding: 40px;
    box-shadow: 
        0 25px 50px rgba(0, 0, 0, 0.15),
        0 0 0 1px rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

h1 {
    text-align: center;
    color: #1a202c;
    margin-bottom: 40px;
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #667eea, #764ba2, #f093fb, #f5576c);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.forms-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 50px;
}

.form-card {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    padding: 30px;
    border-radius: 20px;
    box-shadow: 
        0 10px 30px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.3);
    position: relative;
    overflow: hidden;
}

.form-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4, #feca57);
    background-size: 400% 100%;
    animation: colorFlow 3s ease infinite;
}

@keyframes colorFlow {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.form-card h3 {
    color: #2d3748;
    margin-bottom: 25px;
    font-size: 1.4rem;
    font-weight: 700;
    padding-bottom: 15px;
    position: relative;
}

.form-card h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 2px;
}

.form-group {
    margin-bottom: 24px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #4a5568;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

input[type="text"], textarea, select {
    width: 100%;
    padding: 16px 20px;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    font-size: 16px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: #ffffff;
    font-family: inherit;
}

input[type="text"]:focus, textarea:focus, select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 
        0 0 0 4px rgba(102, 126, 234, 0.1),
        0 4px 12px rgba(102, 126, 234, 0.15);
    transform: translateY(-2px);
}

textarea {
    resize: vertical;
    min-height: 100px;
    line-height: 1.6;
}

.btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 16px 32px;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-transform: uppercase;
    letter-spacing: 1px;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.6s;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 25px rgba(102, 126, 234, 0.3);
}

.btn:hover::before {
    left: 100%;
}

.btn-danger {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
}

.btn-danger:hover {
    box-shadow: 0 12px 25px rgba(255, 107, 107, 0.3);
}

.btn-success {
    background: linear-gradient(135deg, #00b894 0%, #00cec9 100%);
}

.btn-success:hover {
    box-shadow: 0 12px 25px rgba(0, 184, 148, 0.3);
}

.groups-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: 30px;
}

.group-card {
    background: linear-gradient(135deg, #ffffff 0%, #f7fafc 100%);
    border-radius: 20px;
    box-shadow: 
        0 15px 35px rgba(0, 0, 0, 0.1),
        0 5px 15px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    position: relative;
}

.group-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, 
        #ff6b6b 0%, 
        #4ecdc4 20%, 
        #45b7d1 40%, 
        #96ceb4 60%, 
        #feca57 80%, 
        #ff9ff3 100%);
}

.group-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 
        0 25px 50px rgba(0, 0, 0, 0.15),
        0 10px 30px rgba(0, 0, 0, 0.1);
}

.group-header {
    background: linear-gradient(135deg, #2d3748 0%, #4a5568 100%);
    color: white;
    padding: 25px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.group-header::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
}

.group-header h3 {
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.delete-group-btn {
    background: rgba(255, 107, 107, 0.2);
    border: 2px solid rgba(255, 107, 107, 0.3);
    color: #ff6b6b;
    padding: 10px 16px;
    border-radius: 10px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.delete-group-btn:hover {
    background: rgba(255, 107, 107, 0.9);
    color: white;
    transform: scale(1.05);
}

.tasks-list {
    padding: 25px;
    max-height: 450px;
    overflow-y: auto;
}

.tasks-list::-webkit-scrollbar {
    width: 8px;
}

.tasks-list::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 4px;
}

.tasks-list::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 4px;
}

.task-item {
    display: flex;
    align-items: center;
    padding: 20px;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    border-radius: 15px;
    border-left: 5px solid;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.task-item:nth-child(1) { border-left-color: #ff6b6b; }
.task-item:nth-child(2) { border-left-color: #4ecdc4; }
.task-item:nth-child(3) { border-left-color: #45b7d1; }
.task-item:nth-child(4) { border-left-color: #96ceb4; }
.task-item:nth-child(5) { border-left-color: #feca57; }
.task-item:nth-child(6) { border-left-color: #ff9ff3; }
.task-item:nth-child(7) { border-left-color: #54a0ff; }
.task-item:nth-child(8) { border-left-color: #5f27cd; }
.task-item:nth-child(n+9) { border-left-color: #00d2d3; }

.task-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, transparent 0%, rgba(255, 255, 255, 0.1) 100%);
    pointer-events: none;
}

.task-item:hover {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    transform: translateX(8px) translateY(-2px);
    box-shadow: 
        0 8px 25px rgba(0, 0, 0, 0.1),
        0 4px 12px rgba(0, 0, 0, 0.08);
}

.task-item.completed {
    opacity: 0.6;
    background: linear-gradient(135deg, #e2e8f0 0%, #cbd5e0 100%);
}

.task-item.completed .task-content {
    text-decoration: line-through;
}

.task-checkbox {
    margin-right: 20px;
    transform: scale(1.3);
    cursor: pointer;
    accent-color: #667eea;
}

.task-content {
    flex: 1;
}

.task-name {
    font-weight: 700;
    color: #2d3748;
    margin-bottom: 8px;
    font-size: 16px;
    letter-spacing: 0.3px;
}

.task-description {
    color: #718096;
    font-size: 14px;
    line-height: 1.5;
    font-weight: 400;
}

.task-actions {
    display: flex;
    gap: 12px;
    margin-left: 20px;
}

.task-actions button {
    padding: 10px 16px;
    font-size: 13px;
    font-weight: 600;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.edit-btn {
    background: linear-gradient(135deg, #feca57 0%, #ff9ff3 100%);
    color: #2d3748;
}

.edit-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 8px 20px rgba(254, 202, 87, 0.4);
}

.delete-btn {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
    color: white;
}

.delete-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 8px 20px rgba(255, 107, 107, 0.4);
}

.no-tasks {
    text-align: center;
    color: #a0aec0;
    font-style: italic;
    padding: 40px;
    font-size: 16px;
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
    border-radius: 15px;
    border: 2px dashed #cbd5e0;
}

.notification {
    position: fixed;
    top: 30px;
    right: 30px;
    padding: 20px 30px;
    background: linear-gradient(135deg, #00b894 0%, #00cec9 100%);
    color: white;
    border-radius: 15px;
    box-shadow: 
        0 10px 30px rgba(0, 184, 148, 0.3),
        0 5px 15px rgba(0, 0, 0, 0.1);
    transform: translateX(400px);
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1000;
    font-weight: 600;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

.notification.show {
    transform: translateX(0);
    opacity: 1;
}

.notification.error {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
    box-shadow: 
        0 10px 30px rgba(255, 107, 107, 0.3),
        0 5px 15px rgba(0, 0, 0, 0.1);
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    z-index: 2000;
    justify-content: center;
    align-items: center;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    padding: 40px;
    border-radius: 20px;
    width: 90%;
    max-width: 500px;
    box-shadow: 
        0 25px 50px rgba(0, 0, 0, 0.25),
        0 10px 30px rgba(0, 0, 0, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.3);
    position: relative;
    overflow: hidden;
}

.modal-content::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4, #feca57);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.modal-header h2 {
    color: #2d3748;
    font-weight: 700;
    font-size: 1.5rem;
}

.close-btn {
    background: linear-gradient(135deg, #cbd5e0 0%, #a0aec0 100%);
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #4a5568;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.close-btn:hover {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
    color: white;
    transform: rotate(90deg);
}

/* Colorful priority indicators */
.task-item[data-priority="high"]::before {
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.1) 0%, rgba(238, 90, 36, 0.1) 100%);
}

.task-item[data-priority="medium"]::before {
    background: linear-gradient(135deg, rgba(254, 202, 87, 0.1) 0%, rgba(255, 159, 243, 0.1) 100%);
}

.task-item[data-priority="low"]::before {
    background: linear-gradient(135deg, rgba(150, 206, 180, 0.1) 0%, rgba(78, 205, 196, 0.1) 100%);
}

/* Modern animations */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.loading {
    animation: pulse 2s infinite;
}

/* Enhanced mobile responsiveness */
@media (max-width: 768px) {
    .forms-section {
        grid-template-columns: 1fr;
    }
    
    .groups-container {
        grid-template-columns: 1fr;
    }
    
    .container {
        padding: 25px;
        margin: 10px;
        border-radius: 20px;
    }
    
    h1 {
        font-size: 2.2rem;
        margin-bottom: 30px;
    }
    
    .form-card, .modal-content {
        padding: 25px;
    }
    
    .task-actions {
        flex-direction: column;
        gap: 8px;
    }
    
    .task-actions button {
        padding: 8px 14px;
        font-size: 12px;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    .container {
        background: rgba(26, 32, 44, 0.95);
        color: #e2e8f0;
    }
    
    .form-card, .group-card, .modal-content {
        background: linear-gradient(135deg, #2d3748 0%, #4a5568 100%);
        color: #e2e8f0;
    }
    
    .task-item {
        background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
        color: #e2e8f0;
    }
    
    .task-name {
        color: #f7fafc;
    }
    
    .task-description {
        color: #a0aec0;
    }
    
    input[type="text"], textarea, select {
        background: #4a5568;
        color: #e2e8f0;
        border-color: #718096;
    }
    
    input[type="text"]:focus, textarea:focus, select:focus {
        background: #2d3748;
    }
}

/* Smooth transitions for everything */
* {
    transition: color 0.3s ease, background-color 0.3s ease;
}

/* Fun hover effects for interactive elements */
.form-card:hover {
    transform: translateY(-2px);
    box-shadow: 
        0 15px 40px rgba(0, 0, 0, 0.12),
        inset 0 1px 0 rgba(255, 255, 255, 0.9);
}

/* Glassmorphism effect for modern look */
.container, .form-card, .group-card, .modal-content {
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}
    </style>
</head>
<body>
    <div class="container">
        <h1>🚀 Advanced To-Do List Manager</h1>
        
        <div class="forms-section">
            <!-- Add Group Form -->
            <div class="form-card">
                <h3>📁 Create New Group</h3>
                <form id="addGroupForm">
                    <div class="form-group">
                        <label for="group_name">Group Name:</label>
                        <input type="text" id="group_name" name="group_name" required placeholder="Enter group name">
                    </div>
                    <button type="submit" class="btn">Add Group</button>
                </form>
            </div>

            <!-- Add Task Form -->
            <div class="form-card">
                <h3>✅ Create New Task</h3>
                <form id="addTaskForm">
                    <div class="form-group">
                        <label for="task_name">Task Name:</label>
                        <input type="text" id="task_name" name="task_name" required placeholder="Enter task name">
                    </div>
                    <div class="form-group">
                        <label for="task_description">Description (Optional):</label>
                        <textarea id="task_description" name="task_description" placeholder="Enter task description"></textarea>
                    </div>
                    <div class="form-group">
                        <label for="group_id">Select Group:</label>
                        <select id="group_id" name="group_id" required>
                            <option value="">Choose a group</option>
                            <?php foreach ($allGroups as $group): ?>
                                <option value="<?= $group['group_id'] ?>"><?= htmlspecialchars($group['group_name']) ?></option>
                            <?php endforeach; ?>
                        </select>
                    </div>
                    <button type="submit" class="btn">Add Task</button>
                </form>
            </div>
        </div>

        <!-- Groups and Tasks Display -->
        <div class="groups-container">
            <?php if (empty($groupsData)): ?>
                <div class="no-tasks">
                    <h3>No groups found</h3>
                    <p>Start by creating your first group!</p>
                </div>
            <?php else: ?>
                <?php foreach ($groupsData as $group): ?>
                    <div class="group-card">
                        <div class="group-header">
                            <h3><?= htmlspecialchars($group['group_name']) ?></h3>
                            <button class="delete-group-btn" onclick="deleteGroup(<?= $group['group_id'] ?>)">
                                🗑️ Delete Group
                            </button>
                        </div>
                        <div class="tasks-list">
                            <?php if (empty($group['tasks'])): ?>
                                <div class="no-tasks">No tasks in this group yet</div>
                            <?php else: ?>
                                <?php foreach ($group['tasks'] as $task): ?>
                                    <div class="task-item <?= $task['is_done'] === 't' ? 'completed' : '' ?>">
                                        <input type="checkbox" class="task-checkbox" 
                                               <?= $task['is_done'] === 't' ? 'checked' : '' ?>
                                               onchange="toggleTask(<?= $task['task_id'] ?>, this.checked)">
                                        <div class="task-content">
                                            <div class="task-name"><?= htmlspecialchars($task['task_name']) ?></div>
                                            <?php if ($task['task_description']): ?>
                                                <div class="task-description"><?= htmlspecialchars($task['task_description']) ?></div>
                                            <?php endif; ?>
                                        </div>
                                        <div class="task-actions">
                                            <button class="edit-btn" onclick="editTask(<?= $task['task_id'] ?>, '<?= htmlspecialchars($task['task_name'], ENT_QUOTES) ?>', '<?= htmlspecialchars($task['task_description'], ENT_QUOTES) ?>', <?= $group['group_id'] ?>)">
                                                Edit
                                            </button>
                                            <button class="delete-btn" onclick="deleteTask(<?= $task['task_id'] ?>)">
                                                Delete
                                            </button>
                                        </div>
                                    </div>
                                <?php endforeach; ?>
                            <?php endif; ?>
                        </div>
                    </div>
                <?php endforeach; ?>
            <?php endif; ?>
        </div>
    </div>

    <!-- Edit Task Modal -->
    <div id="editModal" class="modal">
        <div class="modal-content">
            <div class="modal-header">
                <h3>Edit Task</h3>
                <button class="close-btn" onclick="closeEditModal()">&times;</button>
            </div>
            <form id="editTaskForm">
                <input type="hidden" id="edit_task_id" name="task_id">
                <div class="form-group">
                    <label for="edit_task_name">Task Name:</label>
                    <input type="text" id="edit_task_name" name="task_name" required>
                </div>
                <div class="form-group">
                    <label for="edit_task_description">Description:</label>
                    <textarea id="edit_task_description" name="task_description"></textarea>
                </div>
                <div class="form-group">
                    <label for="edit_group_id">Group:</label>
                    <select id="edit_group_id" name="group_id" required>
                        <?php foreach ($allGroups as $group): ?>
                            <option value="<?= $group['group_id'] ?>"><?= htmlspecialchars($group['group_name']) ?></option>
                        <?php endforeach; ?>
                    </select>
                </div>
                <div style="display: flex; gap: 10px; justify-content: flex-end;">
                    <button type="button" class="btn btn-danger" onclick="closeEditModal()">Cancel</button>
                    <button type="submit" class="btn btn-success">Update Task</button>
                </div>
            </form>
        </div>
    </div>

    <!-- Notification -->
    <div id="notification" class="notification"></div>

    <script>
        // Show notification
        function showNotification(message, isError = false) {
            const notification = document.getElementById('notification');
            notification.textContent = message;
            notification.className = 'notification' + (isError ? ' error' : '');
            notification.classList.add('show');
            
            setTimeout(() => {
                notification.classList.remove('show');
            }, 3000);
        }

        // Add Group Form Handler
        document.getElementById('addGroupForm').addEventListener('submit', async function(e) {
            e.preventDefault();
            
            const formData = new FormData();
            formData.append('action', 'add_group');
            formData.append('group_name', document.getElementById('group_name').value);
            
            try {
                const response = await fetch('', {
                    method: 'POST',
                    body: formData
                });
                const result = await response.json();
                
                if (result.success) {
                    showNotification(result.message);
                    document.getElementById('group_name').value = '';
                    setTimeout(() => location.reload(), 1000);
                } else {
                    showNotification(result.message, true);
                }
            } catch (error) {
                showNotification('Error adding group', true);
            }
        });

        // Add Task Form Handler
        document.getElementById('addTaskForm').addEventListener('submit', async function(e) {
            e.preventDefault();
            
            const formData = new FormData();
            formData.append('action', 'add_task');
            formData.append('task_name', document.getElementById('task_name').value);
            formData.append('task_description', document.getElementById('task_description').value);
            formData.append('group_id', document.getElementById('group_id').value);
            
            try {
                const response = await fetch('', {
                    method: 'POST',
                    body: formData
                });
                const result = await response.json();
                
                if (result.success) {
                    showNotification(result.message);
                    document.getElementById('addTaskForm').reset();
                    setTimeout(() => location.reload(), 1000);
                } else {
                    showNotification(result.message, true);
                }
            } catch (error) {
                showNotification('Error adding task', true);
            }
        });

        // Toggle Task Status
        async function toggleTask(taskId, isDone) {
            const formData = new FormData();
            formData.append('action', 'toggle_task');
            formData.append('task_id', taskId);
            formData.append('is_done', isDone);
            
            try {
                const response = await fetch('', {
                    method: 'POST',
                    body: formData
                });
                const result = await response.json();
                
                if (result.success) {
                    location.reload();
                }
            } catch (error) {
                showNotification('Error updating task status', true);
            }
        }

        // Delete Task
        async function deleteTask(taskId) {
            if (!confirm('Are you sure you want to delete this task?')) return;
            
            const formData = new FormData();
            formData.append('action', 'delete_task');
            formData.append('task_id', taskId);
            
            try {
                const response = await fetch('', {
                    method: 'POST',
                    body: formData
                });
                const result = await response.json();
                
                if (result.success) {
                    showNotification(result.message);
                    setTimeout(() => location.reload(), 1000);
                } else {
                    showNotification(result.message, true);
                }
            } catch (error) {
                showNotification('Error deleting task', true);
            }
        }

        // Delete Group
        async function deleteGroup(groupId) {
            if (!confirm('Are you sure you want to delete this group and all its tasks?')) return;
            
            const formData = new FormData();
            formData.append('action', 'delete_group');
            formData.append('group_id', groupId);
            
            try {
                const response = await fetch('', {
                    method: 'POST',
                    body: formData
                });
                const result = await response.json();
                
                if (result.success) {
                    showNotification(result.message);
                    setTimeout(() => location.reload(), 1000);
                } else {
                    showNotification(result.message, true);
                }
            } catch (error) {
                showNotification('Error deleting group', true);
            }
        }

        // Edit Task Modal Functions
        function editTask(taskId, taskName, taskDescription, groupId) {
            document.getElementById('edit_task_id').value = taskId;
            document.getElementById('edit_task_name').value = taskName;
            document.getElementById('edit_task_description').value = taskDescription;
            document.getElementById('edit_group_id').value = groupId;
            document.getElementById('editModal').style.display = 'flex';
        }

        function closeEditModal() {
            document.getElementById('editModal').style.display = 'none';
        }

        // Edit Task Form Handler
        document.getElementById('editTaskForm').addEventListener('submit', async function(e) {
            e.preventDefault();
            
            const formData = new FormData();
            formData.append('action', 'update_task');
            formData.append('task_id', document.getElementById('edit_task_id').value);
            formData.append('task_name', document.getElementById('edit_task_name').value);
            formData.append('task_description', document.getElementById('edit_task_description').value);
            formData.append('group_id', document.getElementById('edit_group_id').value);
            
            try {
                const response = await fetch('', {
                    method: 'POST',
                    body: formData
                });
                const result = await response.json();
                
                if (result.success) {
                    showNotification(result.message);
                    closeEditModal();
                    setTimeout(() => location.reload(), 1000);
                } else {
                    showNotification(result.message, true);
                }
            } catch (error) {
                showNotification('Error updating task', true);
            }
        });

        // Close modal when clicking outside
        window.addEventListener('click', function(e) {
            const modal = document.getElementById('editModal');
            if (e.target === modal) {
                closeEditModal();
            }
        });
    </script>
</body>
</html>