<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);
session_start();

// Gatekeeper: redirect if not logged in
if (!isset($_SESSION['is_admin']) || $_SESSION['is_admin'] !== true) {
    header('Location: login.php');
    exit;
}

require_once 'db/config.php';
$pdo = db();

// --- IMAGE SLICING FUNCTION ---
function create_puzzle_pieces($source_image_path, $puzzle_id, $pieces_count) {
    if (!function_exists('gd_info')) {
        error_log("GD Library is not installed or enabled.");
        return false;
    }

    $image_info = getimagesize($source_image_path);
    $source_width = $image_info[0];
    $source_height = $image_info[1];
    $mime_type = $image_info['mime'];

    switch ($mime_type) {
        case 'image/jpeg':
            $source_image = imagecreatefromjpeg($source_image_path);
            break;
        case 'image/png':
            $source_image = imagecreatefrompng($source_image_path);
            break;
        case 'image/gif':
            $source_image = imagecreatefromgif($source_image_path);
            break;
        default:
            error_log("Unsupported image type: " . $mime_type);
            return false;
    }

    if (!$source_image) {
        error_log("Failed to create image from source.");
        return false;
    }

    // Grid dimensions
    $cols = 0;
    $rows = 0;
    if ($pieces_count == 16) { $cols = 4; $rows = 4; }
    elseif ($pieces_count == 32) { $cols = 8; $rows = 4; }
    elseif ($pieces_count == 64) { $cols = 8; $rows = 8; }
    else {
        error_log("Invalid pieces count: " . $pieces_count);
        return false;
    }

    $piece_width = floor($source_width / $cols);
    $piece_height = floor($source_height / $rows);

    $output_dir = __DIR__ . '/puzzles/' . $puzzle_id . '/' . $pieces_count;
    if (!is_dir($output_dir)) {
        mkdir($output_dir, 0777, true);
    }

    for ($r = 0; $r < $rows; $r++) {
        for ($c = 0; $c < $cols; $c++) {
            $piece = imagecreatetruecolor($piece_width, $piece_height);
            imagecopy(
                $piece,
                $source_image,
                0, 0, // dest x, y
                $c * $piece_width, $r * $piece_height, // source x, y
                $piece_width, $piece_height
            );

            $piece_path = $output_dir . '/piece_' . $r . '_' . $c . '.jpg';
            imagejpeg($piece, $piece_path, 90); // Save as JPG with 90% quality
            imagedestroy($piece);
        }
    }

    imagedestroy($source_image);
    return true;
}


// Handle new puzzle upload
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['add_puzzle'])) {
    $puzzle_name = trim($_POST['puzzle_name'] ?? '');
    $pieces = (int)($_POST['pieces'] ?? 16);
    $is_public = isset($_POST['is_public']) ? 1 : 0;
    $image_file = $_FILES['puzzle_image'] ?? null;

    if (!empty($puzzle_name) && $image_file && $image_file['error'] === UPLOAD_ERR_OK) {
        $upload_dir = __DIR__ . '/uploads/';
        if (!is_dir($upload_dir)) {
            mkdir($upload_dir, 0777, true);
        }
        
        $original_filename = basename($image_file['name']);
        $image_extension = pathinfo($original_filename, PATHINFO_EXTENSION);
        $safe_filename = 'puzzle_' . uniqid() . '.' . $image_extension;
        $upload_path = $upload_dir . $safe_filename;

        if (move_uploaded_file($image_file['tmp_name'], $upload_path)) {
            $stmt = $pdo->prepare('INSERT INTO puzzles (name, original_image, file_name, pieces, is_public, created_at) VALUES (?, ?, ?, ?, ?, NOW())');
            $stmt->execute([$puzzle_name, $safe_filename, $safe_filename, $pieces, $is_public]);
            $puzzle_id = $pdo->lastInsertId();

            create_puzzle_pieces($upload_path, $puzzle_id, $pieces);

            header("Location: admin.php?success=1");
            exit;
        }
    }
    header("Location: admin.php?error=1");
    exit;
}


// Handle puzzle deletion
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['delete_puzzle'])) {
    $puzzle_id_to_delete = $_POST['puzzle_id'];
    
    $stmt = $pdo->prepare('SELECT original_image FROM puzzles WHERE id = ?');
    $stmt->execute([$puzzle_id_to_delete]);
    $puzzle = $stmt->fetch(PDO::FETCH_ASSOC);

    if ($puzzle) {
        $original_image_path = __DIR__ . '/uploads/' . $puzzle['original_image'];
        if (file_exists($original_image_path)) {
            unlink($original_image_path);
        }
    }

    $stmt = $pdo->prepare('DELETE FROM puzzles WHERE id = ?');
    $stmt->execute([$puzzle_id_to_delete]);

    $puzzle_dir = __DIR__ . '/puzzles/' . $puzzle_id_to_delete;
    if (is_dir($puzzle_dir)) {
        function delete_directory($dir) {
            if (!is_dir($dir)) return;
            $files = array_diff(scandir($dir), array('.','..'));
            foreach ($files as $file) {
                (is_dir("$dir/$file")) ? delete_directory("$dir/$file") : unlink("$dir/$file");
            }
            rmdir($dir);
        }
        delete_directory($puzzle_dir);
    }
    
    header("Location: admin.php?deleted=1");
    exit;
}


$puzzles = $pdo->query('SELECT id, name, original_image, pieces, is_public, created_at FROM puzzles ORDER BY created_at DESC')->fetchAll(PDO::FETCH_ASSOC);

// Fetch users
$users = $pdo->query('SELECT id, username, email, created_at FROM users ORDER BY created_at DESC')->fetchAll(PDO::FETCH_ASSOC);

?>
<!DOCTYPE html>
<html lang="it">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Pannello di Amministrazione</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css" rel="stylesheet">
    <style>
        .upload-form {
            background-color: #f8f9fa;
            padding: 2rem;
            border-radius: 0.5rem;
            margin-bottom: 2rem;
        }
    </style>
</head>
<body>
    <nav class="navbar navbar-expand-lg navbar-light bg-light">
        <div class="container">
            <a class="navbar-brand" href="#">Admin Puzzle</a>
            <ul class="navbar-nav ms-auto">
                <li class="nav-item">
                    <a class="nav-link" href="logout.php">Logout</a>
                </li>
            </ul>
        </div>
    </nav>

    <div class="container mt-5">
        
        <?php if (isset($_GET['success'])): ?>
            <div class="alert alert-success">Puzzle aggiunto con successo!</div>
        <?php endif; ?>
        <?php if (isset($_GET['deleted'])): ?>
            <div class="alert alert-info">Puzzle eliminato con successo.</div>
        <?php endif; ?>
        <?php if (isset($_GET['error'])): ?>
            <div class="alert alert-danger">Errore durante l'upload. Controlla i dati e riprova.</div>
        <?php endif; ?>

        <!-- Upload Form -->
        <div class="upload-form">
            <h2 class="mb-4">Aggiungi Nuovo Puzzle</h2>
            <form action="admin.php" method="POST" enctype="multipart/form-data">
                <div class="mb-3">
                    <label for="puzzle_name" class="form-label">Nome del Puzzle</label>
                    <input type="text" class="form-control" id="puzzle_name" name="puzzle_name" required>
                </div>
                <div class="mb-3">
                    <label for="puzzle_image" class="form-label">Immagine</label>
                    <input type="file" class="form-control" id="puzzle_image" name="puzzle_image" accept="image/jpeg, image/png, image/gif" required>
                </div>
                <div class="mb-3">
                    <label for="pieces" class="form-label">Numero di Pezzi</label>
                    <select class="form-select" id="pieces" name="pieces">
                        <option value="16">16 (4x4)</option>
                        <option value="32">32 (8x4)</option>
                        <option value="64">64 (8x8)</option>
                    </select>
                </div>
                <div class="form-check mb-3">
                    <input class="form-check-input" type="checkbox" id="is_public" name="is_public" value="1" checked>
                    <label class="form-check-label" for="is_public">
                        Rendi Pubblico
                    </label>
                </div>
                <button type="submit" name="add_puzzle" class="btn btn-primary">Aggiungi Puzzle</button>
            </form>
        </div>


        <h1 class="mb-4">Gestione Puzzle</h1>
        <div class="table-responsive">
            <table class="table table-striped table-bordered">
                <thead class="table-dark">
                    <tr>
                        <th>ID</th>
                        <th>Nome</th>
                        <th>Immagine</th>
                        <th>Pezzi</th>
                        <th>Pubblico</th>
                        <th>Creato il</th>
                        <th>Azioni</th>
                    </tr>
                </thead>
                <tbody>
                    <?php if (empty($puzzles)): ?>
                        <tr>
                            <td colspan="7" class="text-center">Nessun puzzle trovato.</td>
                        </tr>
                    <?php else: ?>
                        <?php foreach ($puzzles as $puzzle):
                            $image_path = __DIR__ . '/uploads/' . $puzzle['original_image'];
                            if (file_exists($image_path)) {
                                $imageUrl = 'uploads/' . htmlspecialchars($puzzle['original_image']) . '?v=' . filemtime($image_path);
                            } else {
                                $imageUrl = 'assets/images/placeholder.png';
                            }
                        ?>
                            <tr>
                                <td><?php echo htmlspecialchars($puzzle['id']); ?></td>
                                <td><a href="puzzle.php?id=<?php echo htmlspecialchars($puzzle['id']); ?>" target="_blank"><?php echo htmlspecialchars($puzzle['name']); ?></a></td>
                                <td><img src="<?php echo $imageUrl; ?>" alt="Puzzle" width="100"></td>
                                <td><?php echo htmlspecialchars($puzzle['pieces']); ?></td>
                                <td><?php echo $puzzle['is_public'] ? 'Sì' : 'No'; ?></td>
                                <td><?php echo htmlspecialchars($puzzle['created_at']); ?></td>
                                <td>
                                    <form method="POST" action="admin.php" onsubmit="return confirm('Sei sicuro di voler eliminare questo puzzle? L'azione è irreversibile.');">
                                        <input type="hidden" name="puzzle_id" value="<?php echo htmlspecialchars($puzzle['id']); ?>">
                                        <button type="submit" name="delete_puzzle" class="btn btn-danger btn-sm">Elimina</button>
                                    </form>
                                </td>
                            </tr>
                        <?php endforeach; ?>
                    <?php endif; ?>
                </tbody>
            </table>
        </div>

        <!-- User Management Section -->
        <div class="mt-5">
            <h1 class="mb-4">Gestione Utenti</h1>
            <div class="table-responsive">
                <table class="table table-striped table-bordered">
                    <thead class="table-dark">
                        <tr>
                            <th>ID</th>
                            <th>Username</th>
                            <th>Email</th>
                            <th>Registrato il</th>
                        </tr>
                    </thead>
                    <tbody>
                        <?php if (empty($users)): ?>
                            <tr>
                                <td colspan="4" class="text-center">Nessun utente trovato.</td>
                            </tr>
                        <?php else: ?>
                            <?php foreach ($users as $user): ?>
                                <tr>
                                    <td><?php echo htmlspecialchars($user['id']); ?></td>
                                    <td><?php echo htmlspecialchars($user['username']); ?></td>
                                    <td><?php echo htmlspecialchars($user['email']); ?></td>
                                    <td><?php echo htmlspecialchars($user['created_at']); ?></td>
                                </tr>
                            <?php endforeach; ?>
                        <?php endif; ?>
                    </tbody>
                </table>
            </div>
        </div>

    </div>

    <footer class="text-center mt-5 py-3 bg-light">
        <p>&copy; <?php echo date("Y"); ?> Puzzle Game</p>
    </footer>
</body>
</html>