<?php

declare(strict_types=1);

$baseDirectory = realpath(__DIR__);

if ($baseDirectory === false) {
    http_response_code(500);
    exit('Unable to resolve base directory.');
}

// Set to true if hidden files such as .env and .git should be displayed.
$showHiddenFiles = false;

// Folders that should not appear in the listing.
$ignoredNames = [
    '.',
    '..',
];

// Get the requested relative directory.
$requestedDirectory = isset($_GET['dir'])
    ? trim((string) $_GET['dir'], "/\\")
    : '';

$currentDirectory = $requestedDirectory === ''
    ? $baseDirectory
    : realpath($baseDirectory . DIRECTORY_SEPARATOR . $requestedDirectory);

// Prevent access outside the base directory.
if (
    $currentDirectory === false ||
    !is_dir($currentDirectory) ||
    (
        $currentDirectory !== $baseDirectory &&
        !str_starts_with(
            $currentDirectory,
            $baseDirectory . DIRECTORY_SEPARATOR
        )
    )
) {
    http_response_code(404);
    exit('Directory not found.');
}

function formatBytes(int $bytes): string
{
    if ($bytes < 1024) {
        return $bytes . ' B';
    }

    $units = ['KB', 'MB', 'GB', 'TB'];
    $size = $bytes / 1024;

    foreach ($units as $unit) {
        if ($size < 1024 || $unit === 'TB') {
            return number_format($size, 2) . ' ' . $unit;
        }

        $size /= 1024;
    }

    return $bytes . ' B';
}

function encodePath(string $path): string
{
    $parts = preg_split('~[\\\\/]~', $path) ?: [];

    return implode(
        '/',
        array_map(
            static fn(string $part): string => rawurlencode($part),
            $parts
        )
    );
}

function getFileIcon(string $filename): string
{
    $extension = strtolower(pathinfo($filename, PATHINFO_EXTENSION));

    return match ($extension) {
        'jpg', 'jpeg', 'png', 'gif', 'webp', 'svg' => '🖼️',
        'mp4', 'mkv', 'avi', 'mov', 'webm' => '🎬',
        'mp3', 'wav', 'ogg', 'flac', 'aac' => '🎵',
        'zip', 'rar', '7z', 'tar', 'gz' => '🗜️',
        'pdf' => '📕',
        'doc', 'docx', 'odt' => '📘',
        'xls', 'xlsx', 'csv' => '📊',
        'ppt', 'pptx' => '📙',
        'php', 'js', 'ts', 'html', 'css', 'json', 'xml', 'rs', 'py' => '💻',
        'txt', 'log', 'md' => '📄',
        default => '📄',
    };
}

$items = scandir($currentDirectory);

if ($items === false) {
    http_response_code(500);
    exit('Unable to read directory.');
}

$directories = [];
$files = [];

foreach ($items as $name) {
    if (in_array($name, $ignoredNames, true)) {
        continue;
    }

    if (!$showHiddenFiles && str_starts_with($name, '.')) {
        continue;
    }

    $absolutePath = $currentDirectory . DIRECTORY_SEPARATOR . $name;

    if (is_link($absolutePath)) {
        continue;
    }

    $relativePath = ltrim(
        substr($absolutePath, strlen($baseDirectory)),
        DIRECTORY_SEPARATOR
    );

    $item = [
        'name' => $name,
        'absolutePath' => $absolutePath,
        'relativePath' => str_replace(
            DIRECTORY_SEPARATOR,
            '/',
            $relativePath
        ),
        'modified' => filemtime($absolutePath) ?: 0,
    ];

    if (is_dir($absolutePath)) {
        $directories[] = $item;
    } elseif (is_file($absolutePath)) {
        $item['size'] = filesize($absolutePath) ?: 0;
        $files[] = $item;
    }
}

usort(
    $directories,
    static fn(array $a, array $b): int =>
        strnatcasecmp($a['name'], $b['name'])
);

usort(
    $files,
    static fn(array $a, array $b): int =>
        strnatcasecmp($a['name'], $b['name'])
);

$currentRelativePath = ltrim(
    substr($currentDirectory, strlen($baseDirectory)),
    DIRECTORY_SEPARATOR
);

$currentRelativePath = str_replace(
    DIRECTORY_SEPARATOR,
    '/',
    $currentRelativePath
);

$parentRelativePath = '';

if ($currentRelativePath !== '') {
    $parentRelativePath = dirname($currentRelativePath);

    if ($parentRelativePath === '.') {
        $parentRelativePath = '';
    }
}

$breadcrumbParts = $currentRelativePath === ''
    ? []
    : explode('/', $currentRelativePath);

$baseUrlPath = rtrim(
    str_replace('\\', '/', dirname($_SERVER['SCRIPT_NAME'] ?? '')),
    '/'
);
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">

    <meta
        name="viewport"
        content="width=device-width, initial-scale=1"
    >

    <title>Directory Listing</title>

    <style>
        * {
            box-sizing: border-box;
        }

        body {
            margin: 0;
            padding: 24px;
            background: #f5f7fb;
            color: #1f2937;
            font-family: Arial, Helvetica, sans-serif;
        }

        .container {
            width: 100%;
            max-width: 1100px;
            margin: 0 auto;
        }

        .header {
            margin-bottom: 20px;
        }

        .header h1 {
            margin: 0 0 10px;
            font-size: 28px;
        }

        .breadcrumb {
            display: flex;
            flex-wrap: wrap;
            gap: 6px;
            font-size: 14px;
        }

        .breadcrumb a {
            color: #2563eb;
            text-decoration: none;
        }

        .breadcrumb a:hover {
            text-decoration: underline;
        }

        .panel {
            overflow: hidden;
            background: #ffffff;
            border: 1px solid #e5e7eb;
            border-radius: 12px;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
        }

        .summary {
            display: flex;
            gap: 16px;
            padding: 14px 18px;
            border-bottom: 1px solid #e5e7eb;
            color: #6b7280;
            font-size: 14px;
        }

        table {
            width: 100%;
            border-collapse: collapse;
        }

        th,
        td {
            padding: 14px 18px;
            border-bottom: 1px solid #e5e7eb;
            text-align: left;
        }

        th {
            background: #f9fafb;
            color: #4b5563;
            font-size: 13px;
            text-transform: uppercase;
        }

        tr:last-child td {
            border-bottom: none;
        }

        tbody tr:hover {
            background: #f8fafc;
        }

        .name {
            display: flex;
            align-items: center;
            gap: 10px;
            min-width: 250px;
        }

        .icon {
            width: 24px;
            text-align: center;
            font-size: 20px;
        }

        .name a {
            color: #111827;
            text-decoration: none;
            word-break: break-word;
        }

        .name a:hover {
            color: #2563eb;
            text-decoration: underline;
        }

        .size,
        .modified {
            color: #6b7280;
            white-space: nowrap;
        }

        .empty {
            padding: 40px;
            color: #6b7280;
            text-align: center;
        }

        @media (max-width: 700px) {
            body {
                padding: 12px;
            }

            .header h1 {
                font-size: 22px;
            }

            th,
            td {
                padding: 12px;
            }

            .modified {
                display: none;
            }

            .summary {
                flex-direction: column;
                gap: 4px;
            }
        }
    </style>
</head>

<body>
<div class="container">
    <div class="header">
        <h1>Directory Listing</h1>

        <div class="breadcrumb">
            <a href="?">Home</a>

            <?php
            $breadcrumbPath = '';

            foreach ($breadcrumbParts as $part):
                $breadcrumbPath = $breadcrumbPath === ''
                    ? $part
                    : $breadcrumbPath . '/' . $part;
            ?>
                <span>/</span>

                <a
                    href="?dir=<?= urlencode($breadcrumbPath) ?>"
                >
                    <?= htmlspecialchars($part, ENT_QUOTES, 'UTF-8') ?>
                </a>
            <?php endforeach; ?>
        </div>
    </div>

    <div class="panel">
        <div class="summary">
            <span>
                <?= count($directories) ?>
                folder<?= count($directories) === 1 ? '' : 's' ?>
            </span>

            <span>
                <?= count($files) ?>
                file<?= count($files) === 1 ? '' : 's' ?>
            </span>
        </div>

        <?php if ($directories === [] && $files === []): ?>
            <div class="empty">
                This directory is empty.
            </div>
        <?php else: ?>
            <table>
                <thead>
                <tr>
                    <th>Name</th>
                    <th>Size</th>
                    <th class="modified">Modified</th>
                </tr>
                </thead>

                <tbody>
                <?php if ($currentRelativePath !== ''): ?>
                    <tr>
                        <td>
                            <div class="name">
                                <span class="icon">⬅️</span>

                                <a
                                    href="<?= $parentRelativePath === ''
                                        ? '?'
                                        : '?dir=' . urlencode($parentRelativePath)
                                    ?>"
                                >
                                    Parent directory
                                </a>
                            </div>
                        </td>

                        <td class="size">—</td>
                        <td class="modified">—</td>
                    </tr>
                <?php endif; ?>

                <?php foreach ($directories as $directory): ?>
                    <tr>
                        <td>
                            <div class="name">
                                <span class="icon">📁</span>

                                <a
                                    href="?dir=<?= urlencode(
                                        $directory['relativePath']
                                    ) ?>"
                                >
                                    <?= htmlspecialchars(
                                        $directory['name'],
                                        ENT_QUOTES,
                                        'UTF-8'
                                    ) ?>
                                </a>
                            </div>
                        </td>

                        <td class="size">Folder</td>

                        <td class="modified">
                            <?= date(
                                'Y-m-d H:i:s',
                                $directory['modified']
                            ) ?>
                        </td>
                    </tr>
                <?php endforeach; ?>

                <?php foreach ($files as $file): ?>
                    <?php
                    $fileUrl = $baseUrlPath
                        . '/'
                        . encodePath($file['relativePath']);
                    ?>

                    <tr>
                        <td>
                            <div class="name">
                                <span class="icon">
                                    <?= getFileIcon($file['name']) ?>
                                </span>

                                <a
                                    href="<?= htmlspecialchars(
                                        $fileUrl,
                                        ENT_QUOTES,
                                        'UTF-8'
                                    ) ?>"
                                    target="_blank"
                                    rel="noopener noreferrer"
                                >
                                    <?= htmlspecialchars(
                                        $file['name'],
                                        ENT_QUOTES,
                                        'UTF-8'
                                    ) ?>
                                </a>
                            </div>
                        </td>

                        <td class="size">
                            <?= formatBytes($file['size']) ?>
                        </td>

                        <td class="modified">
                            <?= date(
                                'Y-m-d H:i:s',
                                $file['modified']
                            ) ?>
                        </td>
                    </tr>
                <?php endforeach; ?>
                </tbody>
            </table>
        <?php endif; ?>
    </div>
</div>
</body>
</html>