<?php
require_once __DIR__ . '/../../config/config.php';
require_once __DIR__ . '/../../includes/workspace.php';

if (!isset($_GET['token'])) {
    die("Invalid request. No token provided.");
}

$token = $_GET['token'];
$database = getDatabaseConnection();

// Get share information
$statement = $database->prepare("SELECT * FROM share WHERE token = ? AND expiration > NOW()");
$statement->bind_param("s", $token);
$statement->execute();
$result = $statement->get_result();

if ($result->num_rows === 0) {
    die("Invalid or expired share link.");
}

$share = $result->fetch_assoc();
$filePath = $share['file_path'];
$downloadAllowed = $share['download_allowed'] == 1;
$result->free();
$statement->close();
$database->close();

// Initialize SFTP
$sftp = initializeSFTP();

if (!$sftp->stat($filePath)) {
    die("File not found: $filePath");
}

$fileName = basename($filePath);
$fileExtension = strtolower(pathinfo($fileName, PATHINFO_EXTENSION));
$fileSize = $sftp->stat($filePath)['size'];

$imageExtensions = ['jpg', 'jpeg', 'png', 'gif', 'bmp', 'webp', 'svg'];
$videoExtensions = ['mp4', 'webm', 'ogg', 'mov', 'avi', 'mkv'];
$audioExtensions = ['mp3', 'wav', 'ogg', 'm4a', 'flac', 'aac'];

$isImage = in_array($fileExtension, $imageExtensions);
$isVideo = in_array($fileExtension, $videoExtensions);
$isAudio = in_array($fileExtension, $audioExtensions);

if (!$isImage && !$isVideo && !$isAudio) {
    die("Unsupported file type");
}

$mimeMap = [
    'mp4' => 'video/mp4',
    'webm' => 'video/mp4',
    'ogg' => 'video/mp4',
    'mov' => 'video/mp4',
    'avi' => 'video/mp4',
    'mkv' => 'video/mp4',

    'jpg' => 'image/jpeg',
    'jpeg' => 'image/jpeg',
    'png' => 'image/png',
    'gif' => 'image/gif',
    'bmp' => 'image/bmp',
    'webp' => 'image/webp',
    'svg' => 'image/svg+xml',

    'mp3' => 'audio/mpeg',
    'wav' => 'audio/wav',
    'm4a' => 'audio/mp4',
    'flac' => 'audio/flac',
    'aac' => 'audio/aac',
];

$mimeType = isset($mimeMap[$fileExtension]) ? $mimeMap[$fileExtension] : 'application/octet-stream';

// If streaming requested, stream file
if (isset($_GET['stream'])) {
    // Similar streaming code as in view.php
    session_write_close();
    while (ob_get_level()) {
        ob_end_clean();
    }
    if (ini_get('zlib.output_compression')) {
        ini_set('zlib.output_compression', 'Off');
    }

    $start = 0;
    $end = $fileSize - 1;
    $length = $fileSize;

    if (isset($_SERVER['HTTP_RANGE'])) {
        $rangeHeader = $_SERVER['HTTP_RANGE'];
        $matches = [];
        if (preg_match('/bytes=(\d+)-(\d*)/', $rangeHeader, $matches)) {
            $start = intval($matches[1]);

            if (!empty($matches[2])) {
                $end = intval($matches[2]);
            }

            $length = $end - $start + 1;

            header('HTTP/1.1 206 Partial Content');
            header('Content-Range: bytes ' . $start . '-' . $end . '/' . $fileSize);
        }
    }

    header("Content-Type: $mimeType");
    header("Accept-Ranges: bytes");
    header("Content-Length: $length");
    header("Cache-Control: no-cache, no-store, must-revalidate");
    header("Pragma: no-cache");
    header("Expires: 0");

    set_time_limit(0);

    $minChunkSize = 64 * 1024;
    $maxChunkSize = 2 * 1024 * 1024;
    $chunkSize = 256 * 1024;

    $currentPosition = $start;
    $bytesRemaining = $length;
    $lastChunkTime = microtime(true);

    try {
        while ($bytesRemaining > 0) {
            if (connection_aborted() || connection_status() !== CONNECTION_NORMAL) {
                break;
            }

            $readSize = min($chunkSize, $bytesRemaining);
            $chunkData = $sftp->get($filePath, false, $currentPosition, $readSize);

            if ($chunkData !== false) {
                $bytesSent = strlen($chunkData);
                echo $chunkData;
                $bytesRemaining -= $bytesSent;
                $currentPosition += $bytesSent;

                if (ob_get_level()) {
                    ob_flush();
                }
                flush();

                $currentTime = microtime(true);
                $timeDiff = $currentTime - $lastChunkTime;
                $lastChunkTime = $currentTime;

                if ($timeDiff > 0) {
                    $speed = $bytesSent / $timeDiff;
                    $chunkSize = min(
                        max($minChunkSize, $chunkSize * (($speed > 512 * 1024) ? 1.5 : 0.8)),
                        $maxChunkSize
                    );
                }
            } else {
                break;
            }

            usleep(100000);
        }
    } catch (Exception $exception) {
        error_log("Shared streaming error: " . $exception->getMessage());
    }
    exit;
}

// Create download handler
if (isset($_GET['download'])) {
    if (!$downloadAllowed) {
        die("Download not permitted for this share.");
    }

    // Download file code similar to download.php
    header("Content-Type: application/octet-stream");
    header("Content-Disposition: attachment; filename=\"$fileName\"");
    header("Content-Length: $fileSize");

    $minChunkSize = 64 * 1024;
    $maxChunkSize = 2 * 1024 * 1024;
    $chunkSize = 256 * 1024;

    $currentPosition = 0;
    $bytesRemaining = $fileSize;

    set_time_limit(0);

    while ($bytesRemaining > 0) {
        $readSize = min($chunkSize, $bytesRemaining);
        $chunkData = $sftp->get($filePath, false, $currentPosition, $readSize);

        if ($chunkData !== false) {
            $bytesRead = strlen($chunkData);
            echo $chunkData;
            $bytesRemaining -= $bytesRead;
            $currentPosition += $bytesRead;
            flush();
        } else {
            break;
        }
    }
    exit;
}

function formatBytes($bytes, $precision = 2) {
    $units = ['B', 'KB', 'MB', 'GB', 'TB'];
    $bytes = max($bytes, 0);
    $pow = floor(($bytes ? log($bytes) : 0) / log(1024));
    $pow = min($pow, count($units) - 1);
    $bytes /= (1 << (10 * $pow));
    return round($bytes, $precision) . ' ' . $units[$pow];
}
?>

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Shared Media - <?= htmlspecialchars($fileName) ?></title>
    <link rel="icon" href="../../img/favicon.ico" type="image/x-icon">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <link rel="stylesheet" href="<?= workspaceAsset('../../', 'css/modern.css') ?>">
    <link rel="stylesheet" href="<?= workspaceAsset('../../', 'css/workspace.css') ?>">
    <link rel="stylesheet" href="<?= workspaceAsset('../../', 'content/ftp/css/view.css') ?>">
    <script src="<?= workspaceAsset('../../', 'js/theme.js') ?>"></script>
    <script src="<?= workspaceAsset('../../', 'js/ui.js') ?>" defer></script>
</head>
<?php renderWorkspaceStart([
    'root' => '../../',
    'active' => 'shared',
    'section' => 'Shared file',
    'eyebrow' => 'Shared with you',
    'title' => $fileName,
    'description' => 'Preview and access the file shared with you.',
    'guest' => true,
    'class' => 'media-page',
]); ?>

<div class="content-toolbar"><span class="badge">Shared link</span><p>Available until <?= htmlspecialchars(date('F j, Y, g:i a', strtotime($share['expiration']))) ?></p></div>
    <section class="content-panel media-panel">
        <article class="col-12">
            <div class="media-container position-relative">
                <?php if ($isImage): ?>
                    <img src="shared.php?token=<?= urlencode($token) ?>&stream=1" alt="<?= htmlspecialchars($fileName) ?>" class="img-fluid">
                <?php elseif ($isVideo): ?>
                <video id="videoPlayer" controls autoplay playsinline>
                    <source src="shared.php?token=<?= urlencode($token) ?>&stream=1" type="<?= $mimeType ?>">
                    Your browser does not support this video format.
                </video>
                <?php if($fileExtension !== 'mp4'): ?>
                <div class="alert alert-warning mt-2">
                    Note: For best results, use MP4 format (H.264 codec). Other formats may not play correctly in all browsers.
                </div>
                <?php endif; ?>
                <?php elseif ($isAudio): ?>
                    <audio controls autoplay style="width: 80%;">
                        <source src="shared.php?token=<?= urlencode($token) ?>&stream=1" type="<?= $mimeType ?>">
                        Your browser does not support the audio element.
                    </audio>
                <?php endif; ?>

                <?php if ($downloadAllowed) : ?>
                <a href="shared.php?token=<?= urlencode($token) ?>&download=1" class="btn btn-success m-3">Download</a>
                <?php endif; ?>
            </div>

            <div class="file-info mt-4">
                <h4>File Information</h4>
                <table class="table table-bordered w-auto mx-auto text-wrap">
                    <tr>
                        <th>File Name</th>
                        <td class="text-break"><?= htmlspecialchars($fileName) ?></td>
                    </tr>
                    <tr>
                        <th>File Type</th>
                        <td><?= htmlspecialchars(strtoupper($fileExtension)) ?></td>
                    </tr>
                    <tr>
                        <th>File Size</th>
                        <td><?= formatBytes($fileSize) ?></td>
                    </tr>
                </table>
            </div>
        </article>
    </section>

    <?php renderWorkspaceEnd(); ?>

<script>
document.addEventListener('DOMContentLoaded', () => {
    const mediaElement = document.querySelector('video, audio');

    if (mediaElement) {
        const savedVolume = localStorage.getItem('mediaVolume');
        if (savedVolume !== null) {
            mediaElement.volume = parseFloat(savedVolume);
        }

        mediaElement.addEventListener('volumechange', () => {
            localStorage.setItem('mediaVolume', mediaElement.volume);
        });
    }
});
</script>
</body>
</html>