<?php
session_start();
// Dummy authentication check - replace with your actual login check
if (!isset($_SESSION['is_admin']) || !$_SESSION['is_admin']) {
    // header('Location: admin_login.php');
    // die('Access Denied. You must be logged in as an admin.');
}

$message = '';
$error = '';

function parse_m3u_attributes($info_line) {
    $attributes = [];
    // Extract the part of the string that contains the attributes
    preg_match_all('/ (\w+-.+?)="(.+?)"/', $info_line, $matches, PREG_SET_ORDER);
    foreach ($matches as $match) {
        $attributes[$match[1]] = $match[2];
    }
    // Get the title from the last part of the line
    $parts = explode(',', $info_line);
    $title = trim(end($parts));
    if ($title) {
        $attributes['title'] = $title;
    }
    return $attributes;
}

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['channels_file'])) {
    $file = $_FILES['channels_file'];
    $overwrite = isset($_POST['overwrite']);

    if ($file['error'] === UPLOAD_ERR_OK) {
        $filename = $file['tmp_name'];
        $content = file_get_contents($filename);
        $lines = explode(PHP_EOL, $content);
        $new_channels = [];
        $malformed_entries = 0;

        if (strpos(trim($lines[0]), '#EXTM3U') !== 0) {
            $error = 'Invalid M3U file. The file must start with #EXTM3U.';
        } else {
            for ($i = 0; $i < count($lines); $i++) {
                $line = trim($lines[$i]);
                if (strpos($line, '#EXTINF') === 0) {
                    $attributes = parse_m3u_attributes($line);
                    $stream_url = isset($lines[$i + 1]) ? trim($lines[$i + 1]) : '';

                    if (!empty($stream_url) && !empty($attributes['title'])) {
                         $new_channels[] = [
                            'title' => $attributes['title'],
                            'category' => $attributes['group-title'] ?? 'General',
                            'poster_url' => $attributes['tvg-logo'] ?? '',
                            'stream_url' => $stream_url,
                        ];
                        $i++; // Skip the next line as it's the URL
                    } else {
                        $malformed_entries++;
                    }
                }
            }

            if (!empty($new_channels)) {
                $content_file = 'premium_content.json';
                $existing_channels = [];
                if (!$overwrite && file_exists($content_file)) {
                    $existing_content = json_decode(file_get_contents($content_file), true);
                    if (is_array($existing_content)) {
                        $existing_channels = $existing_content;
                    }
                }
                
                $last_id = 0;
                if (!empty($existing_channels)) {
                    $last_item = end($existing_channels);
                    $last_id = $last_item['id'] ?? 0;
                }

                foreach($new_channels as &$channel) {
                    $last_id++;
                    $channel['id'] = $last_id;
                }

                $all_channels = array_merge($existing_channels, $new_channels);
                
                if (json_encode($all_channels, JSON_PRETTY_PRINT)) {
                    file_put_contents($content_file, json_encode($all_channels, JSON_PRETTY_PRINT));
                    $message = 'Successfully uploaded and processed ' . count($new_channels) . ' new channels.';
                    if ($malformed_entries > 0) {
                        $error = $malformed_entries . ' entries in your file were malformed and could not be imported.';
                    }
                } else {
                    $error = 'Failed to encode data to JSON. Check for special characters.';
                }

            } else {
                $error = 'No valid channel data found in the uploaded M3U file.';
                if ($malformed_entries > 0) {
                    $error .= ' All entries appear to be malformed.';
                }
            }
        }
    } else {
        $error = 'File upload failed with error code: ' . $file['error'];
    }
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Admin - Upload M3U Playlist</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<nav class="navbar navbar-expand-lg bg-dark navbar-dark">
    <div class="container">
        <a class="navbar-brand" href="admin.php">Admin Panel</a>
        <div class="collapse navbar-collapse">
            <ul class="navbar-nav">
                <li class="nav-item"><a class="nav-link" href="admin_users.php">Users</a></li>
                <li class="nav-item"><a class="nav-link" href="admin_content.php">Content</a></li>
                <li class="nav-item"><a class="nav-link active" href="admin_upload.php">Upload</a></li>
                <li class="nav-item"><a class="nav-link" href="admin_settings.php">Settings</a></li>
            </ul>
        </div>
    </div>
</nav>

<div class="container mt-5">
    <h1 class="mb-4">Upload Premium Channels</h1>

    <?php if ($message): ?>
        <div class="alert alert-success"><?php echo $message; ?></div>
    <?php endif; ?>
    <?php if ($error): ?>
        <div class="alert alert-danger"><?php echo $error; ?></div>
    <?php endif; ?>

    <div class="card">
        <div class="card-body">
            <h5 class="card-title">Upload an M3U Playlist File</h5>
            <p class="card-text">
                The file should be a valid M3U playlist (starting with <code>#EXTM3U</code>). The parser will attempt to extract channel information from <code>#EXTINF</code> lines.
            </p>
            <form action="admin_upload.php" method="post" enctype="multipart/form-data">
                <div class="mb-3">
                    <label for="channels_file" class="form-label">M3U Playlist File (.m3u, .m3u8)</label>
                    <input class="form-control" type="file" id="channels_file" name="channels_file" accept=".m3u,.m3u8,.txt" required>
                </div>
                 <div class="mb-3 form-check">
                    <input type="checkbox" class="form-check-input" id="overwrite" name="overwrite">
                    <label class="form-check-label" for="overwrite">Overwrite existing channels</label>
                    <small class="form-text text-muted d-block">If checked, all current premium channels will be replaced by the ones in this file. If unchecked, new channels will be added to the existing list.</small>
                </div>
                <button type="submit" class="btn btn-primary">Upload</button>
            </form>
        </div>
    </div>
    
    <div class="mt-4">
        <a href="admin.php" class="btn btn-secondary">Back to Admin</a>
    </div>

</div>

<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"></script>
</body>
</html>