<?php
require_once __DIR__ . "/../config.php";
require_once __DIR__ . "/../includes/functions.php";
require_once __DIR__ . "/../includes/version.php";
require_once __DIR__ . "/../includes/backup.php";

if (!defined("UPDATE_MANIFEST_URL")) {
    define("UPDATE_MANIFEST_URL", "");
}

function settingsUpdaterVersionCompareValue(string $version): string
{
    return ltrim(trim($version), "vV");
}

function settingsGetUpdaterStatus(): array
{
    $manifestUrl = trim((string) UPDATE_MANIFEST_URL);
    if ($manifestUrl === "") {
        return [
            "label" => "Update-Ziel ist nicht konfiguriert.",
            "available" => false,
            "version" => "",
        ];
    }

    $context = stream_context_create([
        "http" => [
            "method" => "GET",
            "timeout" => 3,
            "ignore_errors" => true,
            "header" => "User-Agent: PSA-Orderform-Settings/" . APP_VERSION . "\r\n",
        ],
    ]);

    $body = @file_get_contents($manifestUrl, false, $context);
    if ($body === false) {
        return [
            "label" => "Update-Status konnte nicht geladen werden.",
            "available" => false,
            "version" => "",
        ];
    }

    $manifest = json_decode($body, true);
    if (!is_array($manifest)) {
        return [
            "label" => "Update-Status ist ungültig.",
            "available" => false,
            "version" => "",
        ];
    }

    $version = trim((string) ($manifest["version"] ?? $manifest["latest"] ?? ""));
    if (!preg_match('/^v\d+\.\d+\.\d+$/', $version)) {
        return [
            "label" => "Update-Version ist ungültig.",
            "available" => false,
            "version" => "",
        ];
    }

    $available =
        version_compare(
            settingsUpdaterVersionCompareValue($version),
            settingsUpdaterVersionCompareValue(APP_VERSION),
            ">",
        );

    return [
        "label" => $available
            ? "Update verfügbar: " . $version
            : "Kein Update verfügbar.",
        "available" => $available,
        "version" => $version,
    ];
}

function settingsFormatBackupDate(string $date): string
{
    $timestamp = strtotime($date);
    if ($timestamp === false) {
        return $date;
    }

    return date("d.m.Y H:i", $timestamp);
}

function settingsGetBackupUploadLabel(array $backup): string
{
    $uploads =
        isset($backup["remote_uploads"]) && is_array($backup["remote_uploads"])
            ? $backup["remote_uploads"]
            : [];

    if (empty($uploads)) {
        return "Nur lokal";
    }

    $successful = 0;
    foreach ($uploads as $upload) {
        if (is_array($upload) && !empty($upload["success"])) {
            $successful++;
        }
    }

    if ($successful === count($uploads)) {
        return "Remote erfolgreich (" . $successful . ")";
    }
    if ($successful > 0) {
        return "Teilweise erfolgreich (" . $successful . "/" . count($uploads) . ")";
    }

    return "Remote fehlgeschlagen";
}

function settingsGetBackupCapabilityLabel(array $capability): string
{
    if (empty($capability["configured"])) {
        return "nicht konfiguriert";
    }

    return !empty($capability["available"]) ? "bereit" : "nicht verfügbar";
}

function settingsIsSuperAdmin(): bool
{
    return normalizeAdminUsername($_SESSION['admin_username'] ?? "") === "admin";
}

function settingsGetLocalConfigPath(): string
{
    return dirname(__DIR__) . "/config.php";
}

function settingsReadLocalConfig(): string
{
    $path = settingsGetLocalConfigPath();
    if (!is_file($path) || !is_readable($path)) {
        return "";
    }

    $content = file_get_contents($path);
    return $content === false ? "" : $content;
}

function settingsWriteLocalConfig(string $content): void
{
    $content = str_replace("\r\n", "\n", $content);

    if (!str_starts_with(ltrim($content), "<?php")) {
        throw new RuntimeException('Die Konfiguration muss mit "<?php" beginnen.');
    }

    $path = settingsGetLocalConfigPath();
    $tmpFile = $path . ".tmp";

    if (file_put_contents($tmpFile, $content, LOCK_EX) === false) {
        throw new RuntimeException("Konfiguration konnte nicht geschrieben werden.");
    }

    $output = [];
    $exitCode = 0;
    exec(
        escapeshellarg(PHP_BINARY) . " -l " . escapeshellarg($tmpFile) . " 2>&1",
        $output,
        $exitCode,
    );

    if ($exitCode !== 0) {
        @unlink($tmpFile);
        throw new RuntimeException("PHP-Syntaxfehler: " . trim(implode("\n", $output)));
    }

    $backupDir = DATA_DIR . "backups/config/";
    if (!is_dir($backupDir) && !mkdir($backupDir, 02775, true) && !is_dir($backupDir)) {
        @unlink($tmpFile);
        throw new RuntimeException("Sicherungsverzeichnis konnte nicht angelegt werden.");
    }

    if (is_file($path)) {
        $backupPath = $backupDir . "config-" . date("Ymd-His") . ".php.bak";
        if (!copy($path, $backupPath)) {
            @unlink($tmpFile);
            throw new RuntimeException("Sicherung der bestehenden Konfiguration ist fehlgeschlagen.");
        }
    }

    @chmod($tmpFile, 0664);
    if (!rename($tmpFile, $path)) {
        @unlink($tmpFile);
        throw new RuntimeException("Konfiguration konnte nicht gespeichert werden.");
    }

    if (function_exists("opcache_invalidate")) {
        opcache_invalidate($path, true);
    }
}

function settingsFindBackupByFilename(string $filename): ?array
{
    if ($filename === "" || basename($filename) !== $filename) {
        return null;
    }

    foreach (backupListBackups() as $backup) {
        if (($backup["filename"] ?? "") === $filename) {
            return $backup;
        }
    }

    return null;
}

function settingsSendBackupDownload(array $backup): void
{
    $filename = basename((string) ($backup["filename"] ?? ""));
    $path = backupGetDirectory() . $filename;

    if ($filename === "" || !is_file($path) || !is_readable($path)) {
        throw new RuntimeException("Backup-Datei wurde nicht gefunden.");
    }
    $size = filesize($path);
    if ($size === false) {
        throw new RuntimeException("Backup-Dateigröße konnte nicht gelesen werden.");
    }

    logAccess("Backup downloaded", [
        "filename" => $filename,
    ]);

    header("Content-Type: application/zip");
    header('Content-Disposition: attachment; filename="' . $filename . '"');
    header("Content-Length: " . (string) $size);
    header("X-Content-Type-Options: nosniff");

    readfile($path);
    exit();
}

if (empty($_SESSION['admin_logged_in'])) {
    header("Location: login.php");
    exit();
}

$pageTitle = "Einstellungen";
$message = "";
$messageType = "";
$isSuperAdmin = settingsIsSuperAdmin();

if ($_SERVER['REQUEST_METHOD'] === "POST" && isset($_POST['save_settings'])) {
    // Validate CSRF token
    if (!validateCsrfToken($_POST['csrf_token'] ?? "")) {
        $message = "Ungültiges Token. Bitte versuchen Sie es erneut.";
        $messageType = "error";
    } else {
        $settings = array_merge(getSystemSettings(), [
            "order_recipient_email" => $_POST['order_recipient_email'] ?? "",
            "attach_order_pdf_to_admin_email" => isset(
                $_POST['attach_order_pdf_to_admin_email'],
            ),
            "nametag_product_name" => $_POST['nametag_product_name'] ?? "",
        ]);

        if (saveSystemSettings($settings)) {
            logAccess("Admin updated system settings");
            $message = "Einstellungen wurden gespeichert.";
            $messageType = "success";
        } else {
            $message = "Einstellungen konnten nicht gespeichert werden.";
            $messageType = "error";
        }
    }
} elseif ($_SERVER['REQUEST_METHOD'] === "POST" && isset($_POST['create_backup'])) {
    if (!validateCsrfToken($_POST['csrf_token'] ?? "")) {
        $message = "Ungültiges Token. Bitte versuchen Sie es erneut.";
        $messageType = "error";
    } else {
        try {
            $backup = backupCreate("manual");
            $message =
                "Backup wurde erstellt: " .
                $backup["filename"] .
                " (" .
                backupFormatBytes((int) $backup["size"]) .
                ").";
            $messageType = "success";
        } catch (Throwable $exception) {
            $message = "Backup konnte nicht erstellt werden: " . $exception->getMessage();
            $messageType = "error";
        }
    }
} elseif ($_SERVER['REQUEST_METHOD'] === "POST" && isset($_POST['download_backup'])) {
    if (!validateCsrfToken($_POST['csrf_token'] ?? "")) {
        $message = "Ungültiges Token. Bitte versuchen Sie es erneut.";
        $messageType = "error";
    } else {
        try {
            $backup = settingsFindBackupByFilename((string) ($_POST["backup_filename"] ?? ""));
            if ($backup === null) {
                throw new RuntimeException("Backup wurde nicht gefunden.");
            }
            settingsSendBackupDownload($backup);
        } catch (Throwable $exception) {
            $message = "Backup konnte nicht heruntergeladen werden: " . $exception->getMessage();
            $messageType = "error";
        }
    }
} elseif ($_SERVER['REQUEST_METHOD'] === "POST" && isset($_POST['save_local_config'])) {
    if (!$isSuperAdmin) {
        http_response_code(403);
        $message = "Keine Berechtigung für diese Aktion.";
        $messageType = "error";
    } elseif (!validateCsrfToken($_POST['csrf_token'] ?? "")) {
        $message = "Ungültiges Token. Bitte versuchen Sie es erneut.";
        $messageType = "error";
    } else {
        try {
            settingsWriteLocalConfig((string) ($_POST['local_config_content'] ?? ""));
            logAccess("Admin updated local config.php");
            $message = "Lokale Konfiguration wurde gespeichert.";
            $messageType = "success";
        } catch (Throwable $exception) {
            $message = "Konfiguration konnte nicht gespeichert werden: " . $exception->getMessage();
            $messageType = "error";
        }
    }
}

$settings = getSystemSettings();
$updaterStatus = settingsGetUpdaterStatus();
$backupCapabilities = backupRemoteCapabilities();
$backups = backupListBackups();
$localConfigContent = $isSuperAdmin ? settingsReadLocalConfig() : "";

$bodyClass = "admin-page";
include __DIR__ . "/../includes/header.php";
?>

<div class="admin-header">
    <h2>Einstellungen</h2>
    <div>
        <a href="index.php" class="btn btn-secondary">Zurück zum Dashboard</a>
    </div>
</div>

<?php if ($message !== ""): ?>
    <div class="alert alert-<?php echo escape($messageType); ?>">
        <?php echo escape($message); ?>
    </div>
<?php endif; ?>

<div class="panel panel-lg">
    <form method="POST">
        <?php echo csrfField(); ?>
        <div class="form-group">
            <label for="order_recipient_email">Empfängeradresse für interne Bestellungen *</label>
            <input type="email" id="order_recipient_email" name="order_recipient_email" required value="<?php echo escape(
                $settings["order_recipient_email"],
            ); ?>">
        </div>

        <div class="form-group">
            <label class="checkbox-label">
                <input type="checkbox" name="attach_order_pdf_to_admin_email" value="1" <?php echo !empty(
                    $settings["attach_order_pdf_to_admin_email"]
                )
                    ? "checked"
                    : ""; ?>>
                PDF an interne Bestell-E-Mails anhängen
            </label>
        </div>

        <div class="form-group">
            <label for="nametag_product_name">Artikelname für Namensschilder *</label>
            <input type="text" id="nametag_product_name" name="nametag_product_name" required value="<?php echo escape(
                $settings["nametag_product_name"],
            ); ?>">
            <small>Muss exakt dem Produktnamen im Katalog entsprechen. Wird von der Namensschilder-Übersicht verwendet.</small>
        </div>

        <button type="submit" name="save_settings" class="btn">Speichern</button>
    </form>
</div>

<div class="panel panel-lg mt-4">
    <h3>Backups</h3>
    <p>Lokale Aufbewahrung: <?php echo (int) backupGetRetentionLimit(); ?> Backups</p>
    <p>Automatisches Intervall: <?php echo (int) floor(((int) BACKUP_AUTO_INTERVAL_SECONDS) / 86400); ?> Tage</p>
    <p>
        S3: <?php echo escape(settingsGetBackupCapabilityLabel($backupCapabilities["s3"])); ?> ·
        SFTP: <?php echo escape(settingsGetBackupCapabilityLabel($backupCapabilities["sftp"])); ?> ·
        Custom: <?php echo escape(settingsGetBackupCapabilityLabel($backupCapabilities["custom"])); ?> ·
        Managed: <?php echo escape(settingsGetBackupCapabilityLabel($backupCapabilities["managed"])); ?>
    </p>

    <form method="POST" class="inline-form">
        <?php echo csrfField(); ?>
        <button type="submit" name="create_backup" class="btn">Backup erstellen</button>
    </form>

    <h4 class="mt-4">Letzte Backups</h4>
    <?php if (empty($backups)): ?>
        <p>Es wurden noch keine Backups erstellt.</p>
    <?php else: ?>
        <div class="table-responsive">
            <table class="responsive-table">
                <thead>
                    <tr>
                        <th>Erstellt</th>
                        <th>Auslöser</th>
                        <th>Größe</th>
                        <th>Dateien</th>
                        <th>Remote</th>
                        <th>Aktionen</th>
                    </tr>
                </thead>
                <tbody>
                    <?php foreach ($backups as $backup): ?>
                        <tr>
                            <td data-label="Erstellt"><?php echo escape(settingsFormatBackupDate((string) ($backup["created_at"] ?? ""))); ?></td>
                            <td data-label="Auslöser"><?php echo (($backup["trigger"] ?? "") === "automatic") ? "Automatisch" : "Manuell"; ?></td>
                            <td data-label="Größe"><?php echo escape(backupFormatBytes((int) ($backup["size"] ?? 0))); ?></td>
                            <td data-label="Dateien"><?php echo (int) ($backup["file_count"] ?? 0); ?></td>
                            <td data-label="Remote"><?php echo escape(settingsGetBackupUploadLabel($backup)); ?></td>
                            <td data-label="Aktionen">
                                <form method="POST" class="inline-form">
                                    <?php echo csrfField(); ?>
                                    <input type="hidden" name="backup_filename" value="<?php echo escape($backup["filename"] ?? ""); ?>">
                                    <button type="submit" name="download_backup" class="btn btn-secondary btn-small">Download</button>
                                </form>
                            </td>
                        </tr>
                    <?php endforeach; ?>
                </tbody>
            </table>
        </div>
    <?php endif; ?>
</div>

<div class="panel panel-lg mt-4">
    <h3>Updater</h3>
    <p>Installierte Version: <?php echo escape(APP_VERSION); ?></p>
    <p>Update-Status: <?php echo escape($updaterStatus["label"]); ?></p>
    <p><a href="updater.php" class="btn btn-secondary">Updater öffnen</a></p>
</div>

<?php if ($isSuperAdmin): ?>
<div class="panel panel-lg mt-4">
    <h3>Lokale Konfiguration</h3>
    <p>Bearbeitet <code>config.php</code> direkt auf diesem Server. Diese Datei wird beim Update nicht überschrieben.</p>
    <div class="alert alert-warning">Vor dem Speichern wird die PHP-Syntax geprüft und die vorherige Version automatisch gesichert. Fehlerhafte Änderungen können die gesamte Anwendung lahmlegen.</div>
    <form method="POST">
        <?php echo csrfField(); ?>
        <div class="form-group">
            <label for="local_config_content">Inhalt von config.php</label>
            <textarea id="local_config_content" name="local_config_content" rows="24" class="config-editor" spellcheck="false"><?php echo escape(
                $localConfigContent,
            ); ?></textarea>
        </div>
        <button type="submit" name="save_local_config" class="btn">Speichern</button>
    </form>
</div>
<?php endif; ?>

<?php include __DIR__ . "/../includes/footer.php"; ?>