#!/usr/bin/env php
<?php
/**
 * nextcloud-sync.php — push the latest SQLite snapshot to Nextcloud WebDAV.
 *
 * Uploads the newest db-*.db.gz from /var/backups/xamxam to the XAMXAM backup
 * folder on cloud.erg.school, reusing the SMTP credentials (xamxam@erg.be)
 * already stored/decryptable in smtp_settings. Filenames are timestamped and
 * the remote folder is pruned to the most recent N snapshots.
 *
 * Transport is PHP's curl extension (no rclone / shell curl needed): WebDAV
 * upload is an HTTP PUT with Basic auth, then a PROPFIND to verify size.
 *
 * Usage:
 *   php scripts/nextcloud-sync.php                    # keep 7 remote snapshots
 *   REMOTE_KEEP=14 php scripts/nextcloud-sync.php
 *
 * Expected to run from cron shortly after the daily backup snapshot.
 * Exit codes: 0 on success, 1 on failure (logged, never fatal to the backup).
 */

declare(strict_types=1);

// Resolve APP_ROOT robustly — same convention as the other CLI scripts here.
$prodRoot = '/var/www/xamxam';
if (is_dir($prodRoot . '/src') && is_file($prodRoot . '/src/Database.php')) {
    define('APP_ROOT', $prodRoot);
} else {
    define('APP_ROOT', dirname(__DIR__) . '/app');
}

const BACKUP_DIR      = '/var/backups/xamxam';
const WEBDAV_BASE     = 'https://cloud.erg.school/remote.php/dav/files/xamxam%40erg.be/XAMXAM-BCK';
const REMOTE_PREFIX   = 'xamxam-db-';

// Autoload dependencies (PHPMailer, etc.) from composer.
$autoloads = [
    APP_ROOT . '/../vendor/autoload.php',   // repo root / vendor
    APP_ROOT . '/vendor/autoload.php',      // app / vendor
];
foreach ($autoloads as $a) {
    if (is_file($a)) {
        require_once $a;
        break;
    }
}

// Read-only probe: do NOT run schema migrations against the live DB just to
// sync a snapshot. No-op DatabaseMigrations so the Database constructor only
// opens a PDO connection for reading SMTP credentials.
if (!class_exists('DatabaseMigrations', false)) {
    class DatabaseMigrations
    {
        public function run(): void {}
    }
}

require_once APP_ROOT . '/src/Crypto.php';
require_once APP_ROOT . '/src/Database.php';
require_once APP_ROOT . '/src/SmtpRelay.php';

if (!extension_loaded('curl')) {
    error_log('[nextcloud-sync] curl extension not available');
    exit(1);
}

// Remote retention: keep the most recent N snapshots.
$remoteKeep = (int) (getenv('REMOTE_KEEP') ?: 7);
if ($remoteKeep < 1) {
    $remoteKeep = 7;
}

// Locate the newest local snapshot.
$newest = null;
$newestMtime = 0;
foreach (glob(BACKUP_DIR . '/db-*.db.gz') ?: [] as $f) {
    $m = @filemtime($f);
    if ($m !== false && $m > $newestMtime) {
        $newestMtime = $m;
        $newest = $f;
    }
}

if ($newest === null) {
    error_log('[nextcloud-sync] No local snapshot found in ' . BACKUP_DIR);
    exit(1);
}

$localSize = filesize($newest);
$suffix = substr(basename($newest), 0, -strlen('.db.gz')); // strip .db.gz
$remoteName = REMOTE_PREFIX . $suffix . '.db.gz';
$remoteUrl  = rtrim(WEBDAV_BASE, '/') . '/' . rawurlencode($remoteName);

try {
    $db = new Database();
    $s = SmtpRelay::getSettings($db);
    $user = $s['username'];
    $pass = $s['password'];

    if ($user === '' || $pass === '') {
        error_log('[nextcloud-sync] SMTP credentials missing (username/password)');
        exit(1);
    }

    $ch = curl_init($remoteUrl);
    curl_setopt_array($ch, [
        CURLOPT_CUSTOMREQUEST  => 'PUT',
        CURLOPT_USERPWD        => $user . ':' . $pass,
        CURLOPT_HTTPAUTH       => CURLAUTH_BASIC,
        CURLOPT_UPLOAD         => true,            // stream upload, memory-safe
        CURLOPT_INFILE         => fopen($newest, 'rb'),
        CURLOPT_INFILESIZE     => $localSize,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT        => 0,               // no timeout on large uploads
        CURLOPT_SSL_VERIFYPEER => true,
        CURLOPT_SSL_VERIFYHOST => 2,
        CURLOPT_FOLLOWLOCATION => false,
    ]);

    $resp = curl_exec($ch);
    $code = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
    $err  = curl_error($ch);
    curl_close($ch);

    if ($resp === false || ($code !== 201 && $code !== 204)) {
        error_log("[nextcloud-sync] PUT failed (HTTP {$code}): {$err}");
        exit(1);
    }

    // Integrity check — PROPFIND the uploaded file and confirm size matches.
    $remoteSize = webdavSize($remoteUrl, $user, $pass);
    if ($remoteSize !== $localSize) {
        error_log(
            "[nextcloud-sync] size mismatch after upload: local {$localSize} vs remote "
            . ($remoteSize === null ? 'unknown' : $remoteSize)
        );
        exit(1);
    }

    echo "[nextcloud-sync] Uploaded {$remoteName} ({$localSize} bytes) to XAMXAM-BCK\n";
    error_log("[nextcloud-sync] Uploaded {$remoteName} ({$localSize} bytes)");

    // Prune remote to the most recent N files (by name, which is timestamped).
    pruneRemote($user, $pass, $remoteKeep);
    exit(0);
} catch (Throwable $e) {
    error_log('[nextcloud-sync] Error: ' . $e->getMessage());
    exit(1);
}

/**
 * PROPFIND the remote file and return its size in bytes, or null on failure.
 */
function webdavSize(string $url, string $user, string $pass): ?int
{
    $ch = curl_init($url);
    curl_setopt_array($ch, [
        CURLOPT_CUSTOMREQUEST  => 'PROPFIND',
        CURLOPT_USERPWD        => $user . ':' . $pass,
        CURLOPT_HTTPAUTH       => CURLAUTH_BASIC,
        CURLOPT_HTTPHEADER     => ['Depth: 0'],
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT        => 30,
        CURLOPT_SSL_VERIFYPEER => true,
        CURLOPT_SSL_VERIFYHOST => 2,
    ]);

    $body = curl_exec($ch);
    $code = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($body === false || $code !== 207) {
        return null;
    }

    // Nextcloud returns getcontentlength in the PROPFIND response.
    if (preg_match('/<d:getcontentlength[^>]*>(\d+)<\/d:getcontentlength>/i', $body, $m)) {
        return (int) $m[1];
    }
    // Fallback: any numeric "getcontentlength" (namespace may differ).
    if (preg_match('/getcontentlength[^>]*>(\d+)</i', $body, $m)) {
        return (int) $m[1];
    }
    return null;
}

/**
 * List remote snapshots and delete the oldest beyond $keep (by name order).
 */
function pruneRemote(string $user, string $pass, int $keep): bool
{
    $ch = curl_init(rtrim(WEBDAV_BASE, '/') . '/');
    curl_setopt_array($ch, [
        CURLOPT_CUSTOMREQUEST  => 'PROPFIND',
        CURLOPT_USERPWD        => $user . ':' . $pass,
        CURLOPT_HTTPAUTH       => CURLAUTH_BASIC,
        CURLOPT_HTTPHEADER     => ['Depth: 1'],
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT        => 30,
        CURLOPT_SSL_VERIFYPEER => true,
        CURLOPT_SSL_VERIFYHOST => 2,
    ]);

    $body = curl_exec($ch);
    $code = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($body === false || $code !== 207) {
        error_log("[nextcloud-sync] prune: PROPFIND failed (HTTP {$code})");
        return false;
    }

    // Extract hrefs of our snapshot files (names starting with REMOTE_PREFIX).
    $names = [];
    if (preg_match_all('/<d:href>([^<]+)<\/d:href>/i', $body, $m)) {
        foreach ($m[1] as $href) {
            $decoded = rawurldecode(basename(rtrim($href, '/')));
            if (str_starts_with($decoded, REMOTE_PREFIX) && str_ends_with($decoded, '.db.gz')) {
                $names[] = $decoded;
            }
        }
    }

    $names = array_values(array_unique($names));
    sort($names); // ascending; oldest last become deletable

    $excess = count($names) - $keep;
    if ($excess <= 0) {
        return true;
    }

    $toDelete = array_slice($names, 0, $excess); // oldest first
    foreach ($toDelete as $name) {
        $url = rtrim(WEBDAV_BASE, '/') . '/' . rawurlencode($name);
        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_CUSTOMREQUEST  => 'DELETE',
            CURLOPT_USERPWD        => $user . ':' . $pass,
            CURLOPT_HTTPAUTH       => CURLAUTH_BASIC,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 30,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
        ]);
        curl_exec($ch);
        $delCode = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($delCode === 204 || $delCode === 404) {
            echo "[nextcloud-sync] Pruned remote {$name}\n";
        } else {
            error_log("[nextcloud-sync] prune: DELETE {$name} failed (HTTP {$delCode})");
        }
    }

    return true;
}