<?php
declare(strict_types=1);

$config = require __DIR__ . '/config.php';

header('Content-Type: application/json; charset=utf-8');
header('X-Content-Type-Options: nosniff');

$drivers = class_exists('PDO') ? PDO::getAvailableDrivers() : [];
if (!in_array('sqlite', $drivers, true)) {
    require __DIR__ . '/filedb.php';
    exit;
}

function respond(array $payload, int $status = 200): void {
    http_response_code($status);
    echo json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
    exit;
}

function fail(string $message, int $status = 400, array $extra = []): void {
    respond(['ok' => false, 'error' => $message] + $extra, $status);
}

function request_json(int $maxBytes): array {
    $raw = file_get_contents('php://input') ?: '';
    if ($raw === '') return [];
    if (strlen($raw) > $maxBytes) fail('request_too_large', 413);
    $data = json_decode($raw, true);
    if (!is_array($data)) fail('invalid_json', 400);
    return $data;
}

function now_ms(): int {
    return (int) floor(microtime(true) * 1000);
}

function clean_text($value, string $fallback = '', int $max = 80): string {
    $text = trim((string) ($value ?? ''));
    $text = preg_replace('/[\x00-\x1F\x7F]/u', '', $text) ?? '';
    $text = preg_replace('/\s+/u', ' ', $text) ?? '';
    if ($text === '') $text = $fallback;
    if (function_exists('mb_substr')) return mb_substr($text, 0, $max, 'UTF-8');
    return substr($text, 0, $max);
}

function clean_id($value, string $fallback = ''): string {
    $id = trim((string) ($value ?? ''));
    if ($id === '') return $fallback;
    $id = preg_replace('/[^A-Za-z0-9_:\-.]/', '', $id) ?? '';
    return substr($id, 0, 96);
}

function db(array $config): PDO {
    $path = $config['db_path'];
    $dir = dirname($path);
    if (!is_dir($dir) && !mkdir($dir, 0775, true) && !is_dir($dir)) fail('db_directory_unavailable', 500);
    $pdo = new PDO('sqlite:' . $path, null, null, [
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    ]);
    $pdo->exec('PRAGMA foreign_keys = ON');
    $pdo->exec('PRAGMA busy_timeout = 5000');
    $pdo->exec('PRAGMA journal_mode = WAL');
    migrate($pdo);
    return $pdo;
}

function migrate(PDO $db): void {
    $db->exec(<<<SQL
CREATE TABLE IF NOT EXISTS accounts (
  id TEXT PRIMARY KEY,
  name TEXT NOT NULL,
  password_hash TEXT NOT NULL,
  created_at INTEGER NOT NULL,
  updated_at INTEGER NOT NULL,
  disabled_at INTEGER
);
CREATE TABLE IF NOT EXISTS assets (
  id TEXT PRIMARY KEY,
  owner_account_id TEXT NOT NULL,
  author_name TEXT NOT NULL,
  json TEXT NOT NULL,
  version INTEGER NOT NULL DEFAULT 1,
  created_at INTEGER NOT NULL,
  updated_at INTEGER NOT NULL,
  deleted_at INTEGER,
  deleted_by TEXT,
  content_hash TEXT
);
CREATE INDEX IF NOT EXISTS idx_assets_owner ON assets(owner_account_id);
CREATE TABLE IF NOT EXISTS objects (
  id TEXT PRIMARY KEY,
  kind TEXT NOT NULL CHECK(kind IN ('static','dynamic')),
  asset_id TEXT NOT NULL,
  owner_account_id TEXT NOT NULL,
  json TEXT NOT NULL,
  version INTEGER NOT NULL DEFAULT 1,
  published_at INTEGER NOT NULL,
  updated_at INTEGER NOT NULL,
  deleted_at INTEGER,
  deleted_by TEXT,
  moderation_status TEXT NOT NULL DEFAULT 'active'
);
CREATE INDEX IF NOT EXISTS idx_objects_asset ON objects(asset_id);
CREATE INDEX IF NOT EXISTS idx_objects_owner ON objects(owner_account_id);
CREATE INDEX IF NOT EXISTS idx_objects_active ON objects(kind, deleted_at, moderation_status);
CREATE TABLE IF NOT EXISTS votes (
  target_type TEXT NOT NULL CHECK(target_type IN ('asset','object')),
  target_id TEXT NOT NULL,
  voter_account_id TEXT NOT NULL,
  value INTEGER NOT NULL CHECK(value IN (-1,0,1)),
  updated_at INTEGER NOT NULL,
  PRIMARY KEY(target_type, target_id, voter_account_id)
);
CREATE TABLE IF NOT EXISTS reports (
  id TEXT PRIMARY KEY,
  object_id TEXT NOT NULL,
  asset_id TEXT NOT NULL,
  object_kind TEXT NOT NULL CHECK(object_kind IN ('static','dynamic')),
  reporter_account_id TEXT NOT NULL,
  reason TEXT NOT NULL,
  created_at INTEGER NOT NULL,
  status TEXT NOT NULL DEFAULT 'open'
);
CREATE INDEX IF NOT EXISTS idx_reports_object ON reports(object_id);
CREATE TABLE IF NOT EXISTS events (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  type TEXT NOT NULL,
  json TEXT NOT NULL,
  created_at INTEGER NOT NULL
);
CREATE TABLE IF NOT EXISTS commands (
  id TEXT PRIMARY KEY,
  actor_account_id TEXT NOT NULL,
  created_at INTEGER NOT NULL,
  applied_at INTEGER NOT NULL
);
SQL);
}

function authenticate(PDO $db, array $account, bool $createIfMissing = true): array {
    $id = clean_id($account['id'] ?? '');
    $password = (string) ($account['password'] ?? $account['pass'] ?? '');
    $name = clean_text($account['name'] ?? $id, $id, 32);
    if ($id === '' || $password === '') fail('account_required', 401);

    $stmt = $db->prepare('SELECT * FROM accounts WHERE id = ?');
    $stmt->execute([$id]);
    $row = $stmt->fetch();
    $now = now_ms();
    if (!$row) {
        if (!$createIfMissing) fail('account_not_found', 401);
        $hash = password_hash($password, PASSWORD_DEFAULT);
        $db->prepare('INSERT INTO accounts(id, name, password_hash, created_at, updated_at) VALUES(?,?,?,?,?)')
            ->execute([$id, $name, $hash, $now, $now]);
        return ['id' => $id, 'name' => $name, 'created_at' => $now, 'updated_at' => $now];
    }
    if (!empty($row['disabled_at'])) fail('account_disabled', 403);
    if (!password_verify($password, $row['password_hash'])) fail('invalid_account_password', 401);
    if ($name !== '' && $name !== $row['name']) {
        $db->prepare('UPDATE accounts SET name = ?, updated_at = ? WHERE id = ?')->execute([$name, $now, $id]);
        $row['name'] = $name;
        $row['updated_at'] = $now;
    }
    return $row;
}

function record_event(PDO $db, string $type, array $event): int {
    $now = now_ms();
    $db->prepare('INSERT INTO events(type, json, created_at) VALUES(?,?,?)')
        ->execute([$type, json_encode($event, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES), $now]);
    return (int) $db->lastInsertId();
}

function decode_json_row(?string $json): array {
    $decoded = json_decode((string) $json, true);
    return is_array($decoded) ? $decoded : [];
}

function normalize_asset(array $asset, array $actor, array $config): array {
    $id = clean_id($asset['id'] ?? '');
    if ($id === '') fail('asset_id_required');
    $category = (($asset['category'] ?? '') === 'dynamic') ? 'dynamic' : 'static';
    $width = max(1, min(64, (int) ($asset['width'] ?? $asset['w'] ?? $asset['size'] ?? 16)));
    $height = max(1, min(64, (int) ($asset['height'] ?? $asset['ht'] ?? $asset['size'] ?? $width)));
    $asset['id'] = $id;
    $asset['name'] = clean_text($asset['name'] ?? 'Untitled', 'Untitled', 32);
    $asset['category'] = $category;
    $asset['subtype'] = clean_text($asset['subtype'] ?? ($category === 'dynamic' ? 'human' : 'other'), 'other', 24);
    $asset['size'] = max($width, $height);
    $asset['width'] = $width;
    $asset['height'] = $height;
    $asset['author'] = clean_text($actor['name'] ?? $actor['id'], $actor['id'], 32);
    $asset['ownerAccountId'] = $actor['id'];
    $asset['version'] = max(1, (int) ($asset['version'] ?? 1));
    $asset['createdAt'] = (int) ($asset['createdAt'] ?? now_ms());
    $asset['updatedAt'] = now_ms();
    $asset['parentAssetId'] = isset($asset['parentAssetId']) ? clean_id($asset['parentAssetId'], '') : null;
    $asset['originalAssetId'] = isset($asset['originalAssetId']) ? clean_id($asset['originalAssetId'], '') : null;
    if (!isset($asset['pixels']) && !isset($asset['faces'])) fail('asset_pixels_required');
    $json = json_encode($asset, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
    if ($json === false || strlen($json) > 250000) fail('asset_too_large', 413);
    return $asset;
}

function normalize_object(array $object, string $kind, array $actor, array $config): array {
    $id = clean_id($object['id'] ?? '');
    $assetId = clean_id($object['assetId'] ?? '');
    if ($id === '' || $assetId === '') fail('object_id_or_asset_required');
    $object['id'] = $id;
    $object['assetId'] = $assetId;
    $object['ownerAccountId'] = $actor['id'];
    $object['version'] = max(1, (int) ($object['version'] ?? 1));
    $object['status'] = 'active';
    $object['publishedAt'] = (int) ($object['publishedAt'] ?? now_ms());
    if ($kind === 'dynamic') {
        $object['homeX'] = max(0, min((int) $config['world_width'] - 1, (int) round((float) ($object['homeX'] ?? $object['x'] ?? 0))));
        $object['homeY'] = max(0, min((int) $config['world_height'] - 1, (int) round((float) ($object['homeY'] ?? $object['y'] ?? 0))));
        $object['createdAt'] = (int) ($object['createdAt'] ?? now_ms());
    } else {
        $object['x'] = max(0, min((int) $config['world_width'] - 1, (int) round((float) ($object['x'] ?? 0))));
        $object['y'] = max(0, min((int) $config['world_height'] - 1, (int) round((float) ($object['y'] ?? 0))));
        $object['placedAt'] = (int) ($object['placedAt'] ?? now_ms());
    }
    $json = json_encode($object, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
    if ($json === false || strlen($json) > 50000) fail('object_too_large', 413);
    return $object;
}

function ensure_asset_owner(PDO $db, string $assetId, string $actorId): array {
    $stmt = $db->prepare('SELECT * FROM assets WHERE id = ? AND deleted_at IS NULL');
    $stmt->execute([$assetId]);
    $asset = $stmt->fetch();
    if (!$asset) fail('asset_not_found', 404);
    if ($asset['owner_account_id'] !== $actorId) fail('asset_owner_required', 403);
    return $asset;
}

function publish_quota_available(PDO $db, array $actor, array $config): bool {
    $now = now_ms();
    $created = (int) ($actor['created_at'] ?? $now);
    $limit = ($now - $created) < (int) $config['trusted_after_ms'] ? (int) $config['publish_limit_first_day'] : (int) $config['publish_limit_trusted'];
    $since = $now - 60 * 60 * 1000;
    $stmt = $db->prepare('SELECT COUNT(*) AS c FROM objects WHERE owner_account_id = ? AND published_at >= ? AND deleted_at IS NULL');
    $stmt->execute([$actor['id'], $since]);
    return ((int) ($stmt->fetch()['c'] ?? 0)) < $limit;
}

function process_command(PDO $db, array $command, array $actor, array $config): array {
    $cmdId = clean_id($command['id'] ?? '');
    $type = (string) ($command['type'] ?? '');
    if ($cmdId === '' || $type === '') return ['ok' => false, 'id' => $cmdId, 'error' => 'invalid_command'];

    $stmt = $db->prepare('SELECT id FROM commands WHERE id = ?');
    $stmt->execute([$cmdId]);
    if ($stmt->fetch()) return ['ok' => true, 'id' => $cmdId, 'duplicate' => true];

    $now = now_ms();
    if ($type === 'asset.create') {
        $asset = normalize_asset(is_array($command['asset'] ?? null) ? $command['asset'] : [], $actor, $config);
        $existing = $db->prepare('SELECT owner_account_id, deleted_at FROM assets WHERE id = ?');
        $existing->execute([$asset['id']]);
        $row = $existing->fetch();
        if ($row && $row['owner_account_id'] !== $actor['id']) fail('asset_id_already_owned', 403);
        $json = json_encode($asset, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
        $db->prepare('INSERT INTO assets(id, owner_account_id, author_name, json, version, created_at, updated_at, deleted_at, deleted_by, content_hash)
            VALUES(?,?,?,?,?,?,?,?,?,?)
            ON CONFLICT(id) DO UPDATE SET author_name=excluded.author_name, json=excluded.json, version=excluded.version, updated_at=excluded.updated_at, deleted_at=NULL, deleted_by=NULL, content_hash=excluded.content_hash')
            ->execute([$asset['id'], $actor['id'], $asset['author'], $json, $asset['version'], $asset['createdAt'], $asset['updatedAt'], null, null, $asset['contentHash'] ?? null]);
        record_event($db, 'asset.upsert', ['type' => 'asset.upsert', 'assetId' => $asset['id'], 'actorAccountId' => $actor['id']]);
    } elseif ($type === 'asset.delete') {
        $assetId = clean_id($command['assetId'] ?? '');
        ensure_asset_owner($db, $assetId, $actor['id']);
        $db->prepare('UPDATE assets SET deleted_at = ?, deleted_by = ?, updated_at = ? WHERE id = ?')
            ->execute([$now, $actor['id'], $now, $assetId]);
        $db->prepare('UPDATE objects SET deleted_at = ?, deleted_by = ?, updated_at = ? WHERE asset_id = ? AND deleted_at IS NULL')
            ->execute([$now, $actor['id'], $now, $assetId]);
        record_event($db, 'asset.delete', ['type' => 'asset.delete', 'assetId' => $assetId, 'actorAccountId' => $actor['id']]);
    } elseif ($type === 'object.publish' || $type === 'object.move') {
        $kind = (($command['kind'] ?? '') === 'dynamic') ? 'dynamic' : 'static';
        $object = normalize_object(is_array($command['object'] ?? null) ? $command['object'] : [], $kind, $actor, $config);
        ensure_asset_owner($db, $object['assetId'], $actor['id']);
        if ($type === 'object.publish' && !publish_quota_available($db, $actor, $config)) fail('publish_limit_reached', 429);
        $activeCount = (int) $db->query("SELECT COUNT(*) AS c FROM objects WHERE deleted_at IS NULL AND moderation_status = 'active'")->fetch()['c'];
        if ($type === 'object.publish' && $activeCount >= (int) $config['max_world_objects']) fail('world_object_limit_reached', 409);
        $json = json_encode($object, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
        $publishedAt = (int) ($object['publishedAt'] ?? $now);
        $db->prepare('INSERT INTO objects(id, kind, asset_id, owner_account_id, json, version, published_at, updated_at, deleted_at, deleted_by, moderation_status)
            VALUES(?,?,?,?,?,?,?,?,?,?,?)
            ON CONFLICT(id) DO UPDATE SET json=excluded.json, version=excluded.version, published_at=excluded.published_at, updated_at=excluded.updated_at, deleted_at=NULL, deleted_by=NULL, moderation_status=\'active\'')
            ->execute([$object['id'], $kind, $object['assetId'], $actor['id'], $json, $object['version'], $publishedAt, $now, null, null, 'active']);
        record_event($db, 'object.upsert', ['type' => 'object.upsert', 'kind' => $kind, 'objectId' => $object['id'], 'actorAccountId' => $actor['id']]);
    } elseif ($type === 'object.delete') {
        $kind = (($command['kind'] ?? '') === 'dynamic') ? 'dynamic' : 'static';
        $objectId = clean_id($command['objectId'] ?? '');
        $stmt = $db->prepare('SELECT * FROM objects WHERE id = ? AND kind = ? AND deleted_at IS NULL');
        $stmt->execute([$objectId, $kind]);
        $obj = $stmt->fetch();
        if (!$obj) fail('object_not_found', 404);
        if ($obj['owner_account_id'] !== $actor['id']) fail('object_owner_required', 403);
        $db->prepare('UPDATE objects SET deleted_at = ?, deleted_by = ?, updated_at = ? WHERE id = ?')
            ->execute([$now, $actor['id'], $now, $objectId]);
        record_event($db, 'object.delete', ['type' => 'object.delete', 'kind' => $kind, 'objectId' => $objectId, 'actorAccountId' => $actor['id']]);
    } elseif ($type === 'vote.asset' || $type === 'vote.object') {
        $targetType = $type === 'vote.asset' ? 'asset' : 'object';
        $targetId = clean_id($command[$targetType . 'Id'] ?? $command['targetId'] ?? '');
        $value = max(-1, min(1, (int) ($command['value'] ?? $command['delta'] ?? 0)));
        if ($targetId === '') fail('vote_target_required');
        if ($value === 0) {
            $db->prepare('DELETE FROM votes WHERE target_type = ? AND target_id = ? AND voter_account_id = ?')->execute([$targetType, $targetId, $actor['id']]);
        } else {
            $db->prepare('INSERT INTO votes(target_type, target_id, voter_account_id, value, updated_at) VALUES(?,?,?,?,?)
                ON CONFLICT(target_type, target_id, voter_account_id) DO UPDATE SET value=excluded.value, updated_at=excluded.updated_at')
                ->execute([$targetType, $targetId, $actor['id'], $value, $now]);
        }
        record_event($db, 'vote.' . $targetType, ['type' => 'vote.' . $targetType, 'targetId' => $targetId, 'actorAccountId' => $actor['id'], 'value' => $value]);
    } elseif ($type === 'report.object') {
        $objectId = clean_id($command['objectId'] ?? '');
        $assetId = clean_id($command['assetId'] ?? '');
        $kind = (($command['objectKind'] ?? $command['kind'] ?? '') === 'dynamic') ? 'dynamic' : 'static';
        $reason = clean_text($command['reason'] ?? 'other', 'other', 48);
        if ($objectId === '' || $assetId === '') fail('report_target_required');
        $reportId = clean_id($command['reportId'] ?? $command['id'] ?? ('report_' . bin2hex(random_bytes(6))));
        $db->prepare('INSERT OR IGNORE INTO reports(id, object_id, asset_id, object_kind, reporter_account_id, reason, created_at, status) VALUES(?,?,?,?,?,?,?,?)')
            ->execute([$reportId, $objectId, $assetId, $kind, $actor['id'], $reason, $now, 'open']);
        record_event($db, 'report.object', ['type' => 'report.object', 'objectId' => $objectId, 'assetId' => $assetId, 'actorAccountId' => $actor['id'], 'reason' => $reason]);
    } else {
        return ['ok' => false, 'id' => $cmdId, 'error' => 'unsupported_command'];
    }

    $db->prepare('INSERT INTO commands(id, actor_account_id, created_at, applied_at) VALUES(?,?,?,?)')
        ->execute([$cmdId, $actor['id'], (int) ($command['createdAt'] ?? $now), $now]);
    return ['ok' => true, 'id' => $cmdId];
}

function vote_snapshot(PDO $db, string $targetType): array {
    $stmt = $db->prepare('SELECT target_id, voter_account_id, value FROM votes WHERE target_type = ? AND value != 0');
    $stmt->execute([$targetType]);
    $out = [];
    while ($row = $stmt->fetch()) {
        $id = $row['target_id'];
        $value = (int) $row['value'];
        if (!isset($out[$id])) $out[$id] = ['up' => 0, 'down' => 0, 'voters' => []];
        if ($value > 0) $out[$id]['up']++;
        if ($value < 0) $out[$id]['down']++;
        $out[$id]['voters'][$row['voter_account_id']] = $value;
    }
    return $out;
}

function build_snapshot(PDO $db): array {
    $assets = [];
    foreach ($db->query('SELECT json FROM assets WHERE deleted_at IS NULL ORDER BY updated_at DESC LIMIT 2000') as $row) {
        $asset = decode_json_row($row['json']);
        if ($asset) $assets[] = $asset;
    }
    $placed = [];
    $dynamic = [];
    foreach ($db->query("SELECT kind, json FROM objects WHERE deleted_at IS NULL AND moderation_status = 'active' ORDER BY published_at DESC LIMIT 1000") as $row) {
        $obj = decode_json_row($row['json']);
        if (!$obj) continue;
        if ($row['kind'] === 'dynamic') $dynamic[] = $obj;
        else $placed[] = $obj;
    }
    $assetTombstones = [];
    foreach ($db->query('SELECT id, deleted_at, deleted_by, version FROM assets WHERE deleted_at IS NOT NULL') as $row) {
        $assetTombstones[$row['id']] = ['id' => $row['id'], 'deletedAt' => (int) $row['deleted_at'], 'deletedBy' => $row['deleted_by'], 'version' => (int) $row['version']];
    }
    $objectTombstones = [];
    foreach ($db->query('SELECT id, asset_id, deleted_at, deleted_by, version FROM objects WHERE deleted_at IS NOT NULL') as $row) {
        $objectTombstones[$row['id']] = ['id' => $row['id'], 'assetId' => $row['asset_id'], 'deletedAt' => (int) $row['deleted_at'], 'deletedBy' => $row['deleted_by'], 'version' => (int) $row['version']];
    }
    $reports = [];
    foreach ($db->query("SELECT * FROM reports WHERE status = 'open' ORDER BY created_at DESC LIMIT 500") as $row) {
        $reports[] = [
            'id' => $row['id'],
            'objectId' => $row['object_id'],
            'assetId' => $row['asset_id'],
            'objectKind' => $row['object_kind'],
            'reporter' => $row['reporter_account_id'],
            'reason' => $row['reason'],
            'createdAt' => (int) $row['created_at'],
        ];
    }
    $last = $db->query('SELECT COALESCE(MAX(id), 0) AS id FROM events')->fetch();
    return [
        'ok' => true,
        'schema' => 1,
        'serverNow' => now_ms(),
        'lastEventId' => (int) ($last['id'] ?? 0),
        'authority' => ['publish' => 'server', 'objectMove' => 'server', 'dayNight' => 'local', 'dynamicMotion' => 'local'],
        'assets' => $assets,
        'placed' => $placed,
        'dynamicSummons' => $dynamic,
        'assetVotes' => vote_snapshot($db, 'asset'),
        'objectVotes' => vote_snapshot($db, 'object'),
        'moderationReports' => $reports,
        'tombstones' => ['assets' => $assetTombstones, 'objects' => $objectTombstones],
    ];
}

try {
    $action = $_GET['action'] ?? '';
    if ($action === '') {
        $path = trim((string) parse_url($_SERVER['REQUEST_URI'] ?? '', PHP_URL_PATH), '/');
        $action = basename($path) === 'index.php' ? '' : basename($path);
    }
    $database = db($config);

    if ($action === 'health' || $action === '') {
        respond(['ok' => true, 'service' => 'pixel-island-api', 'serverNow' => now_ms(), 'sqlite' => true]);
    }

    if ($action === 'snapshot') {
        respond(build_snapshot($database));
    }

    if ($action === 'account') {
        $data = request_json((int) $config['max_json_bytes']);
        $account = authenticate($database, is_array($data['account'] ?? null) ? $data['account'] : $data, true);
        respond(['ok' => true, 'account' => ['id' => $account['id'], 'name' => $account['name'], 'createdAt' => (int) $account['created_at']]]);
    }

    if ($action === 'commands') {
        $data = request_json((int) $config['max_json_bytes']);
        $actor = authenticate($database, is_array($data['account'] ?? null) ? $data['account'] : [], true);
        $commands = is_array($data['commands'] ?? null) ? $data['commands'] : [];
        if (count($commands) > 100) fail('too_many_commands', 413);
        $applied = [];
        $rejected = [];
        foreach ($commands as $command) {
            if (!is_array($command)) continue;
            try {
                $database->beginTransaction();
                $result = process_command($database, $command, $actor, $config);
                if ($result['ok'] ?? false) {
                    $database->commit();
                    $applied[] = $result['id'];
                } else {
                    $database->rollBack();
                    $rejected[] = $result;
                }
            } catch (Throwable $e) {
                if ($database->inTransaction()) $database->rollBack();
                $rejected[] = ['ok' => false, 'id' => clean_id($command['id'] ?? ''), 'error' => $e->getMessage()];
            }
        }
        respond(['ok' => true, 'appliedCommandIds' => $applied, 'rejectedCommands' => $rejected, 'snapshot' => build_snapshot($database)]);
    }

    fail('unknown_action', 404);
} catch (Throwable $e) {
    fail($e->getMessage(), 500);
}