<?php
namespace Relay\Multisite;

use Relay\Support\RelayError;

/** Relay on a multisite network (spec 2026-10-16 §1): whether it runs there and what the network looks like. */
final class Network
{
    /** The network's own tables (after the base prefix): never part of a subsite, never copied. */
    public const TABLES = ['blogs', 'blogmeta', 'site', 'sitemeta', 'signups', 'registration_log', 'blog_versions'];

    /** Relay runs on every single site, and on a network only when it is network-activated. */
    public static function runs(): bool
    {
        return !is_multisite() || self::network_active();
    }

    public static function network_active(): bool
    {
        if (!is_multisite()) {
            return false;
        }
        $plugins = (array) get_site_option('active_sitewide_plugins', []);
        /** Tests load Relay as a must-use plugin and say so with this filter. */
        return isset($plugins[plugin_basename(RELAY_FILE)]) || (bool) apply_filters('relay_network_active', false);
    }

    /**
     * The plugins the network activates for every site (basenames), as the network stores them, not through the
     * option filters other plugins may add. SiteRelay's own is left out unless $relay.
     *
     * @return string[]
     */
    public static function active_plugins(bool $relay = false): array
    {
        global $wpdb;
        if (!is_multisite()) {
            return [];
        }
        $raw = $wpdb->get_var($wpdb->prepare("SELECT meta_value FROM {$wpdb->sitemeta} WHERE meta_key = 'active_sitewide_plugins' AND site_id = %d", get_current_network_id())); // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- the stored list itself: during a signed request Relay's mu-plugin filters active_sitewide_plugins so only Relay loads
        $plugins = is_string($raw) ? maybe_unserialize($raw) : [];
        $all = array_keys(is_array($plugins) ? $plugins : []);
        return array_values($relay ? $all : array_diff($all, [plugin_basename(RELAY_FILE)]));
    }

    public static function subdomain(): bool
    {
        return is_multisite() && is_subdomain_install();
    }

    /** Networks that still serve uploads through /files/ (ms_files_rewriting) keep them where Relay can't follow. */
    public static function check(): void
    {
        if (is_multisite() && (bool) get_site_option('ms_files_rewriting')) {
            throw new RelayError(
                'multisite.files_rewriting',
                esc_html__('This network still serves uploads through /files/ addresses (ms_files_rewriting), which SiteRelay does not support.', 'siterelay'),
                esc_html__('Move the network to the standard uploads folders first; WordPress has done so for new networks since version 3.5.', 'siterelay')
            );
        }
    }
}