<?php

namespace FluxCDNSecurity;

defined('ABSPATH') || exit;

final class Disconnect
{
    public static function request(): bool
    {
        $connection = Store::get('connection');
        if (! $connection || ! Client::uuid($connection['site_id'] ?? null)) return true;
        if (($connection['url'] ?? '') !== rtrim(is_multisite() ? network_site_url() : site_url(), '/')) return false;
        // Upgrade older saved connections while their ordinary API token is still usable.
        if (empty($connection['disconnect_receipt']) && Client::connectionError() === '') {
            try { Client::rememberReceipt(Client::request('GET', Client::path().'/test', timeout: 5)['data']); $connection = Store::get('connection'); }
            catch (\Throwable) { /* The authenticated legacy endpoint remains available as a fallback. */ }
        }
        $pending = Store::get('disconnects');
        $pending[$connection['site_id']] = ['connection' => $connection, 'attempts' => 0, 'due' => time(), 'created' => time()];
        Store::set('disconnects', $pending);
        self::send($connection['site_id']);
        return ! isset(Store::get('disconnects')[$connection['site_id']]);
    }

    public static function ensure(): void
    {
        $pending = Store::get('disconnects');
        $retrying = array_filter($pending, static fn ($item) => empty($item['terminal']));
        if (! $retrying) { wp_clear_scheduled_hook('flx_security_disconnect'); return; }
        $due = min(array_column($retrying, 'due'));
        $next = wp_next_scheduled('flx_security_disconnect');
        if (! $next || $next > $due) {
            if ($next) wp_clear_scheduled_hook('flx_security_disconnect');
            wp_schedule_single_event(max(time() + 1, $due), 'flx_security_disconnect');
        }
    }

    public static function tick(): void
    {
        $owner = Store::lock();
        if ($owner === false) { self::ensure(); return; }
        try {
            foreach (Store::get('disconnects') as $site => $pending) {
                if (empty($pending['terminal']) && $pending['due'] <= time()) { self::send($site); break; }
            }
        } finally { Store::unlock($owner); }
        self::ensure();
    }

    private static function send(string $site): void
    {
        $pending = Store::get('disconnects');
        $item = $pending[$site] ?? null;
        if (! $item) return;
        $connection = $item['connection'];
        try {
            if (($item['created'] ?? time()) < time() - 7 * DAY_IN_SECONDS || $item['attempts'] >= 168) throw new \RuntimeException('request_rejected');
            if (! empty($connection['disconnect_receipt'])) {
                $result = Client::request('POST', '/disconnect', ['site_id' => $site, 'receipt' => Store::decrypt($connection['disconnect_receipt'])], public: true, timeout: 5);
            } else {
                $result = Client::request('POST', '/sites/'.$site.'/disconnect', token: Store::decrypt($connection['secret']), timeout: 5);
            }
            if (($result['data']['connected'] ?? null) !== false) throw new \RuntimeException('invalid_response');
            unset($pending[$site]);
        } catch (\Throwable $error) {
            if ($error->getMessage() === 'site_disconnected') {
                unset($pending[$site]);
            } elseif (in_array($error->getMessage(), ['invalid_authorization', 'request_rejected', 'invalid_token', 'insufficient_scope', 'connection_required', 'crypto_unavailable', 'invalid_request'], true)) {
                // Keep the unconfirmed outcome, without retaining credentials or scheduling a futile request.
                $pending[$site] = ['terminal' => true, 'attempts' => $item['attempts'], 'created' => $item['created'] ?? time(), 'due' => 0];
            } else {
                $item['created'] ??= time();
                $item['attempts']++;
                $item['due'] = max(time() + min(HOUR_IN_SECONDS, 15 * (2 ** min(8, $item['attempts']))), (int) Store::get('retry_after', 0));
                $pending[$site] = $item;
            }
        }
        if ($pending) Store::set('disconnects', $pending); else Store::remove('disconnects');
        self::ensure();
    }
}