<?php

declare(strict_types=1);

namespace Mod\Names\Controllers;

use Illuminate\Routing\Controller;
use Mod\Chain\Services\DaemonRpc;
use Mod\Gateway\Services\GatewayRegistry;
use Mod\Names\Models\DnsTicket;
use Mod\Names\Models\NameClaim;

/**
 * Prometheus metrics endpoint.
 *
 *   GET /v1/metrics
 *
 * Returns Prometheus text exposition format for Grafana scraping.
 */
class MetricsController extends Controller
{
    public function __invoke(DaemonRpc $rpc, GatewayRegistry $registry): \Illuminate\Http\Response
    {
        $info = $rpc->getInfo();
        $offline = isset($info['_offline']);

        $lines = [];
        $lines[] = '# HELP lthn_chain_height Current blockchain height';
        $lines[] = '# TYPE lthn_chain_height gauge';
        $lines[] = 'lthn_chain_height ' . ($info['height'] ?? 0);

        $lines[] = '# HELP lthn_alias_count Total registered aliases';
        $lines[] = '# TYPE lthn_alias_count gauge';
        $lines[] = 'lthn_alias_count ' . ($info['alias_count'] ?? 0);

        $lines[] = '# HELP lthn_tx_pool_size Pending transactions';
        $lines[] = '# TYPE lthn_tx_pool_size gauge';
        $lines[] = 'lthn_tx_pool_size ' . ($info['tx_pool_size'] ?? 0);

        $lines[] = '# HELP lthn_daemon_online Daemon reachability';
        $lines[] = '# TYPE lthn_daemon_online gauge';
        $lines[] = 'lthn_daemon_online ' . ($offline ? 0 : 1);

        $lines[] = '# HELP lthn_claims_pending Pending name claims';
        $lines[] = '# TYPE lthn_claims_pending gauge';
        $lines[] = 'lthn_claims_pending ' . NameClaim::pending()->count();

        $lines[] = '# HELP lthn_claims_total Total name claims';
        $lines[] = '# TYPE lthn_claims_total counter';
        $lines[] = 'lthn_claims_total ' . NameClaim::count();

        $lines[] = '# HELP lthn_dns_tickets_pending Pending DNS tickets';
        $lines[] = '# TYPE lthn_dns_tickets_pending gauge';
        $lines[] = 'lthn_dns_tickets_pending ' . DnsTicket::pending()->count();

        $lines[] = '# HELP lthn_gateways_live Live paired gateways';
        $lines[] = '# TYPE lthn_gateways_live gauge';
        $lines[] = 'lthn_gateways_live ' . count($registry->liveGateways());

        return response(implode("\n", $lines) . "\n", 200)
            ->header('Content-Type', 'text/plain; charset=utf-8');
    }
}