<?php

declare(strict_types=1);

namespace MageSail\Magesail\Model;

use Magento\Framework\App\DeploymentConfig;

/**
 * Discovers TCP endpoints from app/etc/env.php (via DeploymentConfig) for service-type Holesail tunnels.
 */
class EnvServicePortResolver
{
    private const MYSQL_DEFAULT_KEY = 'mysql_default';

    private const SESSION_REDIS_KEY = 'session_redis';

    private const QUEUE_AMQP_KEY = 'queue_amqp';

    public function __construct(
        private readonly DeploymentConfig $deploymentConfig
    ) {
    }

    /**
     * @return list<array{service_key: string, label: string, host: string, port: int}>
     */
    public function getDiscoveredServices(): array
    {
        $out = [];
        foreach ($this->discoverMysql() as $row) {
            $out[] = $row;
        }
        foreach ($this->discoverCacheFrontends() as $row) {
            $out[] = $row;
        }
        foreach ($this->discoverSessionRedis() as $row) {
            $out[] = $row;
        }
        foreach ($this->discoverAmqp() as $row) {
            $out[] = $row;
        }
        foreach ($this->discoverHttpCacheHosts() as $row) {
            $out[] = $row;
        }
        foreach ($this->discoverCatalogSearch() as $row) {
            $out[] = $row;
        }

        return $out;
    }

    /**
     * @return array{host: string, port: int}|null
     */
    public function resolveService(string $serviceKey): ?array
    {
        foreach ($this->getDiscoveredServices() as $row) {
            if ($row['service_key'] === $serviceKey) {
                return ['host' => $row['host'], 'port' => $row['port']];
            }
        }

        return null;
    }

    /**
     * @return list<array{service_key: string, label: string, host: string, port: int}>
     */
    private function discoverMysql(): array
    {
        $conn = $this->deploymentConfig->get('db/connection/default');
        if (!\is_array($conn)) {
            return [];
        }
        $host = trim((string) ($conn['host'] ?? ''));
        if ($host === '') {
            return [];
        }
        $port = $this->parsePort($conn['port'] ?? null) ?? 3306;

        return [[
            'service_key' => self::MYSQL_DEFAULT_KEY,
            'label' => sprintf('MySQL (db/connection/default) — %s:%d', $host, $port),
            'host' => $host,
            'port' => $port,
        ]];
    }

    /**
     * @return list<array{service_key: string, label: string, host: string, port: int}>
     */
    private function discoverCacheFrontends(): array
    {
        $cache = $this->deploymentConfig->get('cache');
        if (!\is_array($cache)) {
            return [];
        }
        $frontends = $cache['frontend'] ?? null;
        if (!\is_array($frontends)) {
            return [];
        }
        $out = [];
        foreach ($frontends as $name => $frontend) {
            if (!\is_array($frontend)) {
                continue;
            }
            $backend = (string) ($frontend['backend'] ?? '');
            if ($backend === '' || stripos($backend, 'Redis') === false) {
                continue;
            }
            $opts = $frontend['backend_options'] ?? null;
            if (!\is_array($opts)) {
                continue;
            }
            $host = trim((string) ($opts['server'] ?? ''));
            $port = $this->parsePort($opts['port'] ?? null);
            if ($host === '' || $port === null) {
                continue;
            }
            $safeName = preg_replace('/[^a-zA-Z0-9_\-]/', '_', (string) $name) ?: 'frontend';
            $key = 'cache_frontend_' . $safeName;
            $out[] = [
                'service_key' => $key,
                'label' => sprintf('Redis cache (%s) — %s:%d', (string) $name, $host, $port),
                'host' => $host,
                'port' => $port,
            ];
        }

        return $out;
    }

    /**
     * @return list<array{service_key: string, label: string, host: string, port: int}>
     */
    private function discoverSessionRedis(): array
    {
        $session = $this->deploymentConfig->get('session');
        if (!\is_array($session)) {
            return [];
        }
        if (strtolower((string) ($session['save'] ?? '')) !== 'redis') {
            return [];
        }
        $redis = $session['redis'] ?? null;
        if (!\is_array($redis)) {
            return [];
        }
        $host = trim((string) ($redis['host'] ?? ''));
        $port = $this->parsePort($redis['port'] ?? null);
        if ($host === '' || $port === null) {
            return [];
        }

        return [[
            'service_key' => self::SESSION_REDIS_KEY,
            'label' => sprintf('Redis (sessions) — %s:%d', $host, $port),
            'host' => $host,
            'port' => $port,
        ]];
    }

    /**
     * @return list<array{service_key: string, label: string, host: string, port: int}>
     */
    private function discoverAmqp(): array
    {
        $queue = $this->deploymentConfig->get('queue');
        if (!\is_array($queue)) {
            return [];
        }
        $amqp = $queue['amqp'] ?? null;
        if (!\is_array($amqp)) {
            return [];
        }
        $host = trim((string) ($amqp['host'] ?? ''));
        $port = $this->parsePort($amqp['port'] ?? null);
        if ($host === '' || $port === null) {
            return [];
        }

        return [[
            'service_key' => self::QUEUE_AMQP_KEY,
            'label' => sprintf('RabbitMQ (AMQP) — %s:%d', $host, $port),
            'host' => $host,
            'port' => $port,
        ]];
    }

    /**
     * @return list<array{service_key: string, label: string, host: string, port: int}>
     */
    private function discoverHttpCacheHosts(): array
    {
        $hosts = $this->deploymentConfig->get('http_cache_hosts');
        if (!\is_array($hosts)) {
            return [];
        }
        $out = [];
        foreach ($hosts as $i => $entry) {
            if (!\is_array($entry)) {
                continue;
            }
            $host = trim((string) ($entry['host'] ?? ''));
            $port = $this->parsePort($entry['port'] ?? null);
            if ($host === '' || $port === null) {
                continue;
            }
            $key = 'http_cache_' . $i;
            $out[] = [
                'service_key' => $key,
                'label' => sprintf('HTTP cache host — %s:%d', $host, $port),
                'host' => $host,
                'port' => $port,
            ];
        }

        return $out;
    }

    /**
     * Elasticsearch / OpenSearch from catalog/search in env when present.
     *
     * @return list<array{service_key: string, label: string, host: string, port: int}>
     */
    private function discoverCatalogSearch(): array
    {
        $catalog = $this->deploymentConfig->get('catalog');
        if (!\is_array($catalog)) {
            return [];
        }
        $search = $catalog['search'] ?? null;
        if (!\is_array($search)) {
            return [];
        }
        $candidates = [
            [
                'key' => 'catalog_search_elasticsearch7',
                'host' => 'elasticsearch7_server_hostname',
                'port' => 'elasticsearch7_server_port',
                'label' => 'Elasticsearch 7',
            ],
            [
                'key' => 'catalog_search_elasticsearch8',
                'host' => 'elasticsearch8_server_hostname',
                'port' => 'elasticsearch8_server_port',
                'label' => 'Elasticsearch 8',
            ],
            [
                'key' => 'catalog_search_opensearch',
                'host' => 'opensearch_server_hostname',
                'port' => 'opensearch_server_port',
                'label' => 'OpenSearch',
            ],
        ];
        $out = [];
        foreach ($candidates as $c) {
            $host = trim((string) ($search[$c['host']] ?? ''));
            $port = $this->parsePort($search[$c['port']] ?? null);
            if ($host === '' || $port === null) {
                continue;
            }
            $out[] = [
                'service_key' => $c['key'],
                'label' => sprintf('%s — %s:%d', $c['label'], $host, $port),
                'host' => $host,
                'port' => $port,
            ];
        }

        return $out;
    }

    private function parsePort(mixed $value): ?int
    {
        if ($value === null || $value === '') {
            return null;
        }
        $n = (int) $value;

        return ($n >= 1 && $n <= 65535) ? $n : null;
    }
}