<?php

namespace App;

use JumPHP\Kernel\Platform;
use JumPHP\Net\RuntimeLink;
use JumPHP\Net\Tcp;
use JumPHP\Net\TcpConnection;
use JumPHP\Runtime\RuntimeClient;
use JumPHP\Tauri\App;
use JumPHP\Tauri\AppMain;
use JumPHP\Tauri\BrowserRuntime;

/**
 * IDE Remote, PHP side. The pages do the crypto and the protocol (ui/js/channel.js); PHP only
 *  - gives the page its settings and texts (`settings`, `strings`),
 *  - is the page's TCP socket for the DIRECT mode (`direct.open|write|close`, events `direct`): through
 *    JumPHP\Net\Tcp, so it is a plain socket on the desktop and the JumPHP runtime in a browser (rule 4 of AGENTS.md),
 *  - tells the page what the JumPHP runtime says (`runtime.state`, `runtime.pair`).
 * Bytes cross as base64 and stay ciphertext: PHP never sees a key.
 */
final class Main implements AppMain
{
    public const RELAY_DEFAULT = 'wss://jumphp.net/ide-relay/ws';

    /** @var array<string, TcpConnection> */
    private array $connections = [];
    private ?RuntimeClient $client = null;

    public function boot(App $app): void
    {
        $tcp = new Tcp($app->config, $app->http(), fn (): RuntimeLink => $this->runtimeLink($app));
        $app->gameLoop->addPeriodicTimer(0.02, fn () => $tcp->poll());

        $app->command('settings', fn (mixed $p): array => $this->settings($app));
        $app->command('strings', fn (mixed $p): array => $app->config->file('lang.yaml'));

        $app->command('direct.open', function (mixed $p) use ($app, $tcp): array {
            $p = is_array($p) ? $p : [];
            $id = (string)($p['id'] ?? '');
            $host = (string)($p['host'] ?? '');
            $port = (int)($p['port'] ?? 0);
            if ($id === '' || !self::validTarget($host, $port)) {
                return ['ok' => false, 'error' => 'bad target'];
            }
            $c = $tcp->connect($host, $port, 3.0);
            $this->connections[$id] = $c;
            $send = fn (string $type, array $more = []) => $app->send('direct', ['id' => $id, 'type' => $type] + $more);
            $c->on('open', fn () => $send('open'));
            $c->on('data', fn (string $d) => $send('data', ['data' => base64_encode($d)]));
            $c->on('error', fn (string $m) => $send('error', ['message' => $m]));
            $c->on('close', function (?string $why) use ($id, $send): void {
                unset($this->connections[$id]);
                $send('close', ['message' => (string)$why]);
            });
            return ['ok' => true];
        });
        $app->command('direct.write', function (mixed $p): bool {
            $c = $this->connections[(string)($p['id'] ?? '')] ?? null;
            $bytes = base64_decode((string)($p['data'] ?? ''), true);
            if ($c === null || $bytes === false) {
                return false;
            }
            $c->write($bytes);
            return true;
        });
        $app->command('direct.close', function (mixed $p): bool {
            $c = $this->connections[(string)($p['id'] ?? '')] ?? null;
            $c?->close();
            return $c !== null;
        });

        $app->command('runtime.state', fn (mixed $p): array => ['state' => $this->runtimeLink($app)->state()]);
        $app->command('runtime.pair', function (mixed $p) use ($app) {
            $client = $this->runtimeLink($app);
            return $client instanceof RuntimeClient ? $client->pair($app->config->id(), $app->config->title()) : false;
        });
    }

    /** @return array{relay_url:string, net_mode:string, native:bool, version:string, direct_head_start:float} */
    public function settings(App $app): array
    {
        $relay = (string)$app->config->get('ide_relay_url', self::RELAY_DEFAULT);
        return [
            'relay_url' => $relay !== '' ? $relay : self::RELAY_DEFAULT,
            'net_mode' => $app->config->netMode(),
            'native' => !Platform::isWasm(),
            'version' => (string)$app->config->get('version', ''),
            'direct_head_start' => 1.5,
        ];
    }

    /** A LAN or IPv6 literal / name and a real port: nothing else may be dialled from here. */
    public static function validTarget(string $host, int $port): bool
    {
        return $port >= 1 && $port <= 65535 && preg_match('/^[A-Za-z0-9._:\-]{1,253}$/', $host) === 1;
    }

    /** In the browser: the client of the JumPHP runtime (looks for it by itself); elsewhere NoRuntime-like behaviour (plain sockets). */
    private function runtimeLink(App $app): RuntimeLink
    {
        if ($this->client === null && $app->runtime() instanceof BrowserRuntime && Platform::isWasm()) {
            $this->client = new RuntimeClient($app->runtime()->bridge, $app->config);
            $client = $this->client;
            $app->gameLoop->addPeriodicTimer(0.05, fn () => $client->update(0.05));
            $client->autoConnect();
        }
        return $this->client ?? new \JumPHP\Net\NoRuntime();
    }
}