<?php
namespace Mince;

use stdClass;
use Index\Http\{HttpResponseBuilder,HttpRequest};
use Index\Http\Routing\IRouter;
use Ramsey\Uuid\{Uuid,UuidInterface};

final class MojangInterop {
    private const API_SERVER = 'https://api.mojang.com';
    private const SESSION_SERVER = 'https://sessionserver.mojang.com';

    public static function currentTime(): int {
        return (int)(microtime(true) * 1000);
    }

    public static function nameUUIDFromBytes(string $data): UuidInterface {
        $bytes = hash('md5', $data, true);
        $bytes[6] = chr((ord($bytes[6]) & 0x0F) | 0x30); // set version 3
        $bytes[8] = chr((ord($bytes[8]) & 0x3F) | 0x80); // set IETF variant
        return Uuid::fromBytes($bytes);
    }

    public static function createOfflinePlayerUUID(string $name): UuidInterface {
        return self::nameUUIDFromBytes(sprintf('OfflinePlayer:%s', $name));
    }

    public static function isOfflineId(UuidInterface $uuid): bool {
        return $uuid->getVersion() === 3;
    }

    public static function isMojangId(UuidInterface $uuid): bool {
        return $uuid->getVersion() === 4;
    }

    public static function registerRoutes(IRouter $router): void {
        $router->get('/uuid', fn($response, $request) => self::uuidResolver($response, $request));
        $router->get('/blockedservers', fn($response, $request) => self::proxyBlockServers($response, $request));

        // figure out how to proxy these someday to keep online mode working transparently
        $router->get('/session/minecraft/hasJoined', fn() => 501);
        $router->post('/session/minecraft/join', fn() => 501);
    }

    public static function uuidResolver(HttpResponseBuilder $response, HttpRequest $request): string {
        $response->setTypePlain();
        $uuid = self::createOfflinePlayerUUID((string)$request->getParam('name'));

        return (string)match((string)$request->getParam('mode')) {
            'str' => $uuid->toString(),
            'urn' => $uuid->getUrn(),
            'raw' => $uuid->getBytes(),
            'int' => $uuid->getInteger(),
            default => $uuid->getHex(),
        };
    }

    public static function getRequest(string $url, string $userAgent): object {
        $out = new stdClass;
        $curl = curl_init($url);
        curl_setopt_array($curl, [
            CURLOPT_AUTOREFERER => true,
            CURLOPT_FAILONERROR => false,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TCP_NODELAY => true,
            CURLOPT_HEADER => true,
            CURLOPT_NOBODY => false,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TCP_FASTOPEN => true,
            CURLOPT_CONNECTTIMEOUT => 2,
            CURLOPT_PROTOCOLS =>  CURLPROTO_HTTPS,
            CURLOPT_TIMEOUT => 5,
            CURLOPT_USERAGENT => $userAgent,
        ]);
        [$out->headers, $out->body] = explode("\r\n\r\n", curl_exec($curl));
        curl_close($curl);

        $out->headers = explode("\r\n", $out->headers);
        $out->status = explode(' ', array_shift($out->headers), 3);

        return $out;
    }

    public static function sessionServerGetRequest(string $path, string $userAgent): object {
        return self::getRequest(self::SESSION_SERVER . $path, $userAgent);
    }

    public static function apiServerGetRequest(string $path, string $userAgent): object {
        return self::getRequest(self::API_SERVER . $path, $userAgent);
    }

    public static function getBlockedServersRaw(string $userAgent): object {
        return self::sessionServerGetRequest('/blockedservers', $userAgent);
    }

    public static function proxyBlockServers(HttpResponseBuilder $response, HttpRequest $request): string {
        $info = self::getBlockedServersRaw($request->getHeaderLine('User-Agent'));
        $response->setStatusCode((int)$info->status[1]);
        $response->setCacheControl('max-age=300');

        foreach($info->headers as $header) {
            [$name, $value] = explode(':', $header);
            $name = strtolower(trim($name));
            if(str_starts_with($name, 'x-') || $name === 'content-type')
                $response->setHeader($name, $value);
        }

        return $info->body;
    }

    public static function getMinecraftUUIDRaw(string $userName, string $userAgent): object {
        return self::apiServerGetRequest(sprintf('/users/profiles/minecraft/%s', $userName), $userAgent);
    }

    public static function getMinecraftUUID(string $userName, string $userAgent): ?object {
        $info = self::getMinecraftUUIDRaw($userName, $userAgent);
        if($info->status[1] !== '200')
            return null;

        return json_decode($info->body);
    }

    public static function getSessionMinecraftProfileRaw(string $uuid, string $userAgent): object {
        return self::sessionServerGetRequest(sprintf('/session/minecraft/profile/%s', $uuid), $userAgent);
    }

    public static function getSessionMinecraftProfile(string $uuid, string $userAgent): ?object {
        $info = self::getSessionMinecraftProfileRaw($uuid, $userAgent);
        if($info->status[1] !== '200')
            return null;

        return json_decode($info->body);
    }

    public static function proxySessionMinecraftProfile(HttpResponseBuilder $response, HttpRequest $request, string $uuid): string {
        $info = self::getSessionMinecraftProfileRaw($uuid, $request->getHeaderLine('User-Agent'));
        $response->setStatusCode((int)$info->status[1]);
        $response->setCacheControl('max-age=30');

        foreach($info->headers as $header) {
            [$name, $value] = explode(':', $header);
            $name = strtolower(trim($name));
            if(str_starts_with($name, 'x-') || $name === 'content-type')
                $response->setHeader($name, $value);
        }

        return $info->body;
    }
}