<?php

namespace App\Services;

use ErrorException;
use GuzzleHttp\Client;
use GuzzleHttp\Exception\RequestException;

class Translate
{
    /**
     * @var Client HTTP Client
     */
    protected $client;

    /**
     * @var string|null Source language - from where the page should be translated
     */
    protected $source;

    /**
     * @var string Target language - to which language page should be translated
     */
    protected $target;

    /**
     * @var string Url what need to be translated
     */
    protected $url;

    const IFRAME_REGEX = '**some regex**';

    const URL_REGEX = '**some regex**';

    public function __construct(string $target = 'en', string $source = null)
    {
        $this->client = new Client();
        $this->setSource($source)
            ->setTarget($target);
    }

    public function setTarget(string $target) : self
    {
        $this->target = $target;
        return $this;
    }

    public function setSource(string $source = null) : self
    {
        $this->source = $source ?? 'auto';
        return $this;
    }

    public function setUrl(string $url) : self
    {
        $this->url = $url;
        return $this;
    }

    public function translate()
    {
        try {
            $response = $this->client->get(
                sprintf("example.com?hl=%s&sl=%s&u=%s",
                    $this->target,
                    $this->source,
                    $this->url
                )
            );
            $body = $response->getBody();

            //Find iframe url
            preg_match(self::IFRAME_REGEX, $body, $matches);
            $iframeUrl = $matches[1];

            //Send request to iframe url
            $response = $this->client->get($iframeUrl);
            $body = $response->getBody();

            //Find translated page url
            preg_match(self::URL_REGEX, $body, $matches);
            $pageUrl = preg_replace('|&amp;|', '&', $matches[1]);

            $response = $this->client->get($pageUrl);
            $body = $response->getBody();

            return $this->formatBody($body);
        } catch (RequestException $e) {
            throw new ErrorException($e->getMessage());
        }
    }

    private function formatBody(string $body)
    {
        return iconv("Windows-1251", "UTF-8", $body);
    }
}