<?php
declare(strict_types=1);

namespace Esun3d\LanguageUrlStoreResolver\Observer;

use Esun3d\LanguageUrlStoreResolver\Model\Config;
use Esun3d\LanguageUrlStoreResolver\Model\HtmlLinkProcessor;
use Esun3d\LanguageUrlStoreResolver\Model\StoreCodeMapper;
use Magento\Framework\App\Response\Http as HttpResponse;
use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Magento\Store\Model\StoreManagerInterface;
use Psr\Log\LoggerInterface;

class RewritePageLinksObserver implements ObserverInterface
{
    /**
     * @var Config
     */
    private $config;

    /**
     * @var HtmlLinkProcessor
     */
    private $htmlLinkProcessor;

    /**
     * @var StoreManagerInterface
     */
    private $storeManager;

    /**
     * @var StoreCodeMapper
     */
    private $storeCodeMapper;

    /**
     * @var LoggerInterface
     */
    private $logger;

    /**
     * @param Config $config
     * @param HtmlLinkProcessor $htmlLinkProcessor
     * @param StoreManagerInterface $storeManager
     * @param StoreCodeMapper $storeCodeMapper
     * @param LoggerInterface $logger
     */
    public function __construct(
        Config $config,
        HtmlLinkProcessor $htmlLinkProcessor,
        StoreManagerInterface $storeManager,
        StoreCodeMapper $storeCodeMapper,
        LoggerInterface $logger
    ) {
        $this->config = $config;
        $this->htmlLinkProcessor = $htmlLinkProcessor;
        $this->storeManager = $storeManager;
        $this->storeCodeMapper = $storeCodeMapper;
        $this->logger = $logger;
    }

    /**
     * Rewrite internal links after the complete frontend page is rendered.
     *
     * @param Observer $observer
     * @return void
     */
    public function execute(Observer $observer): void
    {
        if (!$this->config->isEnabled()) {
            return;
        }

        $response = $observer->getData('response');
        if (!$response instanceof HttpResponse) {
            return;
        }

        $body = (string)$response->getBody();
        if (stripos($body, '<html') === false || stripos($body, '<a') === false) {
            return;
        }

        try {
            $storeCode = (string)$this->storeManager->getStore()->getCode();
            $language = $this->storeCodeMapper->languageFromStoreCode($storeCode);
            if ($language === null) {
                return;
            }

            $response->setBody($this->htmlLinkProcessor->process($body, $language));
        } catch (\Throwable $exception) {
            $this->logger->error(
                '[LanguageUrlStoreResolver] Failed to convert links in page HTML.',
                ['exception' => $exception]
            );
        }
    }
}