<?php

declare(strict_types=1);

namespace App\Controller\Voucher;

use App\BusProNet\Client\VoucherClient;
use App\BusProNet\Exception\ApiClientException;
use App\BusProNet\Model\Notification;
use App\Exception\VoucherSessionNotFoundException;
use App\Exception\VoucherShopUnavailableException;
use App\Form\Model\VoucherPurchaseDto;
use App\Form\VoucherPurchaseStep1Type;
use App\Service\VoucherPurchaseSessionManager;
use App\Service\VoucherTemplateProvider;
use App\Service\VoucherThumbnailResolver;
use Psr\Log\LoggerInterface;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\ResponseHeaderBag;
use Symfony\Component\Routing\Attribute\Route;
use Symfony\Component\Validator\Validator\ValidatorInterface;

/**
 * Step 1: design, von/für and value, with a PDF preview rendered by BusPro.
 */
class Step1Controller extends AbstractVoucherPurchaseController
{
    public function __construct(
        VoucherPurchaseSessionManager $sessionManager,
        VoucherThumbnailResolver $thumbnailResolver,
        private readonly VoucherTemplateProvider $templateProvider,
        private readonly VoucherClient $voucherClient,
        private readonly ValidatorInterface $validator,
        private readonly LoggerInterface $logger,
    ) {
        parent::__construct($sessionManager, $thumbnailResolver);
    }

    #[Route('/vouchers/create/design', name: 'app_voucher_step_1')]
    public function index(Request $request): Response
    {
        $dto = $this->sessionManager->find($request);
        if (null === $dto) {
            return $this->createSessionExpiredResponse($request);
        }

        try {
            $form = $this->createStepForm($dto);
        } catch (VoucherShopUnavailableException) {
            return $this->createShopUnavailableResponse($request);
        }

        $form->handleRequest($request);

        if (true === $form->isSubmitted() && true === $form->isValid()) {
            $dto->currentStep = 2;
            $this->sessionManager->save($request, $dto);

            return $this->redirectToRoute('app_voucher_step_2');
        }

        return $this->renderStep($dto, $form);
    }

    /**
     * Takes over the current input without validating it and refreshes the summary.
     */
    #[Route('/vouchers/create/refresh', name: 'app_voucher_step_1_refresh', methods: ['POST'])]
    public function refresh(Request $request): Response
    {
        $dto = $this->sessionManager->find($request);
        if (null === $dto) {
            return $this->createSessionExpiredResponse($request);
        }

        try {
            $form = $this->createStepForm($dto, false);
        } catch (VoucherShopUnavailableException) {
            return $this->createShopUnavailableResponse($request);
        }

        $form->handleRequest($request);
        $this->sessionManager->save($request, $dto);

        return $this->htmxOobResponse('voucher/step_1.html.twig', ['voucher_summary'], [
            ...$this->createStepContext($dto),
            'form' => $form->createView(),
        ]);
    }

    /**
     * Takes over the current input like refresh() and opens the preview modal, whose frame loads
     * the PDF from previewPdf().
     */
    #[Route('/vouchers/create/preview', name: 'app_voucher_preview', methods: ['POST'])]
    public function preview(Request $request): Response
    {
        $dto = $this->sessionManager->find($request);
        if (null === $dto) {
            return $this->createSessionExpiredResponse($request);
        }

        try {
            $form = $this->createStepForm($dto, false);
        } catch (VoucherShopUnavailableException) {
            return $this->createShopUnavailableResponse($request);
        }

        $form->handleRequest($request);
        $this->sessionManager->save($request, $dto);

        return $this->render('voucher/modal_preview.html.twig', [
            'previewable' => $this->isPreviewable($dto),
            // busts the browser cache of the frame, the URL is otherwise the same for every input
            'previewVersion' => bin2hex(random_bytes(4)),
        ]);
    }

    #[Route('/vouchers/create/preview.pdf', name: 'app_voucher_preview_pdf', methods: ['GET'])]
    public function previewPdf(Request $request): Response
    {
        try {
            $dto = $this->sessionManager->get($request);
        } catch (VoucherSessionNotFoundException) {
            return $this->createPreviewErrorResponse('Deine Sitzung ist abgelaufen. Bitte starte den Gutscheinkauf neu.');
        }

        if (false === $this->isPreviewable($dto)) {
            return $this->createPreviewErrorResponse('Für die Vorschau bitte zuerst Motiv, Von, Für und Gutscheinwert angeben.');
        }

        // Read-only from here on: release the session lock, so the page's other requests do not
        // wait the seconds BusPro takes to render the PDF.
        $request->getSession()->save();

        try {
            $preview = $this->voucherClient->getVoucherPreview($dto);
        } catch (ApiClientException $e) {
            $this->logger->error('Voucher preview failed', ['error' => $e->getMessage()]);

            return $this->createPreviewErrorResponse('Die Vorschau ist gerade nicht verfügbar. Bitte versuche es später noch einmal.');
        }

        if ($preview instanceof Notification) {
            $this->logger->warning('Voucher preview rejected', ['code' => $preview->code, 'message' => $preview->message]);

            return $this->createPreviewErrorResponse($preview->message ?? 'Die Vorschau ist gerade nicht verfügbar.');
        }

        $response = new Response($preview->pdf, Response::HTTP_OK, ['Content-Type' => 'application/pdf']);
        $response->headers->set('Content-Disposition', $response->headers->makeDisposition(
            ResponseHeaderBag::DISPOSITION_INLINE,
            'gutschein-vorschau.pdf'
        ));
        $response->setPrivate();
        $response->headers->addCacheControlDirective('no-store');

        return $response;
    }

    /**
     * @return FormInterface<VoucherPurchaseDto>
     *
     * @throws VoucherShopUnavailableException
     */
    private function createStepForm(VoucherPurchaseDto $dto, bool $validate = true): FormInterface
    {
        $templates = $this->templateProvider->getTemplates();

        $options = [
            'templates' => $templates->templates,
            'min_amount' => $dto->minAmount,
            'max_amount' => $dto->maxAmount,
        ];
        if (false === $validate) {
            $options['validation_groups'] = false;
        }

        return $this->createForm(VoucherPurchaseStep1Type::class, $dto, $options);
    }

    /**
     * @param FormInterface<VoucherPurchaseDto> $form
     */
    private function renderStep(VoucherPurchaseDto $dto, FormInterface $form): Response
    {
        $templates = $this->templateProvider->getTemplates();

        return $this->render('voucher/step_1.html.twig', [
            ...$this->createStepContext($dto),
            'form' => $form,
            'thumbnails' => $this->thumbnailResolver->resolveAll($templates->templates),
            'previewable' => $this->isPreviewable($dto),
        ]);
    }

    /**
     * The preview takes what step 1 accepts: BusPro refuses it without the names (604/605), and
     * this keeps the button and the route to one rule, the step's own validation group.
     */
    private function isPreviewable(VoucherPurchaseDto $dto): bool
    {
        return 0 === \count($this->validator->validate($dto, null, ['voucher_step_1']));
    }

    private function createShopUnavailableResponse(Request $request): Response
    {
        $this->addFlash('error', 'Gutscheine können gerade nicht gekauft werden. Bitte versuche es später noch einmal.');

        return $this->htmxRedirect($request, $this->generateUrl('app_voucher_error'));
    }

    private function createPreviewErrorResponse(string $message): Response
    {
        return $this->render('voucher/preview_error.html.twig', ['message' => $message], new Response('', Response::HTTP_UNPROCESSABLE_ENTITY));
    }
}