<?php

namespace App\BusProNet\XmlParser;

use App\BusProNet\Model\File;
use Symfony\Component\DomCrawler\Crawler;
use ZipStream\Exception as ZipException;
use ZipStream\ZipStream;

class DocumentsParser
{
    public function parseConfirmation(Crawler $result): ?File
    {
        $pdfData = $this->decode($result->filterXPath('//bestaetigungpdf'));

        return new File('bestaetigung.pdf', $pdfData, 'application/pdf');
    }

    public function parseDocuments(Crawler $result): ?File
    {
        $documents = $result->filterXPath('//reisedokumente/reisedokument');

        if (1 === $documents->count()) {
            $node = $documents->first();
            [$filename, $pdfData] = $this->getFileInfo($node);

            return new File($filename.'.pdf', $pdfData, 'application/pdf');
        }

        // In case of multiple documents create ZIP file
        $stream = fopen('php://temp', 'w+b');
        try {
            // Zero headers trip up some unzip clients, and the data is in memory anyway
            $zip = new ZipStream(
                outputStream: $stream,
                defaultEnableZeroHeader: false,
                sendHttpHeaders: false,
            );

            $documents->each(function (Crawler $node) use ($zip) {
                [$filename, $pdfData] = $this->getFileInfo($node);
                $zip->addFile($filename.'.pdf', $pdfData);
            });

            $zip->finish();
            rewind($stream);

            return new File('reisedokumente.zip', stream_get_contents($stream), 'application/zip');
        } catch (ZipException $e) {
            return null;
        } finally {
            fclose($stream);
        }
    }

    private function decode(Crawler $node): string
    {
        if (0 === $node->count()) {
            throw new \InvalidArgumentException('Missing PDF node in document response.');
        }

        $parts = explode(',', $node->text(), 2);
        if (2 !== count($parts)) {
            throw new \InvalidArgumentException('Invalid PDF payload in document response.');
        }

        [, $pdfData] = $parts;

        return base64_decode($pdfData);
    }

    /** @return array{string, string} */
    private function getFileInfo(Crawler $node): array
    {
        $pdfData = $this->decode($node->filterXPath('.//pdf'));
        $filenameNode = $node->filterXPath('.//datei');
        if (0 === $filenameNode->count()) {
            throw new \InvalidArgumentException('Missing filename node in document response.');
        }

        $filename = $filenameNode->text();

        return [$filename, $pdfData];
    }
}