<?php

namespace App\Services\Billing;

use App\Models\LegacyInvoice;
use Illuminate\Support\Carbon;
use Illuminate\Support\Str;
use Symfony\Component\HttpFoundation\Response;

class LegacyInvoicePdfRenderer
{
    public function inlineResponse(LegacyInvoice $invoice): Response
    {
        $pdf = $this->render($invoice);

        return response($pdf, Response::HTTP_OK, [
            'Content-Type' => 'application/pdf',
            'Content-Disposition' => 'inline; filename="'.$this->filename($invoice).'"',
            'Cache-Control' => 'private, max-age=0, must-revalidate',
        ]);
    }

    public function downloadResponse(LegacyInvoice $invoice): Response
    {
        $pdf = $this->render($invoice);

        return response()->streamDownload(
            static function () use ($pdf): void {
                echo $pdf;
            },
            $this->filename($invoice),
            [
                'Content-Type' => 'application/pdf',
                'Cache-Control' => 'private, max-age=0, must-revalidate',
            ],
        );
    }

    public function render(LegacyInvoice $invoice): string
    {
        $lines = $this->lines($invoice);
        $content = "BT\n/F1 11 Tf\n50 790 Td\n14 TL\n";

        foreach ($lines as $line) {
            $content .= '('.$this->escapePdfText($line).") Tj\nT*\n";
        }

        $content .= "ET\n";

        return $this->buildPdf($content);
    }

    public function filename(LegacyInvoice $invoice): string
    {
        $number = filled($invoice->number) ? (string) $invoice->number : (string) $invoice->legacy_id;
        $number = preg_replace('/[^A-Za-z0-9._-]/', '-', Str::ascii($number)) ?: (string) $invoice->id;

        $portal = preg_replace('/[^A-Za-z0-9._-]/', '-', Str::ascii($invoice->legacy_portal->label()));

        return "{$portal}-RNr-{$number}.pdf";
    }

    /**
     * @return list<string>
     */
    private function lines(LegacyInvoice $invoice): array
    {
        $payload = $invoice->pdf_payload ?? [];
        $billingAddress = data_get($payload, 'billing_address', []);
        $invoiceData = data_get($payload, 'invoice', $invoice->raw_snapshot ?? []);
        $invoice->loadMissing('user.profile');

        $isNetto = (bool) data_get($invoiceData, 'is_netto', false);
        $taxPercent = $this->taxPercent($invoice);
        $amount = $invoice->total_cents / 100;
        $netAmount = $isNetto ? $amount : $amount / (1 + ($taxPercent / 100));
        $taxAmount = $isNetto ? 0 : $amount - $netAmount;
        $servicePeriodBegin = $this->formatLegacyDate(data_get($invoiceData, 'service_period_begin_date'));
        $servicePeriodEnd = $this->formatLegacyDate(data_get($invoiceData, 'service_period_end_date'));
        $serviceName = data_get($payload, 'payment_option_translation.name')
            ?? data_get($payload, 'payment_option.article_number')
            ?? 'Legacy-Leistung';

        return array_values(array_filter([
            $invoice->legacy_portal->label(),
            'adametz.media, Kevin Adametz, In der Lake 4, 33739 Bielefeld',
            'www.businessportal24.com',
            str_repeat('-', 68),
            '',
            'Legacy-Rechnung',
            'Rechnungsdatum: '.$invoice->invoice_date?->format('d.m.Y'),
            '',
            'Rechnungsadresse',
            data_get($billingAddress, 'name'),
            data_get($billingAddress, 'title'),
            data_get($billingAddress, 'address'),
            trim((string) data_get($billingAddress, 'postal_code').' '.(string) data_get($billingAddress, 'city')),
            data_get($billingAddress, 'country_name'),
            $invoice->user?->profile?->tax_id_number ? 'UID-Nr.: '.$invoice->user->profile->tax_id_number : null,
            '',
            'Leistung: '.$serviceName.' auf '.$invoice->legacy_portal->label(),
            $servicePeriodBegin === $servicePeriodEnd
                ? 'Leistungsdatum: '.$servicePeriodBegin
                : 'Leistungszeitraum: '.$servicePeriodBegin.' - '.$servicePeriodEnd,
            'Rechnungsnummer: '.($invoice->number ?? '#'.$invoice->legacy_id),
            '',
            str_repeat('-', 68),
            'Rechnungsstellung: '.$invoice->invoice_date?->format('d.m.Y'),
            str_repeat('-', 68),
            'Netto: '.$this->formatEuro($netAmount),
            $isNetto ? null : 'MwSt. '.$taxPercent.'%: '.$this->formatEuro($taxAmount),
            str_repeat('-', 68),
            'Betrag: '.$this->formatEuro($amount),
            str_repeat('-', 68),
            '',
            'Zahlart: '.($invoice->payment_method ?? 'n/a'),
            'Status: '.($invoice->status ?? 'unknown'),
            $invoice->paid_at ? 'Bezahlt am: '.$invoice->paid_at->format('d.m.Y') : 'Faellig am: '.$invoice->due_date?->format('d.m.Y'),
            '',
            'Bitte ueberweisen Sie den Rechnungsbetrag unter Angabe der Rechnungsnummer '.($invoice->number ?? '#'.$invoice->legacy_id).'.',
            'Bankverbindung: Sparkasse Bielefeld, IBAN DE96 4805 0161 0065 0356 02, BIC SPBIDE3BXXX',
            $isNetto ? 'Reverse Charge: Steuerschuldnerschaft des Leistungsempfaengers.' : null,
            '',
            str_repeat('-', 68),
            'adametz.media | Tel: +49 5206 7076721 | Mail: info@businessportal24.com',
            'Steuernummer: 349 / 5001 / 4350 | USt-ID: DE298729654',
        ], fn (mixed $line): bool => $line !== null && $line !== ''));
    }

    private function taxPercent(LegacyInvoice $invoice): int
    {
        $invoiceDate = $invoice->invoice_date;

        if ($invoiceDate && $invoiceDate->betweenIncluded(Carbon::parse('2020-07-01'), Carbon::parse('2020-12-31'))) {
            return 16;
        }

        return 19;
    }

    private function formatLegacyDate(mixed $value): string
    {
        if (blank($value) || $value === '0000-00-00' || $value === '0000-00-00 00:00:00') {
            return 'n/a';
        }

        return Carbon::parse((string) $value)->format('d.m.Y');
    }

    private function formatEuro(float $amount): string
    {
        return number_format($amount, 2, ',', '.').' EUR';
    }

    private function buildPdf(string $content): string
    {
        $objects = [
            "1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n",
            "2 0 obj\n<< /Type /Pages /Kids [3 0 R] /Count 1 >>\nendobj\n",
            "3 0 obj\n<< /Type /Page /Parent 2 0 R /MediaBox [0 0 595 842] /Resources << /Font << /F1 4 0 R >> >> /Contents 5 0 R >>\nendobj\n",
            "4 0 obj\n<< /Type /Font /Subtype /Type1 /BaseFont /Helvetica >>\nendobj\n",
            "5 0 obj\n<< /Length ".strlen($content)." >>\nstream\n{$content}endstream\nendobj\n",
        ];

        $pdf = "%PDF-1.4\n";
        $offsets = [0];

        foreach ($objects as $object) {
            $offsets[] = strlen($pdf);
            $pdf .= $object;
        }

        $xrefOffset = strlen($pdf);
        $pdf .= "xref\n0 ".(count($objects) + 1)."\n";
        $pdf .= "0000000000 65535 f \n";

        foreach (array_slice($offsets, 1) as $offset) {
            $pdf .= sprintf("%010d 00000 n \n", $offset);
        }

        $pdf .= "trailer\n<< /Size ".(count($objects) + 1)." /Root 1 0 R >>\n";
        $pdf .= "startxref\n{$xrefOffset}\n%%EOF\n";

        return $pdf;
    }

    private function escapePdfText(string $text): string
    {
        $encoded = iconv('UTF-8', 'Windows-1252//TRANSLIT//IGNORE', $text);

        return str_replace(['\\', '(', ')'], ['\\\\', '\(', '\)'], $encoded ?: Str::ascii($text));
    }
}