<?php

namespace App\Http\Controllers\Api\Tenant;

use App\Http\Controllers\Controller;
use App\Models\Event;
use App\Models\EventJoinToken;
use App\Support\JoinTokenLayoutRegistry;
use Dompdf\Dompdf;
use Dompdf\Options;
use Illuminate\Http\Request;
use Illuminate\Support\Str;
use SimpleSoftwareIO\QrCode\Facades\QrCode;

class EventJoinTokenLayoutController extends Controller
{
    public function index(Request $request, Event $event, EventJoinToken $joinToken)
    {
        $this->ensureBelongsToEvent($event, $joinToken);

        $layouts = JoinTokenLayoutRegistry::toResponse(function (string $layoutId, string $format) use ($event, $joinToken) {
            return route('tenant.events.join-tokens.layouts.download', [
                'event' => $event,
                'joinToken' => $joinToken,
                'layout' => $layoutId,
                'format' => $format,
            ]);
        });

        return response()->json([
            'data' => $layouts,
        ]);
    }

    public function download(Request $request, Event $event, EventJoinToken $joinToken, string $layout, string $format)
    {
        $this->ensureBelongsToEvent($event, $joinToken);

        $layoutConfig = JoinTokenLayoutRegistry::find($layout);

        if (! $layoutConfig) {
            abort(404, 'Layout nicht gefunden.');
        }

        if (! in_array($format, ['pdf', 'svg'], true)) {
            abort(404, 'Unbekanntes Exportformat.');
        }

        $layoutConfig = $this->applyCustomization($layoutConfig, $joinToken);

        $tokenUrl = url('/e/'.$joinToken->token);

        $qrPngDataUri = 'data:image/png;base64,'.base64_encode(
            QrCode::format('png')
                ->margin(0)
                ->size($layoutConfig['qr']['size_px'])
                ->generate($tokenUrl)
        );

        $backgroundStyle = $this->buildBackgroundStyle($layoutConfig);
        $eventName = $this->resolveEventName($event);

        $viewData = [
            'layout' => $layoutConfig,
            'event' => $event,
            'eventName' => $eventName,
            'token' => $joinToken,
            'tokenUrl' => $tokenUrl,
            'qrPngDataUri' => $qrPngDataUri,
            'backgroundStyle' => $backgroundStyle,
            'customization' => $joinToken->metadata['layout_customization'] ?? null,
        ];

        $filename = sprintf('%s-%s.%s', Str::slug($eventName ?: 'event'), $layoutConfig['id'], $format);

        if ($format === 'svg') {
            $svg = view('layouts.join-token.svg', $viewData)->render();

            return response($svg)
                ->header('Content-Type', 'image/svg+xml')
                ->header('Content-Disposition', 'attachment; filename="'.$filename.'"');
        }

        $html = view('layouts.join-token.pdf', $viewData)->render();

        $options = new Options;
        $options->set('isHtml5ParserEnabled', true);
        $options->set('isRemoteEnabled', true);
        $options->set('defaultFont', 'Helvetica');

        $dompdf = new Dompdf($options);
        $dompdf->setPaper(strtoupper($layoutConfig['paper']), $layoutConfig['orientation'] === 'landscape' ? 'landscape' : 'portrait');
        $dompdf->loadHtml($html, 'UTF-8');
        $dompdf->render();

        return response($dompdf->output())
            ->header('Content-Type', 'application/pdf')
            ->header('Content-Disposition', 'attachment; filename="'.$filename.'"');
    }

    private function ensureBelongsToEvent(Event $event, EventJoinToken $joinToken): void
    {
        if ($joinToken->event_id !== $event->id) {
            abort(404);
        }
    }

    private function resolveEventName(Event $event): string
    {
        $name = $event->name;

        if (is_array($name)) {
            $locale = $event->default_locale ?? 'de';

            return $name[$locale] ?? $name['de'] ?? reset($name) ?: 'Event';
        }

        return is_string($name) && $name !== '' ? $name : 'Event';
    }

    private function applyCustomization(array $layout, EventJoinToken $joinToken): array
    {
        $customization = data_get($joinToken->metadata, 'layout_customization');

        if (! is_array($customization)) {
            return $layout;
        }

        $layoutId = $customization['layout_id'] ?? null;
        if (is_string($layoutId) && isset($layout['id']) && $layoutId !== $layout['id']) {
            // Allow customization to target a specific layout; if mismatch, skip style overrides.
            // General text overrides are still applied below.
        }

        $colorKeys = [
            'accent' => 'accent_color',
            'text' => 'text_color',
            'background' => 'background_color',
            'secondary' => 'secondary_color',
            'badge' => 'badge_color',
        ];

        foreach ($colorKeys as $layoutKey => $customKey) {
            if (isset($customization[$customKey]) && is_string($customization[$customKey])) {
                $layout[$layoutKey] = $customization[$customKey];
            }
        }

        if (isset($customization['background_gradient']) && is_array($customization['background_gradient'])) {
            $layout['background_gradient'] = $customization['background_gradient'];
        }

        foreach (['headline' => 'name', 'subtitle', 'description', 'badge_label', 'instructions_heading', 'link_heading', 'cta_label', 'cta_caption', 'link_label'] as $customKey => $layoutKey) {
            if (isset($customization[$customKey]) && is_string($customization[$customKey])) {
                $layout[$layoutKey] = $customization[$customKey];
            }
        }

        if (array_key_exists('instructions', $customization) && is_array($customization['instructions'])) {
            $layout['instructions'] = array_values(array_filter($customization['instructions'], fn ($value) => is_string($value) && trim($value) !== ''));
        }

        if (! empty($customization['logo_data_url']) && is_string($customization['logo_data_url'])) {
            $layout['logo_url'] = $customization['logo_data_url'];
        } elseif (! empty($customization['logo_url']) && is_string($customization['logo_url'])) {
            $layout['logo_url'] = $customization['logo_url'];
        }

        return $layout;
    }

    private function buildBackgroundStyle(array $layout): string
    {
        $gradient = $layout['background_gradient'] ?? null;

        if (is_array($gradient) && ! empty($gradient['stops'])) {
            $angle = $gradient['angle'] ?? 180;
            $stops = implode(',', $gradient['stops']);

            return sprintf('linear-gradient(%ddeg,%s)', $angle, $stops);
        }

        return $layout['background'] ?? '#FFFFFF';
    }
}