<?php

namespace App\Services\Qr;

use App\Models\QrCode;
use App\Models\QrDocument;
use App\Models\QrWallet;
use App\Models\User;
use App\Support\Qr\QrStyleDefaults;
use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Str;
use RuntimeException;

class QrCodeManagerService
{
    public function __construct(
        private QrWalletBillingService $billing,
        private QrImageGeneratorService $imageGenerator,
        private QrPayloadValidator $payloadValidator,
    ) {}

    public function walletFor(User $user): QrWallet
    {
        return $user->qrWallet()->firstOrCreate(
            [],
            ['credit_balance' => 0, 'status' => QrWallet::STATUS_ACTIVE],
        );
    }

    /**
     * @param  array<string, mixed>  $data
     */
    public function create(User $user, array $data): QrCode
    {
        $wallet = $this->walletFor($user);
        $type = (string) ($data['type'] ?? '');

        if (! in_array($type, [QrCode::TYPE_PAYMENT, QrCode::TYPE_SHOP], true) && ! $wallet->canCreateQr()) {
            throw new RuntimeException('Add at least GHS ' . number_format(QrWallet::pricePerQr(), 2) . ' to your QR wallet before creating codes.');
        }

        $validated = $this->payloadValidator->validateForCreate($type, $data);
        $style = in_array($type, [QrCode::TYPE_PAYMENT, QrCode::TYPE_SHOP], true)
            ? QrStyleDefaults::defaults()
            : QrStyleDefaults::merge($data['style'] ?? null);

        return DB::transaction(function () use ($user, $wallet, $data, $type, $validated, $style) {
            $documentId = null;
            $content = $validated['content'];

            if ($type === QrCode::TYPE_DOCUMENT) {
                $file = $data['document'] ?? null;
                if (! $file instanceof UploadedFile) {
                    throw new RuntimeException('A PDF document is required for PDF QR codes.');
                }
                $documentId = $this->storeDocument($user, $file, $data['label'] ?? 'Document')->id;
            }

            if ($type === QrCode::TYPE_IMAGE) {
                $images = $this->storeImages($user, $data);
                $content['images'] = $images;
            }

            if ($type === QrCode::TYPE_VCARD && ($data['avatar'] ?? null) instanceof UploadedFile) {
                $content['avatar_path'] = $this->storeVcardAvatar($user, $data['avatar']);
            }

            if ($type === QrCode::TYPE_BOOKING) {
                if (($data['menu_logo'] ?? null) instanceof UploadedFile) {
                    $content['logo_path'] = $this->storeMenuBrandImage($user, $data['menu_logo'], 'menu-logos');
                }
                if (($data['menu_cover'] ?? null) instanceof UploadedFile) {
                    $content['cover_path'] = $this->storeMenuBrandImage($user, $data['menu_cover'], 'menu-covers');
                }
            }

            if ($type === QrCode::TYPE_APP && ($data['app_icon'] ?? null) instanceof UploadedFile) {
                $content['icon_path'] = $this->storeMenuBrandImage($user, $data['app_icon'], 'app-icons');
            }

            if (in_array($type, [QrCode::TYPE_MENU, QrCode::TYPE_SHOP], true)) {
                $content['sections'] = $this->injectItemImages($user, $content['sections'] ?? [], $data, $type);
                if (($data['menu_logo'] ?? null) instanceof UploadedFile) {
                    $content['logo_path'] = $this->storeMenuBrandImage($user, $data['menu_logo'], 'menu-logos');
                }
                if (($data['menu_cover'] ?? null) instanceof UploadedFile) {
                    $content['cover_path'] = $this->storeMenuBrandImage($user, $data['menu_cover'], 'menu-covers');
                }
            }

            if ($type === QrCode::TYPE_BUSINESS) {
                if (($data['business_logo'] ?? null) instanceof UploadedFile) {
                    $content['logo_path'] = $this->storeMenuBrandImage($user, $data['business_logo'], 'business-logos');
                }
                if (($data['business_cover'] ?? null) instanceof UploadedFile) {
                    $content['cover_path'] = $this->storeMenuBrandImage($user, $data['business_cover'], 'business-covers');
                }
            }

            if ($type === QrCode::TYPE_SHOP) {
                if (($data['church_logo'] ?? null) instanceof UploadedFile) {
                    $content['logo_path'] = $this->storeMenuBrandImage($user, $data['church_logo'], 'menu-logos');
                }
                if (($data['church_cover'] ?? null) instanceof UploadedFile) {
                    $content['cover_path'] = $this->storeMenuBrandImage($user, $data['church_cover'], 'menu-covers');
                }
            }

            if ($type === QrCode::TYPE_EVENT) {
                if (($data['event_logo'] ?? null) instanceof UploadedFile) {
                    $content['logo_path'] = $this->storeMenuBrandImage($user, $data['event_logo'], 'event-logos');
                }
                if (($data['event_cover'] ?? null) instanceof UploadedFile) {
                    $content['cover_path'] = $this->storeMenuBrandImage($user, $data['event_cover'], 'event-covers');
                }
            }

            if ($type === QrCode::TYPE_ITINERARY && ($data['itinerary_cover'] ?? null) instanceof UploadedFile) {
                $content['cover_path'] = $this->storeMenuBrandImage($user, $data['itinerary_cover'], 'itinerary-covers');
            }

            if ($type === QrCode::TYPE_PAYMENT && ($data['payment_logo'] ?? null) instanceof UploadedFile) {
                $content['logo_path'] = $this->storeMenuBrandImage($user, $data['payment_logo'], 'payment-logos');
            }

            if ($style['logo_path'] === null && ($data['logo'] ?? null) instanceof UploadedFile && $type !== QrCode::TYPE_PAYMENT) {
                $style['logo_path'] = $this->storeLogo($user, $data['logo']);
            }

            $shortCode = (isset($data['custom_short_code']) && $data['custom_short_code'] !== '')
                ? (string) $data['custom_short_code']
                : $this->generateUniqueShortCode();

            $payload = [
                'content' => $content,
                'style' => $style,
            ];

            // Freeze the WiFi auto-join payload so the printed code never changes on edit.
            if ($type === QrCode::TYPE_WIFI) {
                $payload['wifi_encoded'] = \App\Support\Qr\QrWifiPayload::encode($content);
            }

            $qrCode = QrCode::create([
                'user_id' => $user->id,
                'short_code' => $shortCode,
                'type' => $type,
                'label' => trim((string) $data['label']),
                'destination_url' => $validated['destination_url'],
                'qr_document_id' => $documentId,
                'payload' => $payload,
                'is_active' => true,
                'destination_updated_at' => now(),
            ]);

            if (! in_array($type, [QrCode::TYPE_PAYMENT, QrCode::TYPE_SHOP], true)) {
                $this->billing->debitForQrCreation($wallet, $qrCode);
            }
            $this->imageGenerator->generateAndStore($qrCode);

            return $qrCode->fresh(['document']);
        });
    }

    /**
     * @param  array<string, mixed>  $data
     */
    public function update(QrCode $qrCode, array $data): QrCode
    {
        $content = $qrCode->content();
        $style = $qrCode->style();
        $destinationUrl = $qrCode->destination_url;
        $regenerate = false;

        if (isset($data['label']) && trim((string) $data['label']) !== '') {
            $qrCode->label = trim((string) $data['label']);
        }

        if (array_key_exists('is_active', $data)) {
            $qrCode->is_active = (bool) $data['is_active'];
        }

        $typeFields = array_merge($content, $data);
        if ($this->hasContentChanges($qrCode, $data)) {
            $validated = $this->payloadValidator->validateForUpdate($qrCode, $typeFields);
            $content = $validated['content'];
            $destinationUrl = $validated['destination_url'];
            $qrCode->destination_updated_at = now();
        }

        if ($qrCode->isDocumentType() && isset($data['document']) && $data['document'] instanceof UploadedFile) {
            $document = $this->storeDocument($qrCode->user, $data['document'], $data['label'] ?? $qrCode->label);
            $qrCode->qr_document_id = $document->id;
            $qrCode->destination_updated_at = now();
        }

        if ($qrCode->isImageType()) {
            $newImages = $this->storeImages($qrCode->user, $data, false);
            if ($newImages !== []) {
                $content['images'] = array_merge($content['images'] ?? [], $newImages);
                $qrCode->destination_updated_at = now();
            }
        }

        if ($qrCode->type === QrCode::TYPE_VCARD && ($data['avatar'] ?? null) instanceof UploadedFile) {
            if ($oldPath = $content['avatar_path'] ?? null) {
                Storage::disk('qr')->delete($oldPath);
            }
            $content['avatar_path'] = $this->storeVcardAvatar($qrCode->user, $data['avatar']);
        }

        if ($qrCode->type === QrCode::TYPE_BOOKING) {
            if (($data['menu_logo'] ?? null) instanceof UploadedFile) {
                $content['logo_path'] = $this->storeMenuBrandImage($qrCode->user, $data['menu_logo'], 'menu-logos');
            }
            if (($data['menu_cover'] ?? null) instanceof UploadedFile) {
                $content['cover_path'] = $this->storeMenuBrandImage($qrCode->user, $data['menu_cover'], 'menu-covers');
            }
        }

        if ($qrCode->type === QrCode::TYPE_APP && ($data['app_icon'] ?? null) instanceof UploadedFile) {
            $content['icon_path'] = $this->storeMenuBrandImage($qrCode->user, $data['app_icon'], 'app-icons');
        }

        if (in_array($qrCode->type, [QrCode::TYPE_MENU, QrCode::TYPE_SHOP], true)) {
            $content['sections'] = $this->injectItemImages($qrCode->user, $content['sections'] ?? [], $data, $qrCode->type);
            if (($data['menu_logo'] ?? null) instanceof UploadedFile) {
                $content['logo_path'] = $this->storeMenuBrandImage($qrCode->user, $data['menu_logo'], 'menu-logos');
            }
            if (($data['menu_cover'] ?? null) instanceof UploadedFile) {
                $content['cover_path'] = $this->storeMenuBrandImage($qrCode->user, $data['menu_cover'], 'menu-covers');
            }
        }

        if ($qrCode->type === QrCode::TYPE_BUSINESS) {
            if (($data['business_logo'] ?? null) instanceof UploadedFile) {
                $content['logo_path'] = $this->storeMenuBrandImage($qrCode->user, $data['business_logo'], 'business-logos');
            }
            if (($data['business_cover'] ?? null) instanceof UploadedFile) {
                $content['cover_path'] = $this->storeMenuBrandImage($qrCode->user, $data['business_cover'], 'business-covers');
            }
        }

        if ($qrCode->type === QrCode::TYPE_SHOP) {
            if (($data['church_logo'] ?? null) instanceof UploadedFile) {
                $content['logo_path'] = $this->storeMenuBrandImage($qrCode->user, $data['church_logo'], 'menu-logos');
            }
            if (($data['church_cover'] ?? null) instanceof UploadedFile) {
                $content['cover_path'] = $this->storeMenuBrandImage($qrCode->user, $data['church_cover'], 'menu-covers');
            }
        }

        if ($qrCode->type === QrCode::TYPE_PAYMENT && ($data['payment_logo'] ?? null) instanceof UploadedFile) {
            $content['logo_path'] = $this->storeMenuBrandImage($qrCode->user, $data['payment_logo'], 'payment-logos');
        }

        if ($qrCode->type === QrCode::TYPE_EVENT) {
            if (($data['event_logo'] ?? null) instanceof UploadedFile) {
                $content['logo_path'] = $this->storeMenuBrandImage($qrCode->user, $data['event_logo'], 'event-logos');
            }
            if (($data['event_cover'] ?? null) instanceof UploadedFile) {
                $content['cover_path'] = $this->storeMenuBrandImage($qrCode->user, $data['event_cover'], 'event-covers');
            }
        }

        if ($qrCode->type === QrCode::TYPE_ITINERARY && ($data['itinerary_cover'] ?? null) instanceof UploadedFile) {
            $content['cover_path'] = $this->storeMenuBrandImage($qrCode->user, $data['itinerary_cover'], 'itinerary-covers');
        }

        if ($qrCode->type === QrCode::TYPE_PAYMENT) {
            $style = QrStyleDefaults::defaults();
        } else {
            if (isset($data['style']) && is_array($data['style'])) {
                $style = QrStyleDefaults::merge(array_merge($style, $data['style']));
                $regenerate = true;
            }

            if (($data['logo'] ?? null) instanceof UploadedFile) {
                $style['logo_path'] = $this->storeLogo($qrCode->user, $data['logo']);
                $regenerate = true;
            }

            if (($data['remove_logo'] ?? false) && $style['logo_path']) {
                $style['logo_path'] = null;
                $regenerate = true;
            }
        }

        $qrCode->destination_url = $destinationUrl;
        // Preserve frozen keys (e.g. wifi_encoded) so the printed WiFi code stays put.
        $payload = (array) ($qrCode->payload ?? []);
        $payload['content'] = $content;
        $payload['style'] = $style;
        $qrCode->payload = $payload;
        $qrCode->save();

        if ($regenerate) {
            $this->imageGenerator->generateAndStore($qrCode);
        }

        return $qrCode->fresh(['document']);
    }

    /**
     * Inject uploaded item images into the sections array.
     * Form field: item_images[sectionIndex][itemIndex] (UploadedFile)
     *
     * @param  array<int, mixed>  $sections
     * @param  array<string, mixed>  $data
     * @return array<int, mixed>
     */
    private function injectItemImages(User $user, array $sections, array $data, string $type): array
    {
        $uploads = $data['item_images'] ?? [];
        if (! is_array($uploads) || $uploads === []) {
            return $sections;
        }

        foreach ($uploads as $sIndex => $itemUploads) {
            if (! is_array($itemUploads)) {
                continue;
            }
            foreach ($itemUploads as $iIndex => $file) {
                if (! ($file instanceof UploadedFile)) {
                    continue;
                }
                if (! isset($sections[$sIndex]['items'][$iIndex])) {
                    continue;
                }
                $mime = $file->getMimeType() ?: '';
                if (! str_starts_with($mime, 'image/')) {
                    continue;
                }
                $subdir = $type === QrCode::TYPE_SHOP ? 'shop-items' : 'menu-items';
                $ext = $file->getClientOriginalExtension() ?: 'jpg';
                $path = $user->id . '/' . $subdir . '/' . Str::uuid()->toString() . '.' . $ext;
                $file->storeAs('', $path, 'qr');
                $sections[$sIndex]['items'][$iIndex]['image_path'] = $path;
            }
        }

        return $sections;
    }

    /** @param  array<string, mixed>  $data */
    private function hasContentChanges(QrCode $qrCode, array $data): bool
    {
        $keys = match ($qrCode->type) {
            QrCode::TYPE_URL => ['destination_url'],
            QrCode::TYPE_LINK_LIST => ['links'],
            QrCode::TYPE_VCARD => ['first_name', 'last_name', 'phone', 'email', 'company', 'website', 'address', 'note', 'social'],
            QrCode::TYPE_BUSINESS => ['name', 'tagline', 'phone', 'email', 'website', 'address', 'hours'],
            QrCode::TYPE_SHOP => ['name', 'denomination', 'description', 'phone', 'email', 'website', 'address', 'service_times', 'org_type', 'accepts_payment', 'collection_types', 'brand_color'],
            QrCode::TYPE_EVENT => ['name', 'tagline', 'description', 'location', 'starts_at', 'ends_at', 'organizer', 'website', 'brand_color', 'tiers', 'badge_fields', 'badge_size', 'registration_open'],
            QrCode::TYPE_ITINERARY => ['title', 'subtitle', 'description', 'event_date', 'location', 'brand_color', 'days'],
            QrCode::TYPE_DOCUMENT => ['allow_download'],
            QrCode::TYPE_MENU => ['menu_title', 'sections', 'accepts_payment', 'brand_color', 'shipping_type', 'shipping_fee', 'free_shipping_above'],
            QrCode::TYPE_SHOP => ['shop_title', 'sections', 'currency', 'accepts_payment', 'brand_color', 'shipping_type', 'shipping_fee', 'free_shipping_above'],
            QrCode::TYPE_APP => ['app_name', 'ios_url', 'android_url', 'web_url', 'app_icon'],
            QrCode::TYPE_BOOKING => ['booking_title', 'description', 'services', 'accepts_payment', 'active_days', 'opens_at', 'closes_at', 'brand_color'],
            QrCode::TYPE_WIFI => ['ssid', 'password', 'encryption', 'hidden'],
            QrCode::TYPE_PAYMENT => ['business_name', 'branch_label', 'currency'],
            default => [],
        };

        foreach ($keys as $key) {
            if (array_key_exists($key, $data)) {
                return true;
            }
        }

        return false;
    }

    public function storeDocument(User $user, UploadedFile $file, string $title): QrDocument
    {
        $maxBytes = (int) config('qr.max_pdf_bytes', 104857600);

        if ($file->getSize() > $maxBytes) {
            throw new RuntimeException('PDF must be 100 MB or smaller.');
        }

        $mime = $file->getMimeType() ?: '';
        if (! in_array($mime, ['application/pdf', 'application/x-pdf'], true)) {
            throw new RuntimeException('Only PDF documents are supported.');
        }

        $uuid = Str::uuid()->toString();
        $path = $user->id . '/documents/' . $uuid . '.pdf';

        $file->storeAs('', $path, 'qr');

        return QrDocument::create([
            'user_id' => $user->id,
            'title' => $title,
            'disk' => 'qr',
            'path' => $path,
            'mime_type' => 'application/pdf',
            'size_bytes' => (int) $file->getSize(),
        ]);
    }

    /**
     * @param  array<string, mixed>  $data
     * @return list<array{path: string, title: string}>
     */
    private function storeImages(User $user, array $data, bool $required = true): array
    {
        $files = [];
        if (($data['image'] ?? null) instanceof UploadedFile) {
            $files[] = $data['image'];
        }
        if (is_array($data['images'] ?? null)) {
            foreach ($data['images'] as $file) {
                if ($file instanceof UploadedFile) {
                    $files[] = $file;
                }
            }
        }

        if ($required && $files === []) {
            $this->payloadValidator->validateImageUpload(null);
        }

        $stored = [];
        foreach ($files as $index => $file) {
            $this->payloadValidator->validateImageUpload($file);
            $uuid = Str::uuid()->toString();
            $ext = $file->getClientOriginalExtension() ?: 'jpg';
            $path = $user->id . '/images/' . $uuid . '.' . $ext;
            $file->storeAs('', $path, 'qr');
            $stored[] = [
                'path' => $path,
                'title' => $file->getClientOriginalName() ?: ('Image ' . ($index + 1)),
            ];
        }

        return $stored;
    }

    private function storeVcardAvatar(User $user, UploadedFile $file): string
    {
        $mime = $file->getMimeType() ?: '';
        if (! str_starts_with($mime, 'image/')) {
            throw new RuntimeException('Avatar must be an image file.');
        }

        $ext  = $file->getClientOriginalExtension() ?: 'jpg';
        $path = $user->id . '/vcards/' . Str::uuid()->toString() . '.' . $ext;
        $file->storeAs('', $path, 'qr');

        return $path;
    }

    private function storeBookFile(User $user, UploadedFile $file): array
    {
        $ext  = strtolower($file->getClientOriginalExtension() ?: '');
        $mime = $file->getMimeType() ?: '';

        if ($ext === 'pdf' || in_array($mime, ['application/pdf', 'application/x-pdf'], true)) {
            $type = 'pdf';
        } elseif ($ext === 'epub' || str_contains($mime, 'epub')) {
            $type = 'epub';
        } else {
            throw new RuntimeException('Only PDF and EPUB files are supported for books.');
        }

        $path = $user->id . '/books/' . Str::uuid()->toString() . '.' . $type;
        $file->storeAs('', $path, 'qr');

        return ['path' => $path, 'type' => $type, 'size' => (int) $file->getSize()];
    }

    private function storeMenuBrandImage(User $user, UploadedFile $file, string $subdir): string
    {
        $mime = $file->getMimeType() ?: '';
        if (! str_starts_with($mime, 'image/')) {
            throw new RuntimeException('Only image files are supported.');
        }

        $ext  = $file->getClientOriginalExtension() ?: 'jpg';
        $path = $user->id . '/' . $subdir . '/' . Str::uuid()->toString() . '.' . $ext;
        $file->storeAs('', $path, 'qr');

        return $path;
    }

    private function storeBookCover(User $user, UploadedFile $file): string
    {
        $mime = $file->getMimeType() ?: '';
        if (! str_starts_with($mime, 'image/')) {
            throw new RuntimeException('Book cover must be an image file.');
        }

        $ext  = $file->getClientOriginalExtension() ?: 'jpg';
        $path = $user->id . '/book-covers/' . Str::uuid()->toString() . '.' . $ext;
        $file->storeAs('', $path, 'qr');

        return $path;
    }

    private function storeLogo(User $user, UploadedFile $file): string
    {
        $mime = $file->getMimeType() ?: '';
        if (! str_starts_with($mime, 'image/')) {
            throw new RuntimeException('Logo must be an image file.');
        }

        $path = $user->id . '/logos/' . Str::uuid()->toString() . '.' . ($file->getClientOriginalExtension() ?: 'png');
        $file->storeAs('', $path, 'qr');

        return $path;
    }

    private function generateUniqueShortCode(): string
    {
        $length = (int) config('qr.short_code_length', 8);

        for ($attempt = 0; $attempt < 20; $attempt++) {
            $code = Str::lower(Str::random($length));
            if (! QrCode::query()->where('short_code', $code)->exists()) {
                return $code;
            }
        }

        throw new RuntimeException('Could not generate a unique QR short code.');
    }

    public function delete(QrCode $qrCode): void
    {
        $paths = array_filter([$qrCode->png_path, $qrCode->svg_path]);

        $logoPath = $qrCode->content()['logo_path'] ?? null;
        if (is_string($logoPath) && $logoPath !== '') {
            $paths[] = $logoPath;
        }

        foreach ($paths as $path) {
            Storage::disk('qr')->delete($path);
        }

        $qrCode->delete();
    }
}