<?php
namespace App\Services\Catalog;

use App\Models\Fornitore;
use App\Models\Product;
use App\Models\ProductIdentifier;
use App\Models\ProductMedia;
use App\Models\ProductOffer;
use Illuminate\Support\Arr;
use Illuminate\Support\Collection;
use Illuminate\Support\Str;
use RuntimeException;

class AmazonCreatorsCatalogSyncService
{
    public function __construct(
        private readonly AmazonCreatorsApiService $apiService,
        private readonly ProductOfferService $productOfferService,
    ) {
    }

    /** @return array<string, mixed> */
    public function syncProduct(Product $product, array $options = []): array
    {
        $dryRun = (bool) ($options['dry_run'] ?? false);
        $item   = $this->resolveItemPayload($product, $options);
        if (! is_array($item) || $item === []) {
            throw new RuntimeException('Nessun item Amazon trovato per il prodotto selezionato.');
        }

        $asin = $this->extractAsin($item);
        if ($asin === null) {
            throw new RuntimeException('La risposta Amazon non contiene un ASIN utilizzabile.');
        }

        $title          = $this->extractTitle($item) ?: (string) ($product->name ?? 'Prodotto Amazon');
        $marketplace    = trim((string) ($options['marketplace'] ?? $this->apiService->getMarketplace())) ?: $this->apiService->getMarketplace();
        $associateTag   = trim((string) ($options['associate_tag'] ?? $this->apiService->getAssociateTag() ?? '')) ?: null;
        $detailUrl      = $this->extractDetailPageUrl($item);
        $referralUrl    = $detailUrl !== null ? $this->appendAssociateTag($detailUrl, $associateTag) : $this->productOfferService->buildAmazonReferralUrl($product, $associateTag, $this->mapMarketplaceToLocale($marketplace));
        $price          = $this->extractPriceAmount($item);
        $compareAt      = $this->extractCompareAtAmount($item);
        $currency       = $this->extractCurrency($item) ?? 'EUR';
        $availability   = $this->extractAvailability($item) ?? 'catalog_synced';
        $externalId     = $asin;
        $ean            = $this->extractEan($item);
        $imageUrl       = $this->extractPrimaryImageUrl($item);
        $payloadSummary = [
            'asin'         => $asin,
            'title'        => $title,
            'marketplace'  => $marketplace,
            'detail_url'   => $detailUrl,
            'image_url'    => $imageUrl,
            'price_amount' => $price,
            'currency'     => $currency,
        ];

        $identifiersCreated = 0;
        $mediaCreated       = 0;
        $offer              = null;

        if (! $dryRun) {
            $identifiersCreated += $this->upsertIdentifier($product, 'asin', $asin, 'amazon_creators_api', true) ? 1 : 0;
            if ($ean !== null) {
                $identifiersCreated += $this->upsertIdentifier($product, 'ean', $ean, 'amazon_creators_api', false) ? 1 : 0;
            }

            if ($imageUrl !== null) {
                $mediaCreated += $this->upsertRemoteMedia($product, $imageUrl, $title) ? 1 : 0;
            }

            $offer = $this->productOfferService->syncOffer($product, [
                'source_type'         => 'amazon_creators_api',
                'source_name'         => 'Amazon Creators API',
                'external_product_id' => $externalId,
                'title'               => $title,
                'currency'            => $currency,
                'price_amount'        => $price,
                'price_compare_at'    => $compareAt,
                'availability'        => $availability,
                'external_url'        => $detailUrl,
                'referral_url'        => $referralUrl,
                'referral_code'       => $associateTag,
                'is_internal'         => false,
                'is_active'           => true,
                'meta'                => [
                    'marketplace' => $marketplace,
                    'sync_source' => (string) ($options['source'] ?? 'api'),
                    'payload'     => $payloadSummary,
                ],
            ]);
        }

        return [
            'asin'                => $asin,
            'title'               => $title,
            'detail_url'          => $detailUrl,
            'referral_url'        => $referralUrl,
            'image_url'           => $imageUrl,
            'price_amount'        => $price,
            'price_compare_at'    => $compareAt,
            'currency'            => $currency,
            'availability'        => $availability,
            'ean'                 => $ean,
            'identifiers_created' => $identifiersCreated,
            'media_created'       => $mediaCreated,
            'offer_id'            => $offer instanceof ProductOffer ? (int) $offer->id : null,
            'source'              => (string) ($options['source'] ?? 'api'),
            'dry_run'             => $dryRun,
        ];
    }

    /** @return array<int, array<string, mixed>> */
    public function searchCatalog(string $query, int $limit = 8, array $options = []): array
    {
        $query = trim($query);
        if ($query === '') {
            throw new RuntimeException('Inserisci una query Amazon da cercare.');
        }

        $response = $this->apiService->searchItems($query, [
            'marketplace' => (string) ($options['marketplace'] ?? $this->apiService->getMarketplace()),
        ]);

        return $this->extractItems($response)
            ->take(max(1, $limit))
            ->map(function (array $item): array {
                $asin            = $this->extractAsin($item);
                $ean             = $this->extractEan($item);
                $existingProduct = $this->findExistingProduct($asin, $ean);
                $detailUrl       = $this->extractDetailPageUrl($item);
                $associateTag    = $this->apiService->getAssociateTag();

                return [
                    'asin'                => $asin,
                    'ean'                 => $ean,
                    'title'               => $this->extractTitle($item) ?: 'Prodotto Amazon',
                    'brand'               => $this->extractBrand($item),
                    'price_amount'        => $this->extractPriceAmount($item),
                    'price_compare_at'    => $this->extractCompareAtAmount($item),
                    'currency'            => $this->extractCurrency($item) ?? 'EUR',
                    'availability'        => $this->extractAvailability($item) ?? '',
                    'detail_url'          => $detailUrl,
                    'referral_url'        => $detailUrl !== null ? $this->appendAssociateTag($detailUrl, $associateTag) : null,
                    'image_url'           => $this->extractPrimaryImageUrl($item),
                    'existing_product_id' => $existingProduct?->id,
                    'existing_label'      => $existingProduct instanceof Product
                        ? trim((string) ($existingProduct->internal_code ?? '') . ' · ' . (string) ($existingProduct->name ?? ''))
                        : '',
                    'item_payload'        => $item,
                ];
            })
            ->values()
            ->all();
    }

    /** @return array{product: Product, sync: array<string,mixed>, created: bool} */
    public function importItemForSupplier(Fornitore $fornitore, array $item, array $options = []): array
    {
        $asin = $this->extractAsin($item);
        if ($asin === null) {
            throw new RuntimeException('Il risultato Amazon selezionato non contiene un ASIN valido.');
        }

        $ean     = $this->extractEan($item);
        $title   = $this->extractTitle($item) ?: 'Prodotto Amazon';
        $brand   = $this->extractBrand($item);
        $product = $this->findExistingProduct($asin, $ean);
        $created = false;

        if (! $product instanceof Product) {
            $product = Product::query()->create([
                'default_fornitore_id' => (int) $fornitore->id,
                'type'                 => 'product',
                'canonical_key'        => $this->buildCanonicalKey($title, $asin, $ean),
                'name'                 => $title,
                'brand'                => $brand,
                'model'                => null,
                'description'          => null,
                'track_serials'        => false,
                'is_active'            => true,
                'meta'                 => [
                    'source'       => 'amazon_creators_api',
                    'catalog'      => [
                        'publication_mode' => 'internal_only',
                    ],
                    'verification' => [
                        'status'     => 'pending_review',
                        'channel'    => 'amazon_catalog_search_ui',
                        'updated_at' => now()->toIso8601String(),
                    ],
                    'amazon'       => [
                        'asin'  => $asin,
                        'ean'   => $ean,
                        'title' => $title,
                    ],
                ],
            ]);
            $created = true;
        } else {
            $meta                 = is_array($product->meta ?? null) ? $product->meta : [];
            $meta['source']       = $meta['source'] ?? 'amazon_creators_api';
            $meta['verification'] = [
                'status'     => 'pending_review',
                'channel'    => 'amazon_catalog_search_ui',
                'updated_at' => now()->toIso8601String(),
            ];
            $meta['amazon'] = array_filter([
                'asin'  => $asin,
                'ean'   => $ean,
                'title' => $title,
            ], static fn(mixed $value): bool => $value !== null && $value !== '');

            $product->fill([
                'default_fornitore_id' => $product->default_fornitore_id ?: (int) $fornitore->id,
                'name'                 => trim((string) $product->name) !== '' ? $product->name : $title,
                'brand'                => trim((string) ($product->brand ?? '')) !== '' ? $product->brand : $brand,
                'meta'                 => $meta,
            ]);
            $product->save();
        }

        $sync = $this->syncProduct($product, [
            'item'          => $item,
            'source'        => (string) ($options['source'] ?? 'amazon_catalog_search_ui'),
            'marketplace'   => (string) ($options['marketplace'] ?? $this->apiService->getMarketplace()),
            'associate_tag' => (string) ($options['associate_tag'] ?? ($this->apiService->getAssociateTag() ?? '')),
        ]);

        return [
            'product' => $product->fresh(),
            'sync'    => $sync,
            'created' => $created,
        ];
    }

    /** @return array<string, mixed> */
    private function resolveItemPayload(Product $product, array $options): array
    {
        if (is_array($options['item'] ?? null)) {
            return $options['item'];
        }

        if (is_array($options['response'] ?? null)) {
            $candidate = $this->pickFirstItem((array) $options['response']);

            return is_array($candidate) ? $candidate : [];
        }

        $asin = trim((string) ($options['asin'] ?? $this->findIdentifierValue($product, ['asin']) ?? ''));
        if ($asin !== '') {
            $response = $this->apiService->getItems([$asin], [
                'marketplace' => (string) ($options['marketplace'] ?? $this->apiService->getMarketplace()),
            ]);

            return $this->pickFirstItem($response) ?? [];
        }

        $query = trim((string) ($options['query'] ?? $this->findIdentifierValue($product, ['ean']) ?? $this->buildSearchQuery($product)));
        if ($query === '') {
            return [];
        }

        $response = $this->apiService->searchItems($query, [
            'marketplace' => (string) ($options['marketplace'] ?? $this->apiService->getMarketplace()),
        ]);

        return $this->pickFirstItem($response) ?? [];
    }

    /** @return Collection<int, array<string, mixed>> */
    private function extractItems(array $payload): Collection
    {
        foreach ([
            'items',
            'ItemsResult.Items',
            'SearchResult.Items',
            'GetItemsResult.Items',
            'data.items',
            'data.searchItems.items',
            'data.getItems.items',
        ] as $path) {
            $items = data_get($payload, $path);
            if (is_array($items)) {
                return collect($items)->filter('is_array')->values();
            }
        }

        return collect(isset($payload['asin']) || isset($payload['ASIN']) ? [$payload] : []);
    }

    /** @return array<string, mixed>|null */
    private function pickFirstItem(array $payload): ?array
    {
        foreach ([
            'items',
            'ItemsResult.Items',
            'SearchResult.Items',
            'GetItemsResult.Items',
            'data.items',
            'data.searchItems.items',
            'data.getItems.items',
        ] as $path) {
            $items = data_get($payload, $path);
            if (is_array($items) && isset($items[0]) && is_array($items[0])) {
                return $items[0];
            }
        }

        return isset($payload['asin']) || isset($payload['ASIN']) ? $payload : null;
    }

    private function extractAsin(array $item): ?string
    {
        foreach (['asin', 'ASIN', 'itemId', 'ItemId'] as $path) {
            $value = trim((string) data_get($item, $path, ''));
            if ($value !== '') {
                return $value;
            }
        }

        return null;
    }

    private function extractEan(array $item): ?string
    {
        foreach ([
            'ean',
            'EAN',
            'ExternalIds.EANs.DisplayValues.0',
            'externalIds.eans.0',
            'identifiers.ean',
        ] as $path) {
            $value = preg_replace('/\s+/', '', trim((string) data_get($item, $path, '')));
            if (is_string($value) && $value !== '') {
                return $value;
            }
        }

        return null;
    }

    private function extractTitle(array $item): ?string
    {
        foreach (['title', 'Title', 'ItemInfo.Title.DisplayValue', 'itemInfo.title.displayValue'] as $path) {
            $value = trim((string) data_get($item, $path, ''));
            if ($value !== '') {
                return $value;
            }
        }

        return null;
    }

    private function extractBrand(array $item): ?string
    {
        foreach (['brand', 'Brand', 'ItemInfo.ByLineInfo.Brand.DisplayValue', 'itemInfo.byLineInfo.brand.displayValue'] as $path) {
            $value = trim((string) data_get($item, $path, ''));
            if ($value !== '') {
                return $value;
            }
        }

        return null;
    }

    private function extractDetailPageUrl(array $item): ?string
    {
        foreach (['detailPageURL', 'DetailPageURL', 'detailPageUrl', 'url'] as $path) {
            $value = trim((string) data_get($item, $path, ''));
            if ($value !== '') {
                return $value;
            }
        }

        return null;
    }

    private function extractPrimaryImageUrl(array $item): ?string
    {
        foreach ([
            'Images.Primary.Large.URL',
            'Images.Primary.Medium.URL',
            'Images.Primary.Small.URL',
            'images.primary.large.url',
            'images.primary.medium.url',
            'images.0.url',
            'image',
        ] as $path) {
            $value = trim((string) data_get($item, $path, ''));
            if ($value !== '') {
                return $value;
            }
        }

        return null;
    }

    private function extractPriceAmount(array $item): ?float
    {
        foreach ([
            'Offers.Listings.0.Price.Amount',
            'Offers.Summaries.0.LowestPrice.Amount',
            'offers.listings.0.price.amount',
            'offers.summaries.0.lowestPrice.amount',
            'price.amount',
        ] as $path) {
            $value = data_get($item, $path);
            if (is_numeric($value)) {
                return round((float) $value, 2);
            }
        }

        return null;
    }

    private function extractCompareAtAmount(array $item): ?float
    {
        foreach ([
            'Offers.Listings.0.SavingBasis.Amount',
            'offers.listings.0.savingBasis.amount',
            'price.compareAt.amount',
        ] as $path) {
            $value = data_get($item, $path);
            if (is_numeric($value)) {
                return round((float) $value, 2);
            }
        }

        return null;
    }

    private function extractCurrency(array $item): ?string
    {
        foreach ([
            'Offers.Listings.0.Price.Currency',
            'Offers.Summaries.0.LowestPrice.Currency',
            'offers.listings.0.price.currency',
            'offers.summaries.0.lowestPrice.currency',
            'price.currency',
        ] as $path) {
            $value = trim((string) data_get($item, $path, ''));
            if ($value !== '') {
                return strtoupper($value);
            }
        }

        return null;
    }

    private function extractAvailability(array $item): ?string
    {
        foreach ([
            'Offers.Listings.0.Availability.Message',
            'offers.listings.0.availability.message',
            'availability',
        ] as $path) {
            $value = trim((string) data_get($item, $path, ''));
            if ($value !== '') {
                return $value;
            }
        }

        return null;
    }

    private function appendAssociateTag(string $url, ?string $associateTag): string
    {
        $associateTag = $associateTag !== null ? trim($associateTag) : '';
        if ($associateTag === '') {
            return $url;
        }

        $separator = str_contains($url, '?') ? '&' : '?';

        return str_contains($url, 'tag=') ? $url : ($url . $separator . 'tag=' . rawurlencode($associateTag));
    }

    private function mapMarketplaceToLocale(string $marketplace): string
    {
        return match (Str::lower(trim($marketplace))) {
            'www.amazon.de'    => 'de',
            'www.amazon.fr'    => 'fr',
            'www.amazon.es'    => 'es',
            'www.amazon.co.uk' => 'uk',
            default            => 'it',
        };
    }

    /** @param array<int, string> $types */
    private function findIdentifierValue(Product $product, array $types): ?string
    {
        $value = ProductIdentifier::query()
            ->where('product_id', (int) $product->id)
            ->whereIn('code_type', $types)
            ->orderByDesc('is_primary')
            ->orderBy('id')
            ->value('code_value');

        $value = trim((string) $value);

        return $value !== '' ? $value : null;
    }

    private function buildSearchQuery(Product $product): string
    {
        $parts = array_values(array_unique(array_filter([
            trim((string) ($product->brand ?? '')),
            trim((string) ($product->model ?? '')),
            trim((string) ($product->name ?? '')),
        ], static fn(string $value): bool => $value !== '')));

        return Str::limit(implode(' ', $parts), 120, '');
    }

    private function findExistingProduct(?string $asin, ?string $ean): ?Product
    {
        $codes = array_values(array_filter([
            $this->normalizeCode($asin),
            $this->normalizeCode($ean),
        ]));

        if ($codes === []) {
            return null;
        }

        $productId = ProductIdentifier::query()
            ->whereIn('normalized_code', $codes)
            ->orderByDesc('is_primary')
            ->value('product_id');

        return $productId ? Product::query()->find((int) $productId) : null;
    }

    private function buildCanonicalKey(string $title, ?string $asin, ?string $ean): string
    {
        $base = Str::slug(Str::limit($title, 80, ''));
        $seed = $this->normalizeCode($asin) ?: $this->normalizeCode($ean) ?: Str::upper(Str::random(8));
        $key  = Str::limit(($base !== '' ? $base : 'amazon-item') . '-' . Str::lower($seed), 190, '');

        if (! Product::query()->where('canonical_key', $key)->exists()) {
            return $key;
        }

        return Str::limit($key . '-' . Str::lower(Str::random(4)), 190, '');
    }

    private function normalizeCode(?string $value): ?string
    {
        $value = trim((string) $value);
        if ($value === '') {
            return null;
        }

        $normalized = strtoupper(preg_replace('/[^A-Z0-9]+/', '', $value) ?? '');

        return $normalized !== '' ? $normalized : null;
    }

    private function upsertIdentifier(Product $product, string $type, string $value, string $source, bool $isPrimary): bool
    {
        $value = trim($value);
        if ($value === '') {
            return false;
        }

        $normalized = strtoupper(preg_replace('/[^A-Z0-9]+/', '', $value) ?? '');
        if ($normalized === '') {
            return false;
        }

        $identifier = ProductIdentifier::query()->firstOrNew([
            'product_id'      => (int) $product->id,
            'code_type'       => $type,
            'normalized_code' => $normalized,
        ]);

        $created                      = ! $identifier->exists;
        $identifier->code_role        = $type;
        $identifier->code_value       = $value;
        $identifier->source           = $source;
        $identifier->source_reference = $value;
        $identifier->is_primary       = $isPrimary;
        $identifier->payload          = ['provider' => 'amazon'];
        $identifier->save();

        return $created;
    }

    private function upsertRemoteMedia(Product $product, string $url, string $title): bool
    {
        $url = trim($url);
        if ($url === '' || ! str_starts_with($url, 'http')) {
            return false;
        }

        $media = ProductMedia::query()->firstOrNew([
            'product_id' => (int) $product->id,
            'media_type' => 'image',
            'disk'       => 'remote-url',
            'path'       => $url,
        ]);

        $created      = ! $media->exists;
        $media->title = $title;
        $media->meta  = [
            'provider' => 'amazon_creators_api',
            'remote'   => true,
        ];
        $media->save();

        return $created;
    }
}