<?php

namespace App\Services;

use App\Models\DeliveryTime;
use App\Models\DisposalReason;
use App\Models\Ingredient;
use App\Models\Location;
use App\Models\MaterialQuality;
use App\Models\PackagingItem;
use App\Models\PackagingMaterial;
use App\Models\Product;
use App\Models\ProductIngredient;
use App\Models\Production;
use App\Models\ProductionIngredient;
use App\Models\ProductionPackaging;
use App\Models\StockDisposal;
use App\Models\StockEntry;
use App\Models\StockMovementReason;
use App\Models\StorageSegment;
use App\Models\Supplier;
use App\Models\SupplierCategory;
use App\Models\TaxRate;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\DB;

/**
 * Zentrale Abhängigkeitsprüfung vor dem Löschen von WaWi-Einträgen
 * (Anforderung 15.07.2026): Referenzierte Einträge dürfen nicht gelöscht
 * werden. Liefert je Blocker eine deutschsprachige Begründung; leeres
 * Array = Löschen erlaubt. Soft-gelöschte Referenzen zählen nicht
 * (SoftDeletes-Global-Scope bzw. explizite whereNull-Joins).
 */
class DeletionGuard
{
    /**
     * @return array<int, string>
     */
    public function blockersFor(Model $model): array
    {
        return match (true) {
            $model instanceof TaxRate => $this->taxRateBlockers($model),
            $model instanceof MaterialQuality => $this->materialQualityBlockers($model),
            $model instanceof Location => $this->locationBlockers($model),
            $model instanceof SupplierCategory => $this->supplierCategoryBlockers($model),
            $model instanceof PackagingMaterial => $this->packagingMaterialBlockers($model),
            $model instanceof StorageSegment => $this->storageSegmentBlockers($model),
            $model instanceof Ingredient => $this->ingredientBlockers($model),
            $model instanceof StockEntry => $this->stockEntryBlockers($model),
            $model instanceof Supplier => $this->supplierBlockers($model),
            $model instanceof PackagingItem => $this->packagingItemBlockers($model),
            // Bewusst immer löschbar (keine eingehenden Referenzen):
            $model instanceof DeliveryTime,
            $model instanceof DisposalReason,
            $model instanceof StockMovementReason,
            $model instanceof StockDisposal,
            $model instanceof Production => [],
            default => [],
        };
    }

    /**
     * @return array<int, string>
     */
    protected function taxRateBlockers(TaxRate $taxRate): array
    {
        $blockers = [];
        $this->push($blockers, Ingredient::query()->where('tax_rate_id', $taxRate->id)->count(), ':n Rohstoff(e)');
        $this->push($blockers, StockEntry::query()->where('tax_rate_id', $taxRate->id)->count(), ':n Wareneingänge/Bestellungen');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function materialQualityBlockers(MaterialQuality $quality): array
    {
        $blockers = [];
        $this->push($blockers, Ingredient::query()->where('material_quality_id', $quality->id)->count(), ':n Rohstoff(e)');
        $this->push($blockers, StockEntry::query()->where('quality_id', $quality->id)->count(), ':n Wareneingänge/Bestellungen');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function locationBlockers(Location $location): array
    {
        $blockers = [];
        $this->push($blockers, StockEntry::query()->where('location_id', $location->id)->count(), ':n Wareneingänge/Bestellungen');
        $this->push($blockers, Production::query()->where('location_id', $location->id)->count(), ':n Produktion(en)');
        $this->push($blockers, StockDisposal::query()->where('location_id', $location->id)->count(), ':n Ausschuss-Buchung(en)');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function supplierCategoryBlockers(SupplierCategory $category): array
    {
        $count = DB::table('supplier_supplier_category')
            ->join('suppliers', 'suppliers.id', '=', 'supplier_supplier_category.supplier_id')
            ->whereNull('suppliers.deleted_at')
            ->where('supplier_supplier_category.supplier_category_id', $category->id)
            ->count();

        $blockers = [];
        $this->push($blockers, $count, ':n Lieferant(en)');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function packagingMaterialBlockers(PackagingMaterial $material): array
    {
        $blockers = [];
        $this->push($blockers, PackagingItem::query()->where('packaging_material_id', $material->id)->count(), ':n Verpackungsartikel');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function storageSegmentBlockers(StorageSegment $segment): array
    {
        $column = match ($segment->getTable()) {
            'storage_rooms' => 'storage_room_id',
            'storage_shelves' => 'storage_shelf_id',
            'storage_slots' => 'storage_slot_id',
        };

        $blockers = [];
        $this->push($blockers, Ingredient::query()->where($column, $segment->id)->count(), ':n Rohstoff(e)');
        // AP-51: Lagerplatz jetzt auch an Produkten und Verpackungsartikeln.
        $this->push($blockers, Product::query()->where($column, $segment->id)->count(), ':n Produkt(e)');
        $this->push($blockers, PackagingItem::query()->where($column, $segment->id)->count(), ':n Verpackungsartikel');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function ingredientBlockers(Ingredient $ingredient): array
    {
        $blockers = [];
        $this->push($blockers, ProductIngredient::query()->where('ingredient_id', $ingredient->id)->count(), ':n Rezeptur-Zeile(n)');
        $this->push($blockers, StockEntry::query()->where('ingredient_id', $ingredient->id)->count(), ':n Wareneingänge/Bestellungen');
        $this->push($blockers, StockDisposal::query()->where('ingredient_id', $ingredient->id)->count(), ':n Ausschuss-Buchung(en)');
        $this->push(
            $blockers,
            ProductionIngredient::query()->where('ingredient_id', $ingredient->id)->whereHas('production')->count(),
            ':n Produktions-Verbräuche'
        );

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function stockEntryBlockers(StockEntry $stockEntry): array
    {
        $blockers = [];
        $this->push(
            $blockers,
            ProductionIngredient::query()->where('stock_entry_id', $stockEntry->id)->whereHas('production')->count(),
            ':n Produktions-Verbräuche'
        );
        $this->push($blockers, StockDisposal::query()->where('stock_entry_id', $stockEntry->id)->count(), ':n Ausschuss-Buchung(en)');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function supplierBlockers(Supplier $supplier): array
    {
        $blockers = [];
        $this->push($blockers, StockEntry::query()->where('supplier_id', $supplier->id)->count(), ':n Wareneingänge/Bestellungen');

        return $blockers;
    }

    /**
     * @return array<int, string>
     */
    protected function packagingItemBlockers(PackagingItem $item): array
    {
        $blockers = [];
        $this->push($blockers, StockEntry::query()->where('packaging_item_id', $item->id)->count(), ':n Wareneingänge/Bestellungen');
        $this->push($blockers, StockDisposal::query()->where('packaging_item_id', $item->id)->count(), ':n Ausschuss-Buchung(en)');
        $this->push(
            $blockers,
            ProductionPackaging::query()->where('packaging_item_id', $item->id)->whereHas('production')->count(),
            ':n Produktions-Verbräuche'
        );
        $bomCount = DB::table('product_packagings')
            ->join('products', 'products.id', '=', 'product_packagings.product_id')
            ->whereNull('products.deleted_at')
            ->where('product_packagings.packaging_item_id', $item->id)
            ->count();
        $this->push($blockers, $bomCount, ':n Produkt-Stückliste(n)');

        return $blockers;
    }

    /**
     * Formatiert die Lösch-Blocker als Fehlermeldung fürs Flash-Alert.
     *
     * @param  array<int, string>  $blockers
     */
    public function message(array $blockers): string
    {
        return __('Löschen nicht möglich — der Eintrag wird noch verwendet: :list', [
            'list' => implode(', ', $blockers),
        ]);
    }

    /**
     * @param  array<int, string>  $blockers
     */
    protected function push(array &$blockers, int $count, string $template): void
    {
        if ($count > 0) {
            $blockers[] = str_replace(':n', (string) $count, __($template));
        }
    }
}