<?php

namespace App\Services\Admin\Master\Product;

use App\Enums\ProductStatus;
use App\Models\Product;
use App\Models\ProductVariant;
use App\Services\Concerns\RegistersMedia;
use App\Services\NotificationService;
use App\Services\S3PresignedService;
use App\Services\StockMutationService;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

class ProductVariantService
{
    use RegistersMedia;

    public function __construct(
        private S3PresignedService $s3Service,
        private StockMutationService $stockMutationService,
    ) {}

    private function canVerify(): bool
    {
        $user = auth()->user();

        return $user->hasAnyRole(['developer', 'owner']);
    }

    private function assertNotPending(Product $product): void
    {
        if ($product->status === ProductStatus::PENDING && ! $this->canVerify()) {
            throw ValidationException::withMessages([
                'status' => 'Produk sedang menunggu verifikasi dan tidak dapat diubah.',
            ]);
        }
    }

    public function getForEdit(ProductVariant $variant): array
    {
        $variant->load([
            'productPrices',
            'media',
        ]);

        $media = $variant->getMedia('photos');
        $photoKeys = $media->pluck('file_name')->toArray();
        $photoUrls = $media->map(fn ($m) => $this->s3Service->getTemporaryUrl($m->file_name))->toArray();

        return [
            'id' => $variant->id,
            'product_id' => $variant->product_id,
            'name' => $variant->name,
            'stock' => $variant->stock,
            'reject_stock' => $variant->reject_stock,
            'retail_stock' => $variant->retail_stock,
            'photo_keys' => $photoKeys,
            'photo_urls' => $photoUrls,
            'prices' => $variant->productPrices->map(fn ($p) => [
                'type' => $p->type->value,
                'price' => $p->price,
            ]),
        ];
    }

    public function update(ProductVariant $variant, array $data): ProductVariant
    {
        $this->assertNotPending($variant->product);

        DB::transaction(function () use ($variant, $data) {
            $oldData = $variant->only(['stock', 'reject_stock', 'retail_stock']);

            $variant->update([
                'name' => $data['name'],
                'stock' => $data['stock'],
                'reject_stock' => $data['reject_stock'],
                'retail_stock' => $data['retail_stock'],
            ]);

            $this->stockMutationService->recordAdjustment($variant, $oldData, $data, 'Penyesuaian stok saat edit varian');

            // Upsert prices instead of delete+recreate
            $priceRows = collect($data['prices'])->map(fn ($p) => [
                'variant_id' => $variant->id,
                'type' => $p['type'],
                'price' => $p['price'],
                'created_at' => now(),
                'updated_at' => now(),
            ])->toArray();

            DB::table('product_prices')->upsert(
                $priceRows,
                ['variant_id', 'type'],
                ['price', 'updated_at']
            );

            if (! empty($data['photo_keys']) && is_array($data['photo_keys'])) {
                $variant->clearMediaCollection('photos');
                $this->registerPhotos($variant, $data['photo_keys']);
            }
        });

        NotificationService::notify(
            roles: ['Owner', 'Developer', 'Direktur', 'Admin Toko'],
            title: 'Varian Diperbarui',
            body: "Varian \"{$variant->name}\" berhasil diperbarui".' oleh '.auth()->user()->full_name.'.',
            url: route('admin.master.products.index'),
        );

        return $variant->fresh();
    }

    public function delete(Product $product, ProductVariant $variant): bool
    {
        $this->assertNotPending($product);

        $result = DB::transaction(function () use ($variant) {
            $variant->productPrices()->delete();
            $variant->clearMediaCollection('photos');

            return $variant->delete();
        });

        NotificationService::notify(
            roles: ['Owner', 'Developer', 'Direktur', 'Admin Toko'],
            title: 'Varian Dihapus',
            body: "Varian \"{$variant->name}\" dari produk \"{$product->name}\" berhasil dihapus".' oleh '.auth()->user()->full_name.'.',
            url: route('admin.master.products.index'),
        );

        return $result;
    }

    public function registerPhotos(ProductVariant $variant, array $photoKeys): void
    {
        foreach ($photoKeys as $order => $s3Key) {
            $this->registerMedia(
                model: $variant,
                s3Key: $s3Key,
                collectionName: 'photos',
                orderColumn: $order + 1,
            );
        }
    }

    public function getTemporaryUrls(ProductVariant $variant): array
    {
        $media = $variant->getMedia('photos');

        return $media->map(fn ($m) => $this->s3Service->getTemporaryUrl($m->file_name))->toArray();
    }

    public function transferStock(ProductVariant $variant, array $data): ProductVariant
    {
        $quantity = (int) $data['quantity'];

        $this->assertNotPending($variant->product);

        if ($variant->stock < $quantity) {
            throw ValidationException::withMessages([
                'quantity' => "Stok bagus tidak mencukupi. Stok tersedia: {$variant->stock}.",
            ]);
        }

        DB::transaction(function () use ($variant, $quantity, $data) {
            $stockBefore = $variant->stock;
            $retailBefore = $variant->retail_stock;

            $variant->update([
                'stock' => $stockBefore - $quantity,
                'retail_stock' => $retailBefore + $quantity,
            ]);

            $this->stockMutationService->recordTransfer(
                model: $variant,
                quantity: $quantity,
                fromQuality: 'good',
                toQuality: 'retail',
                fromBefore: $stockBefore,
                toBefore: $retailBefore,
                description: $data['description'] ?? 'Transfer stok bagus ke stok ecer',
            );
        });

        NotificationService::notify(
            roles: ['Owner', 'Developer', 'Direktur', 'Admin Toko'],
            title: 'Transfer Stok',
            body: "{$quantity} unit dari varian \"{$variant->name}\" berhasil ditransfer dari stok bagus ke stok ecer".' oleh '.auth()->user()->full_name.'.',
            url: route('admin.master.products.index'),
        );

        return $variant->fresh();
    }
}