<?php

namespace App\Http\Controllers;

use App\Models\ProductInventory;
use App\Models\ProductSale;
use App\Models\ProductSize;
use Illuminate\Http\Request;
use Illuminate\Http\Response;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;

class ShopifyWebhookController extends Controller
{
    public function ordersPaid(Request $request): Response
    {
        $order   = $request->json()->all();
        $orderId = (string) ($order['id'] ?? '');

        // Idempotency: ignore already-processed orders
        if (ProductSale::where('shopify_order_id', $orderId)->exists()) {
            return response('', 200);
        }

        DB::transaction(function () use ($order, $orderId) {
            foreach ($order['line_items'] ?? [] as $item) {
                $variantId = (string) ($item['variant_id'] ?? '');
                $quantity  = (int)   ($item['quantity']   ?? 0);

                if (!$variantId || $quantity <= 0) {
                    continue;
                }

                $size = ProductSize::where('shopify_variant_id', $variantId)->first();

                if (!$size) {
                    Log::warning('Shopify webhook: unbekannte Variant-ID', [
                        'variant_id' => $variantId,
                        'order_id'   => $orderId,
                    ]);
                    continue;
                }

                // FIFO: älteste verfügbare Einheiten ausbuchen
                ProductInventory::where('size_id', $size->id)
                    ->whereNull('out_at')
                    ->oldest()
                    ->limit($quantity)
                    ->update(['out_at' => now()]);

                ProductSale::create([
                    'product_id'       => $size->product_id,
                    'size_id'          => $size->id,
                    'amount'           => $quantity,
                    'sold_at'          => now(),
                    'shopify_order_id' => $orderId,
                ]);
            }
        });

        return response('', 200);
    }
}