<?php

namespace App\Console\Commands;

use App\Models\ProductInventory;
use App\Models\ProductSize;
use App\Services\ShopifyService;
use Illuminate\Console\Command;
use Illuminate\Support\Facades\DB;

class ShopifySync extends Command
{
    protected $signature   = 'shopify:sync {--dry-run : Änderungen nur anzeigen, nichts speichern}';
    protected $description = 'Gleicht lokalen Lagerbestand mit Shopify-Inventar ab';

    public function handle(ShopifyService $shopify): int
    {
        $dryRun = $this->option('dry-run');
        $variants = $shopify->getAllVariants();

        $added   = 0;
        $removed = 0;
        $inSync  = 0;

        DB::transaction(function () use ($variants, $dryRun, &$added, &$removed, &$inSync) {
            foreach ($variants as $variant) {
                $size = ProductSize::where('shopify_variant_id', $variant['id'])->first();

                if (!$size) {
                    continue; // not mapped yet — run shopify:map first
                }

                $shopifyQty = $variant['inventory_quantity'];
                $localQty   = ProductInventory::where('size_id', $size->id)
                    ->whereNull('out_at')
                    ->count();

                if ($localQty === $shopifyQty) {
                    $inSync++;
                    continue;
                }

                $diff = $shopifyQty - $localQty;

                if ($diff > 0) {
                    // Shopify hat mehr → Einträge hinzufügen
                    $this->line("  +{$diff} {$variant['product_title']} (SKU {$variant['sku']})");
                    if (!$dryRun) {
                        for ($i = 0; $i < $diff; $i++) {
                            ProductInventory::create([
                                'product_id' => $size->product_id,
                                'size_id'    => $size->id,
                            ]);
                        }
                    }
                    $added += $diff;
                } else {
                    // Shopify hat weniger → älteste Einträge als ausgebucht markieren
                    $excess = abs($diff);
                    $this->line("  -{$excess} {$variant['product_title']} (SKU {$variant['sku']})");
                    if (!$dryRun) {
                        ProductInventory::where('size_id', $size->id)
                            ->whereNull('out_at')
                            ->oldest()
                            ->limit($excess)
                            ->update(['out_at' => now()]);
                    }
                    $removed += $excess;
                }
            }
        });

        $this->info("✓ Sync abgeschlossen" . ($dryRun ? ' (dry-run)' : ''));
        $this->info("  In Sync: {$inSync} | Hinzugefügt: {$added} | Ausgebucht: {$removed}");

        return self::SUCCESS;
    }
}