<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Models\Product;
use App\Models\Client;
use App\Models\Sale;
use App\Models\SaleDetail;
use Illuminate\Support\Facades\DB;

class SaleController extends Controller
{
    public function create()
    {
        // Traemos productos con stock y clientes para los selectores
        $products = Product::where('stock_quantity', '>', 0)->get();
        $clients = Client::orderBy('name')->get();

        return view('sales.create', compact('products', 'clients'));
    }

    public function store(Request $request)
    {
        // Validación estricta
        $request->validate([
            'client_id'      => 'nullable|exists:clients,id',
            'payment_method' => 'required|string',
            'items'          => 'required|array',
            'items.*.product_id' => 'required|exists:products,id',
            'items.*.quantity'   => 'required|integer|min:1',
        ]);

        try {
            DB::transaction(function () use ($request) {
                
                $totalVenta = 0;

                // 1. Calcular total previo (Solo habrá 1 item por ahora, pero el bucle sirve igual)
                foreach ($request->items as $itemData) {
                    $product = Product::findOrFail($itemData['product_id']);
                    
                    if ($product->stock_quantity < $itemData['quantity']) {
                        throw new \Exception("Stock insuficiente para: " . $product->name);
                    }
                    
                    $totalVenta += $product->price * $itemData['quantity'];
                }

                // 2. Crear Venta
                $sale = Sale::create([
                    'client_id'      => $request->client_id,
                    'total'          => $totalVenta,
                    'payment_method' => $request->payment_method,
                    // 'user_id' => auth()->id(), // Descomenta si usas autenticación
                ]);

                // 3. Guardar Detalle y Restar Stock
                foreach ($request->items as $itemData) {
                    $product = Product::findOrFail($itemData['product_id']);

                    SaleDetail::create([
                        'sale_id'    => $sale->id,
                        'product_id' => $product->id,
                        'quantity'   => $itemData['quantity'],
                        'price'      => $product->price,
                    ]);

                    $product->decrement('stock_quantity', $itemData['quantity']);
                }
            });

            return redirect()->route('sales.create')->with('success', '¡Venta registrada correctamente!');

        } catch (\Exception $e) {
            return back()->with('error', $e->getMessage())->withInput();
        }
    }
}