<?php

namespace App\Http\Controllers\Shop;

use App\Http\Controllers\Controller;
use App\Models\Product;
use Illuminate\Http\Request;

class CartController extends Controller
{
    public function index()
    {
        $cart = (array) session()->get('cart', []);
        $products = Product::query()
            ->whereIn('id', array_keys($cart))
            ->where('is_active', true)
            ->with('category')
            ->get()
            ->keyBy('id');

        $items = collect($cart)
            ->map(function ($quantity, $productId) use ($products) {
                $product = $products->get((int) $productId);
                if (!$product) {
                    return null;
                }

                $qty = max(1, (int) $quantity);

                return [
                    'product' => $product,
                    'quantity' => $qty,
                    'subtotal' => (float) $product->price * $qty,
                ];
            })
            ->filter()
            ->values();

        return view('shop.cart', [
            'items' => $items,
            'itemsCount' => $items->sum('quantity'),
            'total' => $items->sum('subtotal'),
        ]);
    }

    public function add(Product $product)
    {
        if (!$product->is_active || $product->stock < 1) {
            return back()->with('status', 'Товар сейчас недоступен для заказа.');
        }

        $cart = (array) session()->get('cart', []);
        $current = (int) ($cart[$product->id] ?? 0);

        if ($current >= $product->stock) {
            return back()->with('status', 'В корзине уже максимальное доступное количество.');
        }

        $cart[$product->id] = $current + 1;
        session()->put('cart', $cart);

        return back()->with('status', "Товар \"{$product->name}\" добавлен в корзину.");
    }

    public function update(Request $request, Product $product)
    {
        $validated = $request->validate([
            'quantity' => ['required', 'integer', 'min:1', 'max:99'],
        ]);

        $cart = (array) session()->get('cart', []);
        if (!isset($cart[$product->id])) {
            return back();
        }

        $available = max(0, (int) $product->stock);
        $quantity = min((int) $validated['quantity'], $available);

        if ($quantity < 1) {
            unset($cart[$product->id]);
            session()->put('cart', $cart);

            return back()->with('status', "Товар \"{$product->name}\" удален из корзины.");
        }

        $cart[$product->id] = $quantity;
        session()->put('cart', $cart);

        $message = $quantity < (int) $validated['quantity']
            ? 'Количество ограничено текущим остатком.'
            : 'Количество товара обновлено.';

        return back()->with('status', $message);
    }

    public function remove(Product $product)
    {
        $cart = (array) session()->get('cart', []);
        if (isset($cart[$product->id])) {
            unset($cart[$product->id]);
            session()->put('cart', $cart);
        }

        return back()->with('status', "Товар \"{$product->name}\" удален из корзины.");
    }
}