<?php

namespace App\Http\Controllers\Shop;

use App\Http\Controllers\Controller;
use App\Models\Order;
use App\Models\OrderItem;
use App\Models\Product;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\Rule;

class CheckoutController extends Controller
{
    private const CHECKOUT_CUSTOMER_KEY = 'checkout.customer';

    public function show(Request $request)
    {
        $items = $this->cartItems($request);

        if ($items->isEmpty()) {
            return redirect()->route('cart.index')->with('status', 'Корзина пустая. Добавьте товары перед оформлением.');
        }

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

    public function prepare(Request $request)
    {
        $items = $this->cartItems($request);

        if ($items->isEmpty()) {
            return redirect()->route('cart.index')->with('status', 'Корзина пустая. Добавьте товары перед оформлением.');
        }

        $validated = $request->validate([
            'customer_name' => ['required', 'string', 'max:255'],
            'email' => ['required', 'email', 'max:255'],
            'phone' => ['nullable', 'string', 'max:50'],
            'address' => ['required', 'string', 'max:500'],
            'comment' => ['nullable', 'string', 'max:1000'],
        ]);

        $validated['payment_method'] = 'card_transfer';
        $request->session()->put(self::CHECKOUT_CUSTOMER_KEY, $validated);

        return redirect()->route('checkout.payment');
    }

    public function payment(Request $request)
    {
        $items = $this->cartItems($request);

        if ($items->isEmpty()) {
            return redirect()->route('cart.index')->with('status', 'Корзина пустая. Добавьте товары перед оформлением.');
        }

        $customer = $request->session()->get(self::CHECKOUT_CUSTOMER_KEY);
        if (!is_array($customer)) {
            return redirect()->route('checkout.show')->with('status', 'Сначала заполните данные получателя.');
        }

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

    public function store(Request $request)
    {
        $items = $this->cartItems($request);

        if ($items->isEmpty()) {
            return redirect()->route('cart.index')->with('status', 'Корзина пустая. Добавьте товары перед оформлением.');
        }

        $validated = $request->session()->get(self::CHECKOUT_CUSTOMER_KEY);
        if (!is_array($validated)) {
            return redirect()->route('checkout.show')->with('status', 'Сначала заполните данные получателя.');
        }

        $validator = validator($validated, [
            'customer_name' => ['required', 'string', 'max:255'],
            'email' => ['required', 'email', 'max:255'],
            'phone' => ['nullable', 'string', 'max:50'],
            'address' => ['required', 'string', 'max:500'],
            'comment' => ['nullable', 'string', 'max:1000'],
            'payment_method' => ['required', 'string', Rule::in(['card_transfer'])],
        ]);
        $validated = $validator->validate();

        $order = DB::transaction(function () use ($request, $items, $validated) {
            $order = Order::create([
                'user_id' => optional($request->user())->id,
                'status' => 'new',
                'payment_method' => $validated['payment_method'],
                'total' => $items->sum('subtotal'),
                'items_count' => $items->sum('quantity'),
                'customer_name' => $validated['customer_name'],
                'email' => $validated['email'],
                'phone' => $validated['phone'] ?? null,
                'address' => $validated['address'],
                'comment' => $validated['comment'] ?? null,
            ]);

            $rows = $items->map(function (array $item) use ($order) {
                return [
                    'order_id' => $order->id,
                    'product_id' => $item['product']->id,
                    'name' => $item['product']->name,
                    'price' => $item['product']->price,
                    'quantity' => $item['quantity'],
                    'subtotal' => $item['subtotal'],
                    'created_at' => now(),
                    'updated_at' => now(),
                ];
            })->all();

            OrderItem::insert($rows);

            return $order;
        });

        $request->session()->forget('cart');
        $request->session()->forget(self::CHECKOUT_CUSTOMER_KEY);

        return redirect()->route('checkout.success', $order);
    }

    public function success(Order $order)
    {
        return view('shop.checkout-success', [
            'order' => $order,
        ]);
    }

    private function cartItems(Request $request)
    {
        $cart = (array) $request->session()->get('cart', []);

        $products = Product::query()
            ->whereIn('id', array_keys($cart))
            ->where('is_active', true)
            ->get()
            ->keyBy('id');

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

                $qty = max(1, min((int) $quantity, (int) $product->stock));
                if ($qty < 1) {
                    return null;
                }

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