<?php

namespace App\Http\Controllers\Web;

use App\Http\Controllers\Controller;
use App\Http\Requests\Withdrawal\WithdrawalLookupRequest;
use App\Http\Requests\Withdrawal\WithdrawalStoreRequest;
use App\Mail\MailWithdrawalConfirmation;
use App\Models\OrderWithdrawal;
use App\Models\ShoppingOrder;
use App\Services\Shop;
use App\Services\Util;
use Illuminate\Contracts\View\View;
use Illuminate\Http\RedirectResponse;
use Illuminate\Support\Facades\Mail;

class WithdrawalController extends Controller
{
    /**
     * Bestelltyp einer B2C-Shop-Bestellung (Verbraucher mit Warenkorb/Checkout).
     */
    private const SHOP_PAYMENT_FOR = 6;

    public function create(): View
    {
        return view('web.templates.widerruf', $this->viewData([
            'order' => null,
            'prefill_order' => request('order'),
            'prefill_email' => request('email'),
        ]));
    }

    public function lookup(WithdrawalLookupRequest $request): View|RedirectResponse
    {
        $order = $this->findOrder((string) $request->string('order_number'), (string) $request->string('email'));

        if (! $order) {
            return back()
                ->withInput()
                ->with('alert-error', __('withdrawal.not_found'));
        }

        return view('web.templates.widerruf', $this->viewData([
            'order' => $order,
            'prefill_order' => (string) $request->string('order_number'),
            'prefill_email' => (string) $request->string('email'),
        ]));
    }

    public function store(WithdrawalStoreRequest $request): View|RedirectResponse
    {
        $order = $this->findOrder((string) $request->string('order_number'), (string) $request->string('email'));

        if (! $order) {
            return redirect()
                ->route('withdrawal.create')
                ->with('alert-error', __('withdrawal.not_found'));
        }

        $isPartial = $request->input('scope') === OrderWithdrawal::TYPE_PARTIAL;
        $selectedItems = $this->collectSelectedItems($order, $isPartial ? (array) $request->input('items', []) : []);

        if ($isPartial && empty($selectedItems)) {
            return back()
                ->withInput()
                ->with('alert-error', __('withdrawal.no_items_selected'));
        }

        $withdrawal = OrderWithdrawal::create([
            'shopping_order_id' => $order->id,
            'user_shop_id' => $order->user_shop_id,
            'type' => $isPartial ? OrderWithdrawal::TYPE_PARTIAL : OrderWithdrawal::TYPE_FULL,
            'status' => OrderWithdrawal::STATUS_RECEIVED,
            'order_reference' => (string) $order->id,
            'customer_email' => mb_strtolower((string) $request->string('email')),
            'customer_name' => trim(($order->shopping_user->billing_firstname ?? '').' '.($order->shopping_user->billing_lastname ?? '')) ?: null,
            'reason' => $request->input('reason'),
            'items' => $isPartial ? $selectedItems : $this->collectSelectedItems($order, $this->allItemQuantities($order)),
            'ip_address' => $request->ip(),
            'user_agent' => (string) $request->userAgent(),
            'declared_at' => now(),
        ]);

        $this->sendConfirmation($withdrawal, $order);

        return view('web.templates.widerruf-final', $this->viewData([
            'withdrawal' => $withdrawal,
        ]));
    }

    /**
     * Findet eine Verbraucher-Shop-Bestellung anhand der vom Kunden bekannten Nummer
     * (Bestell-ID, Zahlungsreferenz oder Rechnungsnummer) in Kombination mit der E-Mail-Adresse.
     */
    private function findOrder(string $orderNumber, string $email): ?ShoppingOrder
    {
        $orderNumber = trim($orderNumber);
        $email = mb_strtolower(trim($email));

        if ($orderNumber === '' || $email === '') {
            return null;
        }

        return ShoppingOrder::query()
            ->where('payment_for', self::SHOP_PAYMENT_FOR)
            ->whereHas('shopping_user', function ($query) use ($email): void {
                $query->whereRaw('LOWER(billing_email) = ?', [$email]);
            })
            ->where(function ($query) use ($orderNumber): void {
                if (ctype_digit($orderNumber)) {
                    $query->orWhere('id', (int) $orderNumber);
                }
                $query->orWhereHas('shopping_payments', function ($payment) use ($orderNumber): void {
                    $payment->where('reference', $orderNumber);
                });
                $query->orWhereHas('user_invoices', function ($invoice) use ($orderNumber): void {
                    $invoice->where('full_number', $orderNumber);
                });
            })
            ->with(['shopping_order_items.product', 'shopping_user'])
            ->latest('id')
            ->first();
    }

    /**
     * @return array<int, int>
     */
    private function allItemQuantities(ShoppingOrder $order): array
    {
        return $order->shopping_order_items
            ->mapWithKeys(fn ($item): array => [$item->id => (int) $item->qty])
            ->all();
    }

    /**
     * Erstellt einen Snapshot der widerrufenen Positionen.
     *
     * @param  array<int|string, mixed>  $quantities
     * @return array<int, array{shopping_order_item_id: int, product_id: int|null, name: string, qty: int}>
     */
    private function collectSelectedItems(ShoppingOrder $order, array $quantities): array
    {
        $selected = [];

        foreach ($order->shopping_order_items as $item) {
            $requestedQty = (int) ($quantities[$item->id] ?? 0);

            if ($requestedQty <= 0) {
                continue;
            }

            $qty = min($requestedQty, (int) $item->qty);

            $selected[] = [
                'shopping_order_item_id' => $item->id,
                'product_id' => $item->product_id,
                'name' => $item->product?->getLang('name') ?? ('#'.$item->product_id),
                'qty' => $qty,
            ];
        }

        return $selected;
    }

    private function sendConfirmation(OrderWithdrawal $withdrawal, ShoppingOrder $order): void
    {
        $bcc = config('app.withdrawal_mail');

        Mail::to($withdrawal->customer_email)
            ->bcc($bcc)
            ->locale($order->getLocale())
            ->send(new MailWithdrawalConfirmation($withdrawal, $order));
    }

    /**
     * @param  array<string, mixed>  $extra
     * @return array<string, mixed>
     */
    private function viewData(array $extra = []): array
    {
        return array_merge([
            'user_shop' => Util::getUserShop(),
            'mylangs' => Shop::getLangChange('webshop'),
            'yard_instance' => 'webshop',
        ], $extra);
    }
}