public function getCollectionAddress($purchaseId)
    {
        $purchase = Purchase::findOrFail($purchaseId);

        if ($purchase->item->seller->userId != Auth::user()->userId) {
            return redirect('/inventory/sold')->withErrors([
                "You are not the seller of this item."
            ]);
        }

        if ($purchase->deliveryOption) {
            return redirect('/inventory/sold')->withErrors([
                "This item is not due to be collected."
            ]);
        }

        if ($purchase->hasAddress()) {
            return redirect('/inventory/sold')->withErrors([
                "You have already provided a collection address for this item."
            ]);
        }

        return view('mustard::purchase.collection-address', [
            'countries' => Iso3166::all(),
            'purchase' => $purchase,
        ]);
    }