public function viewProduct($slug)
{
$product= Product::where('slug','=',$slug)->with('categories')->first();
$product_id=$product->id;
$reviews = Review::where('product_id',$product->id)->get();
$recommendProducts=Product::whereHas('recommendProduct', function($query) use ($product_id){
return $query->whereHas('product_id', $product_id);
})->paginate(3);
return view('view-product', compact('product','reviews','recommendProducts'));
}