How to loop inside the foreach

Question

I’m having a hard time getting the code to run.

I have the variable $posts_metas which may be empty or have an array, depending on what the user has already registered in DB.

I also have the variable $ulsthat contains urls of the images the user selected.

I’m trying to do some checks before saving in DB, see comments on the code below:

add_action( 'save_post', function ($post_id) {

if (isset($_POST['my_image_URL'])){ //se existem imagens selecionadas

        $urls = $_POST['my_image_URL']; // variavel urls recebe as urls das imagens

        $posts_metas = get_post_meta( $post_id, 'my-image-for-post' ); // busca no DB posts metas onde a coluna  meta_key sejam = "my-image-for-post" e retorna as urls

        if ($posts_metas === ''){   //se posts metas retornou vazio 

            foreach ($urls as $url){ 

                    add_post_meta( $post_id, 'my-image-for-post',$url ); // apenas cadastra todas urls... ate aqui quando o DB esta vazio cadastra corretamente as urls             

                }
            }       

        }else{ 

            foreach ($urls as $url){                
                foreach( $posts_metas as $value ) {
                    if($value != $url){ 
                        add_post_meta( $post_id, 'my-image-for-post',$url );                
                    }elseif($value === $url ){
                        update_post_meta( $post_id, 'my-image-for-post', $url );
                    }else{
                        add_post_meta( $post_id, 'my-image-for-post',$url );    
                    }               
                }
            }

        }




});

In the else if there is already a meta_key for the post with the value 'my-image-for-post' then have some url registered.

I am trying to perform the following 2 conditions:

1ª if all registered values are different from the new url or if the url does not exist in the DB should add the url.

2nd if the value of the url is identical to an already registered url you should only update

It turns out that after the else, I’m not getting the foreach and loop right

I appreciate help