I'm trying to optimize my functions.php file as I have a Woocommerce site with a bunch of customizations to the theme. Currently, my functions look like the following:

add_action('wp_footer', 'enqueue_product_modals');
function enqueue_product_modals() {
    global $product;  //Accessing the Global
    $product_id = $product-get_id();
    if (is_product()) {
        //Standard Modal:
        require_once 'modal-product.php';

        if (has_term('guitar-pickups', 'product_cat', $product_id)) {
            include_once 'modal-polarity.php';
        };

        if (has_term('mini-humbuckers', 'product_cat', $product_id)) {
            include_once 'modal-minihum.php';
        };
    }
}

add_action('woocommerce_after_single_product_summary', function () {
    global $product; //Accessing the Global Again
    $name = $product-get_name();
    if (have_comments()) {
        echo 'p class=reviews-taglineTrying to leave a review for our ' . $name . '? a class=expand data-toggle=collapse data-target=#review_form_wrapper Leave one here./a/p';
    }
}, 50);

etc.

I understand accessing the global $product multiple times is bad practice. So, I started to rewrite functions by declaring the global $product at the top of my functions.php file, (like I would in JS) and passing it in to each individual function like so:

global $product;

add_action('wp_footer', 'enqueue_product_modals');
function enqueue_product_modals($product) {
    $product_id = $product-get_id();
    if (is_product()) {
       // code here...
    }
}

add_action('woocommerce_after_single_product_summary', function ($product) {

    $name = $product-get_name();
    if (have_comments()) {
       //code here
}, 50);

The problem is that now all functions are broken and when doing a var_dump($product) inside each function $product is an empty string. I am now positive I don't know what I'm doing. Can someone offer any assistance on the correct way to access the $product global in each function...or a better way?

Edit:

I also tried passing the $post object, so rewriting the function like so, but it's still an empty string:

add_action('wp_footer', 'enqueue_product_modals');
function enqueue_product_modals($post) {

    if (is_product()) {

$product = wc_get_product($post-ID); // hoping to use this
        var_dump($post); //Still empty String

    }
}