Automatically adding the product to the cart for only specific user roles.

functions.php

<?php
/*
* Automatically adding the product to the cart for only specific user roles.
*/
function aaptc_add_product_to_cart( $item_key, $product_id ) {
	$product_category_id 	= 123; // cricket bat category id
	$product_cats_ids 		= wc_get_product_term_ids( $product_id, 'product_cat' );
  
  	$user 			= wp_get_current_user(); // This will fetch current user's role
	$allowed_roles 	= array( 'booking_agent', 'perfecth' ); // These are the list of allowed user role.
	if ( array_intersect( $allowed_roles, $user->roles ) ) { // This is the condition to add free product to cart for only specific user roles 
		
	    if ( ! is_admin() && in_array( $product_category_id, $product_cats_ids ) ) {
	        $free_product_id 	= 12989;  // Product Id of the free product which will get added to cart
	        $found 				= false;
	        
	        //check if product already in cart
	        if ( sizeof( WC()->cart->get_cart() ) > 0 ) {
	            foreach ( WC()->cart->get_cart() as $cart_item_key => $values ) {
	                $_product = $values['data'];
	                if ( $_product->get_id() == $free_product_id )
	                    $found = true;
	                
	            }
	            // if product not found, add it
	            if ( ! $found )
	                WC()->cart->add_to_cart( $free_product_id );
	        } else {
	            // if no products in cart, add it
	            WC()->cart->add_to_cart( $free_product_id );
	        }        
	    }

    }    
}
add_action( 'woocommerce_add_to_cart', 'aaptc_add_product_to_cart', 10, 2 );