NS Contact

<?php
/*
Plugin Name: NS Contact
Plugin URI: https://fb.com/touhid.dnj
Description: Just another contact form plugin. Simple but flexible.
Author: Tohidul Islam
Author URI: https://fb.com/touhid.dnj
Text Domain: ns-contact
Domain Path: /languages/
Version: 1.0
*/

define('PLUGIN_DIR',plugin_dir_path(__FILE__));
define('PLUGIN_URL',plugin_dir_url(__FILE__));

/*echo PLUGIN_URL;
echo "<hr />\n";
echo PLUGIN_DIR; die();*/

add_action('admin_menu', 'custom_menu');

function custom_menu() {

    add_menu_page(
        'NS Contact',
        'NS Contact',
        'manage_options',
        'ns-contact',
        'view_contact_callback',
        'dashicons-media-spreadsheet'

    );
    add_submenu_page('ns-contact','View Contacts','View Contacts','manage_options','ns-contact','view_contact_callback',1);
    add_submenu_page('ns-contact','Add Contacts','Add Contacts','manage_options','ns-add-contact','add_contact_callback',2);
}

function ns_contact_enqueue_styles( $hook ) {
/*    if ( 'edit.php' != $hook ) {
        return;
    }*/
//    admin_enqueue_style( 'ns_styles', PLUGIN_URL . 'assets/css/main.css', array(), '1.0' );
    wp_register_style( 'ns_styles', PLUGIN_URL . 'assets/css/main.css', false, '1.0.0' );
    wp_enqueue_style( 'ns_styles' );
    wp_register_script( 'ns_scripts', PLUGIN_URL . 'assets/js/main.js', true, '1.0.0' );
    wp_enqueue_script( 'ns_scripts' );



}
add_action( 'admin_enqueue_scripts', 'ns_contact_enqueue_styles' );


function page_callback(){
echo "<h1 style='color: red;'>Setting - NS Contact</h1>";
}

function view_contact_callback(){
   include_once PLUGIN_DIR.'views/view_contacts.php';
}

function add_contact_callback(){
    include_once PLUGIN_DIR.'views/add_contact.php';
}