en<?php

private static $instance;

    public static function instance() {
        if ( ! self::$instance ) {
            self::$instance = new Woocommerce_Gateway_Green_Money();
            if ( in_array( 'woocommerce/woocommerce.php', apply_filters( 'active_plugins', get_option( 'active_plugins' ) ), true ) ) {
                self::$instance->setup_constants();
                self::$instance->hooks();
                self::$instance->includes();
                self::$instance->load_textdomain();

                add_filter( 'woocommerce_payment_gateways', array( self::$instance, 'add_wc_gateway' ) );
            }
        }
        return self::$instance;
    }

    private function setup_constants() {
        // Plugin path
        define( 'WOO_GM_DIR', plugin_dir_path( __FILE__ ) );

        // Plugin URL
        define( 'WOO_GM_URL', plugin_dir_url( __FILE__ ) );
    }

    private function hooks() {
        register_activation_hook( __FILE__, array( 'Woocommerce_Gateway_Green_Money', 'activate' ) );
        register_deactivation_hook( __FILE__, array( 'Woocommerce_Gateway_Green_Money', 'deactivate' ) );
    }

    private function includes() {
        require_once WOO_GM_DIR . 'includes/gateway.php';
    }

    /**
     * Add the gateway to WooCommerce.
     *
     * @access public
     * @param  array  $methods
     * @return array
     */
    function add_wc_gateway( $methods ) {

        $methods[] = 'WC_Gateway_Green_Money';
        return $methods;
    }

    public function load_textdomain() {
        // Set filter for language directory
        $lang_dir    = WOO_GM_DIR . '/languages/';
        $lang_dir    = apply_filters( 'woo_gateway_green_money_lang_dir', $lang_dir );

        // Traditional WordPress plugin locale filter
        $locale  = apply_filters( 'plugin_locale', get_locale(), '' );
        $mofile  = sprintf( '%1$s-%2$s.mo', 'woocommerce-gateway-green-money', $locale );

        // Setup paths to current locale file
        $mofile_local    = $lang_dir . $mofile;
        $mofile_global   = WP_LANG_DIR . '/woocommerce-gateway-green-money/' . $mofile;

        if ( file_exists( $mofile_global ) ) {
            // Look in global /wp-content/languages/woocommerce-gateway-green-money/ folder
            load_textdomain( 'woocommerce-gateway-green-money', $mofile_global );
        } elseif ( file_exists( $mofile_local ) ) {
            // Look in local /wp-content/plugins/woocommerce-gateway-green-money/languages/ folder
            load_textdomain( 'woocommerce-gateway-green-money', $mofile_local );
        } else {
            // Load the default language files
            load_plugin_textdomain( 'woocommerce-gateway-green-money', false, $lang_dir );
        }
    }// END public function __construct()

     public static function activate() {
         flush_rewrite_rules();
     }

     public static function deactivate() {
         flush_rewrite_rules();
     }

}// END class Woocommerce_Gateway_Green_Money

require_once( ABSPATH . 'wp-admin/includes/plugin.php' );

    $plugins = get_plugins();

    foreach ( $plugins as $plugin_path => $plugin ) {
        if ( 'WooCommerce' === $plugin['Name'] ) {
            define( 'HAS_WOO', true );
            break;
        }
    }
    add_action( 'admin_notices', 'woocommerce_gateway_green_money_notice' );
} else { //else WooCommerce class exists
    return Woocommerce_Gateway_Green_Money::instance();
}