Show Pickup Time with Google calendar link in the Order Details in the Admin Screen

add_google_cal_link.php

<?php
/**
 * Show Pickup Time with Google calendar link in the Order Details in the Admin Screen
 */
if ( class_exists( 'Local_Pickup_Time' ) && class_exists( 'Local_Pickup_Time_Admin' ) ) {
	// Show Pickup Time in the Order Details in the Admin Screen
	remove_action( apply_filters( 'local_pickup_time_admin_location', 'woocommerce_admin_order_data_after_billing_address' ), array( Local_Pickup_Time_Admin::get_instance(), 'show_metabox' ), 10, 1 );
	add_action( apply_filters( 'local_pickup_time_admin_location', 'woocommerce_admin_order_data_after_billing_address' ), 'my_show_metabox', 10, 1 );

	/**
	 * Show Pickup Time with Google calendar link in the Order Details in the Admin Screen
	 *
	 * @param WC_Order $order  The order object.
	 *
	 * @return void
	 */
	function my_show_metabox( $order ) {

		$plugin = Local_Pickup_Time::get_instance();
		$order_meta  = get_post_custom( $order->get_id() );
		$pickup_time = $order_meta[ $plugin->get_order_meta_key() ][0];

		$allowed_html = array(
			'a' => array(
				'href' => array(),
				'class' => array(),
				'style' => array(),
				'target' => array(),
			),
			'p' => array(),
			'strong' => array(),
		);
		
		$event_title = urlencode( __( 'Pickup Time:', 'woocommerce-local-pickup-time' ) . ' ' . esc_html( Local_Pickup_Time_Admin::get_instance()->pickup_time_select_translatable( $pickup_time ) ) );
		$start_date = wp_date( 'Ymd\THi00', $pickup_time );
		$end_date = wp_date( 'Ymd\THi00', $pickup_time + 900 ); // 900 seconds = 15 minutes

		echo wp_kses( '<p><strong>' . __( 'Pickup Time:', 'woocommerce-local-pickup-time' ) . '</strong> ' . esc_html( Local_Pickup_Time_Admin::get_instance()->pickup_time_select_translatable( $pickup_time ) ) . ' <a href="http://www.google.com/calendar/render?action=TEMPLATE&text='.$event_title.'&dates='.$start_date.'/'.$end_date.'&details='.$event_title.'&trp=false" class="dashicons-calendar" style="font-family:\'dashicons\';text-decoration:none;" target="_blank"></a></p>', $allowed_html );

	}
}