finlabsindia/wp-content/plugins/jetpack/json-endpoints/class.wpcom-json-api-get-customcss.php

<?php
/**
 * Custom Css endpoint
 *
 * https://public-api.wordpress.com/rest/v1.1/sites/$site/customcss/
 */

new WPCOM_JSON_API_Get_CustomCss_Endpoint( array (
	'description'      => 'Retrieve custom-css data for a site.',
	'group'            => '__do_not_document',
	'stat'             => 'customcss:1:get',
	'method'           => 'GET',
	'min_version'      => '1.1',
	'path'             => '/sites/%s/customcss',
	'path_labels'      => array(
		'$site' => '(string) Site ID or domain.',
	),
	'response_format'  => array(
		'css' => '(string) The raw CSS.',
		'preprocessor' => '(string) The name of the preprocessor if any.',
		'add_to_existing' => '(bool) False to skip the existing styles.',
	),
	'example_request'  => 'https://public-api.wordpress.com/rest/v1.1/sites/12345678/customcss',
	'example_response' => '
	{
		"css": ".site-title { color: #fff; }",
		"preprocessor": "sass",
		"add_to_existing": "true"
	}'
) );

class WPCOM_JSON_API_Get_CustomCss_Endpoint extends WPCOM_JSON_API_Endpoint {
	/**
	 * API callback.
	 */
	function callback( $path = '', $blog_id = 0 ) {
		// Switch to the given blog.
		$blog_id = $this->api->switch_to_blog_and_validate_user( $this->api->get_blog_id( $blog_id ) );
		if ( is_wp_error( $blog_id ) ) {
			return $blog_id;
		}

		$args = array(
			'css' => Jetpack_Custom_CSS::get_css(),
			'preprocessor' => Jetpack_Custom_CSS::get_preprocessor_key(),
			'add_to_existing' => ! Jetpack_Custom_CSS::skip_stylesheet(),
		);

		$defaults = array(
			'css' => '',
			'preprocessor' => '',
			'add_to_existing' => true,
		);
		return wp_parse_args( $args, $defaults );
	}
}