finlabsindia/wp-content/plugins/jetpack/json-endpoints/class.wpcom-json-api-update-site-homepage-endpoint.php

<?php

new WPCOM_JSON_API_Update_Site_Homepage_Endpoint( array (
	'description'      => 'Set site homepage settings',
	'group'            => '__do_not_document',
	'stat'             => 'sites:1:homepage',
	'method'           => 'POST',
	'min_version'      => '1.1',
	'path'             => '/sites/%s/homepage',
	'path_labels'      => array(
		'$site' => '(string) Site ID or domain.',
	),
	'request_format'  => array(
		'is_page_on_front' => '(bool) True if we will use a page as the homepage; false to use a blog page as the homepage.',
		'page_on_front_id' => '(int) Optional. The ID of the page to use as the homepage if is_page_on_front is true.',
		'page_for_posts_id' => '(int) Optional. The ID of the page to use as the blog page if is_page_on_front is true.',
	),
	'response_format'  => array(
		'is_page_on_front' => '(bool) True if we will use a page as the homepage; false to use a blog page as the homepage.',
		'page_on_front_id' => '(int) The ID of the page to use as the homepage if is_page_on_front is true.',
		'page_for_posts_id' => '(int) The ID of the page to use as the blog page if is_page_on_front is true.',
	),
	'example_request'  => 'https://public-api.wordpress.com/rest/v1.1/sites/82974409/homepage',
	'example_request_data' => array(
		'headers' => array( 'authorization' => 'Bearer YOUR_API_TOKEN' ),
		'body' => array(
			'is_page_on_front' => true,
			'page_on_front_id' => 1,
			'page_for_posts_id' => 0,
		),
	),
	'example_response' => '{"is_page_on_front":true,"page_on_front_id":1,"page_for_posts_id":0}'
) );

class WPCOM_JSON_API_Update_Site_Homepage_Endpoint extends WPCOM_JSON_API_Endpoint {

	function callback( $path = '', $site_id = 0 ) {
		$blog_id = $this->api->switch_to_blog_and_validate_user( $this->api->get_blog_id( $site_id ) );
		if ( is_wp_error( $blog_id ) ) {
			return $blog_id;
		}

		if ( ! current_user_can( 'edit_theme_options' ) ) {
			return new WP_Error( 'unauthorized', 'User is not authorized to access homepage settings', 403 );
		}

		$args = $this->input();
		if ( empty( $args ) || ! is_array( $args ) ) {
			return $this->get_current_settings();
		}

		if ( isset( $args['is_page_on_front'] ) ) {
			$show_on_front = $args['is_page_on_front'] ? 'page' : 'posts';
			update_option( 'show_on_front', $show_on_front );
		}
		if ( isset( $args['page_on_front_id'] ) ) {
			update_option( 'page_on_front', $args['page_on_front_id'] );
		}
		if ( isset( $args['page_for_posts_id'] ) ) {
			update_option( 'page_for_posts', $args['page_for_posts_id'] );
		}

		return $this->get_current_settings();
	}

	function get_current_settings() {
		$is_page_on_front = ( get_option( 'show_on_front' ) === 'page' );
		$page_on_front_id = get_option( 'page_on_front' );
		$page_for_posts_id = get_option( 'page_for_posts' );

		return array(
			'is_page_on_front' => $is_page_on_front,
			'page_on_front_id' => $page_on_front_id,
			'page_for_posts_id' => $page_for_posts_id,
		);
	}
}