uninstall.php

<?php
/**
 * Uninstall Githuber MD plugin.
 *
 * @author Terry Lin
 * @link https://terryl.in/githuber
 *
 * @package Githuber
 * @since 1.0.0
 * @version 1.7.5
 */

// if uninstall.php is not called by WordPress, die.
if ( ! defined( 'WP_UNINSTALL_PLUGIN' ) ) {
	die;
}

if ( ! function_exists( 'githuber_get_option' ) ) {
	/**
	 * Get option.
	 *
	 * @param array  $option  The option name.
	 * @param string $section The section name.
	 * @param string $default The default value.
	 * @return string
	 */
	function githuber_get_option( $option, $section, $default = '' ) {
		$options = get_option( $section );

		if ( isset( $options[ $option ] ) ) {
			return $options[ $option ];
		}
		return $default;
	}
}

if ( 'yes' === githuber_get_option( 'clear_all_settings', 'githuber_preferences' ) ) {
	$options_names = array(
		'githuber_markdown',
		'githuber_modules',
		'githuber_extensions',
		'githuber_preferences',
		'githuber_version',
	);

	foreach ( $options_names as $option_name ) {
		delete_option( $option_name );
		delete_site_option( $option_name );
	}

	delete_option( 'githuber_migration_v162' );

	$post_meta_keys = array(
		'_is_githuber_markdown',
		'_is_githuber_markdown_enabled',
		'_githuber_prismjs',
		'_githuber_highlightjs',
		'_is_githuber_sequence',
		'_is_githuber_flow_chart',
		'_is_githuber_katex',
		'_is_githuber_mermaid',
	);

	// Remove all post_meta generated by Githuber MD.
	foreach ( $post_meta_keys as $meta_key ) {
		delete_post_meta_by_key( $meta_key );
	}
}

// enable rich text.
add_filter( 'user_can_richedit', '__return_true' );