SimpleWebsiteRedirect.php

<?php
/**
 * Simple Website Redirect
 *
 * @package           SimpleWebsiteRedirect
 * @author            Micah Wood
 * @copyright         Copyright 2018-2024 by Micah Wood - All rights reserved.
 * @license           GPL2.0-or-later
 *
 * @wordpress-plugin
 * Plugin Name:       Simple Website Redirect
 * Plugin URI:        https://wpscholar.com/wordpress-plugins/simple-website-redirect/
 * Description:       A simple plugin designed to redirect an entire website (except the WordPress admin) to another website.
 * Version:           1.3.1
 * Requires PHP:      7.4
 * Requires at least: 4.7
 * Author:            Micah Wood
 * Author URI:        https://wpscholar.com
 * Text Domain:       simple-website-redirect
 * Domain Path:       /languages
 * License:           GPL V2 or later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 */

require __DIR__ . '/vendor/autoload.php';

use wpscholar\Url;

/**
 * Class SimpleWebsiteRedirect
 */
class SimpleWebsiteRedirect {

	/**
	 * Plugin version
	 */
	const VERSION = '1.2.9';

	/**
	 * Plugin admin menu page slug.
	 *
	 * @var string
	 */
	const PAGE = 'simple-website-redirect';

	/**
	 * Url instance representing the current URL.
	 *
	 * @var \wpscholar\Url
	 */
	protected static $url;

	/**
	 * Hook our custom functions into WordPress core.
	 */
	public static function initialize() {

		self::$url = new Url();

		load_plugin_textdomain( 'simple-website-redirect', false, __DIR__ . '/languages' );

		add_action( 'init', array( __CLASS__, 'init' ) );
		add_action( 'admin_init', array( __CLASS__, 'admin_init' ) );
		add_action( 'admin_menu', array( __CLASS__, 'admin_menu' ), 99 );
		add_filter( 'plugin_action_links_' . plugin_basename( __FILE__ ), array( __CLASS__, 'plugin_action_links' ) );

		add_filter( 'simple_website_redirect_url', array( __CLASS__, 'filter_redirect_url' ) );
		add_filter( 'simple_website_redirect_should_redirect', array( __CLASS__, 'filter_by_path' ) );
		add_filter( 'simple_website_redirect_should_redirect', array( __CLASS__, 'filter_by_query_params' ) );
		add_filter( 'simple_website_redirect_excluded_paths', array( __CLASS__, 'filter_excluded_paths' ) );
		add_filter( 'simple_website_redirect_excluded_query_params', array( __CLASS__, 'filter_excluded_query_params' ) );

		add_filter( 'allowed_redirect_hosts', array( __CLASS__, 'allowed_redirect_hosts' ) );
	}

	/**
	 * Primary functionality - handles website redirect based on current configuration.
	 */
	public static function init() {
		if ( self::redirects_are_enabled() && self::should_redirect() && php_sapi_name() !== 'cli' ) {
			$redirect_url = self::get_redirect_url();
			if ( $redirect_url ) {
				wp_safe_redirect( $redirect_url, self::get_redirect_type(), 'Simple Website Redirect ' . self::VERSION );
				exit;
			}
		}
	}

	/**
	 * Checks if redirects are enabled.
	 *
	 * @return bool
	 */
	public static function redirects_are_enabled() {
		return wp_validate_boolean( get_option( 'simple_website_redirect_status', false ) );
	}

	/**
	 * Check if we should redirect for the current URL.
	 *
	 * @return bool
	 */
	public static function should_redirect() {

		// Don't redirect if running WP-CLI commands!
		if ( defined( 'WP_CLI' ) ) {
			return false;
		}

		global $pagenow;
		$should_redirect = 'wp-login.php' !== $pagenow && ! is_admin();

		return (bool) apply_filters( 'simple_website_redirect_should_redirect', $should_redirect, self::$url );
	}

	/**
	 * Check if we should preserve URL paths when redirecting.
	 *
	 * @return bool
	 */
	public static function should_preserve_url_paths() {
		return ! filter_var( get_option( 'simple_website_redirect_to_root', false ), FILTER_VALIDATE_BOOLEAN );
	}

	/**
	 * Get the redirect type (301 or 302).
	 *
	 * @return int
	 */
	public static function get_redirect_type() {
		return self::sanitize_redirect_type( get_option( 'simple_website_redirect_type' ) );
	}

	/**
	 * Get the redirect URL.
	 *
	 * @return string
	 */
	public static function get_redirect_url() {
		return apply_filters( 'simple_website_redirect_url', self::sanitize_redirect_url( get_option( 'simple_website_redirect_url' ) ) );
	}

	/**
	 * Get excluded paths as provided by the user.
	 *
	 * @return array
	 */
	public static function get_excluded_paths() {
		return array_filter( explode( ',', get_option( 'simple_website_redirect_exclude_paths', '' ) ) );
	}

	/**
	 * Get excluded query parameters as provided by the user.
	 *
	 * @return array
	 */
	public static function get_excluded_query_params() {
		return self::parse_query_params( get_option( 'simple_website_redirect_exclude_query_params', '' ) . ',page=simple-website-redirect' );
	}

	/**
	 * Filter the redirect URL.
	 *
	 * @param string $url The redirect URL.
	 *
	 * @return string
	 */
	public static function filter_redirect_url( $url ) {
		if ( $url && self::should_preserve_url_paths() ) {
			$current_url  = new Url();
			$redirect_url = new Url( $url );
			$path         = $current_url->path;
			if ( ! empty( $path ) && '/' !== $path ) {
				$redirect_url->path = implode(
					'/',
					array(
						rtrim( $redirect_url->path, '/' ),
						ltrim( $path, '/' ),
					)
				);
			}

			$redirect_url->query = $current_url->query;

			$url = $redirect_url->toString();
		}

		return $url;
	}

	/**
	 * Filter by current path whether or not a redirect should occur.
	 *
	 * @param bool $should_redirect Whether or not a redirect should occur.
	 *
	 * @return bool
	 */
	public static function filter_by_path( $should_redirect ) {
		$excluded_paths = apply_filters( 'simple_website_redirect_excluded_paths', array() );
		foreach ( $excluded_paths as $excluded_path ) {
			if ( 0 === strpos( self::$url->path, $excluded_path ) ) {
				$matches           = 0;
				$excluded_segments = array_filter( explode( '/', $excluded_path ) );
				foreach ( $excluded_segments as $index => $segment ) {
					if ( self::$url->getSegment( $index - 1 ) === $segment ) {
						++$matches;
					} else {
						break;
					}
				}
				if ( count( $excluded_segments ) === $matches ) {
					$should_redirect = false;
					break;
				}
			}
		}

		return $should_redirect;
	}

	/**
	 * Filter by current path whether or not a redirect should occur.
	 *
	 * @param bool $should_redirect Whether or not a redirect should occur.
	 *
	 * @return bool
	 */
	public static function filter_by_query_params( $should_redirect ) {
		$excluded_params = apply_filters(
			'simple_website_redirect_excluded_query_params',
			array(
				'customize_changeset_uuid' => null, // Allows editing via the WordPress Customizer
				'elementor-preview'        => null, // Allows editing via Elementor
				'preview_id'               => null, // Allows previewing in WordPress
				'rest_route'               => null, // Allows REST API requests
			)
		);
		$query_params    = self::$url->getQueryVars();
		foreach ( $excluded_params as $name => $value ) {
			if ( array_key_exists( $name, $query_params ) ) {
				if ( empty( $value ) ) {
					$should_redirect = false;
					break;
				} elseif ( $value === $query_params[ $name ] ) {
					$should_redirect = false;
					break;
				}
			}
		}

		return $should_redirect;
	}

	/**
	 * A collection of excluded paths that shouldn't result in a redirect.
	 *
	 * @param array $excluded_paths Excluded paths.
	 *
	 * @return array
	 */
	public static function filter_excluded_paths( array $excluded_paths ) {
		return array_merge(
			array(
				'/admin',
				'/login',
				'/wp-admin',
				'/wp-json',
				'/wp-login.php',
				'/wp-cron.php',
			),
			$excluded_paths,
			self::get_excluded_paths()
		);
	}

	/**
	 * A collection of excluded query parameters that shouldn't result in a redirect.
	 *
	 * @param array $excluded_params Excluded query parameters.
	 *
	 * @return array
	 */
	public static function filter_excluded_query_params( $excluded_params ) {
		return array_merge( $excluded_params, self::get_excluded_query_params() );
	}

	/**
	 * Parse query parameters into an associative array of key/value pairs.
	 *
	 * @param string|array $query_params Query string or array of strings representing key/value pairs.
	 *
	 * @return array
	 */
	public static function parse_query_params( $query_params ) {
		$params = array();
		$pairs  = is_array( $query_params ) ? $query_params : array_filter( explode( ',', $query_params ) );
		foreach ( $pairs as $pair ) {
			$parts           = explode( '=', $pair, 2 );
			$name            = array_shift( $parts );
			$value           = array_shift( $parts );
			$params[ $name ] = $value;
		}

		return $params;
	}

	/**
	 * Sanitize query params
	 *
	 * @param string $value Comma separated list of query parameters.
	 *
	 * @return string
	 */
	public static function sanitize_query_params( $value ) {
		$params = array();
		if ( ! empty( $value ) ) {
			$parsed = self::parse_query_params( $value );
			$clean  = array_combine(
				array_map( array( __CLASS__, 'sanitize_query_param' ), array_keys( $parsed ) ),
				array_map( array( __CLASS__, 'sanitize_query_param' ), array_values( $parsed ) )
			);

			foreach ( $clean as $k => $v ) {
				$params[] = empty( $v ) ? $k : "$k=$v";
			}
		}

		return implode( ',', $params );
	}

	/**
	 * Sanitize a query parameter name or value.
	 *
	 * @param string $param Query parameter name or value.
	 *
	 * @return string
	 */
	public static function sanitize_query_param( $param ) {
		return (string) preg_replace( '/[^0-9a-zA-Z_\-\+\[\]\=\%]/', '', trim( $param ) );
	}

	/**
	 * Sanitize redirect URL
	 *
	 * @param string $url The redirect URL.
	 *
	 * @return string
	 */
	public static function sanitize_redirect_url( $url ) {
		$clean_url = '';

		if ( $url ) {
			$redirect_url = new Url( $url );
			$site_url     = new Url( site_url() );

			$clean_url = "{$redirect_url->scheme}://{$redirect_url->host}{$redirect_url->path}";

			// If the redirect URL is contained within the site URL, issue a warning.
			if ( is_admin() && false !== strpos( $site_url->host, $redirect_url->host ) ) {
				add_settings_error(
					'simple_website_redirect_url',
					'simple_website_redirect_url',
					__( 'WARNING! You appear to have entered a redirect URL that may point back to the current site and cause an infinite redirect loop. Be sure to review your settings and test with the redirect type set to "Temporary" to avoid accidentally locking yourself out of your website.', 'simple-website-redirect' ),
					'error'
				);
			}
		}

		return $clean_url;
	}

	/**
	 * Sanitize redirect type
	 *
	 * @param int $type Redirect type; can be 301 or 302.
	 *
	 * @return int
	 */
	public static function sanitize_redirect_type( $type ) {
		return 302 === absint( $type ) ? 302 : 301;
	}

	/**
	 * Register our settings.
	 */
	public static function admin_init() {

		$settings = array(
			'simple_website_redirect_url'                  => array( __CLASS__, 'sanitize_redirect_url' ),
			'simple_website_redirect_type'                 => array( __CLASS__, 'sanitize_redirect_type' ),
			'simple_website_redirect_status'               => 'wp_validate_boolean',
			'simple_website_redirect_to_root'              => 'wp_validate_boolean',
			'simple_website_redirect_exclude_paths'        => 'sanitize_text_field',
			'simple_website_redirect_exclude_query_params' => array( __CLASS__, 'sanitize_query_params' ),
		);

		foreach ( $settings as $option_name => $sanitize_callback ) {
			register_setting( self::PAGE, $option_name, $sanitize_callback );
		}

		add_settings_section(
			'settings',
			esc_html__( 'Settings', 'simple-website-redirect' ),
			'__return_null',
			self::PAGE
		);

		add_settings_section(
			'advanced-settings',
			esc_html__( 'Advanced Settings', 'simple-website-redirect' ),
			function () {
				echo '<p>';
				esc_html_e( 'Use the exclude fields to prevent redirects in certain use cases, such as when using a front-end page builder.', 'simple-website-redirect' );
				echo '</p>';
			},
			self::PAGE
		);

		add_settings_field(
			'simple_website_redirect_url',
			esc_html__( 'Redirect URL', 'simple-website-redirect' ),
			array( __CLASS__, 'input_field' ),
			self::PAGE,
			'settings',
			array(
				'name'        => 'simple_website_redirect_url',
				'type'        => 'url',
				'class'       => 'regular-text',
				'placeholder' => 'https://',
			)
		);

		add_settings_field(
			'simple_website_redirect_type',
			esc_html__( 'Redirect Type', 'simple-website-redirect' ),
			array( __CLASS__, 'select_field' ),
			self::PAGE,
			'settings',
			array(
				'name'      => 'simple_website_redirect_type',
				'options'   => array(
					301 => __( 'Permanent', 'simple-website-redirect' ),
					302 => __( 'Temporary', 'simple-website-redirect' ),
				),
				'help_text' => __( 'Always set to "Temporary" when testing.', 'simple-website-redirect' ),
			)
		);

		add_settings_field(
			'simple_website_redirect_status',
			esc_html__( 'Redirect Status', 'simple-website-redirect' ),
			array( __CLASS__, 'select_field' ),
			self::PAGE,
			'settings',
			array(
				'name'    => 'simple_website_redirect_status',
				'options' => array(
					0 => __( 'Disabled', 'simple-website-redirect' ),
					1 => __( 'Enabled', 'simple-website-redirect' ),
				),
			)
		);

		add_settings_field(
			'simple_website_redirect_exclude_query_params',
			esc_html__( 'Exclude Query Parameters', 'simple-website-redirect' ),
			array( __CLASS__, 'input_field' ),
			self::PAGE,
			'advanced-settings',
			array(
				'name'      => 'simple_website_redirect_exclude_query_params',
				'class'     => 'regular-text',
				'help_text' => esc_html__( 'Separate query parameters with commas (e.g. fl_builder, elementor-preview).', 'simple-website-redirect' ),
			)
		);

		add_settings_field(
			'simple_website_redirect_exclude_paths',
			esc_html__( 'Exclude Paths', 'simple-website-redirect' ),
			array( __CLASS__, 'input_field' ),
			self::PAGE,
			'advanced-settings',
			array(
				'name'      => 'simple_website_redirect_exclude_paths',
				'class'     => 'regular-text',
				'help_text' => __( 'Separate paths with commas (e.g. /wp-admin,/wp-login.php).', 'simple-website-redirect' ),
			)
		);

		add_settings_field(
			'simple_website_redirect_to_root',
			esc_html__( 'Preserve URL Paths', 'simple-website-redirect' ),
			array( __CLASS__, 'select_field' ),
			self::PAGE,
			'advanced-settings',
			array(
				'name'    => 'simple_website_redirect_to_root',
				'options' => array(
					0 => esc_html__( 'Yes (Recommended)', 'simple-website-redirect' ),
					1 => esc_html__( 'No (Redirects all pages to the homepage)', 'simple-website-redirect' ),
				),
			)
		);
	}

	/**
	 * Add our custom admin menu page.
	 */
	public static function admin_menu() {

		add_submenu_page(
			'options-general.php',
			esc_html__( 'Simple Website Redirect', 'simple-website-redirect' ),
			esc_html__( 'Website Redirect', 'simple-website-redirect' ),
			'manage_options',
			self::PAGE,
			array( __CLASS__, 'render_page' )
		);
	}

	/**
	 * Render admin page.
	 */
	public static function render_page() {

		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		wp_enqueue_script( 'jquery' );
		settings_errors( self::PAGE );
		?>
		<div class="wrap">
			<h1><?php echo esc_html( get_admin_page_title() ); ?></h1>
			<form action="options.php" method="post">
				<?php
				do_settings_sections( self::PAGE );
				settings_fields( self::PAGE );
				submit_button( esc_html__( 'Save Settings', 'simple-website-redirect' ) );
				?>
			</form>
			<style><?php // phpcs:disable ?>
				.wrap form h2:nth-of-type(2) {
					display: none;
				}

				.wrap form h2:nth-of-type(2) + p {
					display: none;
				}

				.wrap form h2:nth-of-type(2) + p + table {
					display: none;
				}
			</style><?php // phpcs:enable ?>
			<script>
				jQuery(document).ready(function ($) {
					var showText = '<?php echo esc_js( __( 'Show Advanced Settings', 'simple-website-redirect' ) ); ?>';
					var hideText = '<?php echo esc_js( __( 'Hide Advanced Settings', 'simple-website-redirect' ) ); ?>';
					var $toggle = $('<a href="#">' + showText + '</a>');
					var $heading = $('.wrap form h2:nth-of-type(2)');
					var $description = $heading.next();
					var $table = $description.next();
					$table.after($toggle);

					$toggle.click(function (e) {
						e.preventDefault();
						toggle(!$heading.is(':visible'));
					});

					function toggle(show) {
						$toggle.text(show ? hideText : showText);
						$heading.toggle(show);
						$description.toggle(show);
						$table.toggle(show);
					}
				});
			</script>
		</div>
		<?php
	}

	/**
	 * Add settings link to plugin on plugin list in the WP admin.
	 *
	 * @param array $links Existing plugin action links.
	 *
	 * @return array
	 */
	public static function plugin_action_links( $links ) {

		$settings_link = sprintf(
			'<a href="%s">%s</a>',
			esc_url( admin_url( 'options-general.php?page=' . self::PAGE ) ),
			esc_html__( 'Settings', 'simple-website-redirect' )
		);

		$links[] = $settings_link;

		return $links;
	}

	/**
	 * Outputs an input field.
	 *
	 * @param array $args Input field properties.
	 */
	public static function input_field( array $args ) {

		$name = isset( $args['name'] ) ? $args['name'] : '';

		printf(
			'<input type="%s" class="%s" name="%s" value="%s" placeholder="%s" />%s',
			esc_attr( isset( $args['type'] ) ? $args['type'] : 'text' ),
			esc_attr( isset( $args['class'] ) ? $args['class'] : '' ),
			esc_attr( $name ),
			esc_attr( get_option( $name, '' ) ),
			esc_attr( isset( $args['placeholder'] ) ? $args['placeholder'] : '' ),
			isset( $args['help_text'] ) ? sprintf( '<p class="description">%s</p>', esc_html( $args['help_text'] ) ) : '' // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
		);
	}

	/**
	 * Outputs a select field.
	 *
	 * @param array $args Select field properties.
	 */
	public static function select_field( array $args ) {

		$name    = isset( $args['name'] ) ? $args['name'] : '';
		$options = isset( $args['options'] ) ? (array) $args['options'] : array();
		$value   = get_option( $name, '' );

		echo sprintf( '<select name="%s">', esc_attr( $name ) ) . PHP_EOL;

		foreach ( $options as $option_value => $option_label ) {
			printf(
				'<option value="%s"%s>%s</option>',
				esc_attr( $option_value ),
				selected( $option_value, $value, false ),
				esc_html( $option_label )
			);
			echo PHP_EOL;
		}
		echo '</select>' . PHP_EOL;

		if ( ! empty( $args['help_text'] ) ) {
			printf( '<p class="description">%s</p>', esc_html( $args['help_text'] ) );
		}
	}

	/**
	 * Hook to register the provided URL as an allowed redirect host.
	 *
	 * @param array $hosts Allowed redirect hosts
	 *
	 * @return array Allowed redirect hosts
	 */
	public static function allowed_redirect_hosts( $hosts ) {
		$url = get_option( 'simple_website_redirect_url' );
		if ( $url ) {
			$hosts[] = wp_parse_url( $url, PHP_URL_HOST );
		}

		return $hosts;
	}
}

add_action( 'plugins_loaded', array( 'SimpleWebsiteRedirect', 'initialize' ) );