<?php

/**

 * HTTPS migration functions.

 *

 * @package WordPress

 * @since 5.7.0

 */

/**

 * Checks whether WordPress should replace old HTTP URLs to the site with their HTTPS counterpart.

 *

 * If a WordPress site had its URL changed from HTTP to HTTPS, by default this will return `true`, causing WordPress to

 * add frontend filters to replace insecure site URLs that may be present in older database content. The

 * {@see 'wp_should_replace_insecure_home_url'} filter can be used to modify that behavior.

 *

 * @since 5.7.0

 *

 * @return bool True if insecure URLs should replaced, false otherwise.

 */

function wp_should_replace_insecure_home_url() {

	$should_replace_insecure_home_url = wp_is_using_https()

		&& get_option( 'https_migration_required' )

		// For automatic replacement, both 'home' and 'siteurl' need to not only use HTTPS, they also need to be using

		// the same domain.

		&& wp_parse_url( home_url(), PHP_URL_HOST ) === wp_parse_url( site_url(), PHP_URL_HOST );

	/**

	 * Filters whether WordPress should replace old HTTP URLs to the site with their HTTPS counterpart.

	 *

	 * If a WordPress site had its URL changed from HTTP to HTTPS, by default this will return `true`. This filter can

	 * be used to disable that behavior, e.g. after having replaced URLs manually in the database.

	 *

	 * @since 5.7.0

	 *

	 * @param bool $should_replace_insecure_home_url Whether insecure HTTP URLs to the site should be replaced.

	 */

	return apply_filters( 'wp_should_replace_insecure_home_url', $should_replace_insecure_home_url );

}

/**

 * Replaces insecure HTTP URLs to the site in the given content, if configured to do so.

 *

 * This function replaces all occurrences of the HTTP version of the site's URL with its HTTPS counterpart, if

 * determined via {@see wp_should_replace_insecure_home_url()}.

 *

 * @since 5.7.0

 *

 * @param string $content Content to replace URLs in.

 * @return string Filtered content.

 */

function wp_replace_insecure_home_url( $content ) {

	if ( ! wp_should_replace_insecure_home_url() ) {

		return $content;

	}

	$https_url = home_url( '', 'https' );

	$http_url  = str_replace( 'https://', 'http://', $https_url );

	// Also replace potentially escaped URL.

	$escaped_https_url = str_replace( '/', '\/', $https_url );

	$escaped_http_url  = str_replace( '/', '\/', $http_url );

	return str_replace(

		array(

			$http_url,

			$escaped_http_url,

		),

		array(

			$https_url,

			$escaped_https_url,

		),

		$content

	);

}

/**

 * Update the 'home' and 'siteurl' option to use the HTTPS variant of their URL.

 *

 * If this update does not result in WordPress recognizing that the site is now using HTTPS (e.g. due to constants

 * overriding the URLs used), the changes will be reverted. In such a case the function will return false.

 *

 * @since 5.7.0

 *

 * @return bool True on success, false on failure.

 */

function wp_update_urls_to_https() {

	// Get current URL options.

	$orig_home    = get_option( 'home' );

	$orig_siteurl = get_option( 'siteurl' );

	// Get current URL options, replacing HTTP with HTTPS.

	$home    = str_replace( 'http://', 'https://', $orig_home );

	$siteurl = str_replace( 'http://', 'https://', $orig_siteurl );

	// Update the options.

	update_option( 'home', $home );

	update_option( 'siteurl', $siteurl );

	if ( ! wp_is_using_https() ) {

		/*

		 * If this did not result in the site recognizing HTTPS as being used,

		 * revert the change and return false.

		 */

		update_option( 'home', $orig_home );

		update_option( 'siteurl', $orig_siteurl );

		return false;

	}

	// Otherwise the URLs were successfully changed to use HTTPS.

	return true;

}

/**

 * Updates the 'https_migration_required' option if needed when the given URL has been updated from HTTP to HTTPS.

 *

 * If this is a fresh site, a migration will not be required, so the option will be set as `false`.

 *

 * This is hooked into the {@see 'update_option_home'} action.

 *

 * @since 5.7.0

 * @access private

 *

 * @param mixed $old_url Previous value of the URL option.

 * @param mixed $new_url New value of the URL option.

 */

function wp_update_https_migration_required( $old_url, $new_url ) {

	// Do nothing if WordPress is being installed.

	if ( wp_installing() ) {

		return;

	}

	// Delete/reset the option if the new URL is not the HTTPS version of the old URL.

	if ( untrailingslashit( (string) $old_url ) !== str_replace( 'https://', 'http://', untrailingslashit( (string) $new_url ) ) ) {

		delete_option( 'https_migration_required' );

		return;

	}

	// If this is a fresh site, there is no content to migrate, so do not require migration.

	$https_migration_required = get_option( 'fresh_site' ) ? false : true;

	update_option( 'https_migration_required', $https_migration_required );

}