<?php
if ( ! defined( 'ABSPATH' ) ) {
	header( 'Status: 403 Forbidden' );
	header( 'HTTP/1.1 403 Forbidden' );
	exit;
}

/**
 * This class handles Cloudways - CloudFlare microservice action.
 *
 * @since 2.0.15
 * @final
 */
final class Breeze_CloudFlare_Helper {

	private $cw_platform = '';
	private static $processed_home_urls = array();

	function __construct() {
		add_action( 'switch_theme', array( &$this, 'clear_cf_on_changing_theme' ), 11, 3 );
		add_action( 'breeze_scheduled_purge', array( &$this, 'execute_purge' ), 10, 2 );
	}

	/**
	 * Define Microservice url.
	 *
	 * @return false|string
	 * @since 2.0.15
	 * @private
	 */
	private function get_microservice_url() {
		if ( false === self::is_cloudflare_enabled() ) {
			return false;
		}
		$fpc_microservice_url = ''; // default
		$fpc_env_url          = getenv( 'FPC_ENV' );
		/**
		 * Contains the dynamic microservice URL.
		 */
		if ( true === self::is_fp_server() && ! empty( $fpc_env_url ) ) {
			$this->cw_platform    = 'fp';
			$fpc_microservice_url = $fpc_env_url; // TODO Add the hardcoded link for Flexible (stating|production).

			if ( true === self::is_log_enabled() ) {
				$server_type_text = '';
				if ( true === self::is_staging_server() ) {
					$server_type_text = 'Staging';
				}

				if ( true === self::is_production_server() ) {
					$server_type_text = 'Production';
				}

				error_log( 'Cloudways FP (Flexible) is ON: ' . $server_type_text );
			}
		} elseif ( ! empty( $fpc_env_url ) ) {
			$this->cw_platform    = 'fmp';
			$fpc_microservice_url = $fpc_env_url;// FMP
			if ( true === self::is_log_enabled() ) {
				error_log( 'Cloudways FMP (Autoscale) is ON ' );
			}
		}

		/*
		 * Persist the purge API URL/platform from normal requests so cron requests can
		 * still purge when environment variables are not available in that context.
		 */
		if ( ! empty( $fpc_microservice_url ) ) {
			update_option( 'breeze_cf_microservice_url', $fpc_microservice_url );
			update_option( 'breeze_cf_platform', $this->cw_platform );
		} else {
			$cached_microservice_url = get_option( 'breeze_cf_microservice_url', '' );
			$cached_platform         = get_option( 'breeze_cf_platform', '' );

			if ( ! empty( $cached_microservice_url ) ) {
				$fpc_microservice_url = $cached_microservice_url;

				if ( in_array( $cached_platform, array( 'fp', 'fmp' ), true ) ) {
					$this->cw_platform = $cached_platform;
				} else {
					$this->cw_platform = 'fp';
				}
			}
		}

		if ( true === self::is_log_enabled() ) {
			error_log( 'Microservice URL: ' . var_export( $fpc_microservice_url, true ) );
		}

		if ( empty( $fpc_microservice_url ) ) {
			return false;
		}

		return trailingslashit( $fpc_microservice_url );
	}

	/**
	 * Warm up Cloudflare microservice options if they are missing.
	 *
	 * @return void
	 */
	public static function maybe_warmup_microservice_options(): void {
		if ( false === self::is_cloudflare_enabled() ) {
			return;
		}

		$cached_microservice_url = get_option( 'breeze_cf_microservice_url', '' );
		$cached_platform         = get_option( 'breeze_cf_platform', '' );

		if ( ! empty( $cached_microservice_url ) && in_array( $cached_platform, array( 'fp', 'fmp' ), true ) ) {
			return;
		}

		$helper = new self();
		$helper->get_microservice_url();
	}

	/**
	 * Purge Cloudflare cache on theme switch.
	 *
	 * @param string $new_name Name of the new theme.
	 * @param string $new_theme WP_Theme instance of the new theme.
	 * @param string $old_theme WP_Theme instance of the old theme.
	 *
	 * @return void
	 * @since 2.0.15
	 * @public
	 */
	public function clear_cf_on_changing_theme( string $new_name, string $new_theme, string $old_theme ) {
		$list_of_urls[] = get_home_url();
		Breeze_CloudFlare_Helper::reset_all_cache( $list_of_urls );
	}

	/**
	 * Clear the cache for the given url list.
	 * Needs at least one element.
	 *
	 * @param array $specific_urls Array with the list of URLs.
	 * @param string $purge_type Purge type: 'default', 'cron'
	 *
	 * @return bool|string|null
	 * @since 2.0.15
	 * @access public
	 * @static
	 */
	public static function purge_cloudflare_cache_urls( array $specific_urls = array(), string $purge_type = 'default' ) {
		// If we do not have everything that we need, stop the process.
		if ( true === self::is_log_enabled() ) {
			error_log( '######### PURGE CLOUDFLARE ###: ' . var_export( 'Single URL START', true ) );
		}
		if ( false === self::is_cloudflare_enabled() ) {
			return false;
		}
		// Remove any non URL items.
		$specific_urls = ( new Breeze_CloudFlare_Helper() )->remove_not_url_elements( $specific_urls );
		if ( true === self::is_log_enabled() ) {
			error_log( 'single url : ' . var_export( $specific_urls, true ) );
		}

		// Call cache reset.
		return ( new Breeze_CloudFlare_Helper() )->request_cache_reset( $specific_urls, 'purge-fpc-url', $purge_type );
	}

	/**
	 * Purge all cache in CloudFlare.
	 * In multisite clears for all sub-sites.
	 *
	 * @param array $home_url Used by WP-CLI
	 *
	 * @return bool|string|null
	 * @since 2.0.15
	 * @access public
	 * @static
	 */
	public static function reset_all_cache( array $home_url = array() ) {
		// If we do not have everything that we need, stop the process.
		if ( false === self::is_cloudflare_enabled() ) {
			return false;
		}

		/**
		 * Execute code if this function is not called by WP-CLI.
		 */
		if ( empty( $home_url ) ) {

			// For multisite network, clear cache for all sub-sites.
			if ( ( is_multisite() && is_network_admin() ) ) {
				$blogs = get_sites();
				foreach ( $blogs as $blog_data ) {
					$url        = get_home_url( $blog_data->blog_id );
					$home_url[] = trailingslashit( $url );
				}
			} else {
				$home_url[] = trailingslashit( home_url() );
			}
		}

		$home_url_key = hash( 'sha256', serialize( $home_url ) );
		if ( isset( self::$processed_home_urls[ $home_url_key ] ) ) {
			return true;
		}

		$purge_request_endpoint = 'purge-fpc-domain';

		if ( is_multisite() ) {
			if ( is_subdomain_install() ) {
				$home_url = ( new Breeze_CloudFlare_Helper() )->clear_domain_purge_urls( $home_url );
				if ( true === self::is_log_enabled() ) {
					error_log( '######### CF SubDomains: ' . var_export( $home_url, true ) );
				}
			} else {
				$purge_request_endpoint = 'purge-fpc-sub-dir';
				if ( ! empty( $home_url ) ) {
					foreach ( $home_url as &$url ) {
						$url = untrailingslashit( $url );
					}
					if ( true === self::is_log_enabled() ) {
						error_log( '######### CF SubDirectory: ' . var_export( $home_url, true ) );
					}
				}
			}
		} else {
			$home_url = ( new Breeze_CloudFlare_Helper() )->clear_domain_purge_urls( $home_url );
			if ( true === self::is_log_enabled() ) {
				error_log( '######### CF Domain: ' . var_export( $home_url, true ) );
			}
		}

		// Adjust endpoint based on WPML language URL format settings.
		$breeze_helper          = new Breeze_CloudFlare_Helper();
		$purge_request_endpoint = $breeze_helper->get_wpml_adjusted_endpoint( $purge_request_endpoint );

		// If endpoint was changed to sub-dir, we need to process URLs accordingly.
		if ( 'purge-fpc-sub-dir' === $purge_request_endpoint && ! is_multisite() ) {
			if ( ! empty( $home_url ) ) {
				foreach ( $home_url as &$url ) {
					$url = untrailingslashit( $url );
				}
				if ( true === self::is_log_enabled() ) {
					error_log( '######### CF WPML SubDirectory: ' . var_export( $home_url, true ) );
				}
			}
		}

		self::$processed_home_urls[ $home_url_key ] = true;

		return $breeze_helper->request_cache_reset( $home_url, $purge_request_endpoint );
	}

	/**
	 * Adjust the purge endpoint based on WPML language URL format settings.
	 *
	 * This method checks if WPML is active and configured to always show language
	 * directories in URLs. If both conditions are met, it changes the endpoint
	 * from 'purge-fpc-domain' to 'purge-fpc-sub-dir'.
	 *
	 * @param string $current_endpoint The current purge request endpoint.
	 *
	 * @return string The adjusted endpoint based on WPML settings.
	 * @since 2.0.20
	 * @access private
	 */
	private function get_wpml_adjusted_endpoint( string $current_endpoint ): string {
		// Only adjust if current endpoint is 'purge-fpc-domain'.
		if ( 'purge-fpc-domain' !== $current_endpoint ) {
			return $current_endpoint;
		}

		// Check if WPML is active.
		if ( ! defined( 'ICL_SITEPRESS_VERSION' ) ) {
			if ( true === self::is_log_enabled() ) {
				error_log( 'WPML is not active, keeping endpoint: ' . $current_endpoint );
			}
			return $current_endpoint;
		}

		// Get WPML settings.
		$wpml_settings = get_option( 'icl_sitepress_settings' );

		if ( empty( $wpml_settings ) ) {
			if ( true === self::is_log_enabled() ) {
				error_log( 'WPML settings not found, keeping endpoint: ' . $current_endpoint );
			}
			return $current_endpoint;
		}

		// Check language negotiation type (must be 1 for directories).
		$language_negotiation_type = isset( $wpml_settings['language_negotiation_type'] ) ? absint( $wpml_settings['language_negotiation_type'] ) : 0;

		// Check if directory for default language is enabled.
		$directory_for_default_language = isset( $wpml_settings['urls']['directory_for_default_language'] ) ? (bool) $wpml_settings['urls']['directory_for_default_language'] : false;

		if ( true === self::is_log_enabled() ) {
			error_log( 'WPML language_negotiation_type: ' . var_export( $language_negotiation_type, true ) );
			error_log( 'WPML directory_for_default_language: ' . var_export( $directory_for_default_language, true ) );
		}

		// If both conditions are met, change endpoint to subdirectory purge.
		if ( 1 === $language_negotiation_type && true === $directory_for_default_language ) {
			$adjusted_endpoint = 'purge-fpc-sub-dir';
			if ( true === self::is_log_enabled() ) {
				error_log( 'WPML language directories detected, changing endpoint from ' . $current_endpoint . ' to ' . $adjusted_endpoint );
			}
			return $adjusted_endpoint;
		}

		if ( true === self::is_log_enabled() ) {
			error_log( 'WPML conditions not met, keeping endpoint: ' . $current_endpoint );
		}

		return $current_endpoint;
	}

	/** @return bool True if any purge URL contains a WPML directory language segment (e.g. /sk/). */
	private function purge_urls_have_wpml_language_directory( array $purge_url_list ): bool {
		$langs = defined( 'ICL_SITEPRESS_VERSION' ) ? apply_filters( 'wpml_active_languages', null, array( 'skip_missing' => 0 ) ) : null;

		return is_array( $langs ) && ! empty( $langs ) && (bool) preg_grep( '#/(?:' . implode( '|', array_map( function ( $c ) { return preg_quote( strtolower( $c ), '#' ); }, array_keys( $langs ) ) ) . ')(?:/|$)#i', $purge_url_list );
	}

	/**
	 * Clear the list of URLs of HTTP schema and remove the slash at the end.
	 * This is needed for domain CF purge.
	 *
	 * @param array $url_list List of URLs.
	 *
	 * @return array
	 */
	private function clear_domain_purge_urls( array $url_list = array() ): array {
		if ( empty( $url_list ) ) {
			return $url_list;
		}

		foreach ( $url_list as &$url ) {
			$url = trim( $url );
			$url = ltrim( $url, 'https:' );
			$url = ltrim( $url, '//' );
			$url = untrailingslashit( $url );
		}

		return $url_list;
	}

	/**
	 * Remove all array elements which are not a valid URL.
	 *
	 * @param array $url_list Given url list.
	 *
	 * @return array
	 *
	 * @access private
	 * @since 2.0.15
	 */
	private function remove_not_url_elements( array $url_list = array() ): array {
		// Remove any white spaces from URL list.
		$url_list = array_map( 'trim', $url_list );
		// Making sure there are no duplicates.
		$url_list = array_unique( $url_list );

		return array_filter(
			$url_list,
			function ( $value, $index ) {
				return false !== filter_var( $value, FILTER_VALIDATE_URL );
			},
			ARRAY_FILTER_USE_BOTH
		);
	}

	/**
	 * Will return true if defined constants are found.
	 *
	 * @return bool
	 *
	 * @since 2.0.15
	 * @access public
	 * @static
	 */
	public static function is_cloudflare_enabled(): bool {
		$return_value = true;

		if (
			! defined( 'CDN_SITE_ID' ) ||
			! defined( 'CDN_SITE_TOKEN' )
		) {
			if ( true === self::is_log_enabled() ) {
				error_log( 'Error: CDN_SITE_ID or CDN_SITE_TOKEN not defined' );
			}

			$return_value = false;
		}

		$is_cloudways_server = self::is_cloudways_server();

		if ( false === $is_cloudways_server ) {
			$return_value = false;
		}

		return $return_value;
	}

	/**
	 * Detect if it's Cloudways server.
	 *
	 * @return bool
	 * @access public
	 * @since 2.0.19
	 */
	public static function is_cloudways_server(): bool {
		$has_cloudflare_constants = defined( 'CDN_SITE_ID' ) && defined( 'CDN_SITE_TOKEN' );

		if (
			false !== strpos( $_SERVER['DOCUMENT_ROOT'], 'cloudwaysapps' ) ||
			false !== strpos( $_SERVER['DOCUMENT_ROOT'], 'cloudwaysstagingapps' ) ||
			! empty( getenv( 'FPC_ENV' ) ) ||
			$has_cloudflare_constants
		) {
			return true;
		}

		return false;
	}

	public static function is_fmp_server(): bool {

		if (
			! empty( getenv( 'FPC_ENV' ) ) &&
			isset( $_SERVER['HTTP_CF_WORKER'] )
		) {

			if ( true === self::is_log_enabled() ) {
				if ( false !== strpos( getenv( 'FPC_ENV' ), 'uat-' ) ) {
					error_log( '# Microservice Server URL UAT: ON ' );
				}

				if ( false !== strpos( getenv( 'FPC_ENV' ), 'stg-' ) ) {
					error_log( '# Microservice Server URL STG: ON ' );
				}

				if ( false !== strpos( getenv( 'FPC_ENV' ), 'dev-' ) ) {
					error_log( '# Microservice Server URL DEV: ON ' );
				}

				if ( false !== strpos( getenv( 'FPC_ENV' ), 'prod-' ) ) {
					error_log( '# Microservice Server URL PROD: ON ' );
				}
			}

			return true;
		}

		return false;
	}

	/**
	 * Detect if it's Cloudways staging server.
	 *
	 * @return bool
	 * @access public
	 * @since 2.0.19
	 */
	public static function is_staging_server(): bool {

		if (
			false !== strpos( $_SERVER['DOCUMENT_ROOT'], 'cloudwaysstagingapps.com' )
		) {
			if ( true === self::is_log_enabled() ) {
				error_log( 'Cloudways Staging ON ' );
			}

			return true;
		}

		return false;
	}

	/**
	 * Detect if it's Cloudways staging server.
	 *
	 * @return bool
	 * @access public
	 * @since 2.0.19
	 */
	public static function is_production_server(): bool {

		if (
			false !== strpos( $_SERVER['DOCUMENT_ROOT'], 'cloudwaysapps.com' )
		) {
			if ( true === self::is_log_enabled() ) {
				error_log( 'Cloudways Production ON ' );
			}

			return true;
		}

		return false;
	}

	/**
	 * Check if the server type is FP ( Flexible ).
	 *
	 * @return bool
	 * @since 2.0.15
	 */
	public static function is_fp_server(): bool {
		if ( true === self::is_staging_server() || true === self::is_production_server() ) {
			return true;
		}

		return false;
	}

	/**
	 * Spawns a cron job to purge cache asynchronously and triggers it immediately without waiting.
	 *
	 * @param array $purge_url_list List of URLs for which to purge cache.
	 * @param string $endpoint_path Endpoint path to clear URL cache or whole domain cache.
	 *
	 * @return void
	 * @access private
	 * @since 2.0.15
	 */
	private function spawn_cron( array $purge_url_list, string $endpoint_path ) {
		// Schedule the purge for execution at the current time
		wp_schedule_single_event( time() - 1, 'breeze_scheduled_purge', array(
			$purge_url_list,
			$endpoint_path
		) );

		$start_cron = spawn_cron();

		if ( true === self::is_log_enabled() ) {
			error_log( 'CF Purge cron registered!' );
			error_log( 'List of URL(s) to be sent: ' . var_export( $purge_url_list, true ) );
			error_log( 'Cron started (force): ' . var_export( $start_cron, true ) );
		}
	}

	/**
	 * Handles the request for purge
	 *
	 * @param array $purge_url_list list of URLs for which to purge cache;
	 * @param string $endpoint_path Endpoint path to clear URL cache or whole domain cache.
	 * @param string $purge_type Purge type: 'default', 'cron'
	 *
	 * @return bool|string|void
	 * @access private
	 * @since 2.0.15
	 */
	private function request_cache_reset( array $purge_url_list = array(), string $endpoint_path = 'purge-fpc-url', string $purge_type = 'default' ) {

		if (
			false === self::is_cloudflare_enabled() ||
			empty( $purge_url_list )
		) {
			return;
		}

		self::is_fmp_server();

		if ( true === self::is_log_enabled() ) {
			error_log( 'CF purge type: ' . var_export( strtoupper( $purge_type ), true ) );
		}

		if ( 'cron' === $purge_type ) {
			/*
			 * Avoid spawning nested cron jobs when we're already running in a cron context
			 * (e.g. scheduled post publishing). In this case, execute purge immediately.
			 */
			if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
				if ( true === self::is_log_enabled() ) {
					error_log( 'CF purge running immediately because current request is DOING_CRON.' );
				}

				return $this->execute_purge( $purge_url_list, $endpoint_path );
			}

			$this->spawn_cron( $purge_url_list, $endpoint_path );

			return true;
		} else {
			return $this->execute_purge( $purge_url_list, $endpoint_path );
		}
	}

	/**
	 * Executes the purge cache request.
	 *
	 * @param array $purge_url_list list of URLs for which to purge cache;
	 * @param string $endpoint_path Endpoint path to clear URL cache or whole domain cache.
	 *
	 * @return bool|string
	 * @access public
	 * @since 2.0.15
	 */
	public function execute_purge( array $purge_url_list, string $endpoint_path ) {
		// Remove any white spaces from URL list.
		$purge_url_list = array_map( 'trim', $purge_url_list );
		// Making sure there are no duplicates.
		$purge_url_list = array_unique( $purge_url_list );
		// Remove empty values.
		$purge_url_list = array_values( array_filter( $purge_url_list ) );

		if ( empty( $purge_url_list ) ) {
			return false;
		}

		$has_wpml_lang_in_url = $this->purge_urls_have_wpml_language_directory( $purge_url_list );

		// Sub-dir purge API expects full URLs with https (domain purge uses scheme-stripped host paths).
		if ( 'purge-fpc-sub-dir' === $endpoint_path || $has_wpml_lang_in_url ) {
			foreach ( $purge_url_list as &$url ) {
				$url = trim( $url );
				if ( 0 !== stripos( $url, 'http://' ) && 0 !== stripos( $url, 'https://' ) ) {
					$url = 'https://' . ltrim( $url, '/' );
				} else {
					$url = set_url_scheme( $url, 'https' );
				}
			}
			unset( $url );
		}

		$verify_host      = 2;
		$ssl_verification = apply_filters( 'breeze_ssl_check_certificate', true );
		if ( ! is_bool( $ssl_verification ) ) {
			$ssl_verification = true;
		}

		if ( defined( 'WP_DEBUG' ) && true === WP_DEBUG ) {
			$ssl_verification = false;
			$verify_host      = 0;
		}

		// if SSL verification is turned to false then we need to change $verify_host also.
		if ( false === $ssl_verification ) {
			$verify_host = 0;
		}

		$rop_user_agent = 'breeze-plugin-cache-reset';

		$microservice_url = $this->get_microservice_url();

		if ( false === $microservice_url ) {
			if ( true === self::is_log_enabled() ) {
				error_log( 'Error: Microservice url is not defined ' );
			}

			return 'baseUrlNotFound';
		}

		$call_endpoint_url = $microservice_url . $endpoint_path;
		// start connection to microservice.
		if ( true === self::is_log_enabled() ) {
			error_log( '/' . $endpoint_path );
		}

		$connection = curl_init( $call_endpoint_url );
		curl_setopt( $connection, CURLOPT_SSL_VERIFYHOST, $verify_host );
		curl_setopt( $connection, CURLOPT_SSL_VERIFYPEER, $ssl_verification );
		curl_setopt( $connection, CURLOPT_POST, true );
		curl_setopt( $connection, CURLOPT_USERAGENT, $rop_user_agent );
		curl_setopt( $connection, CURLOPT_REFERER, home_url() );

		// Array to send to microservice.
		$data_to_send = array(
			'urls'     => $purge_url_list,
			'appToken' => CDN_SITE_TOKEN,
			'appId'    => CDN_SITE_ID,
			'platform' => $this->cw_platform,
		);
		if ( true === self::is_log_enabled() ) {
			error_log( 'List of URL(s) to be sent: ' . var_export( $data_to_send['urls'], true ) );
			error_log( 'Platform used : ' . var_export( strtoupper( $this->cw_platform ), true ) );
		}

		// Convert data to JSON.
		if ( ! empty( $data_to_send ) ) {
			$data_to_send = wp_json_encode( $data_to_send );
			curl_setopt( $connection, CURLOPT_POSTFIELDS, $data_to_send );
		}

		// Set request headers.
		curl_setopt(
			$connection,
			CURLOPT_HTTPHEADER,
			array(
				'Accept: application/json',
				'Content-Type: application/json',
				'Content-Length: ' . strlen( $data_to_send ),
			)
		);

		/**
		 * Accept up to 3 maximum redirects before cutting the connection.
		 */
		curl_setopt( $connection, CURLOPT_MAXREDIRS, 2 );
		curl_setopt( $connection, CURLOPT_FOLLOWLOCATION, true );
		curl_setopt( $connection, CURLOPT_RETURNTRANSFER, true );
		curl_setopt( $connection, CURLOPT_TIMEOUT, 30 );

		$server_response_body = curl_exec( $connection );
		$http_code            = curl_getinfo( $connection, CURLINFO_HTTP_CODE );
		// Add curl error in logs.
		if ( false === $server_response_body ) {
			$curl_error = curl_error( $connection );
			$curl_errno = curl_errno( $connection );

			if ( true === self::is_log_enabled() ) {
				error_log( 'cURL Error: ' . $curl_error . ' (Code: ' . $curl_errno . ')' );
			}
		}
		curl_close( $connection );
		if ( true === self::is_log_enabled() ) {
			error_log( 'Microservice response: ' . var_export( $server_response_body, true ) );
		}

		return $http_code;
	}

	/**
	 * Check if WP_DEBUG is set to true.
	 * if true then enable logs for this library.
	 *
	 * @return bool
	 *
	 * @since 2.0.15
	 * @access public
	 * @static
	 */
	public static function is_log_enabled(): bool {
		if (
			defined( 'BREEZE_CF_DEBUG' ) &&
			true === filter_var( BREEZE_CF_DEBUG, FILTER_VALIDATE_BOOLEAN )
		) {
			return true;
		}

		return false;
	}
}

new Breeze_CloudFlare_Helper();
