feat: add error monitoring via System Health dashboard

includes/Admin.php

@@ -290,23 +290,19 @@ function commonsbooking_sanitizeArrayorString( $data, $sanitizeFunction = 'sanit
  * @return void
  */
 function commonsbooking_write_log( $log, $backtrace = true ) {
+	$logmessage = is_array( $log ) || is_object( $log ) ? print_r( $log, true ) : (string) $log;
 
-	if ( ! WP_DEBUG_LOG ) {
-		return;
+	if ( $backtrace ) {
+		$bt         = debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS, 2 );
+		$logmessage = ( $bt[0]['file'] ?? '' ) . ':' . ( $bt[0]['line'] ?? 0 ) . ' ' . $logmessage;
 	}
 
-	if ( is_array( $log ) || is_object( $log ) ) {
-		$logmessage = ( print_r( $log, true ) );
-	} else {
-		$logmessage = $log;
-	}
+	// Always persist to the error monitor — works even without WP_DEBUG_LOG
+	\CommonsBooking\Service\ErrorMonitor::record( $logmessage, \CommonsBooking\Service\ErrorMonitor::SEVERITY_WARNING, [], 1 );
 
-	if ( $backtrace ) {
-		$bt         = debug_backtrace();
-		$file       = $bt[0]['file'];
-		$line       = $bt[0]['line'];
-		$logmessage = $file . ':' . $line . ' ' . $logmessage;
+	if ( ! WP_DEBUG_LOG ) {
+		return;
 	}
 
-	error_log( $logmessage );
+	error_log( $logmessage ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
 }

src/API/BaseRoute.php

@@ -131,13 +131,11 @@ public function validateData( $data ) {
 				}
 			}
 		} catch ( Exception $e ) {
-			// phpcs:disable WordPress.PHP.DevelopmentFunctions.error_log_error_log
+			commonsbooking_write_log( 'Problem while trying to access wp rest endpoint url for schema ' . $this->schemaUrl, false );
+			commonsbooking_write_log( (string) $e, false );
 			if ( WP_DEBUG ) {
-				error_log( 'Problem while trying to access wp rest endpoint url for schema ' . $this->schemaUrl );
-				error_log( $e );
 				die;
 			}
-			// phpcs:enable
 		}
 	}
 

src/API/GBFS/BaseRoute.php

@@ -56,9 +56,7 @@ public function getItemData( $request ): array {
 				$itemdata = $this->prepare_item_for_response( $location, $request );
 				$data[]   = $itemdata->data;
 			} catch ( Exception $exception ) {
-				if ( WP_DEBUG ) {
-					error_log( $exception->getMessage() );
-				}
+				commonsbooking_write_log( $exception->getMessage(), false );
 			}
 		}
 

src/API/LocationsRoute.php

@@ -79,9 +79,7 @@ public function getItemData( $request ) {
 				$itemdata   = $this->prepare_item_for_response( $location, $request );
 				$features[] = $itemdata->get_data();
 			} catch ( Exception $exception ) {
-				if ( WP_DEBUG ) {
-					error_log( $exception->getMessage() );
-				}
+				commonsbooking_write_log( $exception->getMessage(), false );
 			}
 		}
 

src/Helper/NominatimGeoCodeService.php

@@ -55,7 +55,7 @@ public function getAddressData( $addressString ): ?Location {
 				return $addresses->first();
 			}
 		} catch ( Exception $exception ) {
-			error_log( $exception->getMessage() );
+			commonsbooking_write_log( $exception->getMessage(), false );
 		}
 
 		return null;

src/Plugin.php

@@ -17,8 +17,11 @@
 use CommonsBooking\Service\Upgrade;
 use CommonsBooking\Settings\Settings;
 use CommonsBooking\Repository\BookingCodes;
+use CommonsBooking\Service\ErrorMonitor;
+use CommonsBooking\Service\TroubleshootingReport;
 use CommonsBooking\View\Dashboard;
 use CommonsBooking\View\MassOperations;
+use CommonsBooking\View\SystemHealth;
 use CommonsBooking\Wordpress\CustomPostType\CustomPostType;
 use CommonsBooking\Wordpress\CustomPostType\Item;
 use CommonsBooking\Wordpress\CustomPostType\Location;
@@ -323,6 +326,13 @@ protected static function addRoleCaps( $postType, $roleName ) {
 	}
 
 	public static function admin_init() {
+		// Handle "clear error log" form submission from System Health page
+		if ( isset( $_POST['cb_clear_error_log'] ) && check_admin_referer( 'cb_clear_error_log' ) ) {
+			ErrorMonitor::clear();
+			wp_safe_redirect( admin_url( 'admin.php?page=cb-system-health&cleared=1' ) );
+			exit;
+		}
+
 		// check if we have a new version and run tasks
 		Upgrade::runTasksAfterUpdate();
 
@@ -408,6 +418,16 @@ public static function addMenuPages() {
 				array( MassOperations::class, 'index' )
 			);
 		}
+
+		// System Health — available to all CB users (not just admins)
+		add_submenu_page(
+			'cb-dashboard',
+			esc_html__( 'System Health', 'commonsbooking' ),
+			esc_html__( 'System Health', 'commonsbooking' ),
+			'manage_' . COMMONSBOOKING_PLUGIN_SLUG,
+			'cb-system-health',
+			array( SystemHealth::class, 'index' )
+		);
 	}
 
 	/**
@@ -425,6 +445,11 @@ public static function handleBookingForms(): void {
 				$e->getMessage(),
 				30 // Expires very quickly, so that outdated messsages will not be shown to the user
 			);
+			ErrorMonitor::record(
+				$e->getMessage(),
+				ErrorMonitor::SEVERITY_WARNING,
+				[ 'type' => 'BookingDeniedException' ]
+			);
 			$targetUrl = $e->getRedirectUrl();
 			if ( $targetUrl ) {
 				header( 'Location: ' . $targetUrl );
@@ -507,6 +532,11 @@ public static function renderError() {
 
 		foreach ( $errorTypes as $errorType ) {
 			if ( $error = get_transient( $errorType ) ) {
+				ErrorMonitor::record(
+					$error,
+					ErrorMonitor::SEVERITY_ERROR,
+					[ 'type' => $errorType, 'source' => 'admin_notice' ]
+				);
 				$class = 'notice notice-error';
 				printf(
 					'<div class="%1$s"><p>%2$s</p></div>',
@@ -772,6 +802,9 @@ public function init() {
 		// Add menu pages
 		add_action( 'admin_menu', array( self::class, 'addMenuPages' ) );
 
+		// Troubleshooting report download (admin_post_ = logged-in users only)
+		add_action( 'admin_post_' . TroubleshootingReport::AJAX_ACTION, array( TroubleshootingReport::class, 'handleDownload' ) );
+
 		// Filter body classes of admin pages
 		add_filter( 'admin_body_class', array( self::class, 'filterAdminBodyClass' ), 10, 1 );
 

src/Repository/Timeframe.php

@@ -695,7 +695,7 @@ function ( $post ) {
 
 						return $timeframe->isBookable();
 					} catch ( Exception $e ) {
-						error_log( $e->getMessage() );
+						commonsbooking_write_log( $e->getMessage(), false );
 
 						return false;
 					}
@@ -721,7 +721,7 @@ function ( $post ) {
 				try {
 					return commonsbooking_isCurrentUserAllowedToBook( $post->ID );
 				} catch ( Exception $e ) {
-					error_log( $e->getMessage() );
+					commonsbooking_write_log( $e->getMessage(), false );
 
 					return false;
 				}

src/Service/BookingRuleApplied.php

@@ -203,13 +203,11 @@ function ( $rule ) {
 			);
 			if ( $json ) {
 				return $json;
-			} elseif ( WP_DEBUG ) {
-				error_log( 'Could not encode rules object.' ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
+			} else {
+				commonsbooking_write_log( 'Could not encode rules object.', false );
 			}
 		} catch ( Exception $e ) {
-			if ( WP_DEBUG ) {
-				error_log( $e->getMessage() ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
-			}
+			commonsbooking_write_log( $e->getMessage(), false );
 		}
 		return ''; // Return an empty string if initialization or encoding fails
 	}

src/Service/Cache.php

@@ -501,8 +501,7 @@ private static function runShortcodeCalls( array $shortCodeCalls ): void {
 				try {
 					$class::$function( $attributes, $shortcodeBody );
 				} catch ( Exception $e ) {
-					// Writes error to log anyway
-					error_log( (string) $e ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
+					commonsbooking_write_log( (string) $e, false );
 				}
 			}
 		}

src/Service/ErrorMonitor.php

@@ -0,0 +1,92 @@
+<?php
+
+namespace CommonsBooking\Service;
+
+/**
+ * Persistent error ring-buffer stored in wp_options.
+ * Accessible to plugin admins without WP_DEBUG_LOG.
+ */
+class ErrorMonitor {
+
+	const OPTION_KEY  = 'commonsbooking_error_log';
+	const MAX_ENTRIES = 100;
+
+	const SEVERITY_ERROR   = 'error';
+	const SEVERITY_WARNING = 'warning';
+	const SEVERITY_INFO    = 'info';
+
+	/**
+	 * Records a message into the ring buffer.
+	 *
+	 * @param string $message    Human-readable description.
+	 * @param string $severity   One of the SEVERITY_* constants.
+	 * @param array  $context    Extra key/value context merged with auto-captured caller info.
+	 * @param int    $traceDepth Frames to skip in debug_backtrace (0 = direct caller of record()).
+	 */
+	public static function record(
+		string $message,
+		string $severity = self::SEVERITY_ERROR,
+		array $context = [],
+		int $traceDepth = 0
+	): void {
+		if ( empty( $message ) ) {
+			return;
+		}
+
+		// Capture caller — skip record() itself + $traceDepth additional frames
+		$bt    = debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS, $traceDepth + 3 );
+		$frame = $bt[ $traceDepth + 1 ] ?? $bt[0];
+
+		$entry = [
+			'timestamp' => time(),
+			'severity'  => $severity,
+			'message'   => $message,
+			'context'   => array_merge(
+				[
+					'file' => $frame['file'] ?? '',
+					'line' => $frame['line'] ?? 0,
+				],
+				$context
+			),
+		];
+
+		$log = get_option( self::OPTION_KEY, [] );
+		array_unshift( $log, $entry );
+		if ( count( $log ) > self::MAX_ENTRIES ) {
+			$log = array_slice( $log, 0, self::MAX_ENTRIES );
+		}
+		// autoload=false: this option can grow large; only load on-demand
+		update_option( self::OPTION_KEY, $log, false );
+	}
+
+	/**
+	 * Returns the most recent entries, newest first.
+	 *
+	 * @param int $limit 0 returns up to MAX_ENTRIES.
+	 * @return array<int, array{timestamp:int, severity:string, message:string, context:array}>
+	 */
+	public static function getEntries( int $limit = 50 ): array {
+		$log = get_option( self::OPTION_KEY, [] );
+		return $limit > 0 ? array_slice( $log, 0, $limit ) : $log;
+	}
+
+	/** Returns the total number of stored entries. */
+	public static function count(): int {
+		return count( get_option( self::OPTION_KEY, [] ) );
+	}
+
+	/** Returns the count of entries matching a specific severity level. */
+	public static function countBySeverity( string $severity ): int {
+		return count(
+			array_filter(
+				get_option( self::OPTION_KEY, [] ),
+				fn( $e ) => ( $e['severity'] ?? '' ) === $severity
+			)
+		);
+	}
+
+	/** Deletes all stored entries. */
+	public static function clear(): void {
+		delete_option( self::OPTION_KEY );
+	}
+}