package barertc import ( "errors" "fmt" "sort" "strings" "sync" "time" "git.kirsle.net/apps/barertc/pkg/config" "git.kirsle.net/apps/barertc/pkg/messages" ) // Functionality for handling server-side message filtering and reporting. // filterMessage will check an incoming user message against the configured // server-side filters and react accordingly. This function also is // responsible for collecting the recent contexts (10 messages per channel). // // Parameters: the rawMsg is their (pre-Markdown-formatted) original message // (for the message context); the msg pointer is their post-formatted one, which // may be modified to censor their word before returning. // // Returns the matching message filter (or nil) and a boolean (matched). func (s *Server) filterMessage(sub *Subscriber, rawMsg messages.Message, msg *messages.Message) (*config.MessageFilter, bool) { // Collect the recent channel context first. if strings.HasPrefix(msg.Channel, "@") { // DM pushDirectMessageContext(sub, sub.Username, msg.Channel[1:], rawMsg) // If either party is an admin user, waive filtering this DM chat. if sub.IsAdmin() { return nil, false } else if other, err := s.GetSubscriber(msg.Channel[1:]); err == nil && other.IsAdmin() { return nil, false } } else { // Public channel pushMessageContext(sub, msg.Channel, rawMsg) } // Check it against the configured filters. var matched bool for _, filter := range config.Current.MessageFilters { if !filter.Enabled { continue } for _, phrase := range filter.IterPhrases() { m := phrase.FindAllStringSubmatch(msg.Message, -1) for _, match := range m { // Found a match! matched = true // Censor it? if filter.CensorMessage { msg.Message = strings.ReplaceAll(msg.Message, match[0], strings.Repeat("*", len(match[0]))) } } } if matched { return filter, true } } return nil, false } // Report the filtered message along with recent context. func (s *Server) reportFilteredMessage(sub *Subscriber, msg messages.Message) error { if !WebhookEnabled(WebhookReport) { return errors.New("report webhook is not enabled on this server") } // Prepare the report. var context string if strings.HasPrefix(msg.Channel, "@") { context = getDirectMessageContext(sub.Username, msg.Channel[1:]) } else { context = getMessageContext(msg.Channel) } if _, err := PostWebhook(WebhookReport, WebhookRequest{ Action: WebhookReport, APIKey: config.Current.AdminAPIKey, Report: WebhookRequestReport{ FromUsername: sub.Username, AboutUsername: sub.Username, Channel: msg.Channel, Timestamp: time.Now().Format(time.RFC1123), Reason: "Server Side Message Filter", Message: msg.Message, Comment: fmt.Sprintf( "This is an automated report via server side chat filters.\n\n"+ "The recent context in this channel included the following conversation:\n\n"+ "%s", context, ), }, }); err != nil { return err } return nil } // Message Context Caching // // Hold the recent (10) messages for each channel so in case of automated // reporting, the context can be delivered in the report. var ( messageContexts = map[string][]string{} messageContextMu sync.RWMutex messageContextSize = 10 ) // Push a message onto the recent messages context. func pushMessageContext(sub *Subscriber, channel string, msg messages.Message) { messageContextMu.Lock() defer messageContextMu.Unlock() // Initialize the context for new channel the first time. if _, ok := messageContexts[channel]; !ok { messageContexts[channel] = []string{} } // Append this message to it. messageContexts[channel] = append(messageContexts[channel], fmt.Sprintf( "%s [%s] %s", time.Now().Format("2006-01-02 15:04:05"), sub.Username, strings.TrimSpace(msg.Message), )) fmt.Printf("Context %s:\n%+v\n", channel, messageContexts[channel]) // Trim the context to recent messages only. if len(messageContexts[channel]) > messageContextSize { messageContexts[channel] = messageContexts[channel][len(messageContexts[channel])-messageContextSize:] } } // Push a message context for DMs. A channel name will be derived consistently // based on the sorted pair of usernames. func pushDirectMessageContext(sub *Subscriber, username1, username2 string, msg messages.Message) { var names = []string{username1, username2} sort.Strings(names) pushMessageContext( sub, fmt.Sprintf("@%s", strings.Join(names, ":")), msg, ) } // Get the recent message context, pretty printed. func getMessageContext(channel string) string { messageContextMu.RLock() defer messageContextMu.RUnlock() if _, ok := messageContexts[channel]; !ok { return "(No recent message history in this channel)" } return strings.Join(messageContexts[channel], "\n\n") } func getDirectMessageContext(username1, username2 string) string { var names = []string{username1, username2} sort.Strings(names) return getMessageContext( fmt.Sprintf("@%s", strings.Join(names, ":")), ) }