package main import ( "context" "os" "os/signal" "strconv" "strings" "syscall" "time" "github.com/spf13/pflag" "github.com/vmihailenco/msgpack/v5" "go.arsenm.dev/go-lemmy" "go.arsenm.dev/go-lemmy/types" "go.arsenm.dev/logger/log" ) func main() { configPath := pflag.StringP("config", "c", "./lemmy-reply-bot.toml", "Path to the config file") dryRun := pflag.BoolP("dry-run", "D", false, "Don't actually send comments, just check for matches") pflag.Parse() ctx := context.Background() ctx, cancel := signal.NotifyContext(ctx, syscall.SIGINT, syscall.SIGTERM) defer cancel() err := loadConfig(*configPath) if err != nil { log.Fatal("Error loading config file").Err(err).Send() } c, err := lemmy.NewWebSocket(cfg.Lemmy.InstanceURL) if err != nil { log.Fatal("Error creating new Lemmy API client").Err(err).Send() } err = c.Login(ctx, types.Login{ UsernameOrEmail: cfg.Lemmy.Account.UserOrEmail, Password: cfg.Lemmy.Account.Password, }) if err != nil { log.Fatal("Error logging in to Lemmy instance").Err(err).Send() } log.Info("Successfully logged in to Lemmy instance").Send() c.SetConnectHandler(func() error { err = c.Request(types.UserOpUserJoin, nil) if err != nil { log.Fatal("Error joining WebSocket user context").Err(err).Send() } err = c.Request(types.UserOpCommunityJoin, types.CommunityJoin{ CommunityID: 0, }) if err != nil { log.Fatal("Error joining WebSocket community context").Err(err).Send() } return nil }) c.ConnectHandler() replyCh := make(chan replyJob, 200) if !*dryRun { go commentReplyWorker(ctx, c, replyCh) } commentWorker(ctx, c, replyCh) } func commentWorker(ctx context.Context, c *lemmy.WSClient, replyCh chan<- replyJob) { repliedIDs := map[int]struct{}{} repliedStore, err := os.Open("replied.bin") if err == nil { err = msgpack.NewDecoder(repliedStore).Decode(&repliedIDs) if err != nil { log.Warn("Error decoding reply store").Err(err).Send() } repliedStore.Close() } ticker := time.NewTicker(10 * time.Second) defer ticker.Stop() for { select { case res := <-c.Responses(): // Check which operation has been sent from the server switch res.Op { case types.UserOpCreateComment, types.UserOpEditComment: var cr types.CommentResponse err = lemmy.DecodeResponse(res.Data, &cr) if err != nil { log.Warn("Error while trying to decode comment").Err(err).Send() continue } if _, ok := repliedIDs[cr.CommentView.Comment.ID]; ok { continue } for i, reply := range cfg.Replies { re := compiledRegexes[reply.Regex] if !re.MatchString(cr.CommentView.Comment.Content) { continue } log.Info("Matched comment body"). Int("reply-index", i). Int("comment-id", cr.CommentView.Comment.ID). Send() job := replyJob{ CommentID: cr.CommentView.Comment.ID, PostID: cr.CommentView.Comment.PostID, } matches := re.FindStringSubmatch(cr.CommentView.Comment.Content) job.Content = expandStr(reply.Msg, func(s string) string { i, err := strconv.Atoi(s) if err != nil { log.Debug("Message variable is not an integer, returning empty string").Str("var", s).Send() return "" } if i+1 > len(matches) { log.Debug("Message variable exceeds match length").Int("length", len(matches)).Int("var", i).Send() return "" } log.Debug("Message variable found, returning").Int("var", i).Str("found", matches[i]).Send() return matches[i] }) replyCh <- job repliedIDs[cr.CommentView.Comment.ID] = struct{}{} } } case <-ctx.Done(): repliedStore, err := os.Create("replied.bin") if err != nil { log.Warn("Error creating reply store file").Err(err).Send() return } err = msgpack.NewEncoder(repliedStore).Encode(repliedIDs) if err != nil { log.Warn("Error encoding replies to reply store").Err(err).Send() } repliedStore.Close() return } } } type replyJob struct { Content string CommentID int PostID int } func commentReplyWorker(ctx context.Context, c *lemmy.WSClient, ch <-chan replyJob) { for { select { case reply := <-ch: err := c.Request(types.UserOpCreateComment, types.CreateComment{ PostID: reply.PostID, ParentID: types.NewOptional(reply.CommentID), Content: reply.Content, }) if err != nil { log.Warn("Error while trying to create new comment").Err(err).Send() } log.Info("Created new comment"). Int("post-id", reply.PostID). Int("parent-id", reply.CommentID). Send() case <-ctx.Done(): return } } } func expandStr(s string, mapping func(string) string) string { strings.ReplaceAll(s, "$$", "${_escaped_dollar_symbol}") return os.Expand(s, func(s string) string { if s == "_escaped_dollar_symbol" { return "$" } return mapping(s) }) }