Add a limit on the number of participants

app.go

@@ -57,15 +57,16 @@ func (a *app) makeBotService() (s *tlg.BotService) {
 		Storage: a.storage,
 		Version: a.version,
 	}
-	handler.Init()
 
-	return &tlg.BotService{
-		Bot: bot,
+	service := tlg.BotService{
+		Bot:     bot,
 		Handler: handler,
 	}
+	service.Init()
+	return &service
 }
 
-func (a app) printVersion() {
+func (a *app) printVersion() {
 	fmt.Printf("Version: %s\nCommit: %s\nRuntime: %s %s/%s\nDate: %s\n",
 		a.version,
 		a.commit,
@@ -75,3 +76,7 @@ func (a app) printVersion() {
 		a.date,
 	)
 }
+
+func (a *app) Close() () {
+	a.storage.Close()
+}

show.go

@@ -2,19 +2,13 @@ package main
 
 import (
 	"fmt"
-	"github.com/taras-by/tbot/store"
-	"log"
 )
 
 func show() (err error) {
+	a := newApp()
+	defer a.Close()
 
-	storage, err := store.NewStorage(Opts.StorePath)
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer storage.Close()
-
-	for _, p := range storage.FindAll() {
+	for _, p := range a.storage.FindAll() {
 		fmt.Printf("Participant: %v\n", p)
 	}
 

store/storage.go

@@ -42,7 +42,7 @@ func NewStorage(storePath string) (*Storage, error) {
 
 func (s *Storage) Close() () {
 	_ = s.db.Close()
-	log.Printf("Storage closed")
+	log.Print("Storage closed")
 }
 
 func (s *Storage) Create(participant Participant) Participant {
@@ -184,6 +184,11 @@ func (s *Storage) FindByChatId(chatId int64) (participants []Participant) {
 	return participants
 }
 
+func (s *Storage) CountByChatId(chatId int64) int {
+	participants := s.FindByChatId(chatId)
+	return len(participants)
+}
+
 func (s *Storage) list(bucketName string) (values [][]byte) {
 	s.db.View(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(bucketName))

tbot.go

@@ -66,7 +66,7 @@ func showCmd() command {
 func runCmd() command {
 	return command{fn: func([]string) error {
 		a := newApp()
-		defer a.storage.Close()
+		defer a.Close()
 		s := a.makeBotService()
 		return s.Run()
 	}}

telegram/handler.go

@@ -13,6 +13,7 @@ import (
 
 const (
 	maxLengthStringArgument = 50
+	maxParticipants         = 100
 )
 
 type MessageHandler struct {
@@ -35,24 +36,6 @@ type conversation struct {
 	message *tgbotapi.Message
 }
 
-func (h *MessageHandler) Init() {
-	h.routes = []route{
-		{`add`, ``, h.addMe},
-		{`add`, `^@(\S+)$`, h.addByLink},
-		{`add`, `^\d+$`, h.addByNumber},
-		{`add`, `^.+$`, h.addByName},
-		{`rm`, ``, h.removeMe},
-		{`rm`, `^@(\S+)$`, h.removeByLink},
-		{`rm`, `^\d+$`, h.removeByNumber},
-		{`rm`, `^.+$`, h.removeByName},
-		{`list`, ``, h.list},
-		{`ping`, ``, h.ping},
-		{`reset`, ``, h.reset},
-		{`start`, ``, h.help},
-		{`help`, ``, h.help},
-	}
-}
-
 func (h *MessageHandler) handle(message *tgbotapi.Message) {
 	if message == nil { // ignore any non-Message Updates
 		return
@@ -128,6 +111,11 @@ func (h *MessageHandler) addMe(c conversation) {
 		}
 	}
 
+	if h.Storage.CountByChatId(c.chatId) >= maxParticipants {
+		h.sendMessageToChat(c.chatId, fmt.Sprintf("Maximum chat participants: *%v*", maxParticipants))
+		return
+	}
+
 	participant := h.Storage.Create(
 		store.Participant{
 			User: store.User{
@@ -142,8 +130,8 @@ func (h *MessageHandler) addMe(c conversation) {
 		},
 	)
 
-	h.sendMessageToChat(c.chatId, fmt.Sprintf("Added %s", store.Escape(participant.Link())))
-	text := h.participantsText(c.chatId)
+	text := fmt.Sprintf("*Added %s*", store.Escape(participant.Link())) + "\n" +
+		h.participantsText(c.chatId)
 	h.sendMessageToChat(c.chatId, text)
 }
 
@@ -162,6 +150,11 @@ func (h *MessageHandler) addByLink(c conversation) {
 		return
 	}
 
+	if h.Storage.CountByChatId(c.chatId) >= maxParticipants {
+		h.sendMessageToChat(c.chatId, fmt.Sprintf("Maximum chat participants: *%v*", maxParticipants))
+		return
+	}
+
 	participant := h.Storage.Create(
 		store.Participant{
 			User: store.User{
@@ -173,13 +166,24 @@ func (h *MessageHandler) addByLink(c conversation) {
 		},
 	)
 
-	h.sendMessageToChat(c.chatId, fmt.Sprintf("Added %s", store.Escape(participant.Link())))
-	text := h.participantsText(c.chatId)
+	text := fmt.Sprintf("*Added %s*", store.Escape(participant.Link())) + "\n" +
+		h.participantsText(c.chatId)
 	h.sendMessageToChat(c.chatId, text)
 }
 
 func (h *MessageHandler) addByName(c conversation) {
 
+	existingParticipant, err := h.Storage.FindByName(c.args, c.chatId)
+	if err == nil && existingParticipant.Id() != "" {
+		h.sendMessageToChat(c.chatId, "User is already in the list of participants")
+		return
+	}
+
+	if h.Storage.CountByChatId(c.chatId) >= maxParticipants {
+		h.sendMessageToChat(c.chatId, fmt.Sprintf("Maximum chat participants: *%v*", maxParticipants))
+		return
+	}
+
 	participant := h.Storage.Create(
 		store.Participant{
 			User: store.User{
@@ -191,8 +195,8 @@ func (h *MessageHandler) addByName(c conversation) {
 		},
 	)
 
-	h.sendMessageToChat(c.chatId, fmt.Sprintf("Added %s", store.Escape(participant.Link())))
-	text := h.participantsText(c.chatId)
+	text := fmt.Sprintf("*Added %s*", store.Escape(participant.Link())) + "\n" +
+		h.participantsText(c.chatId)
 	h.sendMessageToChat(c.chatId, text)
 }
 
@@ -202,10 +206,7 @@ func (h *MessageHandler) addByNumber(c conversation) {
 
 func (h *MessageHandler) removeMe(c conversation) {
 
-	var participant store.Participant
-	var err error
-
-	participant, err = h.Storage.Find(strconv.Itoa(c.message.From.ID), c.chatId)
+	participant, err := h.Storage.Find(strconv.Itoa(c.message.From.ID), c.chatId)
 	if err != nil {
 		participant, err = h.Storage.FindByLink("@"+c.message.From.UserName, c.chatId)
 		if err != nil {
@@ -215,71 +216,62 @@ func (h *MessageHandler) removeMe(c conversation) {
 	}
 
 	h.Storage.Delete(participant)
-	h.sendMessageToChat(c.chatId, fmt.Sprintf("Removed %s", store.Escape(participant.Link())))
 
-	text := h.participantsText(c.chatId)
+	text := fmt.Sprintf("*Removed %s*", store.Escape(participant.Link())) + "\n" +
+		h.participantsText(c.chatId)
 	h.sendMessageToChat(c.chatId, text)
 }
 
 func (h *MessageHandler) removeByNumber(c conversation) {
 
-	var participant store.Participant
-	var err error
-
 	numberString := string(c.checker.Find([]byte(c.args)))
 	number, err := strconv.Atoi(numberString)
 	if err != nil {
 		h.sendMessageToChat(c.chatId, "Wrong parameter")
 		return
 	}
 
-	participant, err = h.Storage.FindByNumber(number, c.chatId)
+	participant, err := h.Storage.FindByNumber(number, c.chatId)
 	if err != nil {
 		h.sendMessageToChat(c.chatId, store.Escape(err.Error()))
 		return
 	}
 
 	h.Storage.Delete(participant)
-	h.sendMessageToChat(c.chatId, fmt.Sprintf("Removed %s", store.Escape(participant.Link())))
 
-	text := h.participantsText(c.chatId)
+	text := fmt.Sprintf("*Removed %s*", store.Escape(participant.Link())) + "\n" +
+		h.participantsText(c.chatId)
 	h.sendMessageToChat(c.chatId, text)
 }
 
 func (h *MessageHandler) removeByLink(c conversation) {
 
-	var participant store.Participant
-	var err error
-
 	linkString := string(c.checker.Find([]byte(c.args)))
-	participant, err = h.Storage.FindByLink(linkString, c.chatId)
+	participant, err := h.Storage.FindByLink(linkString, c.chatId)
 	if err != nil {
 		h.sendMessageToChat(c.chatId, store.Escape(err.Error()))
 		return
 	}
 
 	h.Storage.Delete(participant)
-	h.sendMessageToChat(c.chatId, fmt.Sprintf("Removed %s", store.Escape(participant.Link())))
 
-	text := h.participantsText(c.chatId)
+	text := fmt.Sprintf("*Removed %s*", store.Escape(participant.Link())) + "\n" +
+		h.participantsText(c.chatId)
 	h.sendMessageToChat(c.chatId, text)
 }
 
 func (h *MessageHandler) removeByName(c conversation) {
 
-	var participant store.Participant
-	var err error
-
-	participant, err = h.Storage.FindByName(c.args, c.chatId)
+	participant, err := h.Storage.FindByName(c.args, c.chatId)
 	if err != nil {
 		h.sendMessageToChat(c.chatId, store.Escape(err.Error()))
 		return
 	}
 
 	h.Storage.Delete(participant)
-	h.sendMessageToChat(c.chatId, fmt.Sprintf("Removed %s", store.Escape(participant.Link())))
 
-	text := h.participantsText(c.chatId)
+	text := fmt.Sprintf("*Removed %s*", store.Escape(participant.Link())) + "\n" +
+		h.participantsText(c.chatId)
 	h.sendMessageToChat(c.chatId, text)
 }
 
@@ -323,7 +315,7 @@ func (h *MessageHandler) participantsText(chatId int64) (text string) {
 	if len(participants) == 0 {
 		return "No participants"
 	}
-	text = "List of participants:\n"
+	text = "Participants:\n"
 	for i, p := range participants {
 		text = text + fmt.Sprintf(" *%v)* %v\n", i+1, store.Escape(p.Name()))
 	}

telegram/telegram.go

@@ -9,6 +9,25 @@ type BotService struct {
 	Handler *MessageHandler
 }
 
+func (s *BotService) Init() {
+	h := s.Handler
+	h.routes = []route{
+		{`add`, ``, h.addMe},
+		{`add`, `^@(\S+)$`, h.addByLink},
+		{`add`, `^\d+$`, h.addByNumber},
+		{`add`, `^.+$`, h.addByName},
+		{`rm`, ``, h.removeMe},
+		{`rm`, `^@(\S+)$`, h.removeByLink},
+		{`rm`, `^\d+$`, h.removeByNumber},
+		{`rm`, `^.+$`, h.removeByName},
+		{`list`, ``, h.list},
+		{`ping`, ``, h.ping},
+		{`reset`, ``, h.reset},
+		{`start`, ``, h.help},
+		{`help`, ``, h.help},
+	}
+}
+
 func (s *BotService) Run() error {
 
 	updates, err := s.chatUpdates()