add new all command

db/db.go

@@ -10,7 +10,8 @@ import (
 )
 
 type chatDTO struct {
-	ChatID int64 `bson:"chat_id"`
+	ChatID int64    `bson:"chat_id"`
+	Users  []string `bson:"users"`
 }
 
 var cfg *config.Config
@@ -41,6 +42,10 @@ func AddChat(chatID int64) error {
 }
 
 func AddUserInChat(chatID int64, username string) error {
+	if username == "" {
+		return nil
+	}
+
 	if err := AddChat(chatID); err != nil {
 		return err
 	}
@@ -61,3 +66,20 @@ func AddUserInChat(chatID int64, username string) error {
 	)
 	return err
 }
+
+func GetUsers(chatID int64) ([]string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+
+	client, err := mongo.Connect(ctx, options.Client().ApplyURI(cfg.MongoURL))
+	if err != nil {
+		return nil, err
+	}
+
+	collection := client.Database(cfg.DBName).Collection(cfg.ChatsCollectionName)
+	chatDTO := &chatDTO{}
+	if err := collection.FindOne(ctx, bson.M{"chat_id": chatID}).Decode(chatDTO); err != nil {
+		return nil, err
+	}
+	return chatDTO.Users, err
+}