some fixes and added logging

main.go

@@ -1,11 +1,12 @@
 package main
 
 import (
-	"fmt"
-	"log"
+	"io"
 	"os"
 	"os/signal"
+	"strconv"
 	"syscall"
+	"time"
 
 	"database/sql"
 	"net/url"
@@ -13,6 +14,7 @@ import (
 	"github.com/bwmarrin/discordgo"
 	"github.com/joho/godotenv"
 	_ "github.com/lib/pq"
+	"github.com/sirupsen/logrus"
 )
 
 //TODO: add more error handlings
@@ -21,21 +23,21 @@ var db *sql.DB
 var bot *discordgo.Session
 
 func main() {
-	godotenv.Load()
-
+	logrusInitFile()
 	var err error
+	godotenv.Load()
 	connStr := "postgresql://" + os.Getenv("DB_USER") + ":" + url.QueryEscape(os.Getenv("DB_PASSWORD")) + "@" + os.Getenv("DB_SERVER") + ":" + string(os.Getenv("DB_PORT")) + "/" + os.Getenv("DB_NAME") + "?sslmode=disable&application_name=Discord Bot"
 	db, err = sql.Open("postgres", connStr)
 	if err != nil {
-		log.Fatal(err)
+		logrus.Fatal(err)
 	}
 	initTables()
 	bot, err = discordgo.New("Bot " + os.Getenv("BOT_TOKEN"))
 	if err != nil {
-		fmt.Println("error creating Discord session,", err)
+		logrus.Fatal("error creating Discord session,", err)
 		return
 	} else {
-		fmt.Println("Discord session created")
+		logrus.Info("Discord session created")
 	}
 	bot.Identify.Intents = discordgo.IntentsGuildMessages | discordgo.IntentsGuilds | discordgo.IntentMessageContent | discordgo.IntentGuildMembers
 	bot.AddHandler(ready)
@@ -46,13 +48,37 @@ func main() {
 	bot.AddHandler(guildMemberJoin)
 	err = bot.Open()
 	if err != nil {
-		fmt.Println("error opening connection,", err)
+		logrus.Error("error opening connection,", err)
 		return
 	}
-	fmt.Printf("\nBot is now running as \"%s\"!", bot.State.User.Username)
+	logrus.Infof("\nBot is now running as \"%s\"!", bot.State.User.Username)
 	sc := make(chan os.Signal, 1)
 	signal.Notify(sc, syscall.SIGINT, syscall.SIGTERM, os.Interrupt)
 	<-sc
-	fmt.Println("\nShutting down...")
+	logrus.Info("\nShutting down...")
 	bot.Close()
 }
+
+func logrusInitFile() {
+	logrus.SetLevel(logrus.DebugLevel)
+	logrus.SetFormatter(&logrus.JSONFormatter{})
+	logrus.SetReportCaller(true)
+	timestamp := time.Now().Unix()
+
+	var file_name string = "logs/bot." + strconv.FormatInt(timestamp, 10) + ".log"
+	if _, err := os.Stat("logs"); os.IsNotExist(err) {
+		err := os.Mkdir("logs", 0755)
+		if err != nil {
+			logrus.Error(err)
+			return
+		}
+	}
+	log, err := os.OpenFile(file_name, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		logrus.Error(err)
+		return
+	}
+
+	mw := io.MultiWriter(os.Stdout, log)
+	logrus.SetOutput(mw)
+}