feat: add log to file

cmd/main.go

@@ -1,7 +1,9 @@
 package main
 
 import (
+	"fmt"
 	"os"
+	"stump/internal/utils"
 
 	"stump/internal/db"
 	"stump/internal/logger"
@@ -12,9 +14,19 @@ import (
 )
 
 func main() {
-	err := godotenv.Load()
+	utils.ParseFlags()
+
+	var err error
+
+	err = godotenv.Load()
+	if err != nil {
+		logger.Error("There was a problem loading the .env file: %v", err)
+		os.Exit(1)
+	}
+
+	err = logger.Init()
 	if err != nil {
-		logger.Error("There was a problem loading the .env file")
+		fmt.Printf("failed to initialize logger: %v\n", err)
 		os.Exit(1)
 	}
 

internal/logger/logger.go

@@ -1,14 +1,41 @@
 package logger
 
 import (
+	"fmt"
 	"log"
 	"os"
+	"path/filepath"
+	"stump/internal/utils"
 )
 
 var l *log.Logger
 
-func init() {
-	l = log.New(os.Stdout, "", log.Ldate|log.Ltime)
+const logName = "stump.log"
+
+func Init() error {
+	logToFile := utils.IsFlagSet("log")
+
+	var logOutput *os.File
+
+	if logToFile {
+		logPath, err := utils.GetAppPath()
+		logPath = filepath.Join(logPath, logName)
+
+		if err != nil {
+			return fmt.Errorf("failed to get application data path: %v", err)
+		}
+
+		logOutput, err = os.OpenFile(logPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+		if err != nil {
+			return fmt.Errorf("failed to open log file: %v", err)
+		}
+	} else {
+		logOutput = os.Stdout
+	}
+
+	l = log.New(logOutput, "", log.Ldate|log.Ltime)
+
+	return nil
 }
 
 func Info(msg string, args ...any) {

internal/utils/flags.go

@@ -0,0 +1,15 @@
+package utils
+
+import (
+	"flag"
+)
+
+func ParseFlags() {
+	flag.Bool("log", false, "enable logging to a file")
+}
+
+func IsFlagSet(name string) bool {
+	flag.Parse()
+	flagValue := flag.Lookup(name)
+	return flagValue != nil
+}