feat: add file exists check

lib/download.go

@@ -69,6 +69,16 @@ func (app *App) Download(url string, outputFile string, serviceString string, qu
 		return err
 	}
 
+	fileExists, err := FileExists(outputFile) 
+	if err != nil {
+		return err 
+	}
+
+	if fileExists {
+		app.log("File " + outputFile + " already exists")
+		return nil
+	}
+
 	err = app.DownloadFromUrl(downloadUrl, outputFile)
 	if err != nil {
 		return err

lib/utils.go

@@ -3,6 +3,7 @@ package lib
 import (
 	"errors"
 	"fmt"
+	"os"
 	"path"
 	"strings"
 )
@@ -97,3 +98,16 @@ func GetFormatFromQuality(quality string) (string, error) {
 		return "", errors.New("Invalid quality.")
 	}
 }
+
+func FileExists(file string) (bool, error) {
+	_, err := os.Stat(file)
+	if err == nil {
+		return true, nil
+	}
+
+	if errors.Is(err, os.ErrNotExist) {
+		return false, nil
+	}
+
+	return false, err
+}