Adjust downloader functions

main.go

@@ -24,8 +24,13 @@ func main() {
 	}
 
 	handleGracefulShutdown()
-	if !downloader.FileExists(appSettings.DataFile) {
-		downloader.DownloadFile(appSettings.DataFile, appSettings.DataURL)
+
+	ctx := downloader.NewContext(appSettings.DataFile, appSettings.DataURL)
+	if !ctx.FileExists() {
+		if err := ctx.Download(); err != nil {
+			panic(err)
+		}
+		fmt.Printf("Saved file to %s\n", ctx.Filename)
 	}
 
 	fmt.Printf("Import data from file...\r")

pkg/downloader/downloader.go

@@ -11,34 +11,44 @@ import (
 	"github.com/schollz/progressbar/v3"
 )
 
-func handleError(err error) {
-	fmt.Println(err.Error())
-	os.Exit(0)
+type Context struct {
+	Filename string
+	Link     string
 }
 
-func DownloadFile(path, url string) {
-	resp, err := req.Head(url, nil)
+func NewContext(filename, link string) *Context {
+	return &Context{
+		Filename: filename,
+		Link:     link,
+	}
+}
+
+func (c *Context) Download() error {
+	resp, err := req.Head(c.Link, nil)
 	if err != nil {
 		if strings.Contains(err.Error(), "no such host") {
-			handleError(errors.New("invalid url"))
-		} else if strings.Contains(err.Error(), "certificate signed by unknown authority") {
-			handleError(errors.New("certificate from unknown authority"))
+			return fmt.Errorf("invalid url")
 		}
-		handleError(err)
+		if strings.Contains(err.Error(), "certificate signed by unknown authority") {
+			return fmt.Errorf("certificate from unknown authority")
+		}
+		return err
 	}
 	defer resp.Close()
 	if resp.StatusCode == 404 {
-		handleError(errors.New("invalid url"))
-	} else if resp.StatusCode == 401 {
-		handleError(errors.New("restricted access (credentials required)"))
-	} else if resp.StatusCode != 200 {
-		handleError(errors.New(resp.RawResponse.Status))
+		return fmt.Errorf("invalid url")
+	}
+	if resp.StatusCode == 401 {
+		return fmt.Errorf("restricted access (credentials required)")
+	}
+	if resp.StatusCode != 200 {
+		return fmt.Errorf(resp.RawResponse.Status)
 	}
 	resp.Close()
 
-	resp, err = req.Get(url, nil)
+	resp, err = req.Get(c.Link, nil)
 	if err != nil {
-		handleError(err)
+		return err
 	}
 
 	var filesize int64
@@ -46,9 +56,9 @@ func DownloadFile(path, url string) {
 		filesize = resp.RawResponse.ContentLength
 	}
 
-	destFile, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, 0644)
+	destFile, err := os.OpenFile(c.Filename, os.O_CREATE|os.O_WRONLY, 0644)
 	if err != nil {
-		handleError(err)
+		return err
 	}
 	defer destFile.Close()
 
@@ -59,13 +69,13 @@ func DownloadFile(path, url string) {
 
 	_, err = io.Copy(io.MultiWriter(destFile, bar), resp.RawResponse.Body)
 	if err != nil {
-		handleError(err)
+		return err
 	}
 
-	fmt.Println("Saved file to", path)
+	return nil
 }
 
-func FileExists(path string) bool {
-	_, err := os.Stat(path)
+func (c *Context) FileExists() bool {
+	_, err := os.Stat(c.Filename)
 	return !errors.Is(err, os.ErrNotExist)
 }