refactor: extract processing single link to function

internal/images.go

@@ -13,47 +13,43 @@ type Parameters struct {
 	Referer    string
 }
 
-func downloadWorker(wg *sync.WaitGroup, httClient HttpClent, parameters *Parameters, linksToProcess <-chan string, results chan<- DownloadResult) {
-	for link := range linksToProcess {
-		fileName, err := GetFileNameFromUrl(link)
-		if err != nil {
-			results <- DownloadResult{Url: link, Err: err}
-		}
-
-		filePath := path.Join(parameters.Directory, fileName)
-
-		var referer string
-		if parameters.Referer == "" {
-			referer = getRootUrl(link)
-		} else {
-			referer = parameters.Referer
-		}
-
-		response, err := httClient.Request(link, map[string]string{
-			"User-Agent": parameters.UserAgent,
-			"Referer":    referer,
-		})
-		if err != nil {
-			results <- DownloadResult{Url: link, Err: err}
-		}
-
-		contentType := response.Header.Get("Content-Type")
-		err = validateContentType(contentType, parameters.ImageTypes)
-		if err != nil {
-			results <- DownloadResult{Url: link, Err: err}
-		}
-
-		filePath = addExtensionIfMissing(filePath, contentType)
-
-		err = SaveToFile(response.Body, filePath)
-		if err != nil {
-			results <- DownloadResult{Url: link, Err: err}
-		}
-
-		results <- DownloadResult{Url: link, Err: nil}
-
-		wg.Done()
+func downloadImage(link string, httClient HttpClent, parameters *Parameters) error {
+	fileName, err := GetFileNameFromUrl(link)
+	if err != nil {
+		return err
 	}
+
+	filePath := path.Join(parameters.Directory, fileName)
+
+	var referer string
+	if parameters.Referer == "" {
+		referer = getRootUrl(link)
+	} else {
+		referer = parameters.Referer
+	}
+
+	response, err := httClient.Request(link, map[string]string{
+		"User-Agent": parameters.UserAgent,
+		"Referer":    referer,
+	})
+	if err != nil {
+		return err
+	}
+
+	contentType := response.Header.Get("Content-Type")
+	err = validateContentType(contentType, parameters.ImageTypes)
+	if err != nil {
+		return err
+	}
+
+	filePath = addExtensionIfMissing(filePath, contentType)
+
+	err = SaveToFile(response.Body, filePath)
+	if err != nil {
+		return err
+	}
+
+	return nil
 }
 
 type DownloadResult struct {
@@ -76,7 +72,19 @@ func DownloadImages(links []string, httClient HttpClent, parameters *Parameters)
 	wg.Add(len(links))
 
 	for i := 0; i < parameters.Concurrent; i++ {
-		go downloadWorker(&wg, httClient, parameters, linksToProcess, results)
+		go func() {
+			for link := range linksToProcess {
+				err := downloadImage(link, httClient, parameters)
+
+				if err != nil {
+					results <- DownloadResult{Url: link, Err: err}
+				} else {
+					results <- DownloadResult{Url: link, Err: nil}
+				}
+
+				wg.Done()
+			}
+		}()
 	}
 
 	// wait for all workers to finish