feat: Add strategey flag to support concurrency or sync

src/get.go

@@ -2,6 +2,7 @@ package src
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -15,8 +16,36 @@ import (
 	"github.com/spf13/cobra"
 )
 
+// Strategy
+type strategyEnum string
+
+const (
+	strategySynchronous strategyEnum = "synchronous"
+	strategyConcurrent  strategyEnum = "concurrent"
+)
+
+func (e *strategyEnum) String() string {
+	return string(*e)
+}
+
+func (e *strategyEnum) Set(value string) error {
+	switch value {
+	case "concurrent", "synchronous":
+		*e = strategyEnum(value)
+		return nil
+	default:
+		return errors.New("must be one of 'synchronous' or 'concurrent'")
+	}
+}
+
+func (e *strategyEnum) Type() string {
+	return "strategy"
+}
+
+// Command stuff
 var getFlags struct {
 	inputFile string
+	strategy  strategyEnum
 }
 
 var getCommand = &cobra.Command{
@@ -88,71 +117,100 @@ var getCommand = &cobra.Command{
 			os.Exit(1)
 		}
 
-		// Handle downloading
-		var waitGroup sync.WaitGroup
-		waitGroup.Add(len(argSet))
-
-		for url := range argSet {
-			go func(url string) {
-				defer waitGroup.Done()
-
-				split := strings.Split(url, "/")
-				downloadLocation := filepath.Clean(filepath.Join(dirPath, split[len(split)-1]))
-
-				// Ensure file already does not exist
-				Info("Checking if " + downloadLocation + " already exists")
-				if _, err := os.Stat(downloadLocation); err == nil {
-					fmt.Printf("File already exists for %s\n", downloadLocation)
-					Debug("File: " + downloadLocation + " already exists for " + url)
-					return
-				}
+		downloadFile := func(url string) {
+			split := strings.Split(url, "/")
+			downloadLocation := filepath.Clean(filepath.Join(dirPath, split[len(split)-1]))
 
-				// Get File
-				fmt.Printf("Downloading %s to %s", url, downloadLocation)
-				Info("Getting url: " + url)
+			// Ensure file already does not exist
+			Info("Checking if " + downloadLocation + " already exists")
+			if _, err := os.Stat(downloadLocation); err == nil {
+				fmt.Printf("File already exists for %s\n", downloadLocation)
+				Debug("File: " + downloadLocation + " already exists for " + url)
+				return
+			}
 
-				request, err := http.NewRequest(http.MethodGet, url, http.NoBody)
-				if err != nil {
-					fmt.Println("Failed to create request: " + url)
-					Debug(err.Error())
-					return
-				}
+			// Get File
+			fmt.Printf("Downloading %s to %s", url, downloadLocation)
+			Info("Getting url: " + url)
 
-				response, err := http.DefaultClient.Do(request)
-				if err != nil {
-					fmt.Println("Failed to get url: " + url)
-					Debug(err.Error())
-					return
-				}
-				defer response.Body.Close()
-
-				// Create file
-				Info("Creating file at: " + downloadLocation)
-				out, err := os.Create(downloadLocation)
-				if err != nil {
-					fmt.Println("Failed to create file at: " + downloadLocation)
-					Debug(err.Error())
-					return
-				}
-				defer out.Close()
-
-				// Write to file
-				Info("Writing " + url + " to " + downloadLocation)
-				if _, err := io.Copy(out, response.Body); err != nil {
-					fmt.Printf("Failed to write to file at: %s\n", downloadLocation)
-					Debug(err.Error())
-					return
-				}
+			request, err := http.NewRequest(http.MethodGet, url, http.NoBody)
+			if err != nil {
+				fmt.Println("Failed to create request: " + url)
+				Debug(err.Error())
+				return
+			}
 
-				fmt.Println("Downloaded " + url + " to " + downloadLocation)
-			}(url)
+			response, err := http.DefaultClient.Do(request)
+			if err != nil {
+				fmt.Println("Failed to get url: " + url)
+				Debug(err.Error())
+				return
+			}
+			defer response.Body.Close()
+
+			// Create file
+			Info("Creating file at: " + downloadLocation)
+			out, err := os.Create(downloadLocation)
+			if err != nil {
+				fmt.Println("Failed to create file at: " + downloadLocation)
+				Debug(err.Error())
+				return
+			}
+			defer out.Close()
+
+			// Write to file
+			Info("Writing " + url + " to " + downloadLocation)
+			if _, err := io.Copy(out, response.Body); err != nil {
+				fmt.Printf("Failed to write to file at: %s\n", downloadLocation)
+				Debug(err.Error())
+				return
+			}
+
+			fmt.Println("Downloaded " + url + " to " + downloadLocation)
 		}
 
-		waitGroup.Wait()
+		// Handle downloading
+		switch getFlags.strategy {
+		case strategyConcurrent:
+			fmt.Println("Downloading concurrently...")
+
+			var waitGroup sync.WaitGroup
+			waitGroup.Add(len(argSet))
+
+			for url := range argSet {
+				go func() {
+					defer waitGroup.Done()
+					downloadFile(url)
+				}()
+			}
+
+			waitGroup.Wait()
+		case strategySynchronous:
+			fmt.Println("Downloading synchronously...")
+
+			for url := range argSet {
+				downloadFile(url)
+			}
+		}
 	},
 }
 
 func init() {
+	getFlags.strategy = strategyConcurrent
+
 	rootCommand.AddCommand(getCommand)
 	getCommand.Flags().StringVarP(&getFlags.inputFile, "file", "f", "", "Path to the input file containing the url(s)")
+	getCommand.Flags().VarP(&getFlags.strategy, "strategy", "s", "Strategy to use when downloading (default is concurrent)")
+	if err := getCommand.RegisterFlagCompletionFunc("strategy", strategyCompletion); err != nil {
+		fmt.Println("Failed to register completion for flag -s in get command")
+		Debug(err.Error())
+		os.Exit(1)
+	}
+}
+
+func strategyCompletion(_ *cobra.Command, _ []string, _ string) ([]string, cobra.ShellCompDirective) {
+	return []string{
+		"synchronous\tDownload videos sequentially",
+		"concurrent\tDownload videos concurrently DEFAULT",
+	}, cobra.ShellCompDirectiveNoFileComp
 }