download: add mutual exclusive flag check for exercise and uuid

Author: nywilken

cmd/download.go

@@ -64,32 +64,32 @@ func runDownload(cfg config.Config, flags *pflag.FlagSet, args []string) error {
 	if err != nil {
 		return err
 	}
-	if uuid == "" && slug == "" {
+	if uuid != "" && slug != "" || uuid == slug {
 		return errors.New("need an --exercise name or a solution --uuid")
 	}
 
-	param := "latest"
-	if uuid != "" {
-		param = uuid
-	}
-	url := fmt.Sprintf("%s/solutions/%s", usrCfg.GetString("apibaseurl"), param)
-
-	client, err := api.NewClient(usrCfg.GetString("token"), usrCfg.GetString("apibaseurl"))
+	track, err := flags.GetString("track")
 	if err != nil {
 		return err
 	}
 
-	req, err := client.NewRequest("GET", url, nil)
+	team, err := flags.GetString("team")
 	if err != nil {
 		return err
 	}
 
-	track, err := flags.GetString("track")
+	param := "latest"
+	if uuid != "" {
+		param = uuid
+	}
+	url := fmt.Sprintf("%s/solutions/%s", usrCfg.GetString("apibaseurl"), param)
+
+	client, err := api.NewClient(usrCfg.GetString("token"), usrCfg.GetString("apibaseurl"))
 	if err != nil {
 		return err
 	}
 
-	team, err := flags.GetString("team")
+	req, err := client.NewRequest("GET", url, nil)
 	if err != nil {
 		return err
 	}