From df1af564443778a63ccdbe38a0a7ae4eb97d2df5 Mon Sep 17 00:00:00 2001
From: budougumi0617 <budougumi0617@gmail.com>
Date: Mon, 12 Oct 2020 02:12:01 +0900
Subject: [PATCH] :recycle: change stream by args

---
 cmd/leetgode/main.go | 55 +++++++++++++++++++++++++++++---------------
 1 file changed, 36 insertions(+), 19 deletions(-)

diff --git a/cmd/leetgode/main.go b/cmd/leetgode/main.go
index 908fc56..5e298f6 100644
--- a/cmd/leetgode/main.go
+++ b/cmd/leetgode/main.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"os"
@@ -12,35 +13,51 @@ import (
 )
 
 func main() {
-	flag.Usage = func() {
-		if err := leetgode.ShowUsage(os.Stdout); err != nil {
-			panic(err)
+	os.Exit(run(os.Stdout, os.Stderr, os.Args))
+}
+
+func run(stdout, stderr io.Writer, args []string) int {
+	if len(args) < 2 {
+		cmd := &leetgode.HelpCmd{}
+		if err := cmd.Run(context.Background(), []string{}); err != nil {
+			fmt.Fprintf(stderr, "help comamnd is faield: %v", err)
 		}
+		return 1
 	}
-	flag.Parse()
-	sub := flag.Arg(0)
-	if len(sub) == 0 {
-		cmd := &leetgode.HelpCmd{}
-		if err := cmd.Run(context.Background(), []string{}); err !=nil{
-			fmt.Printf("help comamnd is faield: %v", err)
+	sub := args[1]
+	f := flag.NewFlagSet(sub, flag.ContinueOnError)
+	f.Usage = func() {
+		if err := leetgode.ShowUsage(stdout); err != nil {
+			fmt.Fprintf(stderr, "failed show useage: %v\n", err)
 		}
-		return
 	}
-	// TODO: set os.Stderr if set debug mode
-	log.SetOutput(ioutil.Discard)
+	var v bool
+	f.BoolVar(&v, "v", false, "show debug print")
+	if err := f.Parse(args[2:]); err == flag.ErrHelp {
+		return 1
+	} else if err != nil {
+		fmt.Fprintf(stderr, "%s with invalid args: %v\n", sub, err)
+		return 1
+	}
+
+	log.SetOutput(stderr)
+	if !v {
+		log.SetOutput(ioutil.Discard)
+	}
 
 	if cmd, ok := leetgode.CmdMap[leetgode.CmdName(sub)]; ok {
-		args := flag.Args()[1:]
+		args := f.Args()
 		if len(args) != cmd.MaxArg() {
-			fmt.Printf("%s expects %d options, but %d options\n", cmd.Name(), cmd.MaxArg(), len(args))
-			os.Exit(1)
+			fmt.Fprintf(stderr, "%s expects %d options, but %d options\n", cmd.Name(), cmd.MaxArg(), len(args))
+			return 1
 		}
 		if err := cmd.Run(context.Background(), args); err != nil {
-			log.Printf("main: err %v", err)
-			os.Exit(1)
+			fmt.Fprintf(stderr, "main: err %v", err)
+			return 1
 		}
 	} else {
-		log.Printf("unknown command %q", sub)
-		os.Exit(1)
+		fmt.Fprintf(stderr, "unknown command %q", sub)
+		return 1
 	}
+	return 0
 }