add basic command parser

config/main.go

@@ -4,29 +4,80 @@ import (
 	"errors"
 	"flag"
 	"io/fs"
+	"os"
 
 	"git.faercol.me/faercol/http-boot-config/config/logger"
 	"git.faercol.me/faercol/http-boot-config/config/prober"
 )
 
+type action int
+
+const (
+	actionList action = iota
+	actionGetRemote
+	actionUnknown
+)
+
 type cliArgs struct {
 	debug  bool
 	colour bool
+	action action
 }
 
-func parseArgs() cliArgs {
+var defaultArgs cliArgs = cliArgs{
+	debug:  false,
+	colour: true,
+	action: actionUnknown,
+}
+
+func parseArgs() (cliArgs, error) {
+	args := defaultArgs
+	var firstArg int
+
+	getRemoteFlagSet := flag.NewFlagSet("get-remote", flag.ExitOnError)
+	listFlagSet := flag.NewFlagSet("list", flag.ExitOnError)
+
 	debugFlag := flag.Bool("debug", false, "Display debug logs")
 	noColourFlag := flag.Bool("no-colour", false, "Disable colour logs")
 
-	flag.Parse()
-
-	return cliArgs{
-		debug:  *debugFlag,
-		colour: !*noColourFlag,
+	for i, v := range os.Args {
+		switch v {
+		case "list":
+			args.action = actionList
+		case "get-remote":
+			args.action = actionGetRemote
+		default:
+			continue
+		}
+		firstArg = i + 1
 	}
+
+	switch args.action {
+	case actionList:
+		listFlagSet.Parse(os.Args[firstArg:])
+	case actionGetRemote:
+		getRemoteFlagSet.Parse(os.Args[firstArg:])
+	default:
+		flag.Parse()
+		return cliArgs{}, errors.New("missing an action")
+	}
+
+	flag.Parse()
+	args.debug = *debugFlag
+	args.colour = !*noColourFlag
+	return args, nil
 }
 
-func displayAppList(apps []prober.EfiApp, l *logger.SimpleLogger) {
+func displayAppList(l *logger.SimpleLogger) {
+	l.Info("Checking EFI directory for available boot images...")
+	apps, err := prober.GetEFIApps(l)
+	if err != nil {
+		if errors.Is(err, fs.ErrPermission) {
+			l.Fatal("Permission error, try to run the command as sudo")
+		}
+		l.Fatalf("Failed to check EFI directory: %s", err.Error())
+	}
+
 	l.Info("Found the following EFI applications:")
 	for _, a := range apps {
 		prefix := " "
@@ -37,18 +88,24 @@ func displayAppList(apps []prober.EfiApp, l *logger.SimpleLogger) {
 	}
 }
 
+func getRemoteConfig(l *logger.SimpleLogger) {
+	l.Info("Getting config from remote server...")
+}
+
 func main() {
-	args := parseArgs()
+	args, err := parseArgs()
+	if err != nil {
+		l := logger.New(true, false)
+		l.Fatalf("Invalid command: %s", err.Error())
+	}
 	l := logger.New(args.colour, args.debug)
 
-	l.Info("Checking EFI directory for available boot images...")
-	images, err := prober.GetEFIApps(l)
-	if err != nil {
-		if errors.Is(err, fs.ErrPermission) {
-			l.Fatal("Permission error, try to run the command as sudo")
-		}
-		l.Fatalf("Failed to check EFI directory: %s", err.Error())
+	switch args.action {
+	case actionList:
+		displayAppList(l)
+	case actionGetRemote:
+		getRemoteConfig(l)
+	default:
+		l.Fatal("Unknown action")
 	}
-
-	displayAppList(images, l)
 }