Improve command line argument handling

main.go

@@ -3,71 +3,164 @@ package main
 import (
 	"fmt"
 	"os"
-	"strings"
+	"regexp"
+	"unicode"
 
 	"github.com/NuruProgramming/Nuru/repl"
-	"github.com/NuruProgramming/Nuru/styles"
-	"github.com/charmbracelet/lipgloss"
 )
 
-var (
-	Title = styles.TitleStyle.
-		Render(`
-█░░ █░█ █▀▀ █░█ ▄▀█   █▄█ ▄▀█   █▄░█ █░█ █▀█ █░█
-█▄▄ █▄█ █▄█ █▀█ █▀█   ░█░ █▀█   █░▀█ █▄█ █▀▄ █▄█`)
-	Version = styles.VersionStyle.Render("v0.5.1")
-	Author  = styles.AuthorStyle.Render("by Avicenna")
-	NewLogo = lipgloss.JoinVertical(lipgloss.Center, Title, lipgloss.JoinHorizontal(lipgloss.Center, Author, " | ", Version))
-	Help    = styles.HelpStyle.Italic(false).Render(fmt.Sprintf(`💡 Namna ya kutumia Nuru:
-	%s: Kuanza programu ya Nuru
-	%s: Kuendesha faili la Nuru
-	%s: Kusoma nyaraka za Nuru
-	%s: Kufahamu toleo la Nuru
-`,
-		styles.HelpStyle.Bold(true).Render("nuru"),
-		styles.HelpStyle.Bold(true).Render("nuru jinaLaFile.nr"),
-		styles.HelpStyle.Bold(true).Render("nuru --nyaraka"),
-		styles.HelpStyle.Bold(true).Render("nuru --toleo")))
-)
+type flagsPassed struct {
+	help    bool
+	version bool
+	msaada  bool
+}
+
+type passedArgs struct {
+	flags flagsPassed
+	args  []string
+}
+
+var nuruVersion = "v0.5.1"
 
 func main() {
+	pa, err := parseArgs(os.Args[1:])
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%s\n\n", err)
+		msaada(1)
+	}
 
-	args := os.Args
-	if len(args) < 2 {
+	flags := pa.flags
+	handleFlags(flags)
 
-		help := styles.HelpStyle.Render("💡 Tumia exit() au toka() kuondoka")
-		fmt.Println(lipgloss.JoinVertical(lipgloss.Left, NewLogo, "\n", help))
+	args := pa.args
+	if len(args) <= 0 {
+		pre_text := fmt.Sprintf(`nuru version %s
+tumia toka() ama exit() kundoka.
+`, nuruVersion)
+		fmt.Println(pre_text)
 		repl.Start()
 		return
 	}
 
-	if len(args) == 2 {
-		switch args[1] {
-		case "msaada", "-msaada", "--msaada", "help", "-help", "--help", "-h":
-			fmt.Println(Help)
-		case "version", "-version", "--version", "-v", "v", "--toleo", "-toleo":
-			fmt.Println(NewLogo)
-		case "-docs", "--docs", "-nyaraka", "--nyaraka":
-			repl.Docs()
-		default:
-			file := args[1]
+	content, err := os.ReadFile(args[0])
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Nuru imeshindwa kusoma faili %s\n", args[0])
+		os.Exit(1)
+	}
+	repl.Read(string(content))
 
-			if strings.HasSuffix(file, "nr") || strings.HasSuffix(file, ".sw") {
-				contents, err := os.ReadFile(file)
-				if err != nil {
-					fmt.Println(styles.ErrorStyle.Render("Error: Nuru imeshindwa kusoma faili: ", args[1]))
-					os.Exit(1)
+}
+
+// call the relevant functions or do the neccesary action
+func handleFlags(flags flagsPassed) {
+	if flags.help {
+		help()
+	}
+	if flags.version {
+		version()
+	}
+	if flags.msaada {
+		msaada()
+	}
+}
+
+// parse the arguments passed in from stdin (or where they are received from)
+// It follows closely with the GNU Argument Syntax:
+// https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html
+// Arguments and flags are each populated differently.
+// If any argument is found that is not defined, then parsing stops and an error returned.
+func parseArgs(args []string) (passedArgs, error) {
+	var pa passedArgs
+	for _, arg := range args {
+		var multiple = regexp.MustCompile(`^-[\w]{2,}$`)
+		if multiple.MatchString(arg) {
+			for _, ml := range arg[1:] {
+				if unicode.IsSpace(ml) {
+					continue
+				}
+				switch ml {
+				case 'h':
+					pa.flags.help = true
+				case 'm':
+					pa.flags.msaada = true
+				case 'v':
+					pa.flags.version = true
+				default:
+					return pa, fmt.Errorf("-%s haijafanuliwa kama bendera lakini imepatikana", string(ml))
 				}
+			}
 
-				repl.Read(string(contents))
-			} else {
-				fmt.Println(styles.ErrorStyle.Render("'"+file+"'", "sii faili sahihi. Tumia faili la '.nr' au '.sw'"))
-				os.Exit(1)
+			continue
+		}
+		switch arg {
+		case "--help", "-h":
+			pa.flags.help = true
+		case "--msaada", "-m":
+			pa.flags.msaada = true
+		case "--version", "-v", "--toleo", "-t":
+			pa.flags.version = true
+		default:
+			var re = regexp.MustCompile(`^--?`)
+			if re.MatchString(arg) {
+				return pa, fmt.Errorf("%s haijafanuliwa kama bendera lakini imepatikana", arg)
 			}
+			pa.args = append(pa.args, arg)
 		}
+	}
+
+	return pa, nil
+}
+
+func printHelpMessage(exitCode int, message string) {
+	issue := "If there is an error please file a bug at: https://github.com/NuruProgramming/Nuru/issues"
+	message = fmt.Sprintf("%s\n%s\n", message, issue)
+	if exitCode != 0 {
+		fmt.Fprintf(os.Stderr, message)
 	} else {
-		fmt.Println(styles.ErrorStyle.Render("Error: Operesheni imeshindikana boss."))
-		fmt.Println(Help)
-		os.Exit(1)
+		fmt.Fprintf(os.Stdout, message)
 	}
+	os.Exit(exitCode)
+}
+
+func help(args ...int) {
+	exitCode := 0
+	if len(args) > 0 {
+		exitCode = args[0]
+	}
+	str := `nuru programming language
+
+usage: nuru [option] [file]
+
+Flags:
+--help: Display this help message
+--version: Display the current version
+`
+	printHelpMessage(exitCode, str)
+}
+
+func msaada(args ...int) {
+	exitCode := 0
+	if len(args) > 0 {
+		exitCode = args[0]
+	}
+	ms := `Lugha ya programu ya Nuru
+
+Matumizi: nuru [chaguo] [faili]
+
+Bendera:
+--msaada: Onyesha ujumbe huu wa msaada
+--toleo: Onyesha toleo la sasa
+`
+	printHelpMessage(exitCode, ms)
+}
+
+func version() {
+	ver := fmt.Sprintf(`nuru programming %s
+Copyright (C) 2024 Nuru Authors.
+This is free software; see the source for copying conditions.
+There is NO warranty; not even for MERCHANDABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+`, nuruVersion)
+
+	fmt.Println(ver)
+	os.Exit(0)
 }