fix flag parser

cmd/cli/main.go

@@ -1,9 +1,9 @@
 package main
 
 import (
-	"flag"
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/Mond1c/judge/dsl"
 	"github.com/Mond1c/judge/reporter"
@@ -29,30 +29,30 @@ Example:
 `
 
 func main() {
-	if len(os.Args) >= 2 && os.Args[1] == "aggregate" {
-		runAggregate()
+	args := os.Args[1:]
+
+	if len(args) == 0 || hasFlag(args, "--help") || hasFlag(args, "-h") {
+		fmt.Print(usage)
+		os.Exit(0)
+	}
+
+	if len(args) >= 1 && args[0] == "aggregate" {
+		runAggregate(args[1:])
 		return
 	}
 
-	fs := flag.NewFlagSet("judge", flag.ContinueOnError)
-	fs.SetOutput(os.Stderr)
-	fs.Usage = func() { fmt.Fprint(os.Stderr, usage) }
+	jsonOutput := hasFlag(args, "--json")
+	wrapper := flagValue(args, "--wrapper")
+	binary := flagValue(args, "--binary")
+	positional := positionalArgs(args)
 
-	jsonOutput := fs.Bool("json", false, "output as JSON")
-	wrapper := fs.String("wrapper", "", "exec wrapper command")
-	binary := fs.String("binary", "", "binary name override")
-
-	if err := fs.Parse(os.Args[1:]); err != nil {
-		os.Exit(2)
-	}
-
-	if fs.NArg() < 2 {
+	if len(positional) < 2 {
 		fmt.Fprintf(os.Stderr, "error: need <tests.jdg> and <solution-dir>\n\n%s", usage)
 		os.Exit(1)
 	}
 
-	testFile := fs.Arg(0)
-	solutionDir := fs.Arg(1)
+	testFile := positional[0]
+	solutionDir := positional[1]
 
 	src, err := os.ReadFile(testFile)
 	if err != nil {
@@ -73,12 +73,12 @@ func main() {
 
 	r := runner.New(f, runner.Config{
 		WorkDir:    solutionDir,
-		BinaryName: *binary,
-		Wrapper:    *wrapper,
+		BinaryName: binary,
+		Wrapper:    wrapper,
 	})
 	result := r.Run()
 
-	if *jsonOutput {
+	if jsonOutput {
 		if err := reporter.JSON(os.Stdout, result); err != nil {
 			fatalf("json output error: %v", err)
 		}
@@ -91,12 +91,11 @@ func main() {
 	}
 }
 
-func runAggregate() {
-	if len(os.Args) < 3 {
+func runAggregate(args []string) {
+	if len(args) < 1 {
 		fatalf("usage: judge aggregate <reports-dir>")
 	}
-	dir := os.Args[2]
-	if err := reporter.Aggregate(os.Stdout, dir); err != nil {
+	if err := reporter.Aggregate(os.Stdout, args[0]); err != nil {
 		fatalf("%v", err)
 	}
 }
@@ -105,3 +104,51 @@ func fatalf(msg string, args ...any) {
 	fmt.Fprintf(os.Stderr, "error: "+msg+"\n", args...)
 	os.Exit(1)
 }
+
+func hasFlag(args []string, name string) bool {
+	for _, a := range args {
+		if a == name {
+			return true
+		}
+	}
+	return false
+}
+
+func flagValue(args []string, name string) string {
+	prefix := name + "="
+	for i, a := range args {
+		if a == name && i+1 < len(args) {
+			return args[i+1]
+		}
+		if strings.HasPrefix(a, prefix) {
+			return a[len(prefix):]
+		}
+	}
+	return ""
+}
+
+func positionalArgs(args []string) []string {
+	known := map[string]bool{"--json": true, "--help": true, "-h": true}
+	withValue := map[string]bool{"--wrapper": true, "--binary": true}
+
+	var out []string
+	skip := false
+	for _, a := range args {
+		if skip {
+			skip = false
+			continue
+		}
+		if known[a] {
+			continue
+		}
+		if withValue[a] {
+			skip = true
+			continue
+		}
+		if strings.HasPrefix(a, "--wrapper=") || strings.HasPrefix(a, "--binary=") {
+			continue
+		}
+		out = append(out, a)
+	}
+	return out
+}