Filter By Hak Name

internal/app/app.go

@@ -184,6 +184,15 @@ func runBuildHAKs(ctx context) error {
 		return err
 	}
 
+	filteredHAKs, err := parseBuildHAKArgs(ctx.args[1:])
+	if err != nil {
+		return err
+	}
+	p, err = p.CloneWithHAKNames(filteredHAKs)
+	if err != nil {
+		return err
+	}
+
 	result, err := pipeline.BuildHAKsWithProgress(p, func(message string) {
 		fmt.Fprintf(ctx.stdout, "[build-haks] %s\n", message)
 	})
@@ -200,6 +209,42 @@ func runBuildHAKs(ctx context) error {
 	return nil
 }
 
+func parseBuildHAKArgs(args []string) ([]string, error) {
+	if len(args) == 0 {
+		return nil, nil
+	}
+
+	var filtered []string
+	for index := 0; index < len(args); index++ {
+		arg := args[index]
+		switch arg {
+		case "-h", "--help":
+			return nil, errors.New("usage: build-haks [--hak <hak-name> ...]")
+		case "--hak":
+			index++
+			if index >= len(args) {
+				return nil, errors.New("--hak requires a value")
+			}
+			filtered = append(filtered, args[index])
+		default:
+			if value, ok := parseInlineFlagValue(arg, "--hak"); ok {
+				filtered = append(filtered, value)
+				continue
+			}
+			return nil, fmt.Errorf("unknown build-haks argument %q", arg)
+		}
+	}
+	return filtered, nil
+}
+
+func parseInlineFlagValue(arg, name string) (string, bool) {
+	prefix := name + "="
+	if !strings.HasPrefix(arg, prefix) {
+		return "", false
+	}
+	return strings.TrimSpace(strings.TrimPrefix(arg, prefix)), true
+}
+
 func runExtract(ctx context) error {
 	p, err := loadProject(ctx.cwd)
 	if err != nil {