CLI cleanup to consolidate session-related subcommands

internal/app/session_args.go

@@ -0,0 +1,43 @@
+package app
+
+import (
+	"flag"
+	"fmt"
+	"strings"
+)
+
+func isCLIFlagToken(arg string) bool {
+	return strings.HasPrefix(arg, "-") && arg != "-"
+}
+
+func pullLeadingSessionID(args []string) (string, []string) {
+	if len(args) == 0 || isCLIFlagToken(args[0]) {
+		return "", args
+	}
+	rest := append([]string(nil), args[1:]...)
+	return strings.TrimSpace(args[0]), rest
+}
+
+func applyPositionalSessionID(command, positional string, sessionID *string) error {
+	positional = strings.TrimSpace(positional)
+	if positional == "" {
+		return nil
+	}
+	existing := strings.TrimSpace(*sessionID)
+	if existing != "" && existing != positional {
+		return fmt.Errorf("%s: positional session id %q does not match expected session id %q", command, positional, existing)
+	}
+	*sessionID = positional
+	return nil
+}
+
+func applyParsedSessionIDArg(command string, fs *flag.FlagSet, sessionID *string) error {
+	switch fs.NArg() {
+	case 0:
+		return nil
+	case 1:
+		return applyPositionalSessionID(command, fs.Arg(0), sessionID)
+	default:
+		return fmt.Errorf("%s: unexpected positional arguments", command)
+	}
+}