From 53cdd9c4fce31e0bdebabefd095da4ff23f4c542 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ale=C5=A1=20Mat=C4=9Bj?= <amatej@redhat.com>
Date: Wed, 13 Nov 2024 11:13:52 +0100
Subject: [PATCH] Hint when an unknown option is available on different
 commands

Closes: https://github.com/rpm-software-management/dnf5/issues/1830
---
 dnf5/main.cpp | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/dnf5/main.cpp b/dnf5/main.cpp
index eaae11e69..dcf0bb526 100644
--- a/dnf5/main.cpp
+++ b/dnf5/main.cpp
@@ -1261,13 +1261,59 @@ int main(int argc, char * argv[]) try {
                     context.print_error(libdnf5::utils::sformat(
                         _("{}. Add \"--help\" for more information about the arguments."), ex.what()));
                 }
-                // If the error is an unknown top-level command, suggest
-                // installing a package that provides the command
+
                 if (auto * unknown_arg_ex = dynamic_cast<libdnf5::cli::ArgumentParserUnknownArgumentError *>(&ex)) {
                     if (unknown_arg_ex->get_command() == "dnf5" && unknown_arg_ex->get_argument()[0] != '-') {
+                        // If the error is an unknown top-level command, suggest
+                        // installing a package that provides the command
+
                         context.print_error(libdnf5::utils::sformat(
                             _("It could be a command provided by a plugin, try: dnf5 install 'dnf5-command({})'"),
                             unknown_arg_ex->get_argument()));
+
+                    } else if (unknown_arg_ex->get_argument()[0] == '-') {
+                        // If the error is an unknown option check if it is used by some other command and provide a hint
+
+                        std::unordered_set<std::string> commands_with_option;
+                        // Remove any values passed with the option
+                        std::string tmp =
+                            unknown_arg_ex->get_argument().substr(0, unknown_arg_ex->get_argument().find("="));
+                        // Both short and long options start with a '-', remove it
+                        tmp.erase(0, 1);
+                        std::function<bool(libdnf5::cli::ArgumentParser::NamedArg * arg, const std::string & tmp)>
+                            comparator;
+                        if (tmp[0] == '-') {
+                            // Long option, erase the second '-'
+                            tmp.erase(0, 1);
+                            comparator = [](libdnf5::cli::ArgumentParser::NamedArg * arg,
+                                            const std::string & tmp) -> bool { return (arg->get_long_name() == tmp); };
+                        } else {
+                            // Short option
+                            comparator = [](libdnf5::cli::ArgumentParser::NamedArg * arg,
+                                            const std::string & tmp) -> bool {
+                                return (arg->get_short_name() == tmp[0]);
+                            };
+                        }
+
+                        for (const auto & cmd : arg_parser.get_commands()) {
+                            for (const auto & arg : cmd->get_named_args()) {
+                                if (comparator(arg, tmp)) {
+                                    if (!dynamic_cast<libdnf5::cli::ArgumentParser::CommandAlias *>(cmd.get())) {
+                                        auto invoc = cmd->get_invocation();
+                                        // Erase first element which is the root command (dnf)
+                                        invoc.erase(invoc.begin());
+                                        commands_with_option.insert(libdnf5::utils::string::join(invoc, " "));
+                                    }
+                                }
+                            }
+                        }
+
+                        if (!commands_with_option.empty()) {
+                            context.print_error(libdnf5::utils::sformat(
+                                _("The argument is available for commands: {}. (It has to be placed after the "
+                                  "command.)"),
+                                libdnf5::utils::string::join(commands_with_option, _(", "))));
+                        }
                     }
                 }
                 return static_cast<int>(libdnf5::cli::ExitCode::ARGPARSER_ERROR);