Merge branch 'main' into sb/zen-helpsb/zen-help

- Combine HelpCommand (this branch) with HistoryCommand (main) in zen CLI dispatcher
- Keep filter-aware TuiPickOne rewrite; adopt main's ASCII arrow glyphs in doc comment

1 files changed, 45 insertions, 6 deletions

diff --git a/src/zen/zen.h b/src/zen/zen.h
index 80178910a..5cf3b99ed 100644
--- a/src/zen/zen.h
+++ b/src/zen/zen.h
@@ -9,12 +9,15 @@
 #include <zenutil/config/commandlineoptions.h>
 #include <zenutil/config/loggingconfig.h>
 
+#include <csignal>
+
 namespace zen {
 
 struct ZenCliOptions
 {
-	bool IsDebug   = false;
-	bool IsVerbose = false;
+	bool IsDebug				= false;
+	bool IsVerbose				= false;
+	bool EnableExecutionHistory = true;
 
 	ZenLoggingConfig LoggingConfig;
 
@@ -37,6 +40,33 @@ extern ZenCmdCategory g_ProjectStoreCategory;
 extern ZenCmdCategory g_CacheStoreCategory;
 extern ZenCmdCategory g_StorageCategory;
 
+// RAII wrapper around `signal(2)` that restores the previous handler on scope
+// exit. Use in command Run() methods so an exception during option parsing or
+// execution doesn't leave a handler installed whose flag is scoped to a
+// now-dead lifetime.
+class ScopedSignalHandler
+{
+public:
+	using Handler = void (*)(int);
+
+	ScopedSignalHandler(int SigNum, Handler NewHandler) : m_SigNum(SigNum), m_PrevHandler(std::signal(SigNum, NewHandler)) {}
+
+	~ScopedSignalHandler()
+	{
+		if (m_PrevHandler != SIG_ERR)
+		{
+			std::signal(m_SigNum, m_PrevHandler);
+		}
+	}
+
+	ScopedSignalHandler(const ScopedSignalHandler&) = delete;
+	ScopedSignalHandler& operator=(const ScopedSignalHandler&) = delete;
+
+private:
+	int		m_SigNum;
+	Handler m_PrevHandler;
+};
+
 class ErrorWithReturnCode : public std::runtime_error
 {
 public:
@@ -58,6 +88,11 @@ public:
 	virtual cxxopts::Options& Options()														 = 0;
 	virtual ZenCmdCategory&	  CommandCategory() const;
 
+	// Hidden commands are dispatched normally but omitted from the top-level
+	// `zen --help` listing. Used for deprecated aliases that remain functional
+	// but should not be advertised.
+	virtual bool IsHidden() const { return false; }
+
 	bool			   ParseOptions(int argc, char** argv);
 	static bool		   ParseOptions(cxxopts::Options& Options, int argc, char** argv);
 	static bool		   ParseOptionsPermissive(cxxopts::Options& Options, int argc, char** argv, std::vector<std::string>& OutUnmatched);
@@ -103,15 +138,19 @@ class ZenSubCmdBase
 public:
 	ZenSubCmdBase(std::string_view Name, std::string_view Description);
 	virtual ~ZenSubCmdBase() = default;
-	cxxopts::Options& SubOptions() { return m_SubOptions; }
-	std::string_view  Description() const { return m_Description; }
-	virtual void	  Run(const ZenCliOptions& GlobalOptions) = 0;
+	cxxopts::Options&				SubOptions() { return m_SubOptions; }
+	std::string_view				Description() const { return m_Description; }
+	const std::vector<std::string>& Aliases() const { return m_Aliases; }
+	virtual void					Run(const ZenCliOptions& GlobalOptions) = 0;
 
 protected:
+	void AddAlias(std::string Alias) { m_Aliases.push_back(std::move(Alias)); }
+
 	cxxopts::Options m_SubOptions;
 
 private:
-	std::string m_Description;
+	std::string				 m_Description;
+	std::vector<std::string> m_Aliases;
 };
 
 // Base for commands that host subcommands - handles all dispatch boilerplate