Script.h

/* Copyright (C) 2020-2026 by Marc Boris Duerner
   SPDX-License-Identifier: LGPL-2.1-or-later WITH mif-exception
*/
 
#ifndef PT_LUA_SCRIPT_H
#define PT_LUA_SCRIPT_H
 
#include <Pt/Lua/Api.h>
#include <Pt/System/Selectable.h>
#include <Pt/Signal.h>
 
struct lua_State;
struct lua_Debug;
 
#include <string>
 
#if __cplusplus >= 202002L
#include <Pt/Slot.h>
#include <Pt/Coroutine.h>
#endif
 
namespace Pt {
 
class Any;
 
namespace Reflex { class Type; }
 
namespace Lua {
 
class AsyncCall;
class Context;
class Call;
 
#if __cplusplus >= 202002L
class AsyncAdvance;
#endif

class PT_LUA_API Script : public System::Selectable
                        , public Connectable
{
  public:
    enum Status
    {
      Yield,       
      NativeCall,  
      ScriptOk,    
      ScriptError  
    };

    Script(Context& ctx, const char* script);

    ~Script();

    void beginAdvance();

    Status endAdvance() const;

    Pt::Signal<>& advanced();

    Status advance();

    const std::string& errorMessage() const
    { return _errorMsg; }

    static Script* fromState(lua_State* L);
 
#if __cplusplus >= 202002L
    AsyncAdvance advanceAsync();
#endif
 
  protected:
    bool onRun();
 
    void onAttach(Pt::System::EventLoop& loop);
 
    void onDetach(Pt::System::EventLoop& loop);
 
    void onCancel();
 
  private:
    Script(const Script&);
    Script& operator=(const Script&);
 
#if __cplusplus >= 202002L
    friend class AsyncAdvance;
 
    void attachAwaiter(AsyncAdvance& awaiter);
 
    void detachAwaiter(AsyncAdvance& awaiter);
#endif
 
    bool onCall();
 
    void onAsyncCall();
 
    void onAsyncCallFinished();
 
    bool onAsyncCallReady();
 
    int pushResult(Pt::Any& value, Pt::Reflex::Type& type);
 
    void resume();
 
    bool isCancelled() const;
 
    void setError(const std::string& msg);
 
    static void yieldHook(lua_State* L, lua_Debug* ar);
 
  private:
    Context&      _ctx;
    lua_State*    _co;
    bool          _isCancelled;
    Status        _lastStatus;
    std::string   _errorMsg;
    Pt::Signal<>  _advanced;
 
    Call*         _pendingCall;
    AsyncCall*    _pendingAsyncCall;
    AsyncCall*    _activeAsyncCall;
 
  #if __cplusplus >= 202002L
    AsyncAdvance* _awaiter = nullptr;
  #endif
};
 
#if __cplusplus >= 202002L

class PT_LUA_API AsyncAdvance : public Pt::Awaiter
                              , public Pt::Connectable
{
    public:
    AsyncAdvance(Script& script);

    ~AsyncAdvance();

    Script::Status await_resume();
 
    private:
    friend class Script;
 
    void onBegin() override;
 
    void onCancel() override;
 
    void onDetach();
 
    void onAdvanced();
 
    Script& script();
 
    Script* _script;
    bool _isPending;
};
 
#endif // __cplusplus >= 202002L
 
} // namespace
 
} // namespace
 
#endif // include guard