metin2-client/extension/src/platform/ScriptLib/PythonBoot.cpp

// See PythonBoot.h. The sequence is 40250 UserInterface.cpp:241-352 (RunMainScript) and 419-434 (Main),
// split so the launcher can outlive the call that creates it.
#include "ScriptLib/StdAfx.h"
#include "ScriptLib/PythonLauncher.h"
#include "ScriptLib/Resource.h"
#include "UserInterface/StdAfx.h" // initpack and the rest of the module initializer list
#include "EterPythonLib/StdAfx.h"
#include "EterBase/Timer.h"
#include "EterLib/Util.h"
#include "UserInterface/PythonNetworkStream.h"
#include "UserInterface/AccountConnector.h"
#include "UserInterface/PythonPlayer.h"
#include "GameLib/FlyingObjectManager.h"
#include "EffectLib/EffectManager.h"
#include "PythonBoot.h"
#include "PythonHost.h"
#include "../EterLib/UIRenderCommands.h"
#include "../EterBase/LogBox.h"

#include <condition_variable>
#include <memory>
#include <mutex>
#include <pthread.h>

namespace
{
// 40250 has this on Main()'s stack. CPythonLauncher is a CSingleton, so there is still only ever one.
std::unique_ptr<CPythonLauncher> g_launcher;
std::unique_ptr<UI::CWindowManager> g_window_manager;
std::unique_ptr<CPythonResource> g_resource;
// 40250 CPythonApplication::m_timer; CSlotWindow's cool time and Process() read it via Instance().
std::unique_ptr<CTimer> g_timer;
// 40250 CPythonApplication::m_pyNetworkStream and m_kAccountConnector (CSingletons); the app loop
// processes them every frame and the net module reaches them through Instance().
std::unique_ptr<CPythonNetworkStream> g_network_stream;
std::unique_ptr<CAccountConnector> g_account_connector;
// 40250 CPythonApplication::m_pyPlayer, m_FlyingManager and m_kEftMgr: the loading phase clears them
// (CPythonNetworkStream::SetLoadingPhase). PythonPlayer and FlyingObjectManager are platform/pending stand-ins.
std::unique_ptr<CPythonPlayer> g_player;
std::unique_ptr<CFlyingManager> g_flying_manager;
std::unique_ptr<CEffectManager> g_effect_manager;

bool fail(std::string* error, const std::string& text)
{
	if (error)
		*error = text;
	return false;
}

// PORT: 40250 RunApp() blocks inside app.Loop() (CPythonApplication::Loop, PythonApplication.cpp:980)
// and only returns to run mainStream.Destroy() when the window closes. Godot owns the frame loop here,
// so system.py runs on its own thread and the two threads pass a baton: exactly one of them runs at
// any time. Loop() hands the baton back after every Process(), and the host hands it over once per
// Godot frame (AppFrame). The script keeps its original control flow — including the code after
// app.Loop() — without ever blocking the Godot main thread for more than one Process().
struct ScriptFiber
{
	enum Turn { Host, Script };

	std::mutex mutex;
	std::condition_variable cv;
	Turn turn = Host;
	pthread_t thread{};
	bool alive = false;       // the thread exists and has not been joined
	bool finished = false;    // RunMainScript's body returned
	bool looping = false;     // parked inside CPythonApplication::Loop
	bool quit = false;        // app.Exit / app.Abort / Stop
	bool ok = false;
	std::string error;
	std::string command_line;
};
ScriptFiber g_fiber;
thread_local bool t_on_fiber = false;

// Caller holds the GIL. Returns with the GIL held again after the script has given the baton back.
void hand_to_script()
{
	PyThreadState* state = PyEval_SaveThread();
	{
		std::unique_lock<std::mutex> lock(g_fiber.mutex);
		g_fiber.turn = ScriptFiber::Script;
		g_fiber.cv.notify_all();
		g_fiber.cv.wait(lock, [] { return g_fiber.turn == ScriptFiber::Host; });
	}
	PyEval_RestoreThread(state);
}

void join_fiber()
{
	if (!g_fiber.alive)
		return;
	PyThreadState* state = PyEval_SaveThread();
	pthread_join(g_fiber.thread, nullptr);
	PyEval_RestoreThread(state);
	g_fiber.alive = false;
}

bool run_main_script_body(const char* lpCmdLine, std::string* error);

void* fiber_main(void*)
{
	{
		std::unique_lock<std::mutex> lock(g_fiber.mutex);
		g_fiber.cv.wait(lock, [] { return g_fiber.turn == ScriptFiber::Script; });
	}
	t_on_fiber = true;
	PyGILState_STATE gil = PyGILState_Ensure();
	std::string error;
	const bool ok = run_main_script_body(g_fiber.command_line.c_str(), &error);
	PyGILState_Release(gil);

	std::lock_guard<std::mutex> lock(g_fiber.mutex);
	g_fiber.ok = ok;
	g_fiber.error = error;
	g_fiber.finished = true;
	g_fiber.looping = false;
	g_fiber.turn = ScriptFiber::Host;
	g_fiber.cv.notify_all();
	return nullptr;
}
}

void init_2v0_gameplay_stubs();

namespace PythonBoot
{

bool IsRunning()
{
	return g_launcher != nullptr;
}

void SetUISize(int width, int height)
{
	if (!g_window_manager || width <= 0 || height <= 0) return;
	g_window_manager->SetScreenSize(width, height);
	g_window_manager->SetResolution(width, height);
	UIRenderSetSize(width, height);
}

void UIMouseMove(int x, int y)
{
	if (g_window_manager) g_window_manager->RunMouseMove(x, y);
}

void UIMouseButton(int button, bool pressed, int x, int y)
{
	if (!g_window_manager) return;
	g_window_manager->RunMouseMove(x, y);
	switch (button)
	{
	case 1: if (pressed) g_window_manager->RunMouseLeftButtonDown(x, y); else g_window_manager->RunMouseLeftButtonUp(x, y); break;
	case 2: if (pressed) g_window_manager->RunMouseRightButtonDown(x, y); else g_window_manager->RunMouseRightButtonUp(x, y); break;
	case 3: if (pressed) g_window_manager->RunMouseMiddleButtonDown(x, y); else g_window_manager->RunMouseMiddleButtonUp(x, y); break;
	default: break;
	}
}

// 40250 CPythonApplication::OnKeyDown/OnKeyUp (PythonApplicationEvent.cpp:130-146): ESC first goes
// to RunPressEscapeKey (the OnPressEscapeKey chain every dialog closes on), then to RunKeyDown.
void UIKey(int key, bool pressed)
{
	if (!g_window_manager) return;
	if (pressed)
	{
		if (DIK_ESCAPE == key)
			g_window_manager->RunPressEscapeKey();
		g_window_manager->RunKeyDown(key);
	}
	else
		g_window_manager->RunKeyUp(key);
}

void UIUpdate()
{
	// While system.py is inside app.Loop(), one host frame is one CPythonApplication::Process(),
	// which updates and renders the window tree itself.
	if (IsAppLooping()) { AppFrame(); return; }
	if (g_window_manager) g_window_manager->Update();
}

void UIRender()
{
	if (IsAppLooping()) return;
	UIRenderBeginFrame();
	if (g_window_manager) g_window_manager->Render();
}

bool Start(const char* stdlib_path, std::string* error)
{
	if (g_launcher)
		return true;

	// 40250 Main (UserInterface.cpp:410): if (LocaleService_LoadGlobal(hInstance)) SetDefaultCodePage(...).
	// PORT: the platform LocaleService is already the supplied locale.cfg (en, code page 1252).
	SetDefaultCodePage(LocaleService_GetCodePage());

	const std::string stdlib = (stdlib_path && *stdlib_path) ? stdlib_path : PythonHost::DefaultStdLibPath();
	if (stdlib.empty())
		return fail(error, "no Python standard library path (Metin2Python.stdlib_path / $MT_PYTHON_STDLIB)");

	// The flags have to be set before the interpreter starts, i.e. before the constructor below.
	PythonHost::Configure();

	g_launcher = std::make_unique<CPythonLauncher>(); // Py_Initialize
	// The script fiber (RunMainScript) is a second OS thread; 2.7 creates the GIL lazily.
	PyEval_InitThreads();
	if (!g_launcher->Create())
	{
		Stop();
		return fail(error, "CPythonLauncher::Create failed");
	}

	std::string stdlib_error;
	if (!PythonHost::InstallStdLib(stdlib.c_str(), &stdlib_error))
	{
		Stop();
		return fail(error, "InstallStdLib(" + stdlib + "): " + stdlib_error);
	}
	g_timer = std::make_unique<CTimer>();
	g_resource = std::make_unique<CPythonResource>();
	g_window_manager = std::make_unique<UI::CWindowManager>();
	g_network_stream = std::make_unique<CPythonNetworkStream>();
	g_account_connector = std::make_unique<CAccountConnector>();
	g_player = std::make_unique<CPythonPlayer>();
	g_flying_manager = std::make_unique<CFlyingManager>();
	g_effect_manager = std::make_unique<CEffectManager>();
	return true;
}

}

namespace
{
// Mirrors 40250 RunMainScript. Runs on the script fiber.
bool run_main_script_body(const char* lpCmdLine, std::string* error)
{
	CPythonLauncher& pyLauncher = *g_launcher;

	// The module initializers follow 40250's order; missing modules arrive in later 2V steps.
	initpack();
	initdbg();
	initgrp();
	initgrpImage();
	initgrpText();
	initwndMgr();
	initapp();
	initnet();
	init_2v0_gameplay_stubs();

	ClearLogBoxMessage();

	NANOBEGIN

	// RegisterDebugFlag
	{
		std::string stRegisterDebugFlag;

#ifdef _DISTRIBUTE
		stRegisterDebugFlag ="__DEBUG__ = 0";
#else
		stRegisterDebugFlag ="__DEBUG__ = 1";
#endif

		if (!pyLauncher.RunLine(stRegisterDebugFlag.c_str()))
		{
			TraceError("RegisterDebugFlag Error");
			return fail(error, "RegisterDebugFlag Error: " + LastLogBoxMessage());
		}
	}

	// RegisterCommandLine.
	// PORT: the "-cs"/"-ncs" auto-login argument is passed through unchanged. Decoding it needs
	// EterBase/Utils.cpp SplitLine and EterLib/Util.cpp base64_decode, which are declared but not ported
	// yet; they belong to the login track (批次 2V1) and nothing in this host passes -cs today.
	{
		std::string stRegisterCmdLine;

		std::string stCmdLine = lpCmdLine ? lpCmdLine : "";

		stRegisterCmdLine ="__COMMAND_LINE__ = ";
		stRegisterCmdLine+='"';
		stRegisterCmdLine+=stCmdLine;
		stRegisterCmdLine+='"';

		const CHAR* c_szRegisterCmdLine=stRegisterCmdLine.c_str();
		if (!pyLauncher.RunLine(c_szRegisterCmdLine))
		{
			TraceError("RegisterCommandLine Error");
			return fail(error, "RegisterCommandLine Error: " + LastLogBoxMessage());
		}
	}
	// PORT: 40250 also honours "--pause-before-create-window" here with system("pause") and the XTrap
	// init check. Neither exists on this platform (no console to pause, no XTrap), so only the RunFile
	// is kept.
	{
		if (!pyLauncher.RunFile("system.py"))
		{
			TraceError("RunMain Error");
			return fail(error, "RunMain Error: " + LastLogBoxMessage());
		}
		// system.py catches failures in prototype.py and calls dbg.LogBox. Its outer
		// RunFile then succeeds, so surface that recorded failure to the Godot host.
		if (!LastLogBoxMessage().empty())
			return fail(error, "RunMain Error: " + LastLogBoxMessage());
	}

	NANOEND
	return true;
}
}

namespace PythonBoot
{

bool RunMainScript(const char* lpCmdLine, std::string* error)
{
	if (!g_launcher)
		return fail(error, "PythonBoot::Start has not run");
	if (g_fiber.alive)
		return fail(error, "RunMainScript is already running");

	g_fiber.turn = ScriptFiber::Host;
	g_fiber.finished = g_fiber.looping = g_fiber.quit = g_fiber.ok = false;
	g_fiber.error.clear();
	g_fiber.command_line = lpCmdLine ? lpCmdLine : "";

	// 40250's main thread has the default 1 MB Windows stack; Python frames are deep during
	// uiScriptLocale/ui imports, so give the script thread more than a secondary thread's default.
	pthread_attr_t attr;
	pthread_attr_init(&attr);
	pthread_attr_setstacksize(&attr, 16u * 1024u * 1024u);
	const int rc = pthread_create(&g_fiber.thread, &attr, fiber_main, nullptr);
	pthread_attr_destroy(&attr);
	if (rc != 0)
		return fail(error, "cannot start the script thread");
	g_fiber.alive = true;

	hand_to_script(); // until system.py parks in app.Loop() or returns
	if (g_fiber.finished)
	{
		join_fiber();
		if (!g_fiber.ok)
			return fail(error, g_fiber.error);
	}
	return true;
}

bool IsAppLooping()
{
	return g_fiber.alive && g_fiber.looping && !g_fiber.finished;
}

bool AppFrame()
{
	if (!IsAppLooping())
		return false;
	hand_to_script();
	if (g_fiber.finished)
		join_fiber();
	return IsAppLooping();
}

bool AppLoopWait()
{
	if (!t_on_fiber)
		return false;
	g_fiber.looping = true;
	if (g_fiber.quit)
		return false;
	PyThreadState* state = PyEval_SaveThread();
	{
		std::unique_lock<std::mutex> lock(g_fiber.mutex);
		g_fiber.turn = ScriptFiber::Host;
		g_fiber.cv.notify_all();
		g_fiber.cv.wait(lock, [] { return g_fiber.turn == ScriptFiber::Script; });
	}
	PyEval_RestoreThread(state);
	return !g_fiber.quit;
}

void AppRequestQuit()
{
	g_fiber.quit = true;
}

bool RunLine(const char* source, std::string* error)
{
	if (!g_launcher)
		return fail(error, "PythonBoot::Start has not run");

	ClearLogBoxMessage();
	if (!g_launcher->RunLine(source ? source : ""))
		return fail(error, LastLogBoxMessage());
	return true;
}

void Stop()
{
	if (!g_launcher)
		return;
	// In 40250, closing the window ends Loop(); RunApp() then runs mainStream.Destroy() and returns.
	if (g_fiber.alive)
	{
		AppRequestQuit();
		while (g_fiber.alive && !g_fiber.finished)
			hand_to_script();
		join_fiber();
	}
	g_fiber.finished = false;
	// 40250 Main(): pyLauncher.Clear() runs before app->Destroy()/delete app, so the window manager
	// (a CPythonApplication member) is still alive while Py_Finalize runs the windows' __del__.
	g_launcher->Clear();
	g_effect_manager.reset();
	g_flying_manager.reset();
	g_player.reset();
	g_account_connector.reset();
	g_network_stream.reset();
	g_window_manager.reset();
	g_resource.reset();
	g_timer.reset();
	g_launcher.reset();
}

}

// winuser.h (declared in the port's windows.h shim). WM_QUIT ends 40250's CPythonApplication::Loop;
// here the script fiber's loop ends the same way.
void PostQuitMessage(int)
{
	PythonBoot::AppRequestQuit();
}