//===========================================================================//
// File:    btl4main.cpp                                                      //
// Project: BattleTech           Brick: BattleTech LBE Application launcher   //
//---------------------------------------------------------------------------//
// Win32 entry point for the reconstructed BattleTech port.                   //
//                                                                            //
// Reconstructed/adapted from the Red Planet launcher RP_L4\RPL4.CPP -- the   //
// only game-specific differences are the application class (BTL4Application   //
// vs RPL4Application), the resource file (BTL4.RES), and the program name.   //
// The RP-only mission-review / spool playback branch is intentionally        //
// dropped for the first single-player bring-up.                              //
//===========================================================================//

#define WIN32_LEAN_AND_MEAN
#define _WIN32_WINNT 0x0500
#define WINVER       0x0500

// #define BT_HEAPCHECK            // enable to validate the heap on every alloc (heap-corruption hunt)
#include <windows.h>
#include <shellapi.h>              // CommandLineToArgvW
#include <crtdbg.h>                // _CrtSetDbgFlag (heap validation, gated by BT_HEAPCHECK)
#include <fstream>
#include <iostream>
#include <cstdlib>
#include <cstring>

#include <string>
#include <vector>
#include <bgfload.h>                // LoadBgfFile (BGF probe) -- via game/fwd shim
#include <bt.hpp>                   // BT umbrella -- engine Entity/Application chain (matches btl4app.cpp)
#include "btl4app.hpp"              // BTL4Application (pulls L4Application / Application chain)
#include "appmgr.hpp"               // ApplicationManager
#include "resource.hpp"             // StreamableResourceFile
#include "memreg.hpp"               // Start_Registering / Register_Object / Stop_Registering

// Data version. The check (RESOURCE.cpp StreamableResourceFile ctor) compares our
// version[i] against the file's versionArray[i+1] (it skips the format byte), and the
// file is v1.1.0.6 → versionArray[1..3] = {1,0,6}. So our 3 bytes must be {1,0,6}.
Byte version[3] = { 1, 0, 6 };

extern const char* const ProgName;
const char* const ProgName = "btl4";

Application *btl4App = NULL;
HWND         hWnd    = NULL;

//===========================================================================//
// Bring-up player DRIVE input (Tier 2 locomotion).
//   Populated by the keyboard handler in WndProc below (WASD / arrow keys)
//   and consumed each frame by Mech::PerformAndWatch
//   (decomp/reconstructed/mech4.cpp), which walks the player mech and advances
//   its localToWorld -- the matrix the render tree AND the chase camera are
//   bound to, so the mech moves and the camera follows.
//
//   throttle:  +1 full ahead .. -1 full reverse        turn: +1 right .. -1 left
//     Both are the OUTPUT of the virtual-control integrator in mech4.cpp
//     (dt-scaled, fps-independent) -- the pod's real inputs were an ABSOLUTE
//     analog throttle LEVER + turn stick, which momentary 0/1 keys can't
//     express directly (and at 60fps every key tap = full demand = the "too
//     sensitive controls" report).  The WndProc only records KEY STATE
//     (keyFwd/keyBack/keyLeft/keyRight); mech4 integrates:
//       W/S  = move the persistent throttle lever (tap ~= +/-0.07 fine step,
//              hold sweeps full range in ~1.4s, DETENT at zero: braking stops
//              AT 0 -- release and press S again to engage reverse)
//       A/D  = ramped momentary stick (deflects over ~0.4s, auto-centers)
//       X    = all stop (lever -> 0)
//   forced  :  DEBUG toggle (env BT_FORCE_THROTTLE), default OFF.  When set the
//              mech walks full-ahead with NO keypress -- used only for headless
//              autonomous verification (you can't press keys in a headless run).
//===========================================================================//
//   fire:    weapon trigger held (1 while the fire key is down).
//   fireForced: DEBUG auto-fire (env BT_FORCE_FIRE) -- fires on cooldown with no
//               keypress, for headless verification.
struct BTDriveInput { float throttle; float turn; int forced; int fire; int fireForced; float forcedThrottle;
                      int keyFwd; int keyBack; int keyLeft; int keyRight; int allStop; };
BTDriveInput gBTDrive = { 0.0f, 0.0f, 0, 0, 0, 1.0f, 0, 0, 0, 0, 0 };

LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch (uMsg)
	{
	case WM_KEYDOWN:
	case WM_KEYUP:
		// Drive keys are NOT read here: the engine's keyboard reader
		// (L4CTRL.cpp:1506) GetMessage()s every WM_KEYUP / WM_CHAR out of the
		// queue for its key-command channel, so this WndProc only ever saw the
		// KEYDOWNs -- key state latched on and never released (the "controls
		// incoherent" bug).  The virtual-control integrator in mech4.cpp polls
		// GetAsyncKeyState per frame instead (with a foreground guard), which
		// is immune to message stealing.
		return 0;
	case WM_SIZE:
		// Window-resize aspect fix (task #20): rebuild the projection for the
		// new client aspect so the scene doesn't stretch fat/skinny (the D3D9
		// backbuffer stays at the configured size and is stretched into the
		// client area; rendering with the client aspect cancels the stretch).
		if (wParam != SIZE_MINIMIZED && LOWORD(lParam) > 0 && HIWORD(lParam) > 0)
		{
			extern void L4NotifyWindowResized(int client_w, int client_h);
			L4NotifyWindowResized((int)LOWORD(lParam), (int)HIWORD(lParam));
		}
		return 0;
	case WM_CLOSE:
		DestroyWindow(hWnd);
		return 0;
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	}
	return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
	// Heap-corruption hunt (env BT_HEAPCHECK=1; default OFF -- ~100x slower): validate
	// the whole debug heap on EVERY alloc/free, so an out-of-bounds write is caught at
	// the very next heap op (a stack near the culprit) instead of much later at some
	// unrelated free.  Route the CRT report to the debugger so cdb breaks at detection.
	if (getenv("BT_HEAPCHECK"))
	{
		_CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_CHECK_ALWAYS_DF);
		_CrtSetReportMode(_CRT_ERROR,  _CRTDBG_MODE_DEBUG);
		_CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG);
	}

	// Bring-up: route CRT asserts (e.g. fread stream!=nullptr) to the debugger
	// instead of a modal MessageBox, so cdb breaks at the assert and we can dump
	// the faulting stack in a headless run.  Gated; default OFF (no behavior change).
	if (getenv("BT_ASSERT_TO_DEBUGGER"))
	{
		_CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG);
		_CrtSetReportMode(_CRT_ERROR,  _CRTDBG_MODE_DEBUG);
	}

	// Redirect the engine's std::cout/DEBUG_STREAM to a log file.  BT_LOG names the
	// file (default btl4.log) -- REQUIRED for multi-instance runs from one cwd
	// (instance 2 would truncate instance 1's log).
	std::ofstream logfile;
	logfile.open(getenv("BT_LOG") ? getenv("BT_LOG") : "btl4.log");
	std::cout.rdbuf(logfile.rdbuf());

	// MP wire-format probe (env BT_NET_PROBE=1): print the exact packet constants
	// the console emulator (tools/btconsole.py) must speak, computed from OUR build
	// (message IDs chain across class enums at compile time -- never hand-compute).
	if (getenv("BT_NET_PROBE"))
	{
		std::cout << "[netprobe] ReceiveEggFileMessageID=" << (int)NetworkManager::ReceiveEggFileMessageID
			<< " sizeof(NetworkPacketHeader)=" << sizeof(NetworkPacketHeader)
			<< " sizeof(Receiver__Message)=" << sizeof(Receiver__Message)
			<< " sizeof(ReceiveEggFileMessage)=" << sizeof(NetworkManager::ReceiveEggFileMessage)
			<< " sizeof(Time)=" << sizeof(Time)
			<< " NetworkManagerClientID=" << (int)NetworkClient::NetworkManagerClientID
			<< " RunMissionMessageID=" << (int)Application::RunMissionMessageID
			<< " sizeof(RunMissionMessage)=" << sizeof(Application::RunMissionMessage)
			<< " ApplicationClientID=" << (int)NetworkClient::ApplicationClientID
			<< "\n" << std::flush;
		return 0;
	}

	// BGF loader probe (env BT_PROBE_BGF=<name>[,<name>...] or =ALL): load the named
	// model(s) directly through the engine's LoadBgfFile -- NO app, NO renderer, NO
	// mechs -- then exit.  Isolates the loader: if this crashes/corrupts, the bug is
	// in bgfload.cpp itself (H1); if hundreds of iterations are clean, the in-game
	// corruption comes from elsewhere and the loader's frees only DETECT it (H2).
	// Repeats each load BT_PROBE_N times (default 8).  cwd must be the pod BT dir
	// (the loader indexes VIDEO\ relative to cwd).  Combine with BT_HEAPCHECK=1.
	if (const char *probe = getenv("BT_PROBE_BGF"))
	{
		const int reps = getenv("BT_PROBE_N") ? atoi(getenv("BT_PROBE_N")) : 8;
		std::vector<std::string> names;
		if (_stricmp(probe, "ALL") == 0)
		{
			WIN32_FIND_DATAA fd;
			HANDLE h = FindFirstFileA("VIDEO\\GEO\\*.BGF", &fd);
			if (h != INVALID_HANDLE_VALUE)
			{
				do { names.push_back(fd.cFileName); } while (FindNextFileA(h, &fd));
				FindClose(h);
			}
		}
		else
		{
			std::string s(probe);
			size_t p = 0;
			while (p < s.size())
			{
				size_t c = s.find(',', p);
				if (c == std::string::npos) c = s.size();
				if (c > p) names.push_back(s.substr(p, c - p));
				p = c + 1;
			}
		}
		std::cout << "[probe] BGF probe: " << names.size() << " model(s) x " << reps
			<< " reps, heapcheck=" << (getenv("BT_HEAPCHECK") ? 1 : 0) << "\n" << std::flush;
		int fails = 0;
		for (size_t i = 0; i < names.size(); ++i)
		{
			for (int r = 0; r < reps; ++r)
			{
				BgfData data;
				bool ok = LoadBgfFile(names[i], data);
				if (r == 0 || !ok)
					std::cout << "[probe] " << names[i] << " rep " << r
						<< (ok ? " OK" : " FAIL") << " verts=" << data.verts.size()
						<< " idx=" << data.indices.size() << " tris=" << data.tris
						<< (ok ? "" : (" err=" + data.error)) << "\n" << std::flush;
				if (!ok) ++fails;
				if (!_CrtCheckMemory())
				{
					std::cout << "[probe] *** HEAP CORRUPT after " << names[i]
						<< " rep " << r << " ***\n" << std::flush;
					return 3;
				}
			}
		}
		std::cout << "[probe] DONE: heap clean, fails=" << fails << "\n" << std::flush;
		return 0;
	}

	// Environment defaults (dev box: keyboard controls, single window).
	if (getenv("L4CONTROLS")  == NULL) putenv("L4CONTROLS=KEYBOARD");
	// Renderer config: the real BattleTech DPL environment (paths/fog/lights/
	// ambient/projection + cached shapes).  RP set L4DPLCFG=RPDPL.INI; BT's is
	// BTDPL.INI (in the pod BT dir).  Without this, DPLReadEnvironment falls back
	// to dpldflt.ini and the cavern world never gets its environment.
	if (getenv("L4DPLCFG")    == NULL) putenv("L4DPLCFG=BTDPL.INI");
	if (getenv("DPLARG")      == NULL) putenv("DPLARG=1");
	if (getenv("MULTISAMPLE") == NULL) putenv("MULTISAMPLE=0");
	if (getenv("TARGETFPS")   == NULL) putenv("TARGETFPS=60");
	if (getenv("MAXPARTICLES")== NULL) putenv("MAXPARTICLES=8192");

	// DEBUG (bring-up, default OFF): force the player mech to walk full-ahead with
	// no keypress so locomotion + camera-follow can be verified in a headless run.
	// BT_FORCE_THROTTLE may carry a VALUE: +1 full run, ~0.3 walk, -1 reverse (default 1.0).
	if (getenv("BT_FORCE_THROTTLE") != NULL)
	{
		gBTDrive.forced = 1;
		float v = (float)atof(getenv("BT_FORCE_THROTTLE"));
		gBTDrive.forcedThrottle = (v != 0.0f) ? v : 1.0f;	// bare "1"/empty -> full ahead
	}
	if (getenv("BT_FORCE_FIRE")     != NULL) gBTDrive.fireForced = 1;

	// Optional environ.ini overrides (same convention as RP).
	FILE *file;
	char line[1024];
	if (fopen_s(&file, "environ.ini", "r") == 0)
	{
		while (!feof(file))
		{
			if (fgets(line, sizeof(line), file))
			{
				for (int i = (int)strlen(line); i >= 0; i--)
					if (line[i] == '\n' || line[i] == '\r') line[i] = 0;
				putenv(line);
			}
		}
		fclose(file);
	}

	std::cout << "BattleTech v4.10 (reconstructed port)" << std::endl << std::flush;

	// CPU pin (timing stability).  BT_AFFINITY overrides the mask; =0 disables --
	// required for multi-instance runs (two instances pinned to core 0 starve
	// each other, and the L4NET connect-retry loop busy-waits).
	{
		DWORD_PTR mask = getenv("BT_AFFINITY")
			? (DWORD_PTR)strtoul(getenv("BT_AFFINITY"), 0, 0) : (DWORD_PTR)1;
		if (mask != 0)
			SetThreadAffinityMask(GetCurrentThread(), mask);
	}

	// Parse the command line so the egg (mission descriptor) source is set:
	//   btl4.exe -egg <file.egg>
	// With no network common address (single-user mode), L4NetworkManager reads
	// GetEggNotationFileName() and posts the egg locally -- no real net needed.
	int     argc;
	LPWSTR *argv = CommandLineToArgvW(GetCommandLineW(), &argc);
	if (!L4Application::ParseCommandLine(argc, argv, L4Application::ParseToken))
	{
		std::cout << "ParseCommandLine failed (need: -egg <file>)" << std::endl << std::flush;
		return 1;
	}

	Start_Registering();

	// Create the main window (single 800x600 view for dev; pod multi-monitor is Phase 8).
	WNDCLASS wc;
	if (!hPrevInstance)
	{
		wc.style         = 0;
		wc.lpfnWndProc   = (WNDPROC)WndProc;
		wc.cbClsExtra    = 0;
		wc.cbWndExtra    = 0;
		wc.hInstance     = hInstance;
		wc.hIcon         = LoadIcon((HINSTANCE)NULL, IDI_APPLICATION);
		wc.hCursor       = LoadCursor((HINSTANCE)NULL, IDC_ARROW);
		wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
		wc.lpszMenuName  = NULL;
		wc.lpszClassName = L"MainWndClass";
		if (!RegisterClass(&wc)) return FALSE;
	}

	//
	// Window/backbuffer resolution (task #20): the engine already parses
	// `-res W H` (L4APP.cpp:165) for the D3D backbuffer; the window must match
	// or the render is stretched.  Parse the same args here for the WINDOW
	// (client area = render size); default stays the authentic pod 800x600.
	// Launch with e.g. `-egg DEV.EGG -res 1600 1200` for a 4x-pixel view.
	//
	int winW = 800, winH = 600;
	{
		const char *rp = lpCmdLine ? strstr(lpCmdLine, "-res") : 0;
		if (rp != 0)
		{
			int w = 0, h = 0;
			if (sscanf(rp + 4, " %d %d", &w, &h) == 2 && w >= 320 && h >= 240)
			{
				winW = w;
				winH = h;
			}
		}
	}
	RECT wr = { 0, 0, winW, winH };
	AdjustWindowRect(&wr, WS_OVERLAPPEDWINDOW, FALSE);
	hWnd = CreateWindowEx(0, L"MainWndClass", L"BattleTech", WS_OVERLAPPEDWINDOW,
		0, 0, wr.right - wr.left, wr.bottom - wr.top,
		(HWND)NULL, (HMENU)NULL, hInstance, (LPVOID)NULL);
	if (!hWnd) return FALSE;

	ShowWindow(hWnd, nShowCmd);

	{
		std::cout << "[boot] opening btl4.res..." << std::endl << std::flush;
		StreamableResourceFile resources("btl4.res", version);
		Check(&resources);
		std::cout << "[boot] resources OK; creating ApplicationManager..." << std::endl << std::flush;

		// Frame rate (task #20 perf): TARGETFPS was read with no null check --
		// atoi(NULL) when unset -> garbage frameRate -> the APPMGR frame pacer
		// (end_of_frame = now + 1/frameRate) degenerated and the game ran at a
		// timer-quantized ~15 FPS (66-70ms frames measured) on ANY hardware.
		// Default 60; env TARGETFPS still overrides (clamped to sanity).
		int target_fps = 30;	// the pod's authentic rate; frame work (~20-40ms in
								// this build) misses 60Hz beats -> jitter, but holds
								// 30 rock-steady.  TARGETFPS env still overrides.
		{
			const char *tf = getenv("TARGETFPS");
			if (tf != 0)
			{
				int v = atoi(tf);
				if (v >= 15 && v <= 240)
					target_fps = v;
			}
		}
		std::cout << "[boot] target frame rate: " << target_fps << " fps" << std::endl << std::flush;
		ApplicationManager *app_manager =
			new ApplicationManager(hInstance, hWnd, (Scalar)target_fps);
		Register_Object(app_manager);
		std::cout << "[boot] ApplicationManager OK; creating BTL4Application..." << std::endl << std::flush;

		Application *new_app = new BTL4Application(hInstance, hWnd, &resources);
		btl4App = new_app;
		Register_Object(new_app);
		std::cout << "[boot] BTL4Application OK; StartApplication..." << std::endl << std::flush;
		app_manager->StartApplication(new_app);
		std::cout << "[boot] StartApplication returned; entering RunMissions..." << std::endl << std::flush;

		app_manager->RunMissions();
		std::cout << "[boot] RunMissions returned (mission loop exited)." << std::endl << std::flush;

		btl4App = NULL;
		Unregister_Object(app_manager);
		delete app_manager;
	}

	Stop_Registering();
	return Exit_Code;
}