#pragma warning(disable : 4786)

#include "bbruntime_dll.hpp"
#include "../debugger/debugger.hpp"

using namespace std;

#include <eh.h>
#include <float.h>
#include <map>

#include "bbruntime.hpp"

class DummyDebugger : public Debugger {
	public:
	virtual void debugRun() {}
	virtual void debugStop() {} // bbruntime_panic(0); }
	virtual void debugStmt(int srcpos, const char* file) {}
	virtual void debugEnter(void* frame, void* env, const char* func) {}
	virtual void debugLeave() {}
	virtual void debugLog(const char* msg) {}
	virtual void debugMsg(const char* e, bool serious)
	{
		if (serious)
			MessageBox(0, e, "Error!", MB_OK | MB_TOPMOST | MB_SETFOREGROUND);
	}
	virtual void debugSys(void* msg) {}
};

static HINSTANCE                  hinst;
static map<const char*, void*>    syms;
map<const char*, void*>::iterator sym_it;
static gxRuntime*                 gx_runtime;

static void rtSym(const char* sym, void* pc)
{
	syms[sym] = pc;
}

static void _cdecl seTranslator(unsigned int u, EXCEPTION_POINTERS* pExp)
{
	switch (u) {
	case EXCEPTION_INT_DIVIDE_BY_ZERO:
		bbruntime_panic("Integer divide by zero");
	case EXCEPTION_ACCESS_VIOLATION:
		bbruntime_panic("Memory access violation");
	case EXCEPTION_ILLEGAL_INSTRUCTION:
		bbruntime_panic("Illegal instruction");
	case EXCEPTION_STACK_OVERFLOW:
		bbruntime_panic("Stack overflow!");
	}
	bbruntime_panic("Unknown runtime exception");
}

int Runtime::version()
{
	return VERSION;
}

const char* Runtime::nextSym()
{
	if (!syms.size()) {
		bbruntime_link(rtSym);
		sym_it = syms.begin();
	}
	if (sym_it == syms.end()) {
		syms.clear();
		return 0;
	}
	return (sym_it++)->first;
}

int Runtime::symValue(const char* sym)
{
	map<const char*, void*>::iterator it = syms.find(sym);
	if (it != syms.end())
		return (int)it->second;
	return -1;
}

void Runtime::startup(HINSTANCE h)
{
	hinst = h;
}

void Runtime::shutdown()
{
	trackmem(false);
	syms.clear();
}

void Runtime::execute(void (*pc)(), const char* args, Debugger* dbg)
{
	bool debug = !!dbg;

	static DummyDebugger dummydebug;

	if (!dbg)
		dbg = &dummydebug;

	trackmem(true);

	_se_translator_function old_trans = _set_se_translator(seTranslator);
	_control87(_RC_NEAR | _PC_24 | _EM_INVALID | _EM_ZERODIVIDE | _EM_OVERFLOW | _EM_UNDERFLOW | _EM_INEXACT
				   | _EM_DENORMAL,
			   0xfffff);

	//strip spaces from ends of args...
	string params = args;
	while (params.size() && params[0] == ' ')
		params = params.substr(1);
	while (params.size() && params[params.size() - 1] == ' ')
		params = params.substr(0, params.size() - 1);

	if (gx_runtime = gxRuntime::openRuntime(hinst, params, dbg)) {
		bbruntime_run(gx_runtime, pc, debug);

		gxRuntime* t = gx_runtime;
		gx_runtime   = 0;
		gxRuntime::closeRuntime(t);
	}

	_control87(_CW_DEFAULT, 0xfffff);
	_set_se_translator(old_trans);
}

void Runtime::asyncStop()
{
	if (gx_runtime)
		gx_runtime->asyncStop();
}

void Runtime::asyncRun()
{
	if (gx_runtime)
		gx_runtime->asyncRun();
}

void Runtime::asyncEnd()
{
	if (gx_runtime)
		gx_runtime->asyncEnd();
}

void Runtime::checkmem(streambuf* buf)
{
	ostream out(buf);
	::checkmem(out);
}

Runtime* _cdecl runtimeGetRuntime()
{
	static Runtime runtime;
	return &runtime;
}

/********************** BUTT UGLY DLL->EXE HOOK! *************************/

static void*            module_pc;
static map<string, int> module_syms;
static map<string, int> runtime_syms;
static Runtime*         runtime;

static void fail()
{
	MessageBox(0, "Unable to run Blitz Basic module", 0, 0);
	ExitProcess(-1);
}

struct Sym {
	string name;
	int    value;
};

static Sym getSym(void** p)
{
	Sym   sym;
	char* t = (char*)*p;
	while (char c = *t++)
		sym.name += c;
	sym.value = *(int*)t + (int)module_pc;
	*p        = t + 4;
	return sym;
}

static int findSym(const string& t)
{
	map<string, int>::iterator it;

	it = module_syms.find(t);
	if (it != module_syms.end())
		return it->second;
	it = runtime_syms.find(t);
	if (it != runtime_syms.end())
		return it->second;

	string err = "Can't find symbol: " + t;
	MessageBox(0, err.c_str(), 0, 0);
	ExitProcess(0);
	return 0;
}

static void link()
{
	while (const char* sc = runtime->nextSym()) {
		string t(sc);

		if (t[0] == '_') {
			runtime_syms["_" + t] = runtime->symValue(sc);
			continue;
		}

		if (t[0] == '!')
			t = t.substr(1);

		if (!isalnum(t[0]))
			t = t.substr(1);

		for (int k = 0; k < t.size(); ++k) {
			if (isalnum(t[k]) || t[k] == '_')
				continue;
			t = t.substr(0, k);
			break;
		}

		runtime_syms["_f" + tolower(t)] = runtime->symValue(sc);
	}

	HRSRC hres = FindResource(0, MAKEINTRESOURCE(1111), RT_RCDATA);
	if (!hres)
		fail();
	HGLOBAL hglo = LoadResource(0, hres);
	if (!hglo)
		fail();
	void* p = LockResource(hglo);
	if (!p)
		fail();

	int sz = *(int*)p;
	p      = (int*)p + 1;

	//replace malloc for service pack 2 Data Execution Prevention (DEP).
	module_pc = VirtualAlloc(0, sz, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);

	memcpy(module_pc, p, sz);
	p = (char*)p + sz;

	int k, cnt;

	cnt = *(int*)p;
	p   = (int*)p + 1;
	for (k = 0; k < cnt; ++k) {
		Sym sym = getSym(&p);
		if (sym.value < (int)module_pc || sym.value >= (int)module_pc + sz)
			fail();
		module_syms[sym.name] = sym.value;
	}

	cnt = *(int*)p;
	p   = (int*)p + 1;
	for (k = 0; k < cnt; ++k) {
		Sym  sym  = getSym(&p);
		int* pp   = (int*)sym.value;
		int  dest = findSym(sym.name);
		*pp += dest - (int)pp;
	}

	cnt = *(int*)p;
	p   = (int*)p + 1;
	for (k = 0; k < cnt; ++k) {
		Sym  sym  = getSym(&p);
		int* pp   = (int*)sym.value;
		int  dest = findSym(sym.name);
		*pp += dest;
	}

	runtime_syms.clear();
	module_syms.clear();
}

extern "C" _declspec(dllexport) int _stdcall bbWinMain();
extern "C" BOOL _stdcall _DllMainCRTStartup(HANDLE, DWORD, LPVOID);

bool WINAPI DllMain(HANDLE module, DWORD reason, void* reserved)
{
	return TRUE;
}

int __stdcall bbWinMain()
{
	HINSTANCE inst = GetModuleHandle(0);

	_DllMainCRTStartup(inst, DLL_PROCESS_ATTACH, 0);

#ifdef BETA
	int    ver = VERSION & 0x7fff;
	string t   = "Created with Blitz3D Beta V" + itoa(ver / 100) + "." + itoa(ver % 100);
	MessageBox(GetDesktopWindow(), t.c_str(), "Blitz3D Message", MB_OK);
#endif

#ifdef SCHOOLS
	MessageBox(GetDesktopWindow(), "Created with the schools version of Blitz Basic", "Blitz Basic Message", MB_OK);
#endif

	runtime = runtimeGetRuntime();
	runtime->startup(inst);

	link();

	//get cmd_line and params
	string cmd = GetCommandLine(), params;
	while (cmd.size() && cmd[0] == ' ')
		cmd = cmd.substr(1);
	if (cmd.find('\"') == 0) {
		int n = cmd.find('\"', 1);
		if (n != string::npos) {
			params = cmd.substr(n + 1);
			cmd    = cmd.substr(1, n - 1);
		}
	} else {
		int n = cmd.find(' ');
		if (n != string::npos) {
			params = cmd.substr(n + 1);
			cmd    = cmd.substr(0, n);
		}
	}

	runtime->execute((void (*)())module_pc, params.c_str(), 0);
	runtime->shutdown();

	_DllMainCRTStartup(inst, DLL_PROCESS_DETACH, 0);

	ExitProcess(0);
	return 0;
}