void *mem_alloc(ulong size, byte cat);
void *mem_realloc(void *vptr, ulong size, byte cat);
void mem_free(void *vptr);

void sys_panic(const char *error, const char *fmt, ...) {
	va_list ap;
	va_start(ap, fmt);
	void *rip;
	void *rsp;
	void *rbp;
	void **bt;
	char **bs;
	int frames;
	asm volatile("lea (%%rip),%%rax \n\tmov %%rax,%0" : "=m" (rip) : );
	asm volatile("mov %%rsp,%0" : "=m" (rsp) : );
	asm volatile("mov %%rbp,%0" : "=m" (rbp) : );
	fprintf(stderr, "\n========================= !ABSTURZ! =========================");
	fprintf(stderr, "\n  TRACEBACK [Jetzt: %%rsp=$%llx, %%rbp=$%llx]:", (ulong)(rsp), (ulong)(rbp));
	bs = backtrace_symbols(&rip, 1);
	if(bs) {
		fprintf(stderr, "\n   -> [RIP] %s", bs[0] ? bs[0] : "<unknown>");
		free(bs);
	}
	else {
		fprintf(stderr, "\n   -> [RIP] $%llx", (ulong)(rip));
	}
	if(bt = malloc(128 * sizeof(void *))) {
		// memset(bt, 0, 128 * sizeof(void *));
		frames = backtrace(bt, 128);
		if(bs = backtrace_symbols(bt, frames)) {
			for(int z = 0; (z < frames) && bt[z]; z++) {
				fprintf(stderr, "\n   -> [%03d] %s", z, bs[z] ? bs[z] : "<unknown>");
			}
			free(bs);
		}
		else {
			for(int z = 0; (z < frames) && bt[z]; z++) {
				fprintf(stderr, "\n   -> [%03d] $%llx", z, bt[z]);
			}
		}
		free(bt);
	}
	else {
		fprintf(stderr, "\n  *Konnte keinen Speicher für Traceback reservieren*");
	}
	fprintf(stderr, "\n\n  FEHLER#: %s\n  URSACHE: ", error);
	vfprintf(stderr, fmt, ap);
	fprintf(stderr, "\n======================== ABGEBROCHEN ========================\n\n");
	// abort();
	va_end(ap);
	abort();
}

void sys_abort() {
	sys_panic("MANUAL_ABORT", "*Programm wurde manuell abgebrochen*");
}

ulong sys_segtest(ulong addr) {
	ulong *ptr = (ulong*)addr;
	*ptr = 666ULL;
	return *ptr;
}

ulong sys_fpetest() {
	ulong cma = 666ULL;
	ulong cmb = 0ULL;
	return cma / cmb;
}

ulong sys_overtest(ulong v) {
	ulong cma = 666ULL;
	return sys_overtest(v * cma);
}

ulong sys_illtest() {
	asm volatile(".byte 0x0f, 0x04");
	// asm volatile("jmp *%0" : : "m" (cma));
}

void sys_coretest() {
	srand(time(0));
	sys_panic("CORE_MELTDOWN", "Nuclear processor core meltdown imminent\n\n"
		"  ************************ CAUTION ************************\n"
		"       KCTL: Processor core #%02d has reached a critical\n"
		"         temperature, system explosion is imminent!   \n"
		"           According to the general core density      \n"
		"           calculation routine defined by the SKC     \n"
		"          (Hard) Warfare Testing Facility (SKC-WTF)   \n"
		"         your processor will cause a detonation with  \n"
		"            a radius of (roughly) %d.%d kilometers.     \n"
		"          In addition, it will release appoximately   \n"
		"           %d megajoules of ionizing radiation.    \n"
		"         You have an estimate time of %d minutes and   \n"
		"        %d seconds left to clear the detonation area. \n"
		"  ************************ CAUTION ************************\n"
	, 1 + (rand() % 64), 1 + (rand() % 9), rand() % 10, 10000 + (rand() % 30000), 3 + (rand() % 7), 2 + (rand() % 58));
}

void sys_handle_seg(int sig, siginfo_t *info, void *ucontext) {
	if(info->si_addr) {
		sys_panic("SEGMENTATION_FAULT", "Speicherzugriffsfehler bei $%llx", (ulong)info->si_addr);
	}
	else {
		sys_panic("NULL_POINTER", "Versuchte Zugriff auf Speicher bei $0");
	}
}

void sys_handle_ill(int sig, siginfo_t *info, void *ucontext) {
	sys_panic("ILLEGAL_INSTRUCTION", "Ungültige Prozessorinstruktion bei $%llx", (ulong)info->si_addr);
}

void sys_handle_fpe(int sig, siginfo_t *info, void *ucontext) {
	sys_panic("FLOATING_POINT_EXCEPTION", "Ungültige Gleitkommaoperation bei $%llx", (ulong)info->si_addr);
}

void sys_test_handlers(const char *test) {
	if(!test) {
		return;
	}
	else if(!strcmp("NULL", test)) {
		sys_segtest(0ULL);
	}
	else if(!strcmp("SEG", test)) {
		sys_segtest(0x666ULL);
	}
	else if(!strcmp("FPE", test)) {
		sys_fpetest();
	}
	else if(!strcmp("OVER", test)) {
		sys_overtest(1);
	}
	else if(!strcmp("ILL", test)) {
		sys_illtest();
	}
	else if(!strcmp("ABORT", test)) {
		sys_abort();
	}
	else if(!strcmp("CORE", test)) {
		sys_coretest();
	}
	else if(!strcmp("MEM", test)) {
		mem_alloc(0x7ffffffffffffff0, 0);
	}
}

void *sys_altstack;

void sys_setup_handlers() {
	struct sigaction seg;
	stack_t stack;
	memset(&seg, 0, sizeof(struct sigaction));
	seg.sa_sigaction = sys_handle_seg;
	seg.sa_flags = SA_ONSTACK | SA_SIGINFO;
	sigaction(SIGSEGV, &seg, NULL);
	memset(&seg, 0, sizeof(struct sigaction));
	seg.sa_sigaction = sys_handle_fpe;
	seg.sa_flags = SA_ONSTACK | SA_SIGINFO;
	sigaction(SIGFPE, &seg, NULL);
	memset(&seg, 0, sizeof(struct sigaction));
	seg.sa_sigaction = sys_handle_ill;
	seg.sa_flags = SA_ONSTACK | SA_SIGINFO;
	sigaction(SIGILL, &seg, NULL);
	stack.ss_sp = sys_altstack = malloc(16384);
	stack.ss_flags = 0;
	stack.ss_size = 16384;
	sigaltstack(&stack, NULL);
}

void sys_remove_handlers() {
	free(sys_altstack);
}