#include <stdio.h>

typedef unsigned char Uint8;
typedef signed char Sint8;
typedef unsigned short Uint16;

typedef struct {
	Uint8 dat[0x100], ptr;
} Stack;

typedef struct {
	Uint8 ram[0x10000], dev[0x100];
	Stack wst, rst;
} Uxn;

Uxn uxn;

/* I/O */

Uint8
emu_dei(Uint8 addr)
{
	return uxn.dev[addr];
}

void
emu_deo(Uint8 addr, Uint8 value)
{
	uxn.dev[addr] = value;
	switch(addr) {
	case 0x18: fputc(uxn.dev[0x18], stdout); return;
	case 0x19: fputc(uxn.dev[0x19], stderr); return;
	}
}

/* Unroll */

#define OPC(opc, init, body) {\
	case 0x00|opc: {const int _2=0,_r=0;init body;} break;\
	case 0x20|opc: {const int _2=1,_r=0;init body;} break;\
	case 0x40|opc: {const int _2=0,_r=1;init body;} break;\
	case 0x60|opc: {const int _2=1,_r=1;init body;} break;\
	case 0x80|opc: {const int _2=0,_r=0;int k=uxn.wst.ptr;init uxn.wst.ptr=k;body;} break;\
	case 0xa0|opc: {const int _2=1,_r=0;int k=uxn.wst.ptr;init uxn.wst.ptr=k;body;} break;\
	case 0xc0|opc: {const int _2=0,_r=1;int k=uxn.rst.ptr;init uxn.rst.ptr=k;body;} break;\
	case 0xe0|opc: {const int _2=1,_r=1;int k=uxn.rst.ptr;init uxn.rst.ptr=k;body;} break;\
}

/* Microcode */

#define JMI a = uxn.ram[pc] << 8 | uxn.ram[pc + 1], pc += a + 2;
#define REM if(_r) uxn.rst.ptr -= 1 + _2; else uxn.wst.ptr -= 1 + _2;
#define INC(s) uxn.s.dat[uxn.s.ptr++]
#define DEC(s) uxn.s.dat[--uxn.s.ptr]
#define JMP(i) pc = _2 ? i : pc + (Sint8)i;
#define PO1(o) o = _r ? DEC(rst) : DEC(wst);
#define PO2(o) o = _r ? DEC(rst) | DEC(rst) << 8 : DEC(wst) | DEC(wst) << 8;
#define POx(o) { if(_2) PO2(o) else PO1(o) }
#define PU1(i) { if(_r) INC(rst) = i; else INC(wst) = i; }
#define RP1(i) { if(_r) INC(wst) = i; else INC(rst) = i; }
#define PUx(i) { if(_2) { c = (i); PU1(c >> 8) PU1(c) } else PU1(i) }
#define GET(o) { if(_2) PO1(o[1]) PO1(o[0]) }
#define PUT(i) { PU1(i[0]) if(_2) PU1(i[1]) }
#define DEI(i,o) o[0] = emu_dei(i); if(_2) o[1] = emu_dei(i + 1); PUT(o)
#define DEO(i,j) emu_deo(i, j[0]); if(_2) emu_deo(i + 1, j[1]);
#define PEK(i,o,m) o[0] = uxn.ram[i]; if(_2) o[1] = uxn.ram[(i + 1) & m]; PUT(o)
#define POK(i,j,m) uxn.ram[i] = j[0]; if(_2) uxn.ram[(i + 1) & m] = j[1];

int
uxn_eval(Uint16 pc)
{
	unsigned int a, b, c, x[2], y[2], z[2], step;
	if(!pc || uxn.dev[0x0f]) return 0;
	for(step = 0x80000; step; step--) {
		switch(uxn.ram[pc++]) {
		/* BRK */ case 0x00: return 1;
		/* JCI */ case 0x20: if(DEC(wst)) { JMI break; } pc += 2; break;
		/* JMI */ case 0x40: JMI break;
		/* JSI */ case 0x60: c = pc + 2; INC(rst) = c >> 8; INC(rst) = c; JMI break;
		/* LI2 */ case 0xa0: INC(wst) = uxn.ram[pc++]; /* fall-through */
		/* LIT */ case 0x80: INC(wst) = uxn.ram[pc++]; break;
		/* L2r */ case 0xe0: INC(rst) = uxn.ram[pc++]; /* fall-through */
		/* LIr */ case 0xc0: INC(rst) = uxn.ram[pc++]; break;
		/* INC */ OPC(0x01,POx(a),PUx(a + 1))
		/* POP */ OPC(0x02,REM   ,{})
		/* NIP */ OPC(0x03,GET(x) REM   ,PUT(x))
		/* SWP */ OPC(0x04,GET(x) GET(y),PUT(x) PUT(y))
		/* ROT */ OPC(0x05,GET(x) GET(y) GET(z),PUT(y) PUT(x) PUT(z))
		/* DUP */ OPC(0x06,GET(x),PUT(x) PUT(x))
		/* OVR */ OPC(0x07,GET(x) GET(y),PUT(y) PUT(x) PUT(y))
		/* EQU */ OPC(0x08,POx(a) POx(b),PU1(b == a))
		/* NEQ */ OPC(0x09,POx(a) POx(b),PU1(b != a))
		/* GTH */ OPC(0x0a,POx(a) POx(b),PU1(b > a))
		/* LTH */ OPC(0x0b,POx(a) POx(b),PU1(b < a))
		/* JMP */ OPC(0x0c,POx(a),JMP(a))
		/* JCN */ OPC(0x0d,POx(a) PO1(b),if(b) JMP(a))
		/* JSR */ OPC(0x0e,POx(a),RP1(pc >> 8) RP1(pc) JMP(a))
		/* STH */ OPC(0x0f,GET(x),RP1(x[0]) if(_2) RP1(x[1]))
		/* LDZ */ OPC(0x10,PO1(a),PEK(a, x, 0xff))
		/* STZ */ OPC(0x11,PO1(a) GET(y),POK(a, y, 0xff))
		/* LDR */ OPC(0x12,PO1(a),PEK(pc + (Sint8)a, x, 0xffff))
		/* STR */ OPC(0x13,PO1(a) GET(y),POK(pc + (Sint8)a, y, 0xffff))
		/* LDA */ OPC(0x14,PO2(a),PEK(a, x, 0xffff))
		/* STA */ OPC(0x15,PO2(a) GET(y),POK(a, y, 0xffff))
		/* DEI */ OPC(0x16,PO1(a),DEI(a, x))
		/* DEO */ OPC(0x17,PO1(a) GET(y),DEO(a, y))
		/* ADD */ OPC(0x18,POx(a) POx(b),PUx(b + a))
		/* SUB */ OPC(0x19,POx(a) POx(b),PUx(b - a))
		/* MUL */ OPC(0x1a,POx(a) POx(b),PUx(b * a))
		/* DIV */ OPC(0x1b,POx(a) POx(b),PUx(a ? b / a : 0))
		/* AND */ OPC(0x1c,POx(a) POx(b),PUx(b & a))
		/* ORA */ OPC(0x1d,POx(a) POx(b),PUx(b | a))
		/* EOR */ OPC(0x1e,POx(a) POx(b),PUx(b ^ a))
		/* SFT */ OPC(0x1f,PO1(a) POx(b),PUx(b >> (a & 0xf) << (a >> 4)))
		}
	}
	return 0;
}

void
console_input(char c, int type)
{
	uxn.dev[0x12] = c, uxn.dev[0x17] = type;
	uxn_eval(uxn.dev[0x10] << 8 | uxn.dev[0x11]);
}

int
main(int argc, char **argv)
{
	FILE *f;
	if(argc < 2)
		fprintf(stdout, "usage: %s file.rom [args..]\n", argv[0]);
	else if(!(f = fopen(argv[1], "rb")))
		fprintf(stderr, "uxnmin: Error %s\n", argv[1]);
	else {
		uxn.dev[0x17] = argc - 2;
		fread(&uxn.ram[0x0100], 0xff00, 1, f), fclose(f);
		if(uxn_eval(0x0100) && uxn.dev[0x10]) {
			int i = 2;
			for(; i < argc; i++) {
				char *p = argv[i];
				while(*p) console_input(*p++, 0x2);
				console_input('\n', i == argc - 1 ? 0x4 : 0x3);
			}
			while(!uxn.dev[0x0f]) {
				int c = fgetc(stdin);
				if(c == EOF) {
					console_input(0x00, 0x4);
					break;
				}
				console_input((Uint8)c, 0x1);
			}
		}
	}
	return uxn.dev[0x0f] & 0x7f;
}