#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysymdef.h>
#include <sys/timerfd.h>
#include <unistd.h>
#include <poll.h>

#include "uxn.h"
#include "devices/system.h"
#include "devices/screen.h"
#include "devices/controller.h"
#include "devices/mouse.h"
#include "devices/file.h"
#include "devices/datetime.h"

static XImage *ximage;
static Display *display;
static Visual *visual;
static Window window;

#define WIDTH (64 * 8)
#define HEIGHT (40 * 8)

static int
emu_error(char *msg, const char *err)
{
	fprintf(stderr, "Error %s: %s\n", msg, err);
	return 0;
}

static int
console_input(Uxn *u, char c)
{
	Uint8 *d = &u->dev[0x10];
	d[0x02] = c;
	return uxn_eval(u, GETVEC(d));
}

static void
console_deo(Uint8 *d, Uint8 port)
{
	FILE *fd = port == 0x8 ? stdout : port == 0x9 ? stderr
												  : 0;
	if(fd) {
		fputc(d[port], fd);
		fflush(fd);
	}
}

static Uint8
emu_dei(struct Uxn *u, Uint8 addr)
{
	Uint8 p = addr & 0x0f, d = addr & 0xf0;
	switch(d) {
	case 0x20: return screen_dei(&u->dev[d], p);
	case 0xa0: return file_dei(0, &u->dev[d], p);
	case 0xb0: return file_dei(1, &u->dev[d], p);
	case 0xc0: return datetime_dei(&u->dev[d], p);
	}
	return u->dev[addr];
}

static void
emu_deo(Uxn *u, Uint8 addr, Uint8 v)
{
	Uint8 p = addr & 0x0f, d = addr & 0xf0;
	u->dev[addr] = v;
	switch(d) {
	case 0x00:
		system_deo(u, &u->dev[d], p);
		if(p > 0x7 && p < 0xe)
			screen_palette(&uxn_screen, &u->dev[0x8]);
		break;
	case 0x10: console_deo(&u->dev[d], p); break;
	case 0x20: screen_deo(u->ram, &u->dev[d], p); break;
	case 0xa0: file_deo(0, u->ram, &u->dev[d], p); break;
	case 0xb0: file_deo(1, u->ram, &u->dev[d], p); break;
	}
}

static void
emu_redraw(void)
{
	screen_redraw(&uxn_screen, uxn_screen.pixels);
	XPutImage(display, window, DefaultGC(display, 0), ximage, 0, 0, 0, 0, uxn_screen.width, uxn_screen.height);
}

static void
hide_cursor(void)
{
	Cursor blank;
	Pixmap bitmap;
	XColor black;
	static char empty[] = {0, 0, 0, 0, 0, 0, 0, 0};
	black.red = black.green = black.blue = 0;
	bitmap = XCreateBitmapFromData(display, window, empty, 8, 8);
	blank = XCreatePixmapCursor(display, bitmap, bitmap, &black, &black, 0, 0);
	XDefineCursor(display, window, blank);
	XFreeCursor(display, blank);
	XFreePixmap(display, bitmap);
}

static Uint8
get_button(KeySym sym)
{
	switch(sym) {
	case XK_Up: return 0x10;
	case XK_Down: return 0x20;
	case XK_Left: return 0x40;
	case XK_Right: return 0x80;
	case XK_Control_L: return 0x01;
	case XK_Alt_L: return 0x02;
	case XK_Shift_L: return 0x04;
	case XK_Home: return 0x08;
	}
	return 0x00;
}

static void
emu_event(Uxn *u)
{
	XEvent ev;
	XNextEvent(display, &ev);
	switch(ev.type) {
	case Expose:
		emu_redraw();
		break;
	case ClientMessage: {
		XDestroyImage(ximage);
		XDestroyWindow(display, window);
		XCloseDisplay(display);
		exit(0);
	} break;
	case KeyPress: {
		KeySym sym;
		char buf[7];
		XLookupString((XKeyPressedEvent *)&ev, buf, 7, &sym, 0);
		controller_down(u, &u->dev[0x80], get_button(sym));
		controller_key(u, &u->dev[0x80], sym < 0x80 ? sym : (Uint8)buf[0]);
	} break;
	case KeyRelease: {
		KeySym sym;
		char buf[7];
		XLookupString((XKeyPressedEvent *)&ev, buf, 7, &sym, 0);
		controller_up(u, &u->dev[0x80], get_button(sym));
	} break;
	case ButtonPress: {
		XButtonPressedEvent *e = (XButtonPressedEvent *)&ev;
		if(e->button == 4)
			mouse_scroll(u, &u->dev[0x90], 0, 1);
		else if(e->button == 5)
			mouse_scroll(u, &u->dev[0x90], 0, -1);
		else
			mouse_down(u, &u->dev[0x90], 0x1 << (e->button - 1));
	} break;
	case ButtonRelease: {
		XButtonPressedEvent *e = (XButtonPressedEvent *)&ev;
		mouse_up(u, &u->dev[0x90], 0x1 << (e->button - 1));
	} break;
	case MotionNotify: {
		XMotionEvent *e = (XMotionEvent *)&ev;
		mouse_pos(u, &u->dev[0x90], e->x, e->y);
	} break;
	}
}

static int
init(void)
{
	Atom wmDelete;
	display = XOpenDisplay(NULL);
	visual = DefaultVisual(display, 0);
	window = XCreateSimpleWindow(display, RootWindow(display, 0), 0, 0, uxn_screen.width, uxn_screen.height, 1, 0, 0);
	if(visual->class != TrueColor)
		return emu_error("Init", "True-color visual failed");
	XSelectInput(display, window, ButtonPressMask | ButtonReleaseMask | PointerMotionMask | ExposureMask | KeyPressMask | KeyReleaseMask);
	wmDelete = XInternAtom(display, "WM_DELETE_WINDOW", True);
	XSetWMProtocols(display, window, &wmDelete, 1);
	XMapWindow(display, window);
	ximage = XCreateImage(display, visual, DefaultDepth(display, DefaultScreen(display)), ZPixmap, 0, (char *)uxn_screen.pixels, uxn_screen.width, uxn_screen.height, 32, 0);
	hide_cursor();
	return 1;
}

int
main(int argc, char **argv)
{
	Uxn u;
	int i;
	char expirations[8];
	struct pollfd fds[2];
	static const struct itimerspec screen_tspec = {{0, 16666666}, {0, 16666666}};
	if(argc < 2)
		return emu_error("Usage", "uxncli game.rom args");
	/* start sequence */
	if(!uxn_boot(&u, (Uint8 *)calloc(0x10300, sizeof(Uint8))))
		return emu_error("Boot", "Failed");
	if(!load_rom(&u, argv[1]))
		return emu_error("Load", "Failed");
	fprintf(stderr, "Loaded %s\n", argv[1]);
	u.dei = emu_dei;
	u.deo = emu_deo;
	screen_resize(&uxn_screen, WIDTH, HEIGHT);
	if(!uxn_eval(&u, PAGE_PROGRAM))
		return emu_error("Boot", "Failed to start rom.");
	if(!init())
		return emu_error("Init", "Failed");
	/* console vector */
	for(i = 2; i < argc; i++) {
		char *p = argv[i];
		while(*p) console_input(&u, *p++);
		console_input(&u, '\n');
	}
	fds[0].fd = XConnectionNumber(display);
	fds[1].fd = timerfd_create(CLOCK_MONOTONIC, 0);
	timerfd_settime(fds[1].fd, 0, &screen_tspec, NULL);
	fds[0].events = fds[1].events = POLLIN;
	/* main loop */
	while(1) {
		if(poll(fds, 2, 1000) <= 0)
			continue;
		while(XPending(display))
			emu_event(&u);
		if(poll(&fds[1], 1, 0)) {
			read(fds[1].fd, expirations, 8);    /* Indicate we handled the timer */
			uxn_eval(&u, GETVEC(&u.dev[0x20])); /* Call the vector once, even if the timer fired multiple times */
		}
		if(uxn_screen.fg.changed || uxn_screen.bg.changed)
			emu_redraw();
	}
	XDestroyImage(ximage);
	return 0;
}