#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <memdraw.h>
#include <mouse.h>
#include <keyboard.h>
#include "dat.h"
#include "fns.h"

Mousectl *mctl;
ulong kdown;
double Δt;
Image *screenb;
Memimage *fb;
Memimage *bg, *fg;
Sprite bob;

Rune keys[Ke] = {
 [K↑]	Kup,
 [K↓]	Kdown,
 [K←]	Kleft,
 [K→]	Kright
};

Memimage*
eallocmemimage(Rectangle r, ulong chan)
{
	Memimage *i;

	i = allocmemimage(r, chan);
	if(i == nil)
		sysfatal("allocmemimage: %r");
	memfillcolor(i, DTransparent);
	return i;
}

Memimage*
rgb(ulong c)
{
	Memimage *i;

	i = eallocmemimage(Rect(0,0,1,1), screen->chan);
	i->flags |= Frepl;
	i->clipr = Rect(-1e6, -1e6, 1e6, 1e6);
	memfillcolor(i, c);
	return i;
}

Memimage*
loadtexture(char *path)
{
	Memimage *i;
	int fd;

	fd = open(path, OREAD);
	if(fd < 0)
		sysfatal("open: %r");
	i = readmemimage(fd);
	if(i == nil)
		sysfatal("readmemimage: %r");
	close(fd);
	return i;
}

void
kbdproc(void*)
{
	Rune r, *a;
	char buf[128], *s;
	int fd, n;

	threadsetname("kbdproc");
	if((fd = open("/dev/kbd", OREAD)) < 0)
		sysfatal("kbdproc: %r");
	memset(buf, 0, sizeof buf);
	for(;;){
		if(buf[0] != 0){
			n = strlen(buf)+1;
			memmove(buf, buf+n, sizeof(buf)-n);
		}
		if(buf[0] == 0){
			if((n = read(fd, buf, sizeof(buf)-1)) <= 0)
				break;
			buf[n-1] = 0;
			buf[n] = 0;
		}
		if(buf[0] == 'c'){
			if(utfrune(buf, Kdel)){
				close(fd);
				threadexitsall(nil);
			}
		}
		if(buf[0] != 'k' && buf[0] != 'K')
			continue;
		s = buf+1;
		kdown = 0;
		while(*s){
			s += chartorune(&r, s);
			for(a = keys; a < keys+Ke; a++)
				if(r == *a){
					kdown |= 1 << a-keys;
					break;
				}
		}
	}
}

void
drawproc(void *arg)
{
	Channel *c;

	c = arg;
	for(;;){
		send(c, nil);
		sleep(FPS2MS(60));
	}
}

void
resetfb(void)
{
	freeimage(screenb);
	screenb = allocimage(display, Rect(0,0,Dx(screen->r),Dy(screen->r)), screen->chan, 0, DNofill);
	freememimage(fb);
	fb = eallocmemimage(Rect(0,0,Dx(screen->r),Dy(screen->r)), screen->chan);	
}

void
redraw(void)
{
	Rectangle r;

	memimagedraw(fb, fb->r, bg, ZP, nil, ZP, SoverD);
	memimagedraw(fb, Rpt(subpt(bob.p, Pt(Dx(bob.spr->r),Dy(bob.spr->r))), addpt(bob.p, Pt(32,32))), bob.spr, ZP, nil, ZP, SoverD);
	for(r = fb->r; r.min.y < fb->r.max.y; r.min.y++){
		r.max.y = r.min.y+1;
		loadimage(screenb, r, byteaddr(fb, r.min), bytesperline(r, fb->depth));
	}
	lockdisplay(display);
	draw(screen, screen->r, screenb, nil, ZP);
	flushimage(display, 1);
	unlockdisplay(display);
}


void
mouse(void)
{
}

void
resize(void)
{
	if(getwindow(display, Refnone) < 0)
		fprint(2, "can't reattach to window\n");
	resetfb();
	redraw();
}

void
usage(void)
{
	fprint(2, "usage: %s\n", argv0);
	exits("usage");
}

void
threadmain(int argc, char *argv[])
{
	vlong t0, t;
	Channel *drawc;

	ARGBEGIN{
	default: usage();
	}ARGEND;
	if(argc)
		usage();
	if(initdraw(nil, nil, nil) < 0)
		sysfatal("initdraw: %r");
	if(memimageinit() < 0)
		sysfatal("memimageinit: %r");
	if((mctl = initmouse(nil, screen)) == nil)
		sysfatal("initmouse: %r");
	resetfb();
	bg = rgb(DWhite);
	fg = rgb(DBlack);
	bob.spr = loadtexture("assets/bob.pic");
	bob.p = divpt(fb->r.max, 2);
	drawc = chancreate(1, 0);
	display->locking = 1;
	unlockdisplay(display);
	proccreate(kbdproc, nil, mainstacksize);
	proccreate(drawproc, drawc, mainstacksize);
	t0 = nsec();
	for(;;){
		enum {MOUSE, RESIZE, DRAW};
		Alt a[] = {
			{mctl->c, &mctl->Mouse, CHANRCV},
			{mctl->resizec, nil, CHANRCV},
			{drawc, nil, CHANRCV},
			{nil, nil, CHANNOBLK}
		};
		switch(alt(a)){
		case MOUSE: mouse(); break;
		case RESIZE: resize(); break;
		case DRAW: redraw(); break;
		}
		t = nsec();
		Δt = (t-t0)/1e9;
		t0 = t;
		if(kdown & 1<<K↑)
			bob.p.y--;
		if(kdown & 1<<K↓)
			bob.p.y++;
		if(kdown & 1<<K←)
			bob.p.x--;
		if(kdown & 1<<K→)
			bob.p.x++;
		sleep(16);
	}
}