#include <u.h>
#include <libc.h>
#include <thread.h>
#include <fcall.h>
#include <fs.h>

#define	EVENTSIZE	256
#define	STACK	32768

typedef struct Event Event;
typedef struct Q Q;

struct Event
{
	int	c1;
	int	c2;
	int	q0;
	int	q1;
	int	flag;
	int	nb;
	int	nr;
	char	b[EVENTSIZE*UTFmax+1];
	Rune	r[EVENTSIZE+1];
};

Event blank = {
	'M',
	'X',
	0, 0, 0, 1, 1,
	{ ' ', 0 },
	{ ' ', 0 },
};

struct Q
{
	QLock	lk;
	int		p;
	int		k;
};

Q	q;

int eventfd;
int addrfd;
int datafd;
int ctlfd;
int bodyfd;

char	*typing;
int	ntypeb;
int	ntyper;
int	ntypebreak;
int	debug;

char **prog;
int p[2];
Channel *cpid;
int pid = -1;

void	error(char*);
void	stdinproc(void*);
void	stdoutproc(void*);
void	type(Event*, int, int, int);
void	sende(Event*, int, int, int, int, int);
char	*onestring(int, char**);
int	delete(Event*);
void	deltype(uint, uint);
void	runproc(void*);

void
usage(void)
{
	fprint(2, "usage: win cmd args...\n");
	threadexitsall("usage");
}

int
nopipes(void *v, char *msg)
{
	USED(v);
	if(strcmp(msg, "sys: write on closed pipe") == 0)
		return 1;
	return 0;
}

void
threadmain(int argc, char **argv)
{
	int fd, id;
	char buf[256];
	char buf1[128];
	char *name;
	Fsys *fs;

	ARGBEGIN{
	case 'd':
		debug = 1;
		break;
	default:
		usage();
	}ARGEND

	prog = argv;

	if(argc > 0)
		name = argv[0];
	else
		name = "gnot";

	threadnotify(nopipes, 1);
	if((fs = nsmount("acme", "")) < 0)
		sysfatal("nsmount acme: %r");
	ctlfd = fsopenfd(fs, "new/ctl", ORDWR|OCEXEC);
	if(ctlfd < 0 || read(ctlfd, buf, 12) != 12)
		sysfatal("ctl: %r");
	id = atoi(buf);
	sprint(buf, "%d/tag", id);
	fd = fsopenfd(fs, buf, OWRITE|OCEXEC);
	write(fd, " Send Delete", 12);
	close(fd);
	sprint(buf, "%d/event", id);
	eventfd = fsopenfd(fs, buf, ORDWR|OCEXEC);
	sprint(buf, "%d/addr", id);
	addrfd = fsopenfd(fs, buf, ORDWR|OCEXEC);
	sprint(buf, "%d/data", id);
	datafd = fsopenfd(fs, buf, ORDWR|OCEXEC);
	sprint(buf, "%d/body", id);
	bodyfd = fsopenfd(fs, buf, ORDWR|OCEXEC);
	if(eventfd<0 || addrfd<0 || datafd<0 || bodyfd<0)
		sysfatal("data files: %r");
	fsunmount(fs);

	if(pipe(p) < 0)
		sysfatal("pipe: %r");

	cpid = chancreate(sizeof(ulong), 1);
	threadcreate(runproc, nil, STACK);
	pid = recvul(cpid);
	if(pid == -1)
		sysfatal("exec failed");

	getwd(buf1, sizeof buf1);
	sprint(buf, "name %s/-%s\n0\n", buf1, name);
	write(ctlfd, buf, strlen(buf));
	sprint(buf, "dumpdir %s/\n", buf1);
	write(ctlfd, buf, strlen(buf));
	sprint(buf, "dump %s\n", onestring(argc, argv));
	write(ctlfd, buf, strlen(buf));
	
//	proccreate(stdoutproc, nil, STACK);
	stdinproc(nil);
}

char *shell[] = { "rc", "-i", 0 };
void
runproc(void *v)
{
	int fd[3];
	char *sh;

	USED(v);

	fd[0] = p[1];
	fd[1] = bodyfd;
	fd[2] = bodyfd;
//	fd[1] = p[1];
//	fd[2] = p[1];

	if(prog[0] == nil){
		prog = shell;
		if((sh = getenv("SHELL")) != nil)
			shell[0] = sh;
	}
	threadexec(cpid, fd, prog[0], prog);
	threadexits(nil);
}

void
error(char *s)
{
	if(s)
		fprint(2, "win: %s: %r\n", s);
	else
		s = "kill";
	if(pid != -1)
		postnote(PNGROUP, pid, "hangup");
	threadexitsall(s);
}

char*
onestring(int argc, char **argv)
{
	char *p;
	int i, n;
	static char buf[1024];

	if(argc == 0)
		return "";
	p = buf;
	for(i=0; i<argc; i++){
		n = strlen(argv[i]);
		if(p+n+1 >= buf+sizeof buf)
			break;
		memmove(p, argv[i], n);
		p += n;
		*p++ = ' ';
	}
	p[-1] = 0;
	return buf;
}

int
getec(int efd)
{
	static char buf[8192];
	static char *bufp;
	static int nbuf;

	if(nbuf == 0){
		nbuf = read(efd, buf, sizeof buf);
		if(nbuf <= 0)
			error(nil);
		bufp = buf;
	}
	--nbuf;
	return *bufp++;
}

int
geten(int efd)
{
	int n, c;

	n = 0;
	while('0'<=(c=getec(efd)) && c<='9')
		n = n*10+(c-'0');
	if(c != ' ')
		error("event number syntax");
	return n;
}

int
geter(int efd, char *buf, int *nb)
{
	Rune r;
	int n;

	r = getec(efd);
	buf[0] = r;
	n = 1;
	if(r < Runeself)
		goto Return;
	while(!fullrune(buf, n))
		buf[n++] = getec(efd);
	chartorune(&r, buf);
    Return:
	*nb = n;
	return r;
}

void
gete(int efd, Event *e)
{
	int i, nb;

	e->c1 = getec(efd);
	e->c2 = getec(efd);
	e->q0 = geten(efd);
	e->q1 = geten(efd);
	e->flag = geten(efd);
	e->nr = geten(efd);
	if(e->nr > EVENTSIZE)
		error("event string too long");
	e->nb = 0;
	for(i=0; i<e->nr; i++){
		e->r[i] = geter(efd, e->b+e->nb, &nb);
		e->nb += nb;
	}
	e->r[e->nr] = 0;
	e->b[e->nb] = 0;
	if(getec(efd) != '\n')
		error("event syntax 2");
}

int
nrunes(char *s, int nb)
{
	int i, n;
	Rune r;

	n = 0;
	for(i=0; i<nb; n++)
		i += chartorune(&r, s+i);
	return n;
}

void
stdinproc(void *v)
{
	int cfd = ctlfd;
	int efd = eventfd;
	int dfd = datafd;
	int afd = addrfd;
	int fd0 = p[0];
	Event e, e2, e3, e4;

	USED(v);

	for(;;){
		if(debug)
			fprint(2, "typing[%d,%d)\n", q.p, q.p+ntyper);
		gete(efd, &e);
		if(debug)
			fprint(2, "msg %c%c q[%d,%d)... ", e.c1, e.c2, e.q0, e.q1);
		qlock(&q.lk);
		switch(e.c1){
		default:
		Unknown:
			print("unknown message %c%c\n", e.c1, e.c2);
			break;

		case 'E':	/* write to body; can't affect us */
			if(debug)
				fprint(2, "shift typing %d... ", e.q1-e.q0);
			q.p += e.q1-e.q0;
			break;

		case 'F':	/* generated by our actions; ignore */
			break;

		case 'K':
		case 'M':
			switch(e.c2){
			case 'I':
				if(e.q0 < q.p){
					if(debug)
						fprint(2, "shift typing %d... ", e.q1-e.q0);
					q.p += e.q1-e.q0;
				}
				else if(e.q0 <= q.p+ntyper){
					if(debug)
						fprint(2, "type... ");
					type(&e, fd0, afd, dfd);
				}
				break;

			case 'D':
				q.p -= delete(&e);
				break;

			case 'x':
			case 'X':
				if(e.flag & 2)
					gete(efd, &e2);
				if(e.flag & 8){
					gete(efd, &e3);
					gete(efd, &e4);
				}
				if(e.flag&1 || (e.c2=='x' && e.nr==0 && e2.nr==0)){
					/* send it straight back */
					fprint(efd, "%c%c%d %d\n", e.c1, e.c2, e.q0, e.q1);
					break;
				}
				if(e.q0==e.q1 && (e.flag&2)){
					e2.flag = e.flag;
					e = e2;
				}
				if(e.flag & 8){
					if(e.q1 != e.q0){
						sende(&e, fd0, cfd, afd, dfd, 0);
						sende(&blank, fd0, cfd, afd, dfd, 0);
					}
					sende(&e3, fd0, cfd, afd, dfd, 1);
				}else	 if(e.q1 != e.q0)
					sende(&e, fd0, cfd, afd, dfd, 1);
				break;

			case 'l':
			case 'L':
				/* just send it back */
				if(e.flag & 2)
					gete(efd, &e2);
				fprint(efd, "%c%c%d %d\n", e.c1, e.c2, e.q0, e.q1);
				break;

			case 'd':
			case 'i':
				break;

			default:
				goto Unknown;
			}
		}
		qunlock(&q.lk);
	}
}

void
stdoutproc(void *v)
{
	int fd1 = p[0];
	int afd = addrfd;
	int dfd = datafd;
	int n, m, w, npart;
	char *buf, *s, *t;
	Rune r;
	char x[16], hold[UTFmax];

	USED(v);
	threadnotify(nopipes, 1);
	buf = malloc(8192+UTFmax+1);
	npart = 0;
	for(;;){
		n = read(fd1, buf+npart, 8192);
		if(n < 0)
			error(nil);
		if(n == 0)
			continue;

		/* squash NULs */
		s = memchr(buf+npart, 0, n);
		if(s){
			for(t=s; s<buf+npart+n; s++)
				if(*t = *s)	/* assign = */
					t++;
			n = t-(buf+npart);
		}

		n += npart;

		/* hold on to final partial rune */
		npart = 0;
		while(n>0 && (buf[n-1]&0xC0)){
			--n;
			npart++;
			if((buf[n]&0xC0)!=0x80){
				if(fullrune(buf+n, npart)){
					w = chartorune(&r, buf+n);
					n += w;
					npart -= w;
				}
				break;
			}
		}
		if(n > 0){
			memmove(hold, buf+n, npart);
			buf[n] = 0;
			qlock(&q.lk);
			m = sprint(x, "#%d", q.p);
			if(write(afd, x, m) != m)
				error("stdout writing address");
			if(write(dfd, buf, n) != n)
				error("stdout writing body");
			q.p += nrunes(buf, n);
			qunlock(&q.lk);
			memmove(buf, hold, npart);
		}
	}
}

int
delete(Event *e)
{
	uint q0, q1;
	int deltap;

	q0 = e->q0;
	q1 = e->q1;
	if(q1 <= q.p)
		return e->q1-e->q0;
	if(q0 >= q.p+ntyper)
		return 0;
	deltap = 0;
	if(q0 < q.p){
		deltap = q.p-q0;
		q0 = 0;
	}else
		q0 -= q.p;
	if(q1 > q.p+ntyper)
		q1 = ntyper;
	else
		q1 -= q.p;
	deltype(q0, q1);
	return deltap;
}

void
addtype(int c, uint p0, char *b, int nb, int nr)
{
	int i, w;
	Rune r;
	uint p;
	char *b0;

	for(i=0; i<nb; i+=w){
		w = chartorune(&r, b+i);
		if((r==0x7F||r==3) && c=='K'){
			postnote(PNGROUP, pid, "interrupt");
			/* toss all typing */
			q.p += ntyper+nr;
			ntypebreak = 0;
			ntypeb = 0;
			ntyper = 0;
			/* buglet:  more than one delete ignored */
			return;
		}
		if(r=='\n' || r==0x04)
			ntypebreak++;
	}
	typing = realloc(typing, ntypeb+nb);
	if(typing == nil)
		error("realloc");
	if(p0 == ntyper)
		memmove(typing+ntypeb, b, nb);
	else{
		b0 = typing;
		for(p=0; p<p0 && b0<typing+ntypeb; p++){
			w = chartorune(&r, b0+i);
			b0 += w;
		}
		if(p != p0)
			error("typing: findrune");
		memmove(b0+nb, b0, (typing+ntypeb)-b0);
		memmove(b0, b, nb);
	}
	ntypeb += nb;
	ntyper += nr;
}

void
sendtype(int fd0)
{
	int i, n, nr;

	while(ntypebreak){
		for(i=0; i<ntypeb; i++)
			if(typing[i]=='\n' || typing[i]==0x04){
				n = i + (typing[i] == '\n');
				i++;
				if(write(fd0, typing, n) != n)
					error("sending to program");
				nr = nrunes(typing, i);
				q.p += nr;
				ntyper -= nr;
				ntypeb -= i;
				memmove(typing, typing+i, ntypeb);
				ntypebreak--;
				goto cont2;
			}
		print("no breakchar\n");
		ntypebreak = 0;
cont2:
	}
}

void
deltype(uint p0, uint p1)
{
	int w;
	uint p, b0, b1;
	Rune r;

	/* advance to p0 */
	b0 = 0;
	for(p=0; p<p0 && b0<ntypeb; p++){
		w = chartorune(&r, typing+b0);
		b0 += w;
	}
	if(p != p0)
		error("deltype 1");
	/* advance to p1 */
	b1 = b0;
	for(; p<p1 && b1<ntypeb; p++){
		w = chartorune(&r, typing+b1);
		b1 += w;
		if(r=='\n' || r==0x04)
			ntypebreak--;
	}
	if(p != p1)
		error("deltype 2");
	memmove(typing+b0, typing+b1, ntypeb-b1);
	ntypeb -= b1-b0;
	ntyper -= p1-p0;
}

void
type(Event *e, int fd0, int afd, int dfd)
{
	int m, n, nr;
	char buf[128];

	if(e->nr > 0)
		addtype(e->c1, e->q0-q.p, e->b, e->nb, e->nr);
	else{
		m = e->q0;
		while(m < e->q1){
			n = sprint(buf, "#%d", m);
			write(afd, buf, n);
			n = read(dfd, buf, sizeof buf);
			nr = nrunes(buf, n);
			while(m+nr > e->q1){
				do; while(n>0 && (buf[--n]&0xC0)==0x80);
				--nr;
			}
			if(n == 0)
				break;
			addtype(e->c1, m-q.p, buf, n, nr);
			m += nr;
		}
	}
	sendtype(fd0);
}

void
sende(Event *e, int fd0, int cfd, int afd, int dfd, int donl)
{
	int l, m, n, nr, lastc, end;
	char abuf[16], buf[128];

	end = q.p+ntyper;
	l = sprint(abuf, "#%d", end);
	write(afd, abuf, l);
	if(e->nr > 0){
		write(dfd, e->b, e->nb);
		addtype(e->c1, ntyper, e->b, e->nb, e->nr);
		lastc = e->r[e->nr-1];
	}else{
		m = e->q0;
		lastc = 0;
		while(m < e->q1){
			n = sprint(buf, "#%d", m);
			write(afd, buf, n);
			n = read(dfd, buf, sizeof buf);
			nr = nrunes(buf, n);
			while(m+nr > e->q1){
				do; while(n>0 && (buf[--n]&0xC0)==0x80);
				--nr;
			}
			if(n == 0)
				break;
			l = sprint(abuf, "#%d", end);
			write(afd, abuf, l);
			write(dfd, buf, n);
			addtype(e->c1, ntyper, buf, n, nr);
			lastc = buf[n-1];
			m += nr;
			end += nr;
		}
	}
	if(donl && lastc!='\n'){
		write(dfd, "\n", 1);
		addtype(e->c1, ntyper, "\n", 1, 1);
	}
	write(cfd, "dot=addr", 8);
	sendtype(fd0);
}