#include <u.h>
#include <libc.h>
#include <bio.h>
#include <thread.h>
#include "dat.h"

typedef struct Wpid Wpid;
struct Wpid
{
	int		pid;
	Window	*w;
	Wpid		*next;
};

void	pipectl(void*);

int	pipefd;
Wpid	*wpid;
int	snarffd;

void
newpipewin(int pid, char *p)
{
	Window *w;
	Wpid *wp;

	w = newwindow();
	winname(w, p);
	wintagwrite(w, "Send ", 5);
	threadcreate(pipectl, w, STACK);
	wp = emalloc(sizeof(Wpid));
	wp->pid = pid;
	wp->w = w;
	wp->next = wpid;
	wpid = wp;
}

void
datapipewin(int pid, char *p, int n)
{
	Wpid *wp;

	for(wp=wpid; wp!=nil; wp=wp->next){
		if(wp->pid == pid){
			write(wp->w->data, p, n);
			return;
		}
	}
	fprint(2, "win: can't find window %d for data message\n", pid);
}

void
eofpipewin(int pid)
{
	Wpid *wp, *prev;

	prev = nil;
	for(wp=wpid; wp!=nil; wp=wp->next){
		if(wp->pid == pid){
			winclean(wp->w);
			windormant(wp->w);
			if(prev)
				prev->next = wp->next;
			else
				wpid->next = wp->next;
			free(wp);
			return;
		}
		prev = wp;
	}
	fprint(2, "win: can't find window %d for eof message\n", pid);
}

int
pipecommand(Window *w, char *s)
{
	ulong q0, q1;
	char tmp[32], *t;
	int n, k;

	while(*s==' ' || *s=='\t' || *s=='\n')
		s++;
	if(strcmp(s, "Delete")==0){
		windel(w, 1);
		threadexits(nil);
		return 1;
	}
	if(strcmp(s, "Del")==0){
		if(windel(w, 0))
			threadexits(nil);
		return 1;
	}
	if(strcmp(s, "Send") == 0){
		if(w->addr < 0)
			w->addr = winopenfile(w, "addr");
		ctlprint(w->ctl, "addr=dot\n");
		seek(w->addr, 0UL, 0);
		if(read(w->addr, tmp, 2*12) == 2*12){
			q0 = atol(tmp+0*12);
			q1 = atol(tmp+1*12);
			if(q0 == q1){
				t = nil;
				k = 0;
				if(snarffd > 0){
					seek(0, snarffd, 0);
					for(;;){
						t = realloc(t, k+8192+1);
						if(t == nil)
							error("win: alloc failed: %r\n");
						n = read(snarffd, t+k, 8192);
						if(n <= 0)
							break;
						k += n;
					}
					t[k] = 0;
				}
			}else{
				t = emalloc((q1-q0)*UTFmax+1);
				winread(w, q0, q1, t);
			}
			if(t!=nil && t[0]!='\0')
				sendit(t);
			free(t);
		}
		return 1;
	}
	return 0;
}

void
pipectl(void *v)
{
	Window *w;
	Event *e;

	w = v;
	proccreate(wineventproc, w, STACK);

	winsetaddr(w, "0", 0);
	for(;;){
		e = recvp(w->cevent);
		switch(e->c1){
		default:
		Unknown:
			threadprint(2, "unknown message %c%c\n", e->c1, e->c2);
			break;

		case 'E':	/* write to body; can't affect us */
			break;
	
		case 'F':	/* generated by our actions; ignore */
			break;
	
		case 'K':	/* ignore */
			break;
	
		case 'M':
			switch(e->c2){
			case 'x':
			case 'X':
				execevent(w, e, pipecommand);
				break;
	
			case 'l':	/* reflect all searches back to acme */
			case 'L':
				if(e->flag & 2)
					recvp(w->cevent);
				winwriteevent(w, e);
				break;
	
			case 'I':	/* modify away; we don't care */
			case 'i':
			case 'D':
			case 'd':
				break;
	
			default:
				goto Unknown;
			}
		}
	}
}

void
pipeproc(void *v)
{
	int n;
	char *buf;
	Channel *ch;

	ch = v;
	for(;;){
		buf = emalloc(NPIPE+1);
		n = read(pipefd, buf, NPIPE);
		if(n < 0){
			sendp(ch, nil);
			break;
		}
		if(n == 0)
			continue;
		buf[n] = '\0';
		sendp(ch, buf);
	}
}

void
pipetask(void *v)
{
	char *buf, *datap;
	int pid, c;
	Channel *ch;

	ch = v;

	while((buf = recvp(ch)) != nil){
		datap = strchr(buf, '\n');
		if(datap == nil)
			break;
		datap++;
		pid = atoi((char*)buf+1);
		c = ((uchar*)buf)[0];
		switch(c){
		default:
			fprint(2, "win: unrecognized pipe command '%c'=0x%.2x\n", c, c);
		case 'n':
			newpipewin(pid, datap);
			break;
		case 'd':
			datapipewin(pid, datap, (buf+strlen(buf))-datap);
			break;
		case 'e':
			eofpipewin(pid);
			break;
		}
		free(buf);
	}
}

void
startpipe(void)
{
	int fd, p[2];
	char *user, buf[128];
	Channel *c;

	snarffd = open("/dev/snarf", OREAD|OCEXEC);
	if(pipe(p) < 0)
		error("can't create pipe: %r");
	/* 0 will be server end, 1 will be client end */
	pipefd = p[0];
	user = getenv("user");
	if(user == nil)
		user = "none";
	sprint(buf, "/srv/win.%s.%d", user, getpid());
	fd = create(buf, OWRITE|OCEXEC|ORCLOSE, 0600);
	if(fd < 0)
		error("can't create /srv file: %r");
	if(putenv("winsrv", buf) < 0)
		error("can't write $winsrv: %r");
	if(threadprint(fd, "%d", p[1]) <= 0)
		error("can't write /srv/file: %r");
	/* leave fd open; ORCLOSE will take care of it */

	c = chancreate(sizeof(char*), 0);
	proccreate(pipeproc, c, STACK);
	threadcreate(pipetask, c, STACK);
	close(p[1]);
}