#include	"u.h"
#include	"lib.h"
#include	"mem.h"
#include	"dat.h"
#include	"fns.h"
#include	"io.h"
#include	"errno.h"

#include	"devtab.h"

static struct
{
	Lock;
	int	printing;
	int	c;
}printq;

typedef struct IOQ	IOQ;

#define	NQ	1024
struct IOQ{
	union{
		Lock;
		QLock;
	};
	uchar	buf[NQ];
	uchar	*in;
	uchar	*out;
	int	state;
	Rendez	r;
};

IOQ	lineq;
IOQ	rs232iq;
IOQ	rs232oq;

struct{
	IOQ;
	Lock	put;
}klogq;

struct{
	IOQ;		/* qlock to getc; interrupt putc's */
	int	c;
	int	repeat;
	int	count;
}kbdq;

Ref	raw;		/* whether kbd i/o is raw (rcons is open) */

void
printinit(void)
{

	lock(&printq);		/* allocate lock */
	unlock(&printq);

	kbdq.in = kbdq.buf;
	kbdq.out = kbdq.buf;
	rs232iq.in = rs232iq.buf;
	rs232iq.out = rs232iq.buf;
	rs232oq.in = rs232oq.buf;
	rs232oq.out = rs232oq.buf;
	klogq.in = klogq.buf;
	klogq.out = klogq.buf;
	lineq.in = lineq.buf;
	lineq.out = lineq.buf;
	qlock(&kbdq);		/* allocate qlock */
	qunlock(&kbdq);
	lock(&lineq);		/* allocate lock */
	unlock(&lineq);
	lock(&rs232iq);		/* allocate lock */
	unlock(&rs232iq);
	lock(&rs232oq);		/* allocate lock */
	unlock(&rs232oq);
	lock(&klogq);		/* allocate lock */
	unlock(&klogq);
	lock(&klogq.put);		/* allocate lock */
	unlock(&klogq.put);

	screeninit();
}

/*
 * Print a string on the console.
 */
void
putstrn(char *str, long n)
{
	int s;

	s = splhi();
	lock(&printq);
	printq.printing = 1;
	while(--n >= 0)
		screenputc(*str++);
	printq.printing = 0;
	unlock(&printq);
	splx(s);
}

int
cangetc(IOQ *q)
{
	int n = q->in - q->out;
	if (n < 0)
		n += sizeof(q->buf);
	return n;
}

int
canputc(IOQ *q)
{
	return sizeof(q->buf)-cangetc(q)-1;
}

int
isbrkc(IOQ *q)
{
	uchar *p;

	for(p=q->out; p!=q->in; ){
		if(raw.ref)
			return 1;
		if(*p==0x04 || *p=='\n')
			return 1;
		p++;
		if(p >= q->buf+sizeof(q->buf))
			p = q->buf;
	}
	return 0;
}

int
getc(IOQ *q)
{
	int c;

	if(q->in == q->out)
		return -1;
	c = *q->out++;
	if(q->out == q->buf+sizeof(q->buf))
		q->out = q->buf;
	return c;
}

int
putc(IOQ *q, int c)
{
	uchar *nextin;
	if(q->in >= &q->buf[sizeof(q->buf)-1])
		nextin = q->buf;
	else
		nextin = q->in+1;
	if(nextin == q->out)
		return -1;
	*q->in = c;
	q->in = nextin;
	return 0;
}

void
putstrk(char *str, long n)
{
	int s;

	s = splhi();
	lock(&klogq.put);
	while(--n >= 0){
		*klogq.in++ = *str++;
		if(klogq.in == klogq.buf+sizeof(klogq.buf))
			klogq.in = klogq.buf;
	}
	unlock(&klogq.put);
	splx(s);
	wakeup(&klogq.r);
}

int
sprint(char *s, char *fmt, ...)
{
	return doprint(s, s+PRINTSIZE, fmt, (&fmt+1)) - s;
}

int
print(char *fmt, ...)
{
	char buf[PRINTSIZE];
	int n;

	n = doprint(buf, buf+sizeof(buf), fmt, (&fmt+1)) - buf;
	putstrn(buf, n);
	return n;
}

int
kprint(char *fmt, ...)
{
	char buf[PRINTSIZE];
	int n;

	n = doprint(buf, buf+sizeof(buf), fmt, (&fmt+1)) - buf;
	putstrk(buf, n);
	return n;
}

void
panic(char *fmt, ...)
{
	char buf[PRINTSIZE];
	int n;

	strcpy(buf, "panic: ");
	n = doprint(buf+7, buf+sizeof(buf), fmt, (&fmt+1)) - buf;
	buf[n] = '\n';
	putstrn(buf, n+1);
	exit();
}
int
pprint(char *fmt, ...)
{
	char buf[2*PRINTSIZE];
	Chan *c;
	int n;

	c = u->fd[2];
	if(c==0 || (c->mode!=OWRITE && c->mode!=ORDWR))
		return 0;
	n = sprint(buf, "%s %d: ", u->p->text, u->p->pid);
	n = doprint(buf+n, buf+sizeof(buf), fmt, (&fmt+1)) - buf;
	qlock(c);
	if(waserror()){
		qunlock(c);
		return 0;
	}
	(*devtab[c->type].write)(c, buf, n);
	c->offset += n;
	qunlock(c);
	poperror();
	return n;
}

void
prflush(void)
{
	while(printq.printing)
		delay(100);
}

void
echo(int c)
{
	char ch;

	/*
	 * ^t hack BUG
	 */
	if(c == 0x14)
		DEBUG();
	if(c == 0x16)
		dumpqueues();
	if(c == 0x18)
		mntdump();
	if(raw.ref)
		return;
	if(c == 0x15)
		putstrn("^U\n", 3);
	else{
		ch = c;
		putstrn(&ch, 1);
	}
}

/*
 * Put character into read queue at interrupt time.
 * Always called splhi from proc 0.
 */

void
kbdchar(int c)
{
	if(kbdq.repeat == 1){
		kbdq.c = c;
		kbdq.count = 0;
		kbdq.repeat = 2;
	}
	if(c == '\r')
		c = '\n';
	echo(c);
	*kbdq.in++ = c;
	if(kbdq.in == kbdq.buf+sizeof(kbdq.buf))
		kbdq.in = kbdq.buf;
	if(raw.ref || c=='\n' || c==0x04)
		wakeup(&kbdq.r);
}

void
kbdrepeat(int rep)
{
	if(rep)
		kbdq.repeat = 1;
	else
		kbdq.repeat = 0;
}

void
kbdclock(void)
{
	if(kbdq.repeat==2 && (++kbdq.count&1))
		kbdchar(kbdq.c);
}

void
rs232ichar(int c)
{
	putc(&rs232iq, c);
	wakeup(&rs232iq.r);
}

int
getrs232o(void)
{
	int c;

	c = getc(&rs232oq);
	if(c == -1)
		rs232oq.state = 0;
	wakeup(&rs232oq.r);
	return c;
}

int
consactive(void)
{
	return printq.printing;
}

/*
 * I/O interface
 */
enum{
	Qdir,
	Qcons,
	Qcputime,
	Qnull,
	Qpgrpid,
	Qpid,
	Qppid,
	Qrcons,
	Qrs232,
	Qtime,
	Quser,
	Qklog,
};

Dirtab consdir[]={
	"cons",		Qcons,		0,	0600,
	"cputime",	Qcputime,	72,	0600,
	"null",		Qnull,		0,	0600,
	"pgrpid",	Qpgrpid,	12,	0600,
	"pid",		Qpid,		12,	0600,
	"ppid",		Qppid,		12,	0600,
	"rcons",	Qrcons,		0,	0600,
	"rs232",	Qrs232,		0,	0600,
	"time",		Qtime,		12,	0600,
	"user",		Quser,		0,	0600,
	"klog",		Qklog,		0,	0400,
};

#define	NCONS	(sizeof consdir/sizeof(Dirtab))

static int
consgen(Chan *c, Dirtab *tab, int ntab, int i, Dir *dp)
{
	if(tab==0 || i>=ntab)
		return -1;
	tab += i;
	devdir(c, tab->qid, tab->name, tab->length, tab->perm, dp);
	switch(dp->qid){
	case Qrs232:
		dp->length = cangetc(&rs232iq); break;
	}
	return 1;
}

ulong	boottime;		/* seconds since epoch at boot */

long
seconds(void)
{
	return boottime + TK2SEC(MACHP(0)->ticks);
}

int
readnum(ulong off, char *buf, ulong n, ulong val, int size)
{
	char tmp[64];
	Op op = (Op){ tmp, tmp+sizeof(tmp), &val, size-1, 0, FUNSIGN|FLONG };

	numbconv(&op, 10);
	tmp[size-1] = ' ';
	if(off >= size)
		return 0;
	if(off+n > size)
		n = size-off;
	memcpy(buf, tmp+off, n);
	return n;
}

int
readstr(ulong off, char *buf, ulong n, char *str)
{
	int size;

	size = strlen(str);
	if(off >= size)
		return 0;
	if(off+n > size)
		n = size-off;
	memcpy(buf, str+off, n);
	return n;
}

void
consreset(void)
{
}

void
consinit(void)
{
}

Chan*
consattach(char *spec)
{
	return devattach('c', spec);
}

Chan*
consclone(Chan *c, Chan *nc)
{
	return devclone(c, nc);
}

int
conswalk(Chan *c, char *name)
{
	return devwalk(c, name, consdir, NCONS, consgen);
}

void
consstat(Chan *c, char *dp)
{
	devstat(c, dp, consdir, NCONS, consgen);
}

Chan*
consopen(Chan *c, int omode)
{
	int ch;

	if(c->qid==Quser && omode==(OWRITE|OTRUNC)){
		/* truncate? */
		if(strcmp(u->p->pgrp->user, "bootes") == 0)	/* BUG */
			u->p->pgrp->user[0] = 0;
		else
			error(0, Eperm);
	}
	if(c->qid == Qrcons)
		if(incref(&raw) == 1){
			lock(&lineq);
			while((ch=getc(&kbdq)) != -1){
				*lineq.in++ = ch;
				if(lineq.in == lineq.buf+sizeof(lineq.buf))
					lineq.in = lineq.buf;
			}
			unlock(&lineq);
		}
	return devopen(c, omode, consdir, NCONS, consgen);
}

void
conscreate(Chan *c, char *name, int omode, ulong perm)
{
	error(0, Eperm);
}

void
consclose(Chan *c)
{
	if(c->qid==Qrcons && (c->flag&COPEN))
		decref(&raw);
}

long
consread(Chan *c, void *buf, long n)
{
	int ch, i, j, k;
	ulong l;
	uchar *out;
	char *cbuf = buf;
	char *user;
	int userlen;
	char tmp[6*NUMSIZE];

	if(n <= 0)
		return n;
	switch(c->qid&~CHDIR){
	case Qdir:
		return devdirread(c, buf, n, consdir, NCONS, consgen);

	case Qrcons:
	case Qcons:
		qlock(&kbdq);
		if(waserror()){
			qunlock(&kbdq);
			nexterror();
		}
		while(!cangetc(&lineq)){
			sleep(&kbdq.r, (int(*)(void*))isbrkc, &kbdq);
			do{
				lock(&lineq);
				ch = getc(&kbdq);
				if(raw.ref){
					unlock(&lineq);
					goto Default;
				}
				switch(ch){
				case '\b':
					if(lineq.in != lineq.out){
						if(lineq.in == lineq.buf)
							lineq.in = lineq.buf+sizeof(lineq.buf);
						lineq.in--;
					}
					break;
				case 0x15:
					lineq.in = lineq.out;
					break;
				Default:
				default:
					*lineq.in++ = ch;
					if(lineq.in == lineq.buf+sizeof(lineq.buf))
						lineq.in = lineq.buf;
				}
				unlock(&lineq);
			}while(raw.ref==0 && ch!='\n' && ch!=0x04);
		}
		i = 0;
		while(n > 0){
			ch = getc(&lineq);
			if(ch==-1 || (raw.ref==0 && ch==0x04))
				break;
			i++;
			*cbuf++ = ch;
			--n;
		}
		qunlock(&kbdq);
		return i;

	case Qrs232:
		qlock(&rs232iq);
		if(waserror()){
			qunlock(&rs232iq);
			nexterror();
		}
		while(!cangetc(&rs232iq))
			sleep(&rs232iq.r, (int(*)(void*))cangetc, &rs232iq);
		for(i=0; i<n; i++){
			if((ch=getc(&rs232iq)) == -1)
				break;
			*cbuf++ = ch;
		}
		qunlock(&rs232iq);
		return i;

	case Qcputime:
		k = c->offset;
		if(k >= sizeof tmp)
			return 0;
		if(k+n > sizeof tmp)
			n = sizeof tmp - k;
		/* easiest to format in a separate buffer and copy out */
		for(i=0; i<6 && NUMSIZE*i<k+n; i++){
			l = u->p->time[i];
			if(i == TReal)
				l = MACHP(0)->ticks - l;
			l = TK2MS(l);
			readnum(0, tmp+NUMSIZE*i, NUMSIZE, l, NUMSIZE);
		}
		memcpy(buf, tmp+k, n);
		return n;

	case Qpgrpid:
		return readnum(c->offset, buf, n, u->p->pgrp->pgrpid, NUMSIZE);

	case Qpid:
		return readnum(c->offset, buf, n, u->p->pid, NUMSIZE);

	case Qppid:
		return readnum(c->offset, buf, n, u->p->parentpid, NUMSIZE);

	case Qtime:
		return readnum(c->offset, buf, n, boottime+TK2SEC(MACHP(0)->ticks), 12);

	case Quser:
		return readstr(c->offset, buf, n, u->p->pgrp->user);

	case Qnull:
		return 0;

	case Qklog:
		qlock(&klogq);
		if(waserror()){
			qunlock(&klogq);
			nexterror();
		}
		while(!cangetc(&klogq))
			sleep(&klogq.r, (int(*)(void*))cangetc, &klogq);
		for(i=0; i<n; i++){
			if((ch=getc(&klogq)) == -1)
				break;
			*cbuf++ = ch;
		}
		qunlock(&klogq);
		return i;

	default:
		panic("consread %lux\n", c->qid);
		return 0;
	}
}

long
conswrite(Chan *c, void *va, long n)
{
	char cbuf[64];
	char buf[256];
	long l, m;
	char *a = va;

	switch(c->qid){
	case Qcons:
	case Qrcons:
		/*
		 * Damn. Can't page fault in putstrn, so copy the data locally.
		 */
		l = n;
		while(l > 0){
			m = l;
			if(m > sizeof buf)
				m = sizeof buf;
			memcpy(buf, a, m);
			putstrn(a, m);
			a += m;
			l -= m;
		}
		break;

	case Qrs232:
		qlock(&rs232oq);
		l = n;
		while(--l >= 0) {
			while (putc(&rs232oq, *a) < 0)
				sleep(&rs232oq.r, (int(*)(void*))canputc, &rs232oq);
			a++;
			if(rs232oq.state == 0){
				splhi();
				if(rs232oq.state == 0){
					rs232oq.state = 1;
					duartstartrs232o();
				}
				spllo();
			}
		}
		qunlock(&rs232oq);
		break;

	case Qtime:
		if(n<=0 || boottime!=0)	/* only one write please */
			return 0;
		if(n >= sizeof cbuf)
			n = sizeof cbuf - 1;
		memcpy(cbuf, a, n);
		cbuf[n-1] = 0;
		boottime = strtoul(a, 0, 0);
		break;

	case Quser:
		if(u->p->pgrp->user[0])		/* trying to overwrite /dev/user */
			error(0, Eperm);
		if(c->offset >= NAMELEN-1)
			return 0;
		if(c->offset+n >= NAMELEN-1)
			n = NAMELEN-1 - c->offset;
		memcpy(u->p->pgrp->user+c->offset, a, n);
		u->p->pgrp->user[c->offset+n] = 0;
		break;

	case Qcputime:
	case Qpgrpid:
	case Qpid:
	case Qppid:
		error(0, Eperm);

	case Qnull:
		break;
	default:
		error(0, Egreg);
	}
	return n;
}

void
consremove(Chan *c)
{
	error(0, Eperm);
}

void
conswstat(Chan *c, char *dp)
{
	error(0, Eperm);
}

void
conserrstr(Error *e, char *buf)
{
	rooterrstr(e, buf);
}

void
consuserstr(Error *e, char *buf)
{
	strcpy(buf, u->p->pgrp->user);
}