#include <u.h>
#include <libc.h>
#include <draw.h>
#include <event.h>
#include <bio.h>
#include <keyboard.h>
#include "cons.h"

enum{
	Ehost		= 4,
};

char	*menutext2[] = {
	"backup",
	"forward",
	"reset",
	"clear",
	"send",
	"page",
	0
};

char	*menutext3[] = {
	"24x80",
	"crnl",
	"nl",
	"raw",
	0
};

/* variables associated with the screen */

int	x, y;	/* character positions */
char	*backp;
int	backc;
int	atend;
int	nbacklines;
int	xmax, ymax;
int	blocked;
int	resize_flag;
int	pagemode;
int	olines;
int	peekc;
Menu	menu2;
Menu	menu3;
char	*histp;
char	hist[HISTSIZ];
int	yscrmin, yscrmax;

Image	*text;
Image	*background;
Image	*bordercol;
Image	*cursback;
Image	*red;

/* terminal control */
struct ttystate ttystate[2] = { {0, 1}, {0,0} };

int	NS;
int	CW;
Consstate *cs;
Mouse	mouse;

int	outfd = -1;
Biobuf	*snarffp = 0;

char	*host_buf;
char	*hostp;			/* input from host */
int	host_bsize = 2*BSIZE;
int	hostlength;			/* amount of input from host */
char	echo_input[BSIZE];
char	*echop = echo_input;	/* characters to echo, after canon */
char	sendbuf[BSIZE];	/* hope you can't type ahead more than BSIZE chars */
char	*sendp = sendbuf;

/* functions */
void	initialize(int, char **);
void	ebegin(int);
int	waitchar(void);
int	rcvchar(void);
void	set_input(char *);
void	set_host(Event *);
void	bigscroll(void);
void	readmenu(void);
void	eresized(int);
void	resize(void);
void	send_interrupt(void);
int	alnum(int);
void	escapedump(int,uchar *,int);
char *term;
struct funckey *fk;

int	debug;

void
main(int argc, char **argv)
{
	initialize(argc, argv);
	emulate();
}

void
initialize(int argc, char **argv)
{
	int dayglo = 1;

	rfork(RFENVG|RFNAMEG|RFNOTEG);

	term = "vt100";
	fk = vt100fk;
	ARGBEGIN{
	case '2':
		term = "vt220";
		fk = vt220fk;
		break;
	case 's': /* for sape */
		dayglo = 0;
		break;
	}ARGEND;

	host_buf = malloc(host_bsize);
	hostp = host_buf;
	hostlength = 0;

	if(initdraw(0,0,term) < 0){
		fprint(2, "%s: initdraw failed: %r\n", term);
		exits("initdraw");
	}
	ebegin(Ehost);

	histp = hist;
	menu2.item = menutext2;
	menu3.item = menutext3;
	pagemode = 0;
	blocked = 0;
	NS = font->height ;
	CW = stringwidth(font, "m");
	text = allocimage(display, Rect(0,0,1,1), screen->chan, 1, dayglo?0x00F0F0F0:0);
	background = allocimage(display, Rect(0,0,1,1), screen->chan, 1, dayglo?0x33333333:-1);
	bordercol = allocimage(display, Rect(0,0,1,1), screen->chan, 1, 0xCCCCCCCC);
	cursback = allocimage(display, Rect(0, 0, CW+1, NS+1), screen->chan, 0, DNofill);
	red =  allocimage(display, Rect(0, 0, CW+1, NS+1), screen->chan, 1, DRed);

	eresized(0);

	if(argc > 0) {
		sendnchars(strlen(argv[0]),argv[0]);
		sendnchars(1,"\n");
	}
}

void
clear(Rectangle r)
{
	draw(screen, r, background, nil, ZP);
}

void
newline(void)
{
	nbacklines--;
	if(y >= yscrmax) {
		y = yscrmax;
		if(pagemode && olines >= yscrmax) {
			blocked = 1;
			return;
		}
		scroll(yscrmin+1, yscrmax+1, yscrmin, yscrmax);
	} else
		y++;
	olines++;
}

void
curson(int bl)
{
	Image *col;

	draw(cursback, cursback->r, screen, nil, subpt(pt(x, y),Pt(1,1)));
	if(bl)
		col = red;
	else
		col = bordercol;
	border(screen, Rpt(subpt(pt(x, y), Pt(1, 1)), addpt(pt(x, y), Pt(CW,NS))),
		2, col, ZP);
}

void
cursoff(void)
{
	draw(screen, Rpt(subpt(pt(x, y), Pt(1, 1)), addpt(pt(x, y), Pt(CW,NS))),
		cursback, nil, cursback->r.min);
}

int
get_next_char(void)
{
	int c = peekc;
	peekc = 0;
	if(c > 0)
		return(c);
	while(c <= 0) {
		if(backp) {
			c = *backp;
			if(c && nbacklines >= 0) {
				backp++;
				if(backp >= &hist[HISTSIZ])
					backp = hist;
				return(c);
			}
			backp = 0;
		}
		c = waitchar();
	}
	*histp++ = c;
	if(histp >= &hist[HISTSIZ])
		histp = hist;
	*histp = '\0';
	return(c);
}

int
canon(char *ep, int c)
{
	if(c&0200)
		return(SCROLL);
	switch(c) {
		case '\b':
			if(sendp > sendbuf)
				sendp--;
			*ep++ = '\b';
			*ep++ = ' ';
			*ep++ = '\b';
			break;
		case 0x15:	/* ^U line kill */
			sendp = sendbuf;
			*ep++ = '^';
			*ep++ = 'U';
			*ep++ = '\n';
			break;
		case 0x17:	/* ^W word kill */
			while(sendp > sendbuf && !alnum(*sendp)) {
				*ep++ = '\b';
				*ep++ = ' ';
				*ep++ = '\b';
				sendp--;
			}
			while(sendp > sendbuf && alnum(*sendp)) {
				*ep++ = '\b';
				*ep++ = ' ';
				*ep++ = '\b';
				sendp--;
			}
			break;
		case '\177':	/* interrupt */
			sendp = sendbuf;
			send_interrupt();
			return(NEWLINE);
		case '\021':	/* quit */
		case '\r':
		case '\n':
			if(sendp < &sendbuf[512])
				*sendp++ = '\n';
			sendnchars((int)(sendp-sendbuf), sendbuf);
			sendp = sendbuf;
			if(c == '\n' || c == '\r') {
				*ep++ = '\n';
			}
			*ep = 0;
			return(NEWLINE);
		case '\004':	/* EOT */
			if(sendp == sendbuf) {
				sendnchars(0,sendbuf);
				*ep = 0;
				return(NEWLINE);
			}
			/* fall through */
		default:
			if(sendp < &sendbuf[512])
				*sendp++ = c;
			*ep++ = c;
			break;
		
	}
	*ep = 0;
	return(OTHER);
}

void
sendfk(char *name)
{
	int i;
	static int fd;

	for(i=0; fk[i].name; i++)
		if(strcmp(name, fk[i].name)==0){
			sendnchars2(strlen(fk[i].sequence), fk[i].sequence);
			return;
		}
}

int
waitchar(void)
{
	Event e;
	int c;
	char c2;
	int newmouse;
	int wasblocked;
	int kbdchar = -1;
	char echobuf[3*BSIZE];
	static int lastc = -1;


	for(;;) {
		if(resize_flag)
			resize();
		wasblocked = blocked;
		if(backp)
			return(0);
		if(ecanmouse() && (button2() || button3()))
			readmenu();
		if(snarffp) {
			if((c = Bgetc(snarffp)) < 0) {
				if(lastc != '\n')
					write(outfd,"\n",1);
				Bterm(snarffp);
				snarffp = 0;
				if(lastc != '\n') {
					lastc = -1;
					return('\n');
				}
				lastc = -1;
				continue;
			}
			lastc = c;
			c2 = c;
			write(outfd, &c2, 1);
			return(c);
		}
		if(!blocked && host_avail())
			return(rcvchar());
		if(kbdchar > 0) {
			if(blocked)
				resize();
			if(cs->raw) {
				switch(kbdchar){
				case Kup:
					sendfk("up key");
					break;
				case Kdown:
					sendfk("down key");
					break;
				case Kleft:
					sendfk("left key");
					break;
				case Kright:
					sendfk("right key");
					break;
				default:
					echobuf[0] = kbdchar;
					sendnchars(1, echobuf);
					break;
				}
			} else if(canon(echobuf,kbdchar) == SCROLL) {
				if(!blocked)
					bigscroll();
			} else
				strcat(echo_input,echobuf);
			blocked = 0;
			kbdchar = -1;
			continue;
		}
		curson(wasblocked);	/* turn on cursor while we're waiting */
		do {
			newmouse = 0;
			switch(eread(blocked ? Emouse|Ekeyboard : 
					       Emouse|Ekeyboard|Ehost, &e)) {
			case Emouse:
				mouse = e.mouse;
				if(button2() || button3())
					readmenu();
				else if(resize_flag == 0) {
					/* eresized() is triggered by special mouse event */
					newmouse = 1;
				}
				break;
			case Ekeyboard:
				kbdchar = e.kbdc;
				break;
			case Ehost:
				set_host(&e);
				break;
			default:
				perror("protocol violation");
				exits("protocol violation");
			}
		} while(newmouse == 1);
		cursoff();	/* turn cursor back off */
	}
	return 1;		/* to shut up compiler */
}

void
eresized(int new)
{
	resize_flag = 1+new;
}

void
exportsize(void)
{
	int	fd;
	char	buf[10];

	if((fd = create("/env/LINES", OWRITE, 0644)) > 0) {
		sprint(buf,"%d",ymax+1);
		write(fd,buf,strlen(buf));
		close(fd);
	}
	if((fd = create("/env/COLS", OWRITE, 0644)) > 0) {
		sprint(buf,"%d",xmax+1);
		write(fd,buf,strlen(buf));
		close(fd);
	}
	if((fd = create("/env/TERM", OWRITE, 0644)) > 0) {
		fprint(fd, "%s", term);
		close(fd);
	}
}

void
resize(void)
{
	if(resize_flag > 1 && getwindow(display, Refnone) < 0){
		fprint(2, "can't reattach to window: %r\n");
		exits("can't reattach to window");
	}
	xmax = (Dx(screen->r)-2*XMARGIN)/CW-1;
	ymax = (Dy(screen->r)-2*YMARGIN)/NS-1;
	if(xmax == 0 || ymax == 0)
		exits("window gone");
	x = 0;
	y = 0;
	yscrmin = 0;
	yscrmax = ymax;
	olines = 0;
	exportsize();
	clear(screen->r);
	resize_flag = 0;
}

void
readmenu(void)
{
	Rectangle r;
	int fd;

	if(button3()) {
		menu3.item[1] = ttystate[cs->raw].crnl ? "cr" : "crnl";
		menu3.item[2] = ttystate[cs->raw].nlcr ? "nl" : "nlcr";
		menu3.item[3] = cs->raw ? "cooked" : "raw";

		switch(emenuhit(3, &mouse, &menu3)) {
		case 0:		/* 24x80 */
			r.min = screen->r.min;
			r.max = addpt(screen->r.min,
				Pt(80*CW+2*XMARGIN+2*INSET,
				24*NS+2*YMARGIN+2*INSET));
			fd = open("/dev/wctl", OWRITE);
			if(fd < 0 || fprint(fd, "resize -dx %d -dy %d\n", Dx(r)+2*Borderwidth, Dy(r)+2*Borderwidth) < 0){
				border(screen, r, INSET, bordercol, ZP);
				xmax = 79;
				ymax = 23;
				exportsize();
			}
			if(fd >= 0)
				close(fd);
			return;
		case 1:		/* newline after cr? */
			ttystate[cs->raw].crnl = !ttystate[cs->raw].crnl;
			return;
		case 2:		/* cr after newline? */
			ttystate[cs->raw].nlcr = !ttystate[cs->raw].nlcr;
			return;
		case 3:		/* switch raw mode */
			cs->raw = !cs->raw;
			return;
		}
		return;
	}

	menu2.item[5] = pagemode? "scroll": "page";

	switch(emenuhit(2, &mouse, &menu2)) {

	case 0:		/* back up */
		if(atend == 0) {
			backc++;
			backup(backc);
		}
		return;

	case 1:		/* move forward */
		backc--;
		if(backc >= 0)
			backup(backc);
		else
			backc = 0;
		return;

	case 2:		/* reset */
		backc = 0;
		backup(0);
		return;

	case 3:		/* clear screen */
		eresized(0);
		return;

	case 4:		/* send the snarf buffer */
		snarffp = Bopen("/dev/snarf",OREAD);
		return;

	case 5:		/* pause and clear at end of screen */
		pagemode = 1-pagemode;
		if(blocked && !pagemode) {
			eresized(0);
			blocked = 0;
		}
		return;
	}
}

void
backup(int count)
{
	register n;
	register char *cp;

	eresized(0);
	n = 3*(count+1)*ymax/4;
	cp = histp;
	atend = 0;
	while (n >= 0) {
		cp--;
		if(cp < hist)
			cp = &hist[HISTSIZ-1];
		if(*cp == '\0') {
			atend = 1;
			break;
		}
		if(*cp == '\n')
			n--;
	}
	cp++;
	if(cp >= &hist[HISTSIZ])
		cp = hist;
	backp = cp;
	nbacklines = ymax-2;
}

Point
pt(int x, int y)
{
	return addpt(screen->r.min, Pt(x*CW+XMARGIN,y*NS+YMARGIN));
}

void
scroll(int sy, int ly, int dy, int cy)	/* source, limit, dest, which line to clear */
{
	draw(screen, Rpt(pt(0, dy), pt(xmax+1, dy+ly-sy)), screen, nil, pt(0, sy));
	clear(Rpt(pt(0, cy), pt(xmax+1, cy+1)));
}

void
bigscroll(void)			/* scroll up half a page */
{
	int half = ymax/3;

	if(x == 0 && y == 0)
		return;
	if(y < half) {
		clear(Rpt(pt(0,0),pt(xmax+1,ymax+1)));
		x = y = 0;
		return;
	}
	draw(screen, Rpt(pt(0, 0), pt(xmax+1, ymax+1)), screen, nil, pt(0, half));
	clear(Rpt(pt(0,y-half+1),pt(xmax+1,ymax+1)));
	y -= half;
	if(olines)
		olines -= half;
}

int
number(char *p)
{
	int c, n = 0;

	while ((c = get_next_char()) >= '0' && c <= '9')
		n = n*10 + c - '0';
	*p = c;
	return(n);
}

/* stubs */

void
sendnchars(int n,char *p)
{
	sendnchars2(n, p);
	p[n+1] = 0;
}

void
sendnchars2(int n,char *p)
{
	if(write(outfd,p,n) < 0) {
		close(outfd);
		close(0);
		close(1);
		close(2);
		exits("write");
	}
}

int
host_avail(void)
{
	return(*echop || ((hostp - host_buf) < hostlength));
}

int
rcvchar(void)
{
	int c;
	if(*echop) {
		c = *echop++;
		if(!*echop) {
			echop = echo_input;	
			*echop = 0;
		}
		return c;
	}
	return *hostp++;
}

void
set_host(Event *e)
{
	hostlength = e->n;
	if(hostlength > host_bsize) {
		host_bsize *= 2;
		host_buf = realloc(host_buf,host_bsize);
	}
	hostp = host_buf;
	memmove(host_buf,e->data,hostlength);
	host_buf[hostlength]=0;
}

void
ringbell(void){
}

int
alnum(int c)
{
	if(c >= 'a' && c <= 'z')
		return 1;
	if(c >= 'A' && c <= 'Z')
		return 1;
	if(c >= '0' && c <= '9')
		return 1;
	return 0;
}

void
escapedump(int fd,uchar *str,int len)
{
	int i;

	for(i = 0; i < len; i++) {
		if((str[i] < ' ' || str[i] > '\177') && 
			str[i] != '\n' && str[i] != '\t') fprint(fd,"^%c",str[i]+64);
		else if(str[i] == '\177') fprint(fd,"^$");
		else if(str[i] == '\n') fprint(fd,"^J\n");
		else fprint(fd,"%c",str[i]);
	}
}

void
funckey(int key)
{
	if(key >= NKEYS)
		return;
	if(fk[key].name == 0)
		return;
	sendnchars2(strlen(fk[key].sequence), fk[key].sequence);
}

void
drawstring(Point p, char *str, int standout)
{
	Image *txt, *bg;

	txt = text;
	bg = background;
	if(standout){
		txt = background;
		bg = text;
	}
	draw(screen, Rpt(p, addpt(p, stringsize(font, str))), bg, nil, p);
	string(screen, p, txt, ZP, font, str);
}