#include "sam.h"

void
moveto(File *f, Range r)
{
	Posn p1 = r.p1, p2 = r.p2;

	f->dot.r.p1 = p1;
	f->dot.r.p2 = p2;
	if(f->rasp){
		telldot(f);
		outTsl(Hmoveto, f->tag, f->dot.r.p1);
	}
}

void
telldot(File *f)
{
	if(f->rasp == 0)
		panic("telldot");
	if(f->dot.r.p1==f->tdot.p1 && f->dot.r.p2==f->tdot.p2)
		return;
	outTsll(Hsetdot, f->tag, f->dot.r.p1, f->dot.r.p2);
	f->tdot = f->dot.r;
}

void
tellpat(void)
{
	outTS(Hsetpat, &lastpat);
	patset = FALSE;
}

#define	CHARSHIFT	128

void
lookorigin(File *f, Posn p0, Posn ls)
{
	int nl, nc, c;
	Posn oldp0;

	if(p0 > f->nrunes)
		p0 = f->nrunes;
	oldp0 = p0;
	Fgetcset(f, p0);
	for(nl=nc=c=0; c!=-1 && nl<ls && nc<ls*CHARSHIFT; nc++)
		if((c=Fbgetc(f)) == '\n'){
			nl++;
			oldp0 = p0-nc;
		}
	if(c == -1)
		p0 = 0;
	else if(nl==0){
		if(p0>=CHARSHIFT/2)
			p0-=CHARSHIFT/2;
		else
			p0 = 0;
	}else
		p0 = oldp0;
	outTsl(Horigin, f->tag, p0);
}

int
alnum(int c)
{
	/*
	 * Hard to get absolutely right.  Use what we know about ASCII
	 * and assume anything above the Latin control characters is
	 * potentially an alphanumeric.
	 */
	if(c<=' ')
		return 0;
	if(0x7F<=c && c<=0xA0)
		return 0;
	if(utfrune("!\"#$%&'()*+,-./:;<=>?@[\\]^`{|}~", c))
		return 0;
	return 1;
}

int
clickmatch(File *f, int cl, int cr, int dir)
{
	int c;
	int nest = 1;

	while((c=(dir>0? Fgetc(f) : Fbgetc(f))) > 0)
		if(c == cr){
			if(--nest==0)
				return 1;
		}else if(c == cl)
			nest++;
	return cl=='\n' && nest==1;
}

Rune*
strrune(Rune *s, Rune c)
{
	Rune c1;

	if(c == 0) {
		while(*s++)
			;
		return s-1;
	}

	while(c1 = *s++)
		if(c1 == c)
			return s-1;
	return 0;
}

void
doubleclick(File *f, Posn p1)
{
	int c, i;
	Rune *r, *l;

	if(p1 > f->nrunes)
		return;
	f->dot.r.p1 = f->dot.r.p2 = p1;
	for(i=0; left[i]; i++){
		l = left[i];
		r = right[i];
		/* try left match */
		if(p1 == 0){
			Fgetcset(f, p1);
			c = '\n';
		}else{
			Fgetcset(f, p1-1);
			c = Fgetc(f);
		}
		if(c!=-1 && strrune(l, c)){
			if(clickmatch(f, c, r[strrune(l, c)-l], 1)){
				f->dot.r.p1 = p1;
				f->dot.r.p2 = f->getcp-(c!='\n');
			}
			return;
		}
		/* try right match */
		if(p1 == f->nrunes){
			Fbgetcset(f, p1);
			c = '\n';
		}else{
			Fbgetcset(f, p1+1);
			c = Fbgetc(f);
		}
		if(c!=-1 && strrune(r, c)){
			if(clickmatch(f, c, l[strrune(r, c)-r], -1)){
				f->dot.r.p1 = f->getcp;
				if(c!='\n' || f->getcp!=0 ||
				   (Fgetcset(f, (Posn)0),Fgetc(f))=='\n')
					f->dot.r.p1++;
				f->dot.r.p2 = p1+(p1<f->nrunes && c=='\n');
			}
			return;
		}
	}
	/* try filling out word to right */
	Fgetcset(f, p1);
	while((c=Fgetc(f))!=-1 && alnum(c))
		f->dot.r.p2++;
	/* try filling out word to left */
	Fbgetcset(f, p1);
	while((c=Fbgetc(f))!=-1 && alnum(c))
		f->dot.r.p1--;
}