/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1982-2009 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                  David Korn <dgk@research.att.com>                   *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 *  completion.c - command and file completion for shell editors
 *
 */

#include	"defs.h"
#include	<ast_wchar.h>
#include	"lexstates.h"
#include	"path.h"
#include	"io.h"
#include	"edit.h"
#include	"history.h"

#if !SHOPT_MULTIBYTE
#define mbchar(p)       (*(unsigned char*)p++)
#endif

static char *fmtx(const char *string)
{
	register const char	*cp = string;
	register int	 	n,c;
	unsigned char 		*state = (unsigned char*)sh_lexstates[2]; 
	int offset;
	while((c=mbchar(cp)),(c>UCHAR_MAX)||(n=state[c])==0);
	if(n==S_EOF)
		return((char*)string);
	offset = staktell();
	stakwrite(string,--cp-string);
	while(c=mbchar(cp))
	{
		if(state[c])
			stakputc('\\');
		stakputc(c);
	}
	stakputc(0);
	return(stakptr(offset));
}

static int charcmp(int a, int b, int nocase)
{
	if(nocase)
	{
		if(isupper(a))
			a = tolower(a);
		if(isupper(b))
			b = tolower(b);
	}
	return(a==b);
}

/*
 *  overwrites <str> to common prefix of <str> and <newstr>
 *  if <str> is equal to <newstr> returns  <str>+strlen(<str>)+1
 *  otherwise returns <str>+strlen(<str>)
 */
static char *overlaid(register char *str,register const char *newstr,int nocase)
{
	register int c,d;
	while((c= *(unsigned char *)str) && ((d= *(unsigned char*)newstr++),charcmp(c,d,nocase)))
		str++;
	if(*str)
		*str = 0;
	else if(*newstr==0)
		str++;
	return(str);
}


/*
 * returns pointer to beginning of expansion and sets type of expansion
 */
static char *find_begin(char outbuff[], char *last, int endchar, int *type)
{
	register char	*cp=outbuff, *bp, *xp;
	register int 	c,inquote = 0, inassign=0;
	int		mode=*type;
	bp = outbuff;
	*type = 0;
	while(cp < last)
	{
		xp = cp;
		switch(c= mbchar(cp))
		{
		    case '\'': case '"':
			if(!inquote)
			{
				inquote = c;
				bp = xp;
				break;
			}
			if(inquote==c)
				inquote = 0;
			break;
		    case '\\':
			if(inquote != '\'')
				mbchar(cp);
			break;
		    case '$':
			if(inquote == '\'')
				break;
			c = *(unsigned char*)cp;
			if(mode!='*' && (isaletter(c) || c=='{'))
			{
				int dot = '.';
				if(c=='{')
				{
					xp = cp;
					mbchar(cp);
					c = *(unsigned char*)cp;
					if(c!='.' && !isaletter(c))
						break;
				}
				else
					dot = 'a';
				while(cp < last)
				{
					if((c= mbchar(cp)) , c!=dot && !isaname(c))
						break;
				}
				if(cp>=last && c!= '}')
				{
					*type='$';
					return(++xp);
				}
			}
			else if(c=='(')
			{
				*type = mode;
				xp = find_begin(cp,last,')',type);
				if(*(cp=xp)!=')')
					bp = xp;
				else
					cp++;
			}
			break;
		    case '=':
			if(!inquote)
			{
				bp = cp;
				inassign = 1;
			}
			break;
		    case ':':
			if(!inquote && inassign)
				bp = cp;
			break;
		    case '~':
			if(*cp=='(')
				break;
			/* fall through */
		    default:
			if(c && c==endchar)
				return(xp);
			if(!inquote && ismeta(c))
			{
				bp = cp;
				inassign = 0;
			}
			break;
		}
	}
	if(inquote && *bp==inquote)
		*type = *bp++;
	return(bp);
}

/*
 * file name generation for edit modes
 * non-zero exit for error, <0 ring bell
 * don't search back past beginning of the buffer
 * mode is '*' for inline expansion,
 * mode is '\' for filename completion
 * mode is '=' cause files to be listed in select format
 */

int ed_expand(Edit_t *ep, char outbuff[],int *cur,int *eol,int mode, int count)
{
	struct comnod	*comptr;
	struct argnod	*ap;
	register char	*out;
	char 		*av[2], *begin , *dir=0;
	int		addstar=0, rval=0, var=0, strip=1;
	int 		nomarkdirs = !sh_isoption(SH_MARKDIRS);
	sh_onstate(SH_FCOMPLETE);
	if(ep->e_nlist)
	{
		if(mode=='=' && count>0)
		{
			if(count> ep->e_nlist)
				return(-1);
			mode = '?';
			av[0] = ep->e_clist[count-1];
			av[1] = 0;
		}
		else
		{
			stakset(ep->e_stkptr,ep->e_stkoff);
			ep->e_nlist = 0;
		}
	}
	comptr = (struct comnod*)stakalloc(sizeof(struct comnod));
	ap = (struct argnod*)stakseek(ARGVAL);
#if SHOPT_MULTIBYTE
	{
		register int c = *cur;
		register genchar *cp;
		/* adjust cur */
		cp = (genchar *)outbuff + *cur;
		c = *cp;
		*cp = 0;
		*cur = ed_external((genchar*)outbuff,(char*)stakptr(0));
		*cp = c;
		*eol = ed_external((genchar*)outbuff,outbuff);
	}
#endif /* SHOPT_MULTIBYTE */
	out = outbuff + *cur + (sh_isoption(SH_VI)!=0);
	comptr->comtyp = COMSCAN;
	comptr->comarg = ap;
	ap->argflag = (ARG_MAC|ARG_EXP);
	ap->argnxt.ap = 0;
	ap->argchn.cp = 0;
	{
		register int c;
		char *last = out;
		c =  *(unsigned char*)out;
		var = mode;
		begin = out = find_begin(outbuff,last,0,&var);
		/* addstar set to zero if * should not be added */
		if(var=='$')
		{
			stakputs("${!");
			stakwrite(out,last-out);
			stakputs("@}");
			out = last;
		}
		else
		{
			addstar = '*';
			while(out < last)
			{
				c = *(unsigned char*)out;
				if(isexp(c))
					addstar = 0;
				if (c == '/')
				{
					if(addstar == 0)
						strip = 0;
					dir = out+1;
				}
				stakputc(c);
				out++;
			}
		}
		if(mode=='?')
			mode = '*';
		if(var!='$' && mode=='\\' && out[-1]!='*')
			addstar = '*';
		if(*begin=='~' && !strchr(begin,'/'))
			addstar = 0;
		stakputc(addstar);
		ap = (struct argnod*)stakfreeze(1);
	}
	if(mode!='*')
		sh_onoption(SH_MARKDIRS);
	{
		register char	**com;
		char		*cp=begin, *left=0, *saveout=".";
		int	 	nocase=0,narg,cmd_completion=0;
		register 	int size='x';
		while(cp>outbuff && ((size=cp[-1])==' ' || size=='\t'))
			cp--;
		if(!var && !strchr(ap->argval,'/') && (((cp==outbuff&&sh.nextprompt==1) || (strchr(";&|(",size)) && (cp==outbuff+1||size=='('||cp[-2]!='>') && *begin!='~' )))
		{
			cmd_completion=1;
			sh_onstate(SH_COMPLETE);
		}
		if(ep->e_nlist)
		{
			narg = 1;
			com = av;
			if(dir)
				begin += (dir-begin);
		}
		else
		{
			com = sh_argbuild(ep->sh,&narg,comptr,0);
			/* special handling for leading quotes */
			if(begin>outbuff && (begin[-1]=='"' || begin[-1]=='\''))
			begin--;
		}
		sh_offstate(SH_COMPLETE);
                /* allow a search to be aborted */
		if(sh.trapnote&SH_SIGSET)
		{
			rval = -1;
			goto done;
		}
		/*  match? */
		if (*com==0 || (narg <= 1 && (strcmp(ap->argval,*com)==0) || (addstar && com[0][strlen(*com)-1]=='*')))
		{
			rval = -1;
			goto done;
		}
		if(mode=='=')
		{
			if (strip && !cmd_completion)
			{
				register char **ptrcom;
				for(ptrcom=com;*ptrcom;ptrcom++)
					/* trim directory prefix */
					*ptrcom = path_basename(*ptrcom);
			}
			sfputc(sfstderr,'\n');
			sh_menu(sfstderr,narg,com);
			sfsync(sfstderr);
			ep->e_nlist = narg;
			ep->e_clist = com;
			goto done;
		}
		/* see if there is enough room */
		size = *eol - (out-begin);
		if(mode=='\\')
		{
			int c;
			if(dir)
			{
				c = *dir;
				*dir = 0;
				saveout = begin;
			}
			if(saveout=astconf("PATH_ATTRIBUTES",saveout,(char*)0))
				nocase = (strchr(saveout,'c')!=0);
			if(dir)
				*dir = c;
			/* just expand until name is unique */
			size += strlen(*com);
		}
		else
		{
			size += narg;
			{
				char **savcom = com;
				while (*com)
					size += strlen(cp=fmtx(*com++));
				com = savcom;
			}
		}
		/* see if room for expansion */
		if(outbuff+size >= &outbuff[MAXLINE])
		{
			com[0] = ap->argval;
			com[1] = 0;
		}
		/* save remainder of the buffer */
		if(*out)
			left=stakcopy(out);
		if(cmd_completion && mode=='\\')
			out = strcopy(begin,path_basename(cp= *com++));
		else if(mode=='*')
		{
			if(ep->e_nlist && dir && var)
			{
				if(*cp==var)
					cp++;
				else
					*begin++ = var;
				out = strcopy(begin,cp);
				var = 0;
			}
			else
				out = strcopy(begin,fmtx(*com));
			com++;
		}
		else
			out = strcopy(begin,*com++);
		if(mode=='\\')
		{
			saveout= ++out;
			while (*com && *begin)
			{
				if(cmd_completion)
					out = overlaid(begin,path_basename(*com++),nocase);
				else
					out = overlaid(begin,*com++,nocase);
			}
			mode = (out==saveout);
			if(out[-1]==0)
				out--;
			if(mode && out[-1]!='/')
			{
				if(cmd_completion)
				{
					Namval_t *np;
					/* add as tracked alias */
					Pathcomp_t *pp;
					if(*cp=='/' && (pp=path_dirfind(sh.pathlist,cp,'/')) && (np=nv_search(begin,sh.track_tree,NV_ADD)))
						path_alias(np,pp);
					out = strcopy(begin,cp);
				}
				/* add quotes if necessary */
				if((cp=fmtx(begin))!=begin)
					out = strcopy(begin,cp);
				if(var=='$' && begin[-1]=='{')
					*out = '}';
				else
					*out = ' ';
				*++out = 0;
			}
			else if(out[-1]=='/' && (cp=fmtx(begin))!=begin)
			{
				out = strcopy(begin,cp);
				if(out[-1] =='"' || out[-1]=='\'')
					  *--out = 0;;
			}
			if(*begin==0)
				ed_ringbell();
		}
		else
		{
			while (*com)
			{
				*out++  = ' ';
				out = strcopy(out,fmtx(*com++));
			}
		}
		if(ep->e_nlist)
		{
			cp = com[-1];
			if(cp[strlen(cp)-1]!='/')
			{
				if(var=='$' && begin[-1]=='{')
					*out = '}';
				else
					*out = ' ';
				out++;
			}
			else if(out[-1] =='"' || out[-1]=='\'')
				out--;
			*out = 0;
		}
		*cur = (out-outbuff);
		/* restore rest of buffer */
		if(left)
			out = strcopy(out,left);
		*eol = (out-outbuff);
	}
 done:
	sh_offstate(SH_FCOMPLETE);
	if(!ep->e_nlist)
		stakset(ep->e_stkptr,ep->e_stkoff);
	if(nomarkdirs)
		sh_offoption(SH_MARKDIRS);
#if SHOPT_MULTIBYTE
	{
		register int c,n=0;
		/* first re-adjust cur */
		c = outbuff[*cur];
		outbuff[*cur] = 0;
		for(out=outbuff; *out;n++)
			mbchar(out);
		outbuff[*cur] = c;
		*cur = n;
		outbuff[*eol+1] = 0;
		*eol = ed_internal(outbuff,(genchar*)outbuff);
	}
#endif /* SHOPT_MULTIBYTE */
	return(rval);
}

/*
 * look for edit macro named _i
 * if found, puts the macro definition into lookahead buffer and returns 1
 */
int ed_macro(Edit_t *ep, register int i)
{
	register char *out;
	Namval_t *np;
	genchar buff[LOOKAHEAD+1];
	if(i != '@')
		ep->e_macro[1] = i;
	/* undocumented feature, macros of the form <ESC>[c evoke alias __c */
	if(i=='_')
		ep->e_macro[2] = ed_getchar(ep,1);
	else
		ep->e_macro[2] = 0;
	if (isalnum(i)&&(np=nv_search(ep->e_macro,sh.alias_tree,HASH_SCOPE))&&(out=nv_getval(np)))
	{
#if SHOPT_MULTIBYTE
		/* copy to buff in internal representation */
		int c = 0;
		if( strlen(out) > LOOKAHEAD )
		{
			c = out[LOOKAHEAD];
			out[LOOKAHEAD] = 0;
		}
		i = ed_internal(out,buff);
		if(c)
			out[LOOKAHEAD] = c;
#else
		strncpy((char*)buff,out,LOOKAHEAD);
		buff[LOOKAHEAD] = 0;
		i = strlen((char*)buff);
#endif /* SHOPT_MULTIBYTE */
		while(i-- > 0)
			ed_ungetchar(ep,buff[i]);
		return(1);
	} 
	return(0);
}

/*
 * Enter the fc command on the current history line
 */
int ed_fulledit(Edit_t *ep)
{
	register char *cp;
	if(!sh.hist_ptr)
		return(-1);
	/* use EDITOR on current command */
	if(ep->e_hline == ep->e_hismax)
	{
		if(ep->e_eol<0)
			return(-1);
#if SHOPT_MULTIBYTE
		ep->e_inbuf[ep->e_eol+1] = 0;
		ed_external(ep->e_inbuf, (char *)ep->e_inbuf);
#endif /* SHOPT_MULTIBYTE */
		sfwrite(sh.hist_ptr->histfp,(char*)ep->e_inbuf,ep->e_eol+1);
		sh_onstate(SH_HISTORY);
		hist_flush(sh.hist_ptr);
	}
	cp = strcopy((char*)ep->e_inbuf,e_runvi);
	cp = strcopy(cp, fmtbase((long)ep->e_hline,10,0));
	ep->e_eol = ((unsigned char*)cp - (unsigned char*)ep->e_inbuf)-(sh_isoption(SH_VI)!=0);
	return(0);
}
