#

/*	permuted title index
	ptx [-t] [-i ignore] [-o only] [-w num] [-f] [input] [output]
	Ptx reads the input file and permutes on words in it.
	It excludes all words in the ignore file.
	Alternately it includes words in the only file.
	if neither is given it excludes the words in
	/sys/man/man0/permind/ignore.

	The width of the output line can be changed to num
	characters.  If omitted 72 is default unless troff than 100.
	the -f flag tells the program to fold the output
	the -t flag says the output is for troff and the
	output is then wider.

	*/

#include <u.h>
#include <libc.h>
#include <stdio.h>
#include <ctype.h>
#define DEFLTX "/sys/lib/man/permind/ignore"
#define TILDE 0177
#define	N 30
#define	MAX	N*BUFSIZ
#define LMAX	200
#define MAXT	2048
#define MASK	03777
#define SET	1

#define isabreak(c) (btable[c])

char *getline(void);
void msg(char *, char *);
void diag(char *, char *);
void cmpline(char *);
int cmpword(char *, char *, char *);
void putline(char *, char *);
void getsort(void);
char *rtrim(char *, char *, int);
char *ltrim(char *, char *, int);
void putout(char *, char *);
int hash(char *, char *);
int storeh(int, char *);

int status;


char *hasht[MAXT];
char line[LMAX];
char btable[128];
int ignore;
int only;
int llen = 72;
int gap = 3;
int gutter = 3;
int mlen = LMAX;
int wlen;
int rflag;
int halflen;
char *strtbufp, *endbufp;
char *empty = "";

char *infile;
FILE *inptr = stdin;

char *outfile;
FILE *outptr = stdout;

char *sortfile;	/* output of sort program */
char nofold[] = {'-', 'd', 't', TILDE, 0};
char fold[] = {'-', 'd', 'f', 't', TILDE, 0};
char *sortopt = nofold;
FILE *sortptr;

char *bfile;	/*contains user supplied break chars */
FILE *bptr;

main(int argc, char **argv)
{
	int c;
	char *bufp;
	char *pend;

	char *xfile;
	FILE *xptr;
	Waitmsg w;


/*	argument decoding	*/

	xfile = DEFLTX;
	argv++;
	while(argc>1 && **argv == '-') {
		switch (*++*argv){

		case 'r':
			rflag++;
			break;
		case 'f':
			sortopt = fold;
			break;

		case 'w':
			if(argc >= 2) {
				argc--;
				wlen++;
				llen = atoi(*++argv);
				if(llen == 0)
					diag("Wrong width:",*argv);
				if(llen > LMAX) {
					llen = LMAX;
					msg("Lines truncated to 200 chars.",empty);
				}
				break;
			}

		case 't':
			if(wlen == 0)
				llen = 100;
			break;
		case 'g':
			if(argc >=2) {
				argc--;
				gap = gutter = atoi(*++argv);
			}
			break;

		case 'i':
			if(only) 
				diag("Only file already given.",empty);
			if (argc>=2){
				argc--;
				ignore++;
				xfile = *++argv;
			}
			break;

		case 'o':
			if(ignore)
				diag("Ignore file already given",empty);
			if (argc>=2){
				only++;
				argc--;
				xfile = *++argv;
			}
			break;

		case 'b':
			if(argc>=2) {
				argc--;
				bfile = *++argv;
			}
			break;

		default:
			msg("Illegal argument:",*argv);
		}
		argc--;
		argv++;
	}

	if(argc>3)
		diag("Too many filenames",empty);
	else if(argc==3){
		infile = *argv++;
		outfile = *argv;
		if((outptr = fopen(outfile,"w")) == NULL)
			diag("Cannot open output file:",outfile);
	} else if(argc==2) {
		infile = *argv;
		outfile = 0;
	}


	/* Default breaks of blank, tab and newline */
	btable[' '] = SET;
	btable['\t'] = SET;
	btable['\n'] = SET;
	if(bfile) {
		if((bptr = fopen(bfile,"r")) == NULL)
			diag("Cannot open break char file",bfile);

		while((c = getc(bptr)) != EOF)
			btable[c] = SET;
	}

/*	Allocate space for a buffer.  If only or ignore file present
	read it into buffer. Else read in default ignore file
	and put resulting words in buffer.
	*/


	if((strtbufp = calloc(N,BUFSIZ)) == NULL)
		diag("Out of memory space",empty);
	bufp = strtbufp;
	endbufp = strtbufp+MAX;

	if((xptr = fopen(xfile,"r")) == NULL)
		diag("Cannot open  file",xfile);

	while(bufp < endbufp && (c = getc(xptr)) != EOF) {
		if(isabreak(c)) {
			if(storeh(hash(strtbufp,bufp),strtbufp))
				diag("Too many words",xfile);
			*bufp++ = '\0';
			strtbufp = bufp;
		}
		else {
			*bufp++ = (isupper(c)?tolower(c):c);
		}
	}
	if (bufp >= endbufp)
		diag("Too many words in file",xfile);
	endbufp = --bufp;

	/* open output file for sorting */

	sortfile = "ptxsort";
	if((sortptr = fopen(sortfile, "w")) == NULL)
		diag("Cannot open output for sorting:",sortfile);

/*	get a line of data and compare each word for
	inclusion or exclusion in the sort phase
*/

	if (infile!=0 && (inptr = fopen(infile,"r")) == NULL)
		diag("Cannot open data: ",infile);
	while(pend=getline())
		cmpline(pend);
	fclose(sortptr);

	if(fork()==0){
		execl("/bin/sort", "sort", sortopt, "+0", "-1", "+1",
			sortfile, "-o", sortfile, 0);
		remove(sortfile);
		diag("Sort exec failed","");
	}
	if(wait(&w)<0 || w.msg[0]!=0) {
		remove(sortfile);
		diag("Sort failed","");
	}

	getsort();
	remove(sortfile);
fflush(0);
_exits(0);
/* I don't know what's wrong with the atexit func... */
/*	exits(0);	*/
}

void
msg(char *s, char *arg)
{
	fprintf(stderr,"ptx: %s %s\n",s,arg);
	return;
}

void
diag(char *s, char *arg)
{

	msg(s,arg);
	exits(s);
}


char*
getline(void)
{

	int c;
	char *linep;
	char *endlinep;


	endlinep= line + mlen;
	linep = line;
	/* Throw away leading white space */

	while(isspace(c=getc(inptr)))
		;
	if(c==EOF)
		return(0);
	ungetc(c,inptr);
	while(( c=getc(inptr)) != EOF) {
		switch (c) {

			case '\t':
				if(linep<endlinep)
					*linep++ = ' ';
				break;
			case '\n':
				while(isspace(*--linep));
				*++linep = '\n';
				return(linep);
			default:
				if(linep < endlinep)
					*linep++ = c;
		}
	}
	return(0);
}

void
cmpline(char *pend)
{

	char *pstrt, *pchar, *cp;
	char **hp;
	int flag;

	pchar = line;
	if(rflag)
		while(pchar<pend&&!isspace(*pchar))
			pchar++;
	while(pchar<pend){
	/* eliminate white space */
		if(isabreak(*pchar++))
			continue;
		pstrt = --pchar;

		flag = 1;
		while(flag){
			if(isabreak(*pchar)) {
				hp = &hasht[hash(pstrt,pchar)];
				pchar--;
				while(cp = *hp++){
					if(hp == &hasht[MAXT])
						hp = hasht;
	/* possible match */
					if(cmpword(pstrt,pchar,cp)){
	/* exact match */
						if(!ignore && only)
							putline(pstrt,pend);
						flag = 0;
						break;
					}
				}
	/* no match */
				if(flag){
					if(ignore || !only)
						putline(pstrt,pend);
					flag = 0;
				}
			}
		pchar++;
		}
	}
}

int
cmpword(char *cpp, char *pend, char *hpp)
{
	char c;

	while(*hpp != '\0'){
		c = *cpp++;
		if((isupper(c)?tolower(c):c) != *hpp++)
			return(0);
	}
	if(--cpp == pend) return(1);
	return(0);
}

void
putline(char *strt, char *end)
{
	char *cp;

	for(cp=strt; cp<end; cp++)
		putc(*cp, sortptr);
	/* Add extra blank before TILDE to sort correctly
	   with -fd option */
	putc(' ',sortptr);
	putc(TILDE,sortptr);
	for (cp=line; cp<strt; cp++)
		putc(*cp,sortptr);
	putc('\n',sortptr);
}

void
getsort(void)
{
	int c;
	char *tilde, *linep, *ref;
	char *p1a,*p1b,*p2a,*p2b,*p3a,*p3b,*p4a,*p4b;
	int w;

	if((sortptr = fopen(sortfile,"r")) == NULL)
		diag("Cannot open sorted data:",sortfile);

	halflen = (llen-gutter)/2;
	linep = line;
	while((c = getc(sortptr)) != EOF) {
		switch(c) {

		case TILDE:
			tilde = linep;
			break;

		case '\n':
			while(isspace(linep[-1]))
				linep--;
			ref = tilde;
			if(rflag) {
				while(ref<linep&&!isspace(*ref))
					ref++;
				*ref++ = 0;
			}
		/* the -1 is an overly conservative test to leave
		   space for the / that signifies truncation*/
			p3b = rtrim(p3a=line,tilde,halflen-1);
			if(p3b-p3a>halflen-1)
				p3b = p3a+halflen-1;
			p2a = ltrim(ref,p2b=linep,halflen-1);
			if(p2b-p2a>halflen-1)
				p2a = p2b-halflen-1;
			p1b = rtrim(p1a=p3b+(isspace(p3b[0])!=0),tilde,
				w=halflen-(p2b-p2a)-gap);
			if(p1b-p1a>w)
				p1b = p1a;
			p4a = ltrim(ref,p4b=p2a-(isspace(p2a[-1])!=0),
				w=halflen-(p3b-p3a)-gap);
			if(p4b-p4a>w)
				p4a = p4b;
			fprintf(outptr,".xx \"");
			putout(p1a,p1b);
	/* tilde-1 to account for extra space before TILDE */
			if(p1b!=(tilde-1) && p1a!=p1b)
				fprintf(outptr,"/");
			fprintf(outptr,"\" \"");
			if(p4a==p4b && p2a!=ref && p2a!=p2b)
				fprintf(outptr,"/");
			putout(p2a,p2b);
			fprintf(outptr,"\" \"");
			putout(p3a,p3b);
	/* ++p3b to account for extra blank after TILDE */
	/* ++p3b to account for extra space before TILDE */
			if(p1a==p1b && ++p3b!=tilde)
				fprintf(outptr,"/");
			fprintf(outptr,"\" \"");
			if(p1a==p1b && p4a!=ref && p4a!=p4b)
				fprintf(outptr,"/");
			putout(p4a,p4b);
			if(rflag)
				fprintf(outptr,"\" %s\n",tilde);
			else
				fprintf(outptr,"\"\n");
			linep = line;
			break;

		case '"':
	/* put double " for "  */
			*linep++ = c;
		default:
			*linep++ = c;
		}
	}
}

char*
rtrim(char *a, char *c, int d)
{
	char *b,*x;
	b = c;
	for(x=a+1; x<=c&&x-a<=d; x++)
		if((x==c||isspace(x[0]))&&!isspace(x[-1]))
			b = x;
	if(b<c&&!isspace(b[0]))
		b++;
	return(b);
}

char*
ltrim(char *c, char *b, int d)
{
	char *a,*x;
	a = c;
	for(x=b-1; x>=c&&b-x<=d; x--)
		if(!isspace(x[0])&&(x==c||isspace(x[-1])))
			a = x;
	if(a>c&&!isspace(a[-1]))
		a--;
	return(a);
}

void
putout(char *strt, char *end)
{
	char *cp;

	cp = strt;

	for(cp=strt; cp<end; cp++) {
		putc(*cp,outptr);
	}
}

int
hash(char *strtp, char *endp)
{
	char *cp, c;
	int i, j, k;

	/* Return zero hash number for single letter words */
	if((endp - strtp) == 1)
		return(0);

	cp = strtp;
	c = *cp++;
	i = (isupper(c)?tolower(c):c);
	c = *cp;
	j = (isupper(c)?tolower(c):c);
	i = i*j;
	cp = --endp;
	c = *cp--;
	k = (isupper(c)?tolower(c):c);
	c = *cp;
	j = (isupper(c)?tolower(c):c);
	j = k*j;

	k = (i ^ (j>>2)) & MASK;
	return(k);
}

int
storeh(int num, char *strtp)
{
	int i;

	for(i=num; i<MAXT; i++) {
		if(hasht[i] == 0) {
			hasht[i] = strtp;
			return(0);
		}
	}
	for(i=0; i<num; i++) {
		if(hasht[i] == 0) {
			hasht[i] = strtp;
			return(0);
		}
	}
	return(1);
}