/* -*-c,save-*- */
/*
 * rsent.c - random sentence (prog. 16.8 of Algorithms in SNOBOL4)
 * Robert Heller. Created: Sat Feb 22, 1986 15:52:57.06
 * Last Mod: 
 * 
 */

#include <stdio.h>

#include "patdef.h"

#define LOCAL static

/* #define DEBUG /* debug hackery */

#ifdef DEBUG
#define LOCAL /* static */
#endif

LOCAL PATTERN_NODE *syn_var,*asgn_var,*exp_var,*lit_text;

#define MAXVAR 10

LOCAL STRING_DESCR VAR,CODE,N,TEXT;
LOCAL char *VARS[MAXVAR];

#define MAXLINE 4096

#define TMPLINE 256

typedef struct {
    char *synname;
    char *synval;
    } SYNVAR;

#define MAXSYN 512

LOCAL SYNVAR rsent_tbl[MAXSYN];
LOCAL int rsent_cnt = 0;

char *calloc(),*malloc(),*fgets(),*index();
FILE *fopen();
ARG_DESCR *acons();

rsent_init(filename)
char *filename;
{
    register FILE *syndeffl;
    static char buffer[MAXLINE],aline[TMPLINE];
    register char *p,*q;
    register PATTERN_NODE *ec,*getnm;
    register int n;
    STRING_DESCR NM,matched;
    int syncmp();

    pattern_init();
    ec = cassign(breakk_c(">"),acons(STRING,&VAR));
    ec = concat(ec,c_lit_string(">"));
    ec = concat(c_lit_string("<"),ec);
    syn_var = concat(pos(0),ec);
    ec = cassign(breakk_c("\\"),acons(STRING,&VAR));
    ec = concat(ec,c_lit_string("\\"));
    ec = concat(ec,cassign(breakk_c("="),acons(STRING,&N)));
    ec = concat(ec,c_lit_string("="));
    ec = concat(c_lit_string("="),ec);
    asgn_var = concat(pos(0),ec);
    ec = cassign(breakk_c(")"),acons(STRING,&N));
    ec = concat(ec,c_lit_string(")"));
    ec = concat(cassign(any_c("@?/"),acons(STRING,&CODE)),ec);
    ec = concat(c_lit_string("("),ec);
    exp_var = concat(pos(0),ec);
    lit_text = cassign(breakk_c("<=("),acons(STRING,&TEXT));

    for (n=0;n<MAXVAR;n++) VARS[n] = NULL;

    ec = concat(c_lit_string("END"),rpos(0));
    ec = alt(c_lit_string("<"),ec);
    ec = concat(pos(0),ec);
    getnm = cassign(breakk_c(">"),acons(STRING,&NM));
    getnm = concat(getnm,c_lit_string(">::="));
    getnm = concat(c_lit_string("<"),getnm);

    syndeffl = fopen(filename,"r");
    if (syndeffl == NULL) {
	perror("rsent_init (fopen)");
	abort(0);
	}
    p = fgets(buffer,MAXLINE,syndeffl);
    if (p == NULL) {
	perror("rsent_init (fgets)");
	abort(0);
	}
    q = index(p,'\n');
    if (q != NULL) *q = '\0';
    trim(buffer);
    for (;;) {
	for (;;) {
	    p = fgets(aline,TMPLINE,syndeffl);
	    if (p == NULL) break;
	    q = index(p,'\n');
	    if (q != NULL) *q = '\0';
	    trim(aline);
	    if (pmatch(aline,ec,&matched) == MATCH_SUCCESS) break;
	    strcat(buffer,aline);
	    }
	if (p == NULL) strcpy(aline,"END");
	pmatch(buffer,getnm,&matched);
	p = (&buffer[matched.length-1]);
	*p = '|';
	q = malloc(strlen(p)+1);
	strcpy(q,p);
	p = NM.base+NM.offset;
	rsent_tbl[rsent_cnt].synval = q;
	q = malloc(NM.length+1);
	strncpy(q,p,NM.length);
	q[NM.length] = '\0';
	rsent_tbl[rsent_cnt].synname = q;
	rsent_cnt++;
	if (strcmp(aline,"END") == 0) break;
	strcpy(buffer,aline);
	}
    fclose(syndeffl);
    qsort(rsent_tbl,rsent_cnt,sizeof(SYNVAR),syncmp);
    }
syncmp(a,b)
register SYNVAR *a,*b;
{
    return(strcmp(a->synname,b->synname));
    }
trim(s)
register char *s;
{
    register char *p;

    p = s+strlen(s);
    p--;
    while (*p <= ' ' && p > s) *p-- = '\0';
    }
rsentence(stack,s)
register char *stack,*s;
{
    char temp1[MAXLINE],temp2[MAXLINE],syn[TMPLINE];
    register int n;
    STRING_DESCR matched;
    register SYNVAR *svar;
    register char *p;
    SYNVAR *rsen_lkp();

    *s = '\0';
    strcpy(temp1,stack);
#ifdef DEBUG
    printf("***In rsentence: temp1 = %s\n",temp1);
#endif
    for (;;) {
#ifdef DEBUG
	printf("***              temp1 = %s\n",temp1);
	printf("***              s = %s\n",s);
#endif
	if (pmatch(temp1,syn_var,&matched) == MATCH_SUCCESS) {
	    strncpy(syn,VAR.base+VAR.offset,VAR.length);
	    syn[VAR.length] = '\0';
	    svar = rsen_lkp(syn);
	    if (svar != NULL) {
		rselect(svar->synval,temp2);
		strcat(temp2,temp1+matched.length);
		strcpy(temp1,temp2);
		continue;
		}
	    else {
		strcpy(temp2,temp1+matched.length);
		strcpy(temp1,temp2);
		}
	    }
	else if (pmatch(temp1,exp_var,&matched) == MATCH_SUCCESS) {
	    n = atoi(N.base+N.offset);
	    switch(*(CODE.base+CODE.offset)) {
		case '@' :
		    if (n < 0 || n >= MAXVAR) {	
			fprintf(stderr,
				"rsentence: var# out of range (%d)\n",n);
			abort(n);
			}
		    if (VARS[n] != NULL) strcpy(temp2,VARS[n]);
		    else temp2[0] = '\0';
		    break;
		case '?' : sprintf(temp2,"%d",(rand() % n)+1); break;
		case '/' :
		    if (n < 0 || n >= MAXVAR) {
			fprintf(stderr,
				"rsentence: var# out of range (%d)\n",n);
			abort(n);
			}
		    if (VARS[n] != NULL) sprintf(temp2,"%d",strlen(VARS[n]));
		    else strcpy(temp2,"0");
		    break;
		}
	    strcat(s,temp2);
	    strcpy(temp2,temp1+matched.length);
	    strcpy(temp1,temp2);
	    }
	else if (pmatch(temp1,asgn_var,&matched) == MATCH_SUCCESS) {
	    n = atoi(N.base+N.offset);
	    strncpy(syn+1,VAR.base+VAR.offset,VAR.length);
	    syn[0] = '<';
	    syn[VAR.length+1] = '>';
	    syn[VAR.length+2] = '\0';
	    rsentence(syn,temp2);
	    VARS[n] = malloc(strlen(temp2)+1);
	    strcpy(VARS[n],temp2);
	    strcat(s,temp2);
	    strcpy(temp2,temp1+matched.length);
	    strcpy(temp1,temp2);
	    }
	else if (pmatch(temp1,lit_text,&matched) == MATCH_SUCCESS) {
	    p = s+strlen(s);
	    strncat(s,TEXT.base+TEXT.offset,TEXT.length);
	    p[TEXT.length] = '\0';
	    strcpy(temp1,temp1+matched.length);
	    }
	else {
	    strcat(s,temp1);
	    break;
	    }
	}
    }
s_rsentv(n,str)
register int n;
register char *str;
{
    VARS[n] = str;
    }
char *g_rsentv(n)
register int n;
{
    return(VARS[n]);
    }
f_rsentv(n)
register int n;
{
    if (VARS[n] != NULL) free(VARS[n]);
    }
SYNVAR *rsen_lkp(synn)
register char *synn;
{
    register first,last,indx,cmp;
    
    first = 0; last = rsent_cnt;
    while (first < last) {
	indx = ((last - first) >> 1) + first;
	cmp = strcmp(synn,rsent_tbl[indx].synname);
	if (cmp == 0) return(&rsent_tbl[indx]);
	else if (cmp < 0) last = indx;
	else first = indx+1;
	}
    return(NULL);
    }