/**********
Copyright 1990 Regents of the University of California.  All rights reserved.
Author: 1986 Wayne A. Christopher, U. C. Berkeley CAD Group
Modified 1999 Emmanuel Rouat
**********/

/*
 * The main entry point for the help system.
 */

#include "ngspice/ngspice.h"
#include "ngspice/cpstd.h"
#include "ngspice/hlpdefs.h"
#include "ngspice/suffix.h"

extern char *cp_tildexpand(const char *string);

char *hlp_directory;
extern char *hlp_filelist[];
int hlp_ftablesize = 0;


void
hlp_main(char *path, wordlist *wl)
{
    topic *top;
    fplace *place;

    hlp_directory = path;

    if (wl) {
        while (wl) {
            if ((place = findglobalsubject(wl->wl_word)) == NULL) {
                fprintf(stderr, "Error: No such topic: %s\n",
                        wl->wl_word);
                wl = wl->wl_next;
                continue;
            }
            if ((top = hlp_read(place)) == NULL) {
                fprintf(stderr, "Error: can't read topic\n");
                wl = wl->wl_next;
                continue;
            }
            hlp_provide(top);
            wl = wl->wl_next;
        }
    } else {
        if ((place = findglobalsubject("main")) == NULL) {
            fprintf(stderr, "Error: no main topic\n");
            return;
        }
        if ((top = hlp_read(place)) == NULL) {
            fprintf(stderr, "Error: can't read topic\n");
            return;
        }
        hlp_provide(top);
    }

#ifdef X_DISPLAY_MISSING
    hlp_free();
#endif

}


fplace *
findglobalsubject(char *subject)
{

    fplace *place;
    char **dict;
    long fpos;

    place = NULL;
    for (dict = hlp_filelist; *dict && **dict; dict++) {
        fpos = findsubject(*dict, subject);
        if (fpos != -1) {
            place = TMALLOC(fplace, 1);
            place->fpos = fpos;
            place->filename = copy(*dict);
            place->fp = hlp_fopen(*dict);
            break;
        }
    }
    return (place);
}


/* see if file is on filelist */
bool
hlp_approvedfile(char *filename)
{
    char **s;

    for (s = hlp_filelist; *s && **s; s++)
        if (cieq(*s, filename))
            return (TRUE);

    return (FALSE);
}


/* keep file pointers on top level files so we don't always have to do
   fopen's */
FILE *
hlp_fopen(char *filename)
{
    static struct {
        char filename[BSIZE_SP];
        FILE *fp;
    } hlp_ftable[32];
    int i;
    char buf[BSIZE_SP];

    for (i = 0; i < hlp_ftablesize; i++)
        if (cieq(filename, hlp_ftable[i].filename))
            return (hlp_ftable[i].fp);

    /* not already in table */
    strcpy(buf, hlp_directory); /* set up pathname */
    strcat(buf, DIR_PATHSEP);
    strcat(buf, filename);
    strcat(buf, ".txt");
    hlp_pathfix(buf);
    if ((hlp_ftable[hlp_ftablesize].fp = fopen(buf, "r")) == NULL) {
        perror(buf);
        return (NULL);
    }

    strcpy(hlp_ftable[hlp_ftablesize].filename, filename);
    hlp_ftablesize++;

    return (hlp_ftable[hlp_ftablesize - 1].fp);

}


/* ARGSUSED */
void
hlp_pathfix(char *buf)
{
    char *s, *t, *u, bufx[1025];
    char *dir_pathsep;

    dir_pathsep = DIR_PATHSEP;

    if (!buf)
        return;

    s = cp_tildexpand(buf);
    if (sizeof(DIR_PATHSEP) == 2) {
        if (*dir_pathsep != '/') {
            for (t = s; *t; t++) {
                if (*t == '/')
                    *t = *dir_pathsep;
            }
        } else
            strcpy(buf, s);
    } else {
        /* For vms; this probably doesn't work, but neither did the old code */
        for (s = bufx, t = buf; *t; t++) {
            if (*t == '/')
                for (u = DIR_PATHSEP; *u; u++)
                    *s++ = *u;
            else
                *s++ = *t;
        }
        *s = '\0';
        strcpy(buf, s);
    }

    if (s)
        tfree(s);
}