/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#include <ctype.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <locale.h>
#include <euc.h>
#include <stdlib.h>

#define boolean int
#define TRUE 1
#define FALSE 0
#define NIL 0
#define STANDARD 0
#define ALTERNATE 1

/*
 * Vfontedpr.
 *
 * Dave Presotto 1/12/81 (adapted from an earlier version by Bill Joy)
 *
 */

#define STRLEN 10               /* length of strings introducing things */
#define PNAMELEN 40             /* length of a function/procedure name */
#define PSMAX 20                /* size of procedure name stacking */

/* regular expression routines */

char    *expmatch();            /* match a string to an expression */
char    *STRNCMP();             /* a different kind of strncmp */
char    *convexp();             /* convert expression to internal form */

char    *tgetstr();             /* extract a string-valued capability */
boolean isproc();
char    *ctime();
char    *strchr();

/*
 *      The state variables
 */

boolean incomm;                 /* in a comment of the primary type */
boolean instr;                  /* in a string constant */
boolean inchr;                  /* in a string constant */
boolean nokeyw = FALSE;         /* no keywords being flagged */
boolean doindex = FALSE;        /* form an index */
boolean twocol = FALSE;         /* in two-column mode */
boolean filter = FALSE;         /* act as a filter (like eqn) */
boolean pass = FALSE;           /* when acting as a filter, pass indicates
                                 * whether we are currently processing
                                 * input.
                                 */
boolean prccont;                /* continue last procedure */
int     comtype;                /* type of comment */
int     margin;
int     psptr;                  /* the stack index of the current procedure */
char    pstack[PSMAX][PNAMELEN+1];      /* the procedure name stack */
int     plstack[PSMAX];         /* the procedure nesting level stack */
int     blklevel;               /* current nesting level */
int     prclevel;               /* nesting level at which procedure definitions
                                   may be found, -1 if none currently valid
                                   (meaningful only if l_prclevel is true) */
char    *defsfile = "/usr/lib/vgrindefs";       /* name of language definitions file */
char    pname[BUFSIZ+1];

/*
 *      The language specific globals
 */

char    *language = "c";        /* the language indicator */
char    *l_keywds[BUFSIZ/2];    /* keyword table address */
char    *l_prcbeg;              /* regular expr for procedure begin */
char    *l_combeg;              /* string introducing a comment */
char    *l_comend;              /* string ending a comment */
char    *l_acmbeg;              /* string introducing a comment */
char    *l_acmend;              /* string ending a comment */
char    *l_blkbeg;              /* string begining of a block */
char    *l_blkend;              /* string ending a block */
char    *l_strbeg;              /* delimiter for string constant */
char    *l_strend;              /* delimiter for string constant */
char    *l_chrbeg;              /* delimiter for character constant */
char    *l_chrend;              /* delimiter for character constant */
char    *l_prcenable;           /* re indicating that procedure definitions
                                   can be found in the next lexical level --
                                   kludge for lisp-like languages that use
                                   something like
                                           (defun (proc ...)
                                                (proc ...)
                                           )
                                   to define procedures */
char    l_escape;               /* character used to  escape characters */
boolean l_toplex;               /* procedures only defined at top lex level */
boolean l_prclevel;             /* procedure definitions valid only within
                                   the nesting level indicated by the px
                                   (l_prcenable) capability */

/*
 *  for the benefit of die-hards who aren't convinced that tabs
 *  occur every eight columns
 */
short tabsize = 8;

/*
 *  global variables also used by expmatch
 */
boolean _escaped;               /* if last character was an escape */
char    *Start;                 /* start of the current string */
boolean l_onecase;              /* upper and lower case are equivalent */
char    *l_idchars;             /* characters legal in identifiers in addition
                                   to letters and digits (default "_") */

static void putcp(int c);
static int width(char *s, char *os);
static int tabs(char *s, char *os);
static void putKcp(char *start, char *end, boolean force);
static void putScp(char *os);
static int iskw(char *s);

/*
 * The code below emits troff macros and directives that consume part of the
 * troff macro and register space.  See tmac.vgrind for an enumeration of
 * these macros and registers.
 */

int
main(int argc, char *argv[])
{
    FILE *in;
    char *fname;
    struct stat stbuf;
    char buf[BUFSIZ];
    char idbuf[256];    /* enough for all 8 bit chars */
    char strings[2 * BUFSIZ];
    char defs[2 * BUFSIZ];
    int needbp = 0;
    int i;
    char *cp;

        (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN     "SYS_TEST"
#endif
        (void) textdomain(TEXT_DOMAIN);

    /*
     * Dump the name by which we were invoked.
     */
    argc--, argv++;

    /*
     * Process arguments.  For the sake of compatibility with older versions
     * of the program, the syntax accepted below is very idiosyncratic.  Some
     * options require space between the option and its argument; others
     * disallow it.  No options may be bundled together.
     *
     * Actually, there is one incompatibility.  Files and options formerly
     * could be arbitrarily intermixed, but this is no longer allowed.  (This
     * possiblity was never documented.)
     */
    while (argc > 0 && *argv[0] == '-') {
        switch (*(cp = argv[0] + 1)) {

        case '\0':                              /* - */
            /* Take input from stdin. */
            /*
             * This option implies the end of the flag arguments.  Leave the
             * "-" in place for the file processing code to see.
             */
            goto flagsdone;

        case '2':                               /* -2 */
            /* Enter two column mode. */
            twocol = 1;
            printf("'nr =2 1\n");
            break;

        case 'd':                               /* -d <defs-file> */
            /* Specify the language description file. */
            defsfile = argv[1];
            argc--, argv++;
            break;

        case 'f':                               /* -f */
            /* Act as a filter like eqn. */
            filter = 1;
            /*
             * Slide remaining arguments down one position and postpend "-",
             * to force reading from stdin.
             */
            for (i = 0; i < argc - 1; i++)
                argv[i] = argv[i + 1];
            argv[argc - 1] = "-";
            continue;

        case 'h':                               /* -h [header] */
            /* Specify header string. */
            if (argc == 1) {
                printf("'ds =H\n");
                break;
            }
            printf("'ds =H %s\n", argv[1]);
            argc--, argv++;
            break;

        case 'l':                               /* -l<language> */
            /* Specify the language. */
            language = cp + 1;
            break;

        case 'n':                               /* -n */
            /* Indicate no keywords. */
            nokeyw = 1;
            break;

        case 's':                               /* -s<size> */
            /* Specify the font size. */
            i = 0;
            cp++;
            while (*cp)
                i = i * 10 + (*cp++ - '0');
            printf("'nr vP %d\n", i);
            break;

        case 't':                               /* -t */
            /* Specify a nondefault tab size. */
            tabsize = 4;
            break;

        case 'x':                               /* -x */
            /* Build an index. */
            doindex = 1;
            /* This option implies "-n" as well; turn it on. */
            argv[0] = "-n";
            continue;
        }

        /* Advance to next argument. */
        argc--, argv++;
    }

flagsdone:

    /*
     * Get the language definition from the defs file.
     */
    i = tgetent (defs, language, defsfile);
    if (i == 0) {
        fprintf (stderr, gettext("no entry for language %s\n"), language);
        exit (0);
    } else  if (i < 0) {
        fprintf (stderr,  gettext("cannot find vgrindefs file %s\n"), defsfile);
        exit (0);
    }
    cp = strings;
    if (tgetstr ("kw", &cp) == NIL)
        nokeyw = TRUE;
    else  {
        char **cpp;

        cpp = l_keywds;
        cp = strings;
        while (*cp) {
            while (*cp == ' ' || *cp =='\t')
                *cp++ = '\0';
            if (*cp)
                *cpp++ = cp;
            while (*cp != ' ' && *cp  != '\t' && *cp)
                cp++;
        }
        *cpp = NIL;
    }
    cp = buf;
    l_prcbeg = convexp (tgetstr ("pb", &cp));
    cp = buf;
    l_combeg = convexp (tgetstr ("cb", &cp));
    cp = buf;
    l_comend = convexp (tgetstr ("ce", &cp));
    cp = buf;
    l_acmbeg = convexp (tgetstr ("ab", &cp));
    cp = buf;
    l_acmend = convexp (tgetstr ("ae", &cp));
    cp = buf;
    l_strbeg = convexp (tgetstr ("sb", &cp));
    cp = buf;
    l_strend = convexp (tgetstr ("se", &cp));
    cp = buf;
    l_blkbeg = convexp (tgetstr ("bb", &cp));
    cp = buf;
    l_blkend = convexp (tgetstr ("be", &cp));
    cp = buf;
    l_chrbeg = convexp (tgetstr ("lb", &cp));
    cp = buf;
    l_chrend = convexp (tgetstr ("le", &cp));
    cp = buf;
    l_prcenable = convexp (tgetstr ("px", &cp));
    cp = idbuf;
    l_idchars = tgetstr ("id", &cp);
    /* Set default, for compatibility with old version */
    if (l_idchars == NIL)
        l_idchars = "_";
    l_escape = '\\';
    l_onecase = tgetflag ("oc");
    l_toplex = tgetflag ("tl");
    l_prclevel = tgetflag ("pl");

    /*
     * Emit a call to the initialization macro.  If not in filter mode, emit a
     * call to the vS macro, so that tmac.vgrind can uniformly assume that all
     * program input is bracketed with vS-vE pairs.
     */
    printf("'vI\n");
    if (!filter)
        printf("'vS\n");

    if (doindex) {
        /*
         * XXX: Hard-wired spacing information.  This should probably turn
         *      into the emission of a macro invocation, so that tmac.vgrind
         *      can make up its own mind about what spacing is appropriate.
         */
        if (twocol)
            printf("'ta 2.5i 2.75i 4.0iR\n'in .25i\n");
        else
            printf("'ta 4i 4.25i 5.5iR\n'in .5i\n");
    }

    while (argc > 0) {
        if (strcmp(argv[0], "-") == 0) {
            /* Embed an instance of the original stdin. */
            in = fdopen(fileno(stdin), "r");
            fname = "";
        } else {
            /* Open the file for input. */
            if ((in = fopen(argv[0], "r")) == NULL) {
                perror(argv[0]);
                exit(1);
            }
            fname = argv[0];
        }
        argc--, argv++;

        /*
         * Reinitialize for the current file.
         */
        incomm = FALSE;
        instr = FALSE;
        inchr = FALSE;
        _escaped = FALSE;
        blklevel = 0;
        prclevel = -1;
        for (psptr=0; psptr<PSMAX; psptr++) {
            pstack[psptr][0] = '\0';
            plstack[psptr] = 0;
        }
        psptr = -1;
        printf("'-F\n");
        if (!filter) {
            char *cp;

            printf(".ds =F %s\n", fname);
            if (needbp) {
                needbp = 0;
                printf(".()\n");
                printf(".bp\n");
            }
            fstat(fileno(in), &stbuf);
            cp = ctime(&stbuf.st_mtime);
            cp[16] = '\0';
            cp[24] = '\0';
            printf(".ds =M %s %s\n", cp+4, cp+20);
            printf("'wh 0 vH\n");
            printf("'wh -1i vF\n");
        }
        if (needbp && filter) {
            needbp = 0;
            printf(".()\n");
            printf(".bp\n");
        }

        /*
         *      MAIN LOOP!!!
         */
        while (fgets(buf, sizeof buf, in) != NULL) {
            if (buf[0] == '\f') {
                printf(".bp\n");
            }
            if (buf[0] == '.') {
                printf("%s", buf);
                if (!strncmp (buf+1, "vS", 2))
                    pass = TRUE;
                if (!strncmp (buf+1, "vE", 2))
                    pass = FALSE;
                continue;
            }
            prccont = FALSE;
            if (!filter || pass)
                putScp(buf);
            else
                printf("%s", buf);
            if (prccont && (psptr >= 0))
                printf("'FC %s\n", pstack[psptr]);
#ifdef DEBUG
            printf ("com %o str %o chr %o ptr %d\n", incomm, instr, inchr, psptr);
#endif
            margin = 0;
        }

        needbp = 1;
        (void) fclose(in);
    }

    /* Close off the vS-vE pair. */
    if (!filter)
        printf("'vE\n");

    return (0);
}

#define isidchr(c) (isalnum(c) || ((c) != NIL && strchr(l_idchars, (c)) != NIL))

static void
putScp(char *os)
{
    char *s = os;                       /* pointer to unmatched string */
    char dummy[BUFSIZ];                 /* dummy to be used by expmatch */
    char *comptr;                       /* end of a comment delimiter */
    char *acmptr;                       /* end of a comment delimiter */
    char *strptr;                       /* end of a string delimiter */
    char *chrptr;                       /* end of a character const delimiter */
    char *blksptr;                      /* end of a lexical block start */
    char *blkeptr;                      /* end of a lexical block end */

    Start = os;                 /* remember the start for expmatch */
    _escaped = FALSE;
    if (nokeyw || incomm || instr)
        goto skip;
    if (isproc(s)) {
        printf("'FN %s\n", pname);
        if (psptr < PSMAX-1) {
            ++psptr;
            strncpy (pstack[psptr], pname, PNAMELEN);
            pstack[psptr][PNAMELEN] = '\0';
            plstack[psptr] = blklevel;
        }
    }
    /*
     * if l_prclevel is set, check to see whether this lexical level
     * is one immediately below which procedure definitions are allowed.
     */
    if (l_prclevel && !incomm && !instr && !inchr) {
        if (expmatch (s, l_prcenable, dummy) != NIL)
            prclevel = blklevel + 1;
    }
skip:
    do {
        /* check for string, comment, blockstart, etc */
        if (!incomm && !instr && !inchr) {

            blkeptr = expmatch (s, l_blkend, dummy);
            blksptr = expmatch (s, l_blkbeg, dummy);
            comptr = expmatch (s, l_combeg, dummy);
            acmptr = expmatch (s, l_acmbeg, dummy);
            strptr = expmatch (s, l_strbeg, dummy);
            chrptr = expmatch (s, l_chrbeg, dummy);

            /* start of a comment? */
            if (comptr != NIL)
                if ((comptr < strptr || strptr == NIL)
                  && (comptr < acmptr || acmptr == NIL)
                  && (comptr < chrptr || chrptr == NIL)
                  && (comptr < blksptr || blksptr == NIL)
                  && (comptr < blkeptr || blkeptr == NIL)) {
                    putKcp (s, comptr-1, FALSE);
                    s = comptr;
                    incomm = TRUE;
                    comtype = STANDARD;
                    if (s != os)
                        printf ("\\c");
                    printf ("\\c\n'+C\n");
                    continue;
                }

            /* start of a comment? */
            if (acmptr != NIL)
                if ((acmptr < strptr || strptr == NIL)
                  && (acmptr < chrptr || chrptr == NIL)
                  && (acmptr < blksptr || blksptr == NIL)
                  && (acmptr < blkeptr || blkeptr == NIL)) {
                    putKcp (s, acmptr-1, FALSE);
                    s = acmptr;
                    incomm = TRUE;
                    comtype = ALTERNATE;
                    if (s != os)
                        printf ("\\c");
                    printf ("\\c\n'+C\n");
                    continue;
                }

            /* start of a string? */
            if (strptr != NIL)
                if ((strptr < chrptr || chrptr == NIL)
                  && (strptr < blksptr || blksptr == NIL)
                  && (strptr < blkeptr || blkeptr == NIL)) {
                    putKcp (s, strptr-1, FALSE);
                    s = strptr;
                    instr = TRUE;
                    continue;
                }

            /* start of a character string? */
            if (chrptr != NIL)
                if ((chrptr < blksptr || blksptr == NIL)
                  && (chrptr < blkeptr || blkeptr == NIL)) {
                    putKcp (s, chrptr-1, FALSE);
                    s = chrptr;
                    inchr = TRUE;
                    continue;
                }

            /* end of a lexical block */
            if (blkeptr != NIL) {
                if (blkeptr < blksptr || blksptr == NIL) {
                    /* reset prclevel if necessary */
                    if (l_prclevel && prclevel == blklevel)
                        prclevel = -1;
                    putKcp (s, blkeptr - 1, FALSE);
                    s = blkeptr;
                    blklevel--;
                    if (psptr >= 0 && plstack[psptr] >= blklevel) {

                        /* end of current procedure */
                        if (s != os)
                            printf ("\\c");
                        printf ("\\c\n'-F\n");
                        blklevel = plstack[psptr];

                        /* see if we should print the last proc name */
                        if (--psptr >= 0)
                            prccont = TRUE;
                        else
                            psptr = -1;
                    }
                    continue;
                }
            }

            /* start of a lexical block */
            if (blksptr != NIL) {
                putKcp (s, blksptr - 1, FALSE);
                s = blksptr;
                blklevel++;
                continue;
            }

        /* check for end of comment */
        } else if (incomm) {
            comptr = expmatch (s, l_comend, dummy);
            acmptr = expmatch (s, l_acmend, dummy);
            if (((comtype == STANDARD) && (comptr != NIL)) ||
                ((comtype == ALTERNATE) && (acmptr != NIL))) {
                if (comtype == STANDARD) {
                    putKcp (s, comptr-1, TRUE);
                    s = comptr;
                } else {
                    putKcp (s, acmptr-1, TRUE);
                    s = acmptr;
                }
                incomm = FALSE;
                printf("\\c\n'-C\n");
                continue;
            } else {
                putKcp (s, s + strlen(s) -1, TRUE);
                s = s + strlen(s);
                continue;
            }

        /* check for end of string */
        } else if (instr) {
            if ((strptr = expmatch (s, l_strend, dummy)) != NIL) {
                putKcp (s, strptr-1, TRUE);
                s = strptr;
                instr = FALSE;
                continue;
            } else {
                putKcp (s, s+strlen(s)-1, TRUE);
                s = s + strlen(s);
                continue;
            }

        /* check for end of character string */
        } else if (inchr) {
            if ((chrptr = expmatch (s, l_chrend, dummy)) != NIL) {
                putKcp (s, chrptr-1, TRUE);
                s = chrptr;
                inchr = FALSE;
                continue;
            } else {
                putKcp (s, s+strlen(s)-1, TRUE);
                s = s + strlen(s);
                continue;
            }
        }

        /* print out the line */
        putKcp (s, s + strlen(s) -1, FALSE);
        s = s + strlen(s);
    } while (*s);
}

static void
putKcp(char *start, char *end, boolean force)
        /* start - start of string to write */
        /* end - end of string to write */
        /* force - true if we should force nokeyw */
{
    int i;
    int xfld = 0;

    while (start <= end) {
        if (doindex) {
            if (*start == ' ' || *start == '\t') {
                if (xfld == 0)
                    printf("
");
                printf("\t");
                xfld = 1;
                while (*start == ' ' || *start == '\t')
                    start++;
                continue;
            }
        }

        /* take care of nice tab stops */
        if (*start == '\t') {
            while (*start == '\t')
                start++;
            i = tabs(Start, start) - margin / tabsize;
            printf ("\\h'|%dn'",
                    i * (tabsize == 4 ? 5 : 10) + 1 - margin % tabsize);
            continue;
        }

        if (!nokeyw && !force)
            if (  (*start == '#'   ||  isidchr(*start))
               && (start == Start || !isidchr(start[-1]))
               ) {
                i = iskw(start);
                if (i > 0) {
                    printf("\\*(+K");
                    do
                        putcp(*start++);
                    while (--i > 0);
                    printf("\\*(-K");
                    continue;
                }
            }

        putcp (*start++);
    }
}


static int
tabs(char *s, char *os)
{

    return (width(s, os) / tabsize);
}

static int
width(char *s, char *os)
{
        int i = 0;
        unsigned char c;
        int n;

        while (s < os) {
                if (*s == '\t') {
                        i = (i + tabsize) &~ (tabsize-1);
                        s++;
                        continue;
                }
                c = *(unsigned char *)s;
                if (c < ' ')
                        i += 2, s++;
                else if (c >= 0200) {
                        if ((n = mblen(s, MB_CUR_MAX)) > 0) {
                                i += csetcol(csetno(c));
                                s += n;
                        } else
                                s++;
                } else
                        i++, s++;
        }
        return (i);
}

static void
putcp(int c)
{

        switch(c) {

        case 0:
                break;

        case '\f':
                break;

        case '{':
                printf("\\*(+K{\\*(-K");
                break;

        case '}':
                printf("\\*(+K}\\*(-K");
                break;

        case '\\':
                printf("\\e");
                break;

        case '_':
                printf("\\*_");
                break;

        case '-':
                printf("\\*-");
                break;

                /*
                 * The following two cases deal with the accent characters.
                 * If they're part of a comment, we assume that they're part
                 * of running text and hand them to troff as regular quote
                 * characters.  Otherwise, we assume they're being used as
                 * special characters (e.g., string delimiters) and arrange
                 * for troff to render them as accents.  This is an imperfect
                 * heuristic that produces slightly better appearance than the
                 * former behavior of unconditionally rendering the characters
                 * as accents.  (See bug 1040343.)
                 */

        case '`':
                if (incomm)
                        printf("`");
                else
                        printf("\\`");
                break;

        case '\'':
                if (incomm)
                        printf("'");
                else
                        printf("\\'");
                break;

        case '.':
                printf("\\&.");
                break;

                /*
                 * The following two cases contain special hacking
                 * to make C-style comments line up.  The tests aren't
                 * really adequate; they lead to grotesqueries such
                 * as italicized multiplication and division operators.
                 * However, the obvious test (!incomm) doesn't work,
                 * because incomm isn't set until after we've put out
                 * the comment-begin characters.  The real problem is
                 * that expmatch() doesn't give us enough information.
                 */

        case '*':
                if (instr || inchr)
                        printf("*");
                else
                        printf("\\f2*\\fP");
                break;

        case '/':
                if (instr || inchr)
                        printf("/");
                else
                        printf("\\f2\\h'\\w' 'u-\\w'/'u'/\\fP");
                break;

        default:
                if (c < 040)
                        putchar('^'), c |= '@';
                /* FALLTHROUGH */
        case '\t':
        case '\n':
                putchar(c);
        }
}

/*
 *      look for a process beginning on this line
 */
boolean
isproc(char *s)
{
    pname[0] = '\0';
    if (l_prclevel ? (prclevel == blklevel) : (!l_toplex || blklevel == 0))
        if (expmatch (s, l_prcbeg, pname) != NIL) {
            return (TRUE);
        }
    return (FALSE);
}


/*
 * iskw - check to see if the next word is a keyword
 *      Return its length if it is or 0 if it isn't.
 */

static int
iskw(char *s)
{
        char **ss = l_keywds;
        int i = 1;
        char *cp = s;

        /* Get token length. */
        while (++cp, isidchr(*cp))
                i++;

        while (cp = *ss++) {
                if (!STRNCMP(s,cp,i) && !isidchr(cp[i]))
                        return (i);
        }
        return (0);
}