/*
 * The functions in this file implement commands that search in the forward
 * and backward directions. There are no special characters in the search
 * strings. Probably should have a regular expression search, or something
 * like that.
 *
 * REVISION HISTORY:
 *
 * ?    Steve Wilhite, 1-Dec-85
 *      - massive cleanup on code.
 */

#include        <stdio.h>
#include        "ueed.h"

/*
 * Search forward. Get a search string from the user, and search, beginning at
 * ".", for the string. If found, reset the "." to be just after the match
 * string, and [perhaps] repaint the display. Bound to "C-S".
 */
forwsearch(f, n)
    {
    register LINE *clp;
    register int cbo;
    register LINE*tlp;
    register int tbo;
    register int c;
    register char *pp;
    register int s;

    if ((s = readpattern("Search")) != TRUE)
        return (s);

    clp = curwp->w_dotp;
    cbo = curwp->w_doto;

    while (clp != curbp->b_linep)
        {
        if (cbo == llength(clp))
            {
            clp = lforw(clp);
            cbo = 0;
            c = '\n';
            }
        else
            c = lgetc(clp, cbo++);

        if (eq(c, pat[0]) != FALSE)
            {
            tlp = clp;
            tbo = cbo;
            pp  = &pat[1];

            while (*pp != 0)
                {
                if (tlp == curbp->b_linep)
                    goto fail;

                if (tbo == llength(tlp))
                    {
                    tlp = lforw(tlp);
                    tbo = 0;
                    c = '\n';
                    }
                else
                    c = lgetc(tlp, tbo++);

                if (eq(c, *pp++) == FALSE)
                    goto fail;
                }

            curwp->w_dotp  = tlp;
            curwp->w_doto  = tbo;
            curwp->w_flag |= WFMOVE;
            return (TRUE);
            }
fail:;
        }

    mlwrite("Not found");
    return (FALSE);
    }

/*
 * Reverse search. Get a search string from the user, and search, starting at
 * "." and proceeding toward the front of the buffer. If found "." is left
 * pointing at the first character of the pattern [the last character that was
 j matched]. Bound to "C-R".
 */
backsearch(f, n)
    {
    register LINE *clp;
    register int cbo;
    register LINE *tlp;
    register int tbo;
    register int c;
    register char *epp;
    register char *pp;
    register int s;

    if ((s = readpattern("Reverse search")) != TRUE)
        return (s);

    for (epp = &pat[0]; epp[1] != 0; ++epp)
        ;

    clp = curwp->w_dotp;
    cbo = curwp->w_doto;

    for (;;)
        {
        if (cbo == 0)
            {
            clp = lback(clp);

            if (clp == curbp->b_linep)
                {
                mlwrite("Not found");
                return (FALSE);
                }

            cbo = llength(clp)+1;
            }

        if (--cbo == llength(clp))
            c = '\n';
        else
            c = lgetc(clp, cbo);

        if (eq(c, *epp) != FALSE)
            {
            tlp = clp;
            tbo = cbo;
            pp  = epp;

            while (pp != &pat[0])
                {
                if (tbo == 0)
                    {
                    tlp = lback(tlp);
                    if (tlp == curbp->b_linep)
                        goto fail;

                    tbo = llength(tlp)+1;
                    }

                if (--tbo == llength(tlp))
                    c = '\n';
                else
                    c = lgetc(tlp, tbo);

                if (eq(c, *--pp) == FALSE)
                    goto fail;
                }

            curwp->w_dotp  = tlp;
            curwp->w_doto  = tbo;
            curwp->w_flag |= WFMOVE;
            return (TRUE);
            }
fail:;
        }
    }

/*
 * Compare two characters. The "bc" comes from the buffer. It has it's case
 * folded out. The "pc" is from the pattern.
 */
eq(bc, pc)
    int bc;
    int pc;
    {
    if (bc>='a' && bc<='z')
        bc -= 0x20;

    if (pc>='a' && pc<='z')
        pc -= 0x20;

    if (bc == pc)
        return (TRUE);

    return (FALSE);
    }

/*
 * Read a pattern. Stash it in the external variable "pat". The "pat" is not
 * updated if the user types in an empty line. If the user typed an empty line,
 * and there is no old pattern, it is an error. Display the old pattern, in the
 * style of Jeff Lomicka. There is some do-it-yourself control expansion.
 */
readpattern(prompt)
    char *prompt;
    {
    register char *cp1;
    register char *cp2;
    register int c;
    register int s;
    char tpat[NPAT+20];

    cp1 = &tpat[0];                     /* Copy prompt */
    cp2 = prompt;

    while ((c = *cp2++) != '\0')
        *cp1++ = c;

    if (pat[0] != '\0')                 /* Old pattern */
        {
        *cp1++ = ' ';
        *cp1++ = '[';
        cp2 = &pat[0];

        while ((c = *cp2++) != 0)
            {
            if (cp1 < &tpat[NPAT+20-6]) /* "??]: \0" */
                {
                if (c<0x20 || c==0x7F) {
                    *cp1++ = '^';
                    c ^= 0x40;
                    }
                else if (c == '%')      /* Map "%" to */
                    *cp1++ = c;         /* "%%". */

                *cp1++ = c;
                }
            }

        *cp1++ = ']';
        }

    *cp1++ = ':';                       /* Finish prompt */
    *cp1++ = ' ';
    *cp1++ = '\0';
    s = mlreply(tpat, tpat, NPAT);      /* Read pattern */

    if (s == TRUE)                      /* Specified */
        strcpy(pat, tpat);
    else if (s == FALSE && pat[0] != 0)         /* CR, but old one */
        s = TRUE;

    return (s);
    }