[nmh] / uip / burst.c

/*
 * burst.c -- explode digests into individual messages
 *
 * This code is Copyright (c) 2002, by the authors of nmh.  See the
 * COPYRIGHT file in the root directory of the nmh distribution for
 * complete copyright information.
 */

#include <h/mh.h>
#include <h/utils.h>
#include <h/mhparse.h>

#define BURST_SWITCHES \
    X("inplace", 0, INPLSW) \
    X("noinplace", 0, NINPLSW) \
    X("mime", 0, MIMESW) \
    X("nomime", 0, NMIMESW) \
    X("automime", 0, AUTOMIMESW) \
    X("quiet", 0, QIETSW) \
    X("noquiet", 0, NQIETSW) \
    X("verbose", 0, VERBSW) \
    X("noverbose", 0, NVERBSW) \
    X("version", 0, VERSIONSW) \
    X("help", 0, HELPSW) \

#define X(sw, minchars, id) id,
DEFINE_SWITCH_ENUM(BURST);
#undef X

#define X(sw, minchars, id) { sw, minchars, id },
DEFINE_SWITCH_ARRAY(BURST, switches);
#undef X

struct smsg {
    off_t s_start;
    off_t s_stop;
};

/*
 * For the MIME parsing routines
 */

int debugsw = 0;

/*
 * static prototypes
 */
static int find_delim (int, struct smsg *, int *);
static void find_mime_parts (CT, struct smsg *, int *);
static void burst (struct msgs **, int, struct smsg *, int, int, int,
                   char *, int);
static void cpybrst (FILE *, FILE *, char *, char *, int, int);

/*
 * A macro to check to see if we have reached a message delimiter
 * (an encapsulation boundary, EB, in RFC 934 parlance).
 *
 * According to RFC 934, an EB is simply a line which starts with
 * a "-" and is NOT followed by a space.  So even a single "-" on a line
 * by itself would be an EB.
 */

#define CHECKDELIM(buffer) (buffer[0] == '-' && buffer[1] != ' ')

int
main (int argc, char **argv)
{
    int inplace = 0, quietsw = 0, verbosw = 0, mimesw = 1;
    int hi, msgnum, numburst;
    char *cp, *maildir, *folder = NULL, buf[BUFSIZ];
    char **argp, **arguments;
    struct msgs_array msgs = { 0, 0, NULL };
    struct smsg *smsgs;
    struct msgs *mp;

    if (nmh_init(argv[0], 1)) { return 1; }

    arguments = getarguments (invo_name, argc, argv, 1);
    argp = arguments;

    while ((cp = *argp++)) {
        if (*cp == '-') {
            switch (smatch (++cp, switches)) {
            case AMBIGSW: 
                ambigsw (cp, switches);
                done (1);
            case UNKWNSW: 
                adios (NULL, "-%s unknown\n", cp);

            case HELPSW: 
                snprintf (buf, sizeof(buf), "%s [+folder] [msgs] [switches]",
                        invo_name);
                print_help (buf, switches, 1);
                done (0);
            case VERSIONSW:
                print_version(invo_name);
                done (0);

            case INPLSW: 
                inplace++;
                continue;
            case NINPLSW: 
                inplace = 0;
                continue;

            case MIMESW:
                mimesw = 2;
                continue;
            case NMIMESW:
                mimesw = 0;
                continue;
            case AUTOMIMESW:
                mimesw = 1;
                continue;

            case QIETSW: 
                quietsw++;
                continue;
            case NQIETSW: 
                quietsw = 0;
                continue;

            case VERBSW: 
                verbosw++;
                continue;
            case NVERBSW: 
                verbosw = 0;
                continue;
            }
        }
        if (*cp == '+' || *cp == '@') {
            if (folder)
                adios (NULL, "only one folder at a time!");
            else
                folder = pluspath (cp);
        } else {
            app_msgarg(&msgs, cp);
        }
    }

    if (!context_find ("path"))
        free (path ("./", TFOLDER));
    if (!msgs.size)
        app_msgarg(&msgs, "cur");
    if (!folder)
        folder = getfolder (1);
    maildir = m_maildir (folder);

    if (chdir (maildir) == NOTOK)
        adios (maildir, "unable to change directory to");

    /* read folder and create message structure */
    if (!(mp = folder_read (folder, 1)))
        adios (NULL, "unable to read folder %s", folder);

    /* check for empty folder */
    if (mp->nummsg == 0)
        adios (NULL, "no messages in %s", folder);

    /* parse all the message ranges/sequences and set SELECTED */
    for (msgnum = 0; msgnum < msgs.size; msgnum++)
        if (!m_convert (mp, msgs.msgs[msgnum]))
            done (1);
    seq_setprev (mp);   /* set the previous-sequence */

    smsgs = mh_xcalloc(MAXFOLDER + 2, sizeof *smsgs);

    hi = mp->hghmsg + 1;

    /* burst all the SELECTED messages */
    for (msgnum = mp->lowsel; msgnum <= mp->hghsel; msgnum++) {
        if (is_selected (mp, msgnum)) {
            if ((numburst = find_delim (msgnum, smsgs, &mimesw)) >= 1) {
                if (verbosw)
                    printf ("%d message%s exploded from digest %d\n",
                            numburst, numburst > 1 ? "s" : "", msgnum);
                burst (&mp, msgnum, smsgs, numburst, inplace, verbosw,
                       maildir, mimesw);
            } else {
                if (numburst == 0) {
                    if (!quietsw)
                        inform("message %d not in digest format, continuing...",
                                  msgnum);
                }  /* this pair of braces was missing before 1999-07-15 */
                else
                    adios (NULL, "burst() botch -- you lose big");
            }
        }
    }

    free(smsgs);
    context_replace (pfolder, folder);  /* update current folder */

    /*
     * If -inplace is given, then the first message burst becomes
     * the current message (which will now show a table of contents).
     * Otherwise, the first message extracted from the first digest
     * becomes the current message.
     */
    if (inplace) {
        if (mp->lowsel != mp->curmsg)
            seq_setcur (mp, mp->lowsel);
    } else {
        if (hi <= mp->hghmsg)
            seq_setcur (mp, hi);
    }

    seq_save (mp);      /* synchronize message sequences */
    context_save ();    /* save the context file         */
    folder_free (mp);   /* free folder/message structure */
    done (0);
    return 1;
}


/*
 * Scan the message and find the beginning and
 * end of all the messages in the digest.
 *
 * If requested, see if the message is MIME-formatted and contains any
 * message/rfc822 parts; if so, burst those parts.
 */

static int
find_delim (int msgnum, struct smsg *smsgs, int *mimesw)
{
    int wasdlm = 0, msgp;
    off_t pos;
    char c, *msgnam;
    char buffer[BUFSIZ];
    FILE *in;
    CT content;

    msgnam = m_name (msgnum);

    /*
     * If mimesw is 1 or 2, try to see if it's got proper MIME formatting.
     */

    if (*mimesw > 0) {
        content = parse_mime(msgnam);
        if (! content && *mimesw == 2)
            return 0;
        if (content) {
            smsgs[0].s_start = 0;
            smsgs[0].s_stop = content->c_begin - 1;
            msgp = 1;
            find_mime_parts(content, smsgs, &msgp);
            free_content(content);
            if (msgp == 1 && *mimesw == 2) {
                adios (msgnam, "does not have any message/rfc822 parts");
            } else if (msgp > 1) {
                *mimesw = 1;
                return (msgp - 1);
            }
        }
    }

    *mimesw = 0;

    if ((in = fopen (msgnam, "r")) == NULL)
        adios (msgnam, "unable to read message");

    for (msgp = 0, pos = 0L; msgp <= MAXFOLDER;) {
        /*
         * We're either at the beginning of the whole message, or
         * we're just past the delimiter of the last message.
         * Swallow lines until we get to something that's not a newline
         */
        while (fgets (buffer, sizeof(buffer), in) && buffer[0] == '\n')
            pos += (long) strlen (buffer);
        if (feof (in))
            break;

        /*
         * Reset to the beginning of the last non-blank line, and save our
         * starting position.  This is where the encapsulated message
         * starts.
         */
        fseeko (in, pos, SEEK_SET);
        smsgs[msgp].s_start = pos;

        /*
         * Read in lines until we get to a message delimiter.
         *
         * Previously we checked to make sure the preceding line and
         * next line was a newline.  That actually does not comply with
         * RFC 934, so make sure we break on a message delimiter even
         * if the previous character was NOT a newline.
         */
        for (c = 0; fgets (buffer, sizeof(buffer), in); c = buffer[0]) {
            if ((wasdlm = CHECKDELIM(buffer)))
                break;
            else
                pos += (long) strlen (buffer);
        }

        /*
         * Only count as a new message if we got the message delimiter.
         * Swallow a blank line if it was right before the message delimiter.
         */
        if (smsgs[msgp].s_start != pos && wasdlm)
            smsgs[msgp++].s_stop = (c == '\n' && wasdlm) ? pos - 1 : pos;

        if (feof (in)) {
#if 0
            if (wasdlm) {
                smsgs[msgp - 1].s_stop -= ((long) strlen (buffer) + 1);
                msgp++;         /* fake "End of XXX Digest" */
            }
#endif
            break;
        }
        pos += (long) strlen (buffer);
    }

    fclose (in);
    return (msgp - 1);          /* return the number of messages burst */
}


/*
 * Find any MIME content in the message that is a message/rfc822 and add
 * it to the list of messages to burst.
 */

static void
find_mime_parts (CT content, struct smsg *smsgs, int *msgp)
{
    struct multipart *m;
    struct part *part;

    /*
     * If we have a message/rfc822, then it's easy.
     */

    if (content->c_type == CT_MESSAGE &&
                        content->c_subtype == MESSAGE_RFC822) {
        smsgs[*msgp].s_start = content->c_begin;
        smsgs[*msgp].s_stop = content->c_end;
        (*msgp)++;
        return;
    }

    /*
     * Otherwise, if we do have multiparts, try all of the sub-parts.
     */

    if (content->c_type == CT_MULTIPART) {
        m = (struct multipart *) content->c_ctparams;

        for (part = m->mp_parts; part; part = part->mp_next)
            find_mime_parts(part->mp_part, smsgs, msgp);
    }

    return;
}


/*
 * Burst out the messages in the digest into the folder
 */

static void
burst (struct msgs **mpp, int msgnum, struct smsg *smsgs, int numburst,
        int inplace, int verbosw, char *maildir, int mimesw)
{
    int i, j, mode;
    char *msgnam;
    char f1[BUFSIZ], f2[BUFSIZ], f3[BUFSIZ];
    FILE *in, *out;
    struct stat st;
    struct msgs *mp;

    if ((in = fopen (msgnam = m_name (msgnum), "r")) == NULL)
        adios (msgnam, "unable to read message");

    mode =
      fstat (fileno(in), &st) != NOTOK ? (int) (st.st_mode & 0777) : m_gmprot();
    mp = *mpp;

    /*
     * See if we have enough space in the folder
     * structure for all the new messages.
     */
    if ((mp->hghmsg + numburst > mp->hghoff) &&
        !(mp = folder_realloc (mp, mp->lowoff, mp->hghmsg + numburst)))
        adios (NULL, "unable to allocate folder storage");
    *mpp = mp;

    j = mp->hghmsg;             /* old value */
    mp->hghmsg += numburst;
    mp->nummsg += numburst;

    /*
     * If this is not the highest SELECTED message, then
     * increment mp->hghsel by numburst, since the highest
     * SELECTED is about to be slid down by that amount.
     */
    if (msgnum < mp->hghsel)
        mp->hghsel += numburst;

    /*
     * If -inplace is given, renumber the messages after the
     * source message, to make room for each of the messages
     * contained within the digest.
     *
     * This is equivalent to refiling a message from the point
     * of view of the external hooks.
     */
    if (inplace) {
        for (i = mp->hghmsg; j > msgnum; i--, j--) {
            strncpy (f1, m_name (i), sizeof(f1));
            strncpy (f2, m_name (j), sizeof(f2));
            if (does_exist (mp, j)) {
                if (verbosw)
                    printf ("message %d becomes message %d\n", j, i);

                if (rename (f2, f1) == NOTOK)
                    admonish (f1, "unable to rename %s to", f2);

                (void)snprintf(f1, sizeof (f1), "%s/%d", maildir, i);
                (void)snprintf(f2, sizeof (f2), "%s/%d", maildir, j);
                ext_hook("ref-hook", f1, f2);

                copy_msg_flags (mp, i, j);
                clear_msg_flags (mp, j);
                mp->msgflags |= SEQMOD;
            }
        }
    }
    
    unset_selected (mp, msgnum);

    /* new hghmsg is hghmsg + numburst
     *
     * At this point, there is an array of numburst smsgs, each element of
     * which contains the starting and stopping offsets (seeks) of the message
     * in the digest.  The inplace flag is set if the original digest is replaced
     * by a message containing the table of contents.  smsgs[0] is that table of
     * contents.  Go through the message numbers in reverse order (high to low).
     *
     * Set f1 to the name of the destination message, f2 to the name of a scratch
     * file.  Extract a message from the digest to the scratch file.  Move the
     * original message to a backup file if the destination message number is the
     * same as the number of the original message, which only happens if the
     * inplace flag is set.  Then move the scratch file to the destination message.
     *
     * Moving the original message to the backup file is equivalent to deleting the
     * message from the point of view of the external hooks.  And bursting each
     * message is equivalent to adding a new message.
     */

    i = inplace ? msgnum + numburst : mp->hghmsg;
    for (j = numburst; j >= (inplace ? 0 : 1); i--, j--) {
        char *tempfile;

        if ((tempfile = m_mktemp2(NULL, invo_name, NULL, &out)) == NULL) {
            adios(NULL, "unable to create temporary file in %s",
                  get_temp_dir());
        }
        strncpy (f2, tempfile, sizeof(f2));
        strncpy (f1, m_name (i), sizeof(f1));

        if (verbosw && i != msgnum)
            printf ("message %d of digest %d becomes message %d\n", j, msgnum, i);

        chmod (f2, mode);
        fseeko (in, smsgs[j].s_start, SEEK_SET);
        cpybrst (in, out, msgnam, f2,
                (int) (smsgs[j].s_stop - smsgs[j].s_start), mimesw);
        fclose (out);

        if (i == msgnum) {
            strncpy (f3, m_backup (f1), sizeof(f3));
            if (rename (f1, f3) == NOTOK)
                admonish (f3, "unable to rename %s to", f1);

            (void)snprintf(f3, sizeof (f3), "%s/%d", maildir, i);
            ext_hook("del-hook", f3, NULL);
        }
        if (rename (f2, f1) == NOTOK)
            admonish (f1, "unable to rename %s to", f2);

        (void)snprintf(f3, sizeof (f3), "%s/%d", maildir, i);
        ext_hook("add-hook", f3, NULL);

        copy_msg_flags (mp, i, msgnum);
        mp->msgflags |= SEQMOD;
    }

    fclose (in);
}


#define S1  0
#define S2  1
#define S3  2
#define S4  3

/*
 * Copy a message which is being burst out of a digest.
 * It will remove any "dashstuffing" in the message.
 */

static void
cpybrst (FILE *in, FILE *out, char *ifile, char *ofile, int len, int mime)
{
    int c, state;

    for (state = mime ? S4 : S1; (c = fgetc (in)) != EOF && len > 0; len--) {
        if (c == 0)
            continue;
        switch (state) {
            case S1: 
                switch (c) {
                    case '-': 
                        state = S3;
                        break;

                    default: 
                        state = S2;
                        /* FALLTHRU */
                    case '\n': 
                        fputc (c, out);
                        break;
                }
                break;

            case S2: 
                switch (c) {
                    case '\n': 
                        state = S1;
                        /* FALLTHRU */
                    default: 
                        fputc (c, out);
                        break;
                }
                break;

            case S3: 
                switch (c) {
                    case ' ': 
                        state = S2;
                        break;

                    default: 
                        state = (c == '\n') ? S1 : S2;
                        fputc ('-', out);
                        fputc (c, out);
                        break;
                }
                break;

            case S4:
                fputc (c, out);
                break;
        }
    }

    if (ferror (in) && !feof (in))
        adios (ifile, "error reading");
    if (ferror (out))
        adios (ofile, "error writing");
}