/*      $NetBSD: main.c,v 1.32 2025/07/09 16:59:54 rillig Exp $ */

/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1980, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)main.c      8.2 (Berkeley) 4/20/95";
#else
__RCSID("$NetBSD: main.c,v 1.32 2025/07/09 16:59:54 rillig Exp $");
#endif
#endif /* not lint */

#define EXTERN
#include "rcv.h"
#undef EXTERN
#include <assert.h>
#include <util.h>

#include "extern.h"
#include "sig.h"

#ifdef USE_EDITLINE
#include "complete.h"
#endif
#include "format.h"
#ifdef MIME_SUPPORT
#include "mime.h"
#endif
#ifdef THREAD_SUPPORT
#include "thread.h"
#endif

/*
 * Mail -- a mail program
 *
 * Startup -- interface with user.
 */

__dead
static void
usage(void)
{
#ifdef MIME_SUPPORT
        (void)fputs("\
Usage: mail [-EiInv] [-r rcfile] [-s subject] [-a file] [-c cc-addr]\n\
            [-b bcc-addr] to-addr ... [- sendmail-options ...]\n\
       mail [-EiInNv] [-H[colon-modifier]] -f [name]\n\
       mail [-EiInNv] [-H[colon-modifier]] [-u user]\n",
                                stderr);
#else /* MIME_SUPPORT */
        (void)fputs("\
Usage: mail [-EiInv] [-r rcfile] [-s subject] [-c cc-addr] [-b bcc-addr]\n\
            to-addr ... [- sendmail-options ...]\n\
       mail [-EiInNv] [-H[colon-modifier]] -f [name]\n\
       mail [-EiInNv] [-H[colon-modifier]] [-u user]\n",
                                stderr);
#endif /* MIME_SUPPORT */
        exit(1);
}

/*
 * Compute what the screen size for printing headers should be.
 * We use the following algorithm for the height:
 *      If baud rate < 1200, use  9
 *      If baud rate = 1200, use 14
 *      If baud rate > 1200, use 24 or ws_row
 * Width is either 80 or ws_col;
 */
PUBLIC void
setscreensize(void)
{
        struct termios tbuf;
        struct winsize ws;
        speed_t ospeed;
        char *cp;

        if (ioctl(1, TIOCGWINSZ, &ws) < 0)
                ws.ws_col = ws.ws_row = 0;
        if (tcgetattr(1, &tbuf) < 0)
                ospeed = 9600;
        else
                ospeed = cfgetospeed(&tbuf);
        if (ospeed < 1200)
                screenheight = 9;
        else if (ospeed == 1200)
                screenheight = 14;
        else if (ws.ws_row != 0)
                screenheight = ws.ws_row;
        else
                screenheight = 24;
        if ((realscreenheight = ws.ws_row) == 0)
                realscreenheight = 24;
        if ((screenwidth = ws.ws_col) == 0)
                screenwidth = 80;
        /*
         * Possible overrides from the rcfile.
         */
        if ((cp = value(ENAME_SCREENWIDTH)) != NULL) {
                int width;
                width = *cp ? atoi(cp) : 0;
                if (width >= 0)
                        screenwidth = width;
        }
        if ((cp = value(ENAME_SCREENHEIGHT)) != NULL) {
                int height;
                height = *cp ? atoi(cp) : 0;
                if (height >= 0) {
                        realscreenheight = height;
                        screenheight = height;
                }
        }
}

/*
 * Break up a white-space or comma delimited name list so that aliases
 * can get expanded.  Without this, the CC: or BCC: list is broken too
 * late for alias expansion to occur.
 */
PUBLIC struct name *
lexpand(char *str, int ntype)
{
        char *list;
        struct name *np = NULL;
        char *word, *p;

        list = estrdup(str);
        word = list;
        for (word = list; *word; word = p) {
                word = skip_WSP(word);
                for (p = word;
                     *p && !is_WSP(*p) && *p != ',';
                     p++)
                        continue;
                if (*p)
                        *p++ = '\0';
                np = cat(np, nalloc(word, ntype));
        }

        free(list);
        return np;
}

PUBLIC int
main(int argc, char *argv[])
{
        jmp_buf jmpbuf;
        struct sigaction sa;
        struct name *to, *cc, *bcc, *smopts;
#ifdef MIME_SUPPORT
        struct name *attach_optargs;
        struct name *attach_end;
#endif
        char *subject;
        const char *ef;
        char nosrc = 0;
        const char *rc;
        int Hflag;
        int i;

        /*
         * For portability, call setprogname() early, before
         * getprogname() is called.
         */
        (void)setprogname(argv[0]);

        /*
         * Set up a reasonable environment.
         * Figure out whether we are being run interactively,
         * start the SIGCHLD catcher, and so forth.
         * (Other signals are setup later by sig_setup().)
         */
        (void)sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_RESTART;
        sa.sa_handler = sigchild;
        (void)sigaction(SIGCHLD, &sa, NULL);

        if (isatty(0))
                assign(ENAME_INTERACTIVE, "");
        image = -1;

        /*
         * Now, determine how we are being used.
         * We successively pick off - flags.
         * If there is anything left, it is the base of the list
         * of users to mail to.  Argp will be set to point to the
         * first of these users.
         */
        rc = NULL;
        ef = NULL;
        to = NULL;
        cc = NULL;
        bcc = NULL;
        smopts = NULL;
        subject = NULL;
        Hflag = 0;
#ifdef MIME_SUPPORT
        attach_optargs = NULL;
        attach_end = NULL;
        while ((i = getopt(argc, argv, ":~EH:INT:a:b:c:dfinr:s:u:v")) != -1)
#else
        while ((i = getopt(argc, argv, ":~EH:INT:b:c:dfinr:s:u:v")) != -1)
#endif
        {
                switch (i) {
                case 'T':
                        /*
                         * Next argument is temp file to write which
                         * articles have been read/deleted for netnews.
                         */
                        Tflag = optarg;
                        if ((i = creat(Tflag, 0600)) < 0) {
                                warn("%s", Tflag);
                                exit(1);
                        }
                        (void)close(i);
                        break;
#ifdef MIME_SUPPORT
                case 'a': {
                        struct name *np;
                        np = nalloc(optarg, 0);
                        if (attach_end == NULL)
                                attach_optargs = np;
                        else {
                                np->n_blink = attach_end;
                                attach_end->n_flink = np;
                        }
                        attach_end = np;
                        break;
                }
#endif
                case 'u':
                        /*
                         * Next argument is person to pretend to be.
                         */
                        myname = optarg;
                        (void)unsetenv("MAIL");
                        break;
                case 'i':
                        /*
                         * User wants to ignore interrupts.
                         * Set the variable "ignore"
                         */
                        assign(ENAME_IGNORE, "");
                        break;
                case 'd':
                        debug++;
                        break;
                case 'r':
                        rc = optarg;
                        break;
                case 's':
                        /*
                         * Give a subject field for sending from
                         * non terminal
                         */
                        subject = optarg;
                        break;
                case 'f':
                        /*
                         * User is specifying file to "edit" with Mail,
                         * as opposed to reading system mailbox.
                         * If no argument is given after -f, we read his
                         * mbox file.
                         *
                         * getopt() can't handle optional arguments, so here
                         * is an ugly hack to get around it.
                         */
                        if ((argv[optind]) && (argv[optind][0] != '-'))
                                ef = argv[optind++];
                        else
                                ef = "&";
                        break;
                case 'H':
                        /*
                         * Print out the headers and quit.
                         */
                        Hflag = get_Hflag(argv);
                        break;
                case 'n':
                        /*
                         * User doesn't want to source /usr/lib/Mail.rc
                         */
                        nosrc++;
                        break;
                case 'N':
                        /*
                         * Avoid initial header printing.
                         */
                        assign(ENAME_NOHEADER, "");
                        break;
                case 'v':
                        /*
                         * Send mailer verbose flag
                         */
                        assign(ENAME_VERBOSE, "");
                        break;
                case 'I':
                case '~':
                        /*
                         * We're interactive
                         */
                        assign(ENAME_INTERACTIVE, "");
                        break;
                case 'c':
                        /*
                         * Get Carbon Copy Recipient list
                         */
                        cc = cat(cc, lexpand(optarg, GCC));
                        break;
                case 'b':
                        /*
                         * Get Blind Carbon Copy Recipient list
                         */
                        bcc = cat(bcc, lexpand(optarg, GBCC));

                        break;
                case 'E':
                        /*
                         * Don't send empty files.
                         */
                        assign(ENAME_DONTSENDEMPTY, "");
                        break;
                case ':':
                        /*
                         * An optarg was expected but not found.
                         */
                        if (optopt == 'H') {
                                Hflag = get_Hflag(NULL);
                                break;
                        }
                        (void)fprintf(stderr,
                            "%s: option requires an argument -- %c\n",
                            getprogname(), optopt);

                        /* FALLTHROUGH */
                case '?':
                        /*
                         * An unknown option flag.  We need to do the
                         * error message.
                         */
                        if (optopt != '?')
                                (void)fprintf(stderr,
                                    "%s: unknown option -- %c\n", getprogname(),
                                    optopt);
                        usage();        /* print usage message and die */
                        /*NOTREACHED*/
                }
        }
        for (i = optind; (argv[i]) && (*argv[i] != '-'); i++)
                to = cat(to, nalloc(argv[i], GTO));
        for (/*EMPTY*/; argv[i]; i++)
                smopts = cat(smopts, nalloc(argv[i], GSMOPTS));
        /*
         * Check for inconsistent arguments.
         */
        if (to == NULL && (subject != NULL || cc != NULL || bcc != NULL))
                errx(EXIT_FAILURE, "You must specify direct recipients with -s, -c, or -b.");
        if (ef != NULL && to != NULL) {
                errx(EXIT_FAILURE, "Cannot give -f and people to send to.");
        }
        if (Hflag != 0 && to != NULL)
                errx(EXIT_FAILURE, "Cannot give -H and people to send to.");
#ifdef MIME_SUPPORT
        if (attach_optargs != NULL && to == NULL)
                errx(EXIT_FAILURE, "Cannot give -a without people to send to.");
#endif
        tinit();        /* must be done before loading the rcfile */
        input = stdin;
        mailmode = Hflag ? mm_hdrsonly :
            to ? mm_sending : mm_receiving;

        spreserve();
        if (!nosrc)
                load(_PATH_MASTER_RC);
        /*
         * Expand returns a savestr, but load only uses the file name
         * for fopen, so it's safe to do this.
         */
        if (rc == NULL && (rc = getenv("MAILRC")) == NULL)
                rc = "~/.mailrc";
        load(expand(rc));
        setscreensize();        /* do this after loading the rcfile */

#ifdef USE_EDITLINE
        /*
         * This is after loading the MAILRC so we can use value().
         * Avoid editline in mm_hdrsonly mode or pipelines will screw
         * up.  XXX - there must be a better way!
         */
        if (mailmode != mm_hdrsonly)
                init_editline();
#endif

        sig_setup();

        switch (mailmode) {
        case mm_sending:
                (void)mail(to, cc, bcc, smopts, subject,
                    mime_attach_optargs(attach_optargs));
                /*
                 * why wait?
                 */
                exit(senderr);

        case mm_receiving:
        case mm_hdrsonly:
                /*
                 * Ok, we are reading mail.
                 * Decide whether we are editing a mailbox or reading
                 * the system mailbox, and open up the right stuff.
                 */
                if (ef == NULL)
                        ef = "%";
                if (setfile(ef) < 0)
                        exit(1);                /* error already reported */
                if (value(ENAME_QUIET) == NULL)
                        (void)printf("Mail version %s.  Type ? for help.\n",
                            version);
                if (mailmode == mm_hdrsonly)
                        show_headers_and_exit(Hflag);   /* NORETURN */
                announce();
                (void)fflush(stdout);

                if (setjmp(jmpbuf) != 0) {
                        /* Return here if quit() fails below. */
                        (void)printf("Use 'exit' to quit without saving changes.\n");
                }
                commands();

                /* Ignore these signals from now on! */
                (void)signal(SIGHUP, SIG_IGN);
                (void)signal(SIGINT, SIG_IGN);
                (void)signal(SIGQUIT, SIG_IGN);
                quit(jmpbuf);
                break;

        default:
                assert(/*CONSTCOND*/0);
                break;
        }

        return 0;
}