/*      $OpenBSD: edit.c,v 1.21 2019/06/28 13:35:01 deraadt Exp $       */
/*      $NetBSD: edit.c,v 1.5 1996/06/08 19:48:20 christos 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/types.h>
#include <sys/wait.h>

#include "rcv.h"
#include <errno.h>
#include <fcntl.h>
#include "extern.h"

int editit(const char *, const char *);

/*
 * Mail -- a mail program
 *
 * Perform message editing functions.
 */

/*
 * Edit a message list.
 */
int
editor(void *v)
{
        int *msgvec = v;

        return(edit1(msgvec, 'e'));
}

/*
 * Invoke the visual editor on a message list.
 */
int
visual(void *v)
{
        int *msgvec = v;

        return(edit1(msgvec, 'v'));
}

/*
 * Edit a message by writing the message into a funnily-named file
 * (which should not exist) and forking an editor on it.
 * We get the editor from the stuff above.
 */
int
edit1(int *msgvec, int type)
{
        int nl = 0, c, i;
        FILE *fp;
        struct sigaction oact;
        sigset_t oset;
        struct message *mp;
        off_t size;

        /*
         * Deal with each message to be edited . . .
         */
        for (i = 0; msgvec[i] && i < msgCount; i++) {
                if (i > 0) {
                        char buf[100];
                        char *p;

                        printf("Edit message %d [ynq]? ", msgvec[i]);
                        if (fgets(buf, sizeof(buf), stdin) == NULL)
                                break;
                        for (p = buf; *p == ' ' || *p == '\t'; p++)
                                ;
                        if (*p == 'q')
                                break;
                        if (*p == 'n')
                                continue;
                }
                dot = mp = &message[msgvec[i] - 1];
                touch(mp);
                (void)ignoresig(SIGINT, &oact, &oset);
                fp = run_editor(setinput(mp), (off_t)mp->m_size, type, readonly);
                if (fp != NULL) {
                        (void)fseek(otf, 0L, SEEK_END);
                        size = ftell(otf);
                        mp->m_block = blockof(size);
                        mp->m_offset = offsetof(size);
                        mp->m_size = fsize(fp);
                        mp->m_lines = 0;
                        mp->m_flag |= MODIFY;
                        rewind(fp);
                        while ((c = getc(fp)) != EOF) {
                                if (c == '\n') {
                                        mp->m_lines++;
                                        nl++;
                                } else
                                        nl = 0;
                                if (putc(c, otf) == EOF)
                                        break;
                        }
                        for (; nl < 2; nl++) {
                                mp->m_lines++;
                                mp->m_size++;
                                putc('\n', otf);
                        }
                        if (ferror(otf))
                                warn("%s", tmpdir);
                        (void)Fclose(fp);
                }
                (void)sigprocmask(SIG_SETMASK, &oset, NULL);
                (void)sigaction(SIGINT, &oact, NULL);
        }
        return(0);
}

/*
 * Run an editor on the file at "fpp" of "size" bytes,
 * and return a new file pointer.
 * Signals must be handled by the caller.
 * "Type" is 'e' for _PATH_EX, 'v' for _PATH_VI.
 */
FILE *
run_editor(FILE *fp, off_t size, int type, int readonly)
{
        FILE *nf = NULL;
        int t;
        time_t modtime;
        char *edit, tempname[PATHSIZE];
        struct stat statb;

        (void)snprintf(tempname, sizeof(tempname),
            "%s/mail.ReXXXXXXXXXX", tmpdir);
        if ((t = mkstemp(tempname)) == -1 ||
            (nf = Fdopen(t, "w")) == NULL) {
                warn("%s", tempname);
                goto out;
        }
        if (readonly && fchmod(t, 0400) == -1) {
                warn("%s", tempname);
                (void)rm(tempname);
                goto out;
        }
        if (size >= 0)
                while (--size >= 0 && (t = getc(fp)) != EOF)
                        (void)putc(t, nf);
        else
                while ((t = getc(fp)) != EOF)
                        (void)putc(t, nf);
        (void)fflush(nf);
        if (fstat(fileno(nf), &statb) == -1)
                modtime = 0;
        else
                modtime = statb.st_mtime;
        if (ferror(nf)) {
                (void)Fclose(nf);
                warn("%s", tempname);
                (void)rm(tempname);
                nf = NULL;
                goto out;
        }
        if (Fclose(nf) < 0) {
                warn("%s", tempname);
                (void)rm(tempname);
                nf = NULL;
                goto out;
        }
        nf = NULL;
        if (type == 'e') {
                edit = value("EDITOR");
                if (edit == NULL || edit[0] == '\0')
                        edit = _PATH_EX;
        } else {
                edit = value("VISUAL");
                if (edit == NULL || edit[0] == '\0')
                        edit = _PATH_VI;
        }
        if (editit(edit, tempname) == -1) {
                (void)rm(tempname);
                goto out;
        }
        /*
         * If in read only mode or file unchanged, just remove the editor
         * temporary and return.
         */
        if (readonly) {
                (void)rm(tempname);
                goto out;
        }
        if (stat(tempname, &statb) == -1) {
                warn("%s", tempname);
                goto out;
        }
        if (modtime == statb.st_mtime) {
                (void)rm(tempname);
                goto out;
        }
        /*
         * Now switch to new file.
         */
        if ((nf = Fopen(tempname, "a+")) == NULL) {
                warn("%s", tempname);
                (void)rm(tempname);
                goto out;
        }
        (void)rm(tempname);
out:
        return(nf);
}

/*
 * Execute an editor on the specified pathname, which is interpreted
 * from the shell.  This means flags may be included.
 *
 * Returns -1 on error, or the exit value on success.
 */
int
editit(const char *ed, const char *pathname)
{
        char *argp[] = {"sh", "-c", NULL, NULL}, *p;
        sig_t sighup, sigint, sigquit, sigchld;
        pid_t pid;
        int saved_errno, st, ret = -1;

        if (ed == NULL)
                ed = getenv("VISUAL");
        if (ed == NULL || ed[0] == '\0')
                ed = getenv("EDITOR");
        if (ed == NULL || ed[0] == '\0')
                ed = _PATH_VI;
        if (asprintf(&p, "%s %s", ed, pathname) == -1)
                return (-1);
        argp[2] = p;

        sighup = signal(SIGHUP, SIG_IGN);
        sigint = signal(SIGINT, SIG_IGN);
        sigquit = signal(SIGQUIT, SIG_IGN);
        sigchld = signal(SIGCHLD, SIG_DFL);
        if ((pid = fork()) == -1)
                goto fail;
        if (pid == 0) {
                execv(_PATH_BSHELL, argp);
                _exit(127);
        }
        while (waitpid(pid, &st, 0) == -1)
                if (errno != EINTR)
                        goto fail;
        if (!WIFEXITED(st))
                errno = EINTR;
        else
                ret = WEXITSTATUS(st);

 fail:
        saved_errno = errno;
        (void)signal(SIGHUP, sighup);
        (void)signal(SIGINT, sigint);
        (void)signal(SIGQUIT, sigquit);
        (void)signal(SIGCHLD, sigchld);
        free(p);
        errno = saved_errno;
        return (ret);
}