/*      $OpenBSD: main.c,v 1.43 2021/10/24 21:24:17 deraadt Exp $       */

/*-
 * Copyright (c) 1992, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *      Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <bitstring.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "common.h"
#include "../vi/vi.h"

#ifdef DEBUG
static void      attach(GS *);
#endif
static int       v_obsolete(char *[]);

enum pmode pmode;

/*
 * editor --
 *      Main editor routine.
 *
 * PUBLIC: int editor(GS *, int, char *[]);
 */
int
editor(GS *gp, int argc, char *argv[])
{
        extern int optind;
        extern char *optarg;
        const char *p;
        EVENT ev;
        FREF *frp;
        SCR *sp;
        size_t len;
        u_int flags;
        int ch, flagchk, secure, startup, readonly, rval, silent;
        char *tag_f, *wsizearg, path[256];

        static const char *optstr[3] = {
#ifdef DEBUG
                "c:D:FlRrSsT:t:vw:",
                "c:D:eFlRrST:t:w:",
                "c:D:eFlrST:t:w:"
#else
                "c:FlRrSst:vw:",
                "c:eFlRrSt:w:",
                "c:eFlrSt:w:"
#endif
        };

        if (pledge("stdio rpath wpath cpath fattr flock getpw tty proc exec",
            NULL) == -1) {
                perror("pledge");
                goto err;
        }

        /* Initialize the busy routine, if not defined by the screen. */
        if (gp->scr_busy == NULL)
                gp->scr_busy = vs_busy;
        /* Initialize the message routine, if not defined by the screen. */
        if (gp->scr_msg == NULL)
                gp->scr_msg = vs_msg;

        /* Common global structure initialization. */
        TAILQ_INIT(&gp->dq);
        TAILQ_INIT(&gp->hq);
        LIST_INIT(&gp->ecq);
        LIST_INSERT_HEAD(&gp->ecq, &gp->excmd, q);
        gp->noprint = DEFAULT_NOPRINT;

        /* Structures shared by screens so stored in the GS structure. */
        TAILQ_INIT(&gp->frefq);
        TAILQ_INIT(&gp->dcb_store.textq);
        LIST_INIT(&gp->cutq);
        LIST_INIT(&gp->seqq);

        /* Set initial screen type and mode based on the program name. */
        readonly = 0;
        if (!strcmp(getprogname(), "ex") || !strcmp(getprogname(), "nex"))
                LF_INIT(SC_EX);
        else {
                /* Nview, view are readonly. */
                if (!strcmp(getprogname(), "nview") ||
                    !strcmp(getprogname(), "view"))
                        readonly = 1;
                
                /* Vi is the default. */
                LF_INIT(SC_VI);
        }

        /* Convert old-style arguments into new-style ones. */
        if (v_obsolete(argv))
                return (1);

        /* Parse the arguments. */
        flagchk = '\0';
        tag_f = wsizearg = NULL;
        secure = silent = 0;
        startup = 1;

        /* Set the file snapshot flag. */
        F_SET(gp, G_SNAPSHOT);

        pmode = MODE_EX;
        if (!strcmp(getprogname(), "ex"))
                pmode = MODE_EX;
        else if (!strcmp(getprogname(), "vi"))
                pmode = MODE_VI;
        else if (!strcmp(getprogname(), "view"))
                pmode = MODE_VIEW;

        while ((ch = getopt(argc, argv, optstr[pmode])) != -1)
                switch (ch) {
                case 'c':               /* Run the command. */
                        /*
                         * XXX
                         * We should support multiple -c options.
                         */
                        if (gp->c_option != NULL) {
                                warnx("only one -c command may be specified.");
                                return (1);
                        }
                        gp->c_option = optarg;
                        break;
#ifdef DEBUG
                case 'D':
                        switch (optarg[0]) {
                        case 's':
                                startup = 0;
                                break;
                        case 'w':
                                attach(gp);
                                break;
                        default:
                                warnx("-D requires s or w argument.");
                                return (1);
                        }
                        break;
#endif
                case 'e':               /* Ex mode. */
                        LF_CLR(SC_VI);
                        LF_SET(SC_EX);
                        break;
                case 'F':               /* No snapshot. */
                        F_CLR(gp, G_SNAPSHOT);
                        break;
                case 'R':               /* Readonly. */
                        readonly = 1;
                        break;
                case 'r':               /* Recover. */
                        if (flagchk == 't') {
                                warnx(
                                    "only one of -r and -t may be specified.");
                                return (1);
                        }
                        flagchk = 'r';
                        break;
                case 'S':
                        secure = 1;
                        break;
                case 's':
                        silent = 1;
                        break;
#ifdef DEBUG
                case 'T':               /* Trace. */
                        if ((gp->tracefp = fopen(optarg, "w")) == NULL) {
                                warn("%s", optarg);
                                goto err;
                        }
                        (void)fprintf(gp->tracefp,
                            "\n===\ntrace: open %s\n", optarg);
                        fflush(gp->tracefp);
                        break;
#endif
                case 't':               /* Tag. */
                        if (flagchk == 'r') {
                                warnx(
                                    "only one of -r and -t may be specified.");
                                return (1);
                        }
                        if (flagchk == 't') {
                                warnx("only one tag file may be specified.");
                                return (1);
                        }
                        flagchk = 't';
                        tag_f = optarg;
                        break;
                case 'v':               /* Vi mode. */
                        LF_CLR(SC_EX);
                        LF_SET(SC_VI);
                        break;
                case 'w':
                        wsizearg = optarg;
                        break;
                case '?':
                default:
                        (void)gp->scr_usage();
                        return (1);
                }
        argc -= optind;
        argv += optind;

        if (secure)
                if (pledge("stdio rpath wpath cpath fattr flock getpw tty", NULL) == -1) {
                        perror("pledge");
                        goto err;
                }

        /*
         * -s option is only meaningful to ex.
         *
         * If not reading from a terminal, it's like -s was specified.
         */
        if (silent && !LF_ISSET(SC_EX)) {
                warnx("-s option is only applicable to ex.");
                goto err;
        }
        if (LF_ISSET(SC_EX) && F_ISSET(gp, G_SCRIPTED))
                silent = 1;

        /*
         * Build and initialize the first/current screen.  This is a bit
         * tricky.  If an error is returned, we may or may not have a
         * screen structure.  If we have a screen structure, put it on a
         * display queue so that the error messages get displayed.
         *
         * !!!
         * Everything we do until we go interactive is done in ex mode.
         */
        if (screen_init(gp, NULL, &sp)) {
                if (sp != NULL)
                        TAILQ_INSERT_HEAD(&gp->dq, sp, q);
                goto err;
        }
        F_SET(sp, SC_EX);
        TAILQ_INSERT_HEAD(&gp->dq, sp, q);

        if (v_key_init(sp))             /* Special key initialization. */
                goto err;

        { int oargs[5], *oargp = oargs;
        if (readonly)                   /* Command-line options. */
                *oargp++ = O_READONLY;
        if (secure)
                *oargp++ = O_SECURE;
        *oargp = -1;                    /* Options initialization. */
        if (opts_init(sp, oargs))
                goto err;
        }
        if (wsizearg != NULL) {
                ARGS *av[2], a, b;
                (void)snprintf(path, sizeof(path), "window=%s", wsizearg);
                a.bp = (CHAR_T *)path;
                a.len = strlen(path);
                b.bp = NULL;
                b.len = 0;
                av[0] = &a;
                av[1] = &b;
                (void)opts_set(sp, av, NULL);
        }
        if (silent) {                   /* Ex batch mode option values. */
                O_CLR(sp, O_AUTOPRINT);
                O_CLR(sp, O_PROMPT);
                O_CLR(sp, O_VERBOSE);
                O_CLR(sp, O_WARN);
                F_SET(sp, SC_EX_SILENT);
        }

        sp->rows = O_VAL(sp, O_LINES);  /* Make ex formatting work. */
        sp->cols = O_VAL(sp, O_COLUMNS);

        if (!silent && startup) {       /* Read EXINIT, exrc files. */
                if (ex_exrc(sp))
                        goto err;
                if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE)) {
                        if (screen_end(sp))
                                goto err;
                        goto done;
                }
        }

        /*
         * List recovery files if -r specified without file arguments.
         * Note, options must be initialized and startup information
         * read before doing this.
         */
        if (flagchk == 'r' && argv[0] == NULL) {
                if (rcv_list(sp))
                        goto err;
                if (screen_end(sp))
                        goto err;
                goto done;
        }

        /*
         * !!!
         * Initialize the default ^D, ^U scrolling value here, after the
         * user has had every opportunity to set the window option.
         *
         * It's historic practice that changing the value of the window
         * option did not alter the default scrolling value, only giving
         * a count to ^D/^U did that.
         */
        sp->defscroll = (O_VAL(sp, O_WINDOW) + 1) / 2;

        /*
         * If we don't have a command-line option, switch into the right
         * editor now, so that we position default files correctly, and
         * so that any tags file file-already-locked messages are in the
         * vi screen, not the ex screen.
         *
         * XXX
         * If we have a command-line option, the error message can end
         * up in the wrong place, but I think that the combination is
         * unlikely.
         */
        if (gp->c_option == NULL) {
                F_CLR(sp, SC_EX | SC_VI);
                F_SET(sp, LF_ISSET(SC_EX | SC_VI));
        }

        /* Open a tag file if specified. */
        if (tag_f != NULL && ex_tag_first(sp, tag_f))
                goto err;

        /*
         * Append any remaining arguments as file names.  Files are recovery
         * files if -r specified.  If the tag option or ex startup commands
         * loaded a file, then any file arguments are going to come after it.
         */
        if (*argv != NULL) {
                if (sp->frp != NULL) {
                        size_t l;
                        /* Cheat -- we know we have an extra argv slot. */
                        l = strlen(sp->frp->name) + 1;
                        if ((*--argv = malloc(l)) == NULL) {
                                warn(NULL);
                                goto err;
                        }
                        (void)strlcpy(*argv, sp->frp->name, l);
                }
                sp->argv = sp->cargv = argv;
                F_SET(sp, SC_ARGNOFREE);
                if (flagchk == 'r')
                        F_SET(sp, SC_ARGRECOVER);
        }

        /*
         * If the ex startup commands and or/the tag option haven't already
         * created a file, create one.  If no command-line files were given,
         * use a temporary file.
         */
        if (sp->frp == NULL) {
                if (sp->argv == NULL) {
                        if ((frp = file_add(sp, NULL)) == NULL)
                                goto err;
                } else  {
                        if ((frp = file_add(sp, (CHAR_T *)sp->argv[0])) == NULL)
                                goto err;
                        if (F_ISSET(sp, SC_ARGRECOVER))
                                F_SET(frp, FR_RECOVER);
                }

                if (file_init(sp, frp, NULL, 0))
                        goto err;
                if (EXCMD_RUNNING(gp)) {
                        (void)ex_cmd(sp);
                        if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE)) {
                                if (screen_end(sp))
                                        goto err;
                                goto done;
                        }
                }
        }

        /*
         * Check to see if we need to wait for ex.  If SC_SCR_EX is set, ex
         * was forced to initialize the screen during startup.  We'd like to
         * wait for a single character from the user, but we can't because
         * we're not in raw mode.  We can't switch to raw mode because the
         * vi initialization will switch to xterm's alternate screen, causing
         * us to lose the messages we're pausing to make sure the user read.
         * So, wait for a complete line.  
         */
        if (F_ISSET(sp, SC_SCR_EX)) {
                p = msg_cmsg(sp, CMSG_CONT_R, &len);
                (void)write(STDOUT_FILENO, p, len);
                for (;;) {
                        if (v_event_get(sp, &ev, 0, 0))
                                goto err;
                        if (ev.e_event == E_INTERRUPT ||
                            (ev.e_event == E_CHARACTER &&
                            (ev.e_value == K_CR || ev.e_value == K_NL)))
                                break;
                        (void)gp->scr_bell(sp);
                }
        }

        /* Switch into the right editor, regardless. */
        F_CLR(sp, SC_EX | SC_VI);
        F_SET(sp, LF_ISSET(SC_EX | SC_VI) | SC_STATUS_CNT);

        /*
         * Main edit loop.  Vi handles split screens itself, we only return
         * here when switching editor modes or restarting the screen.
         */
        while (sp != NULL)
                if (F_ISSET(sp, SC_EX) ? ex(&sp) : vi(&sp))
                        goto err;

done:   rval = 0;
        if (0)
err:            rval = 1;

        /* Clean out the global structure. */
        v_end(gp);

        return (rval);
}

/*
 * v_end --
 *      End the program, discarding screens and most of the global area.
 *
 * PUBLIC: void v_end(GS *);
 */
void
v_end(GS *gp)
{
        MSGS *mp;
        SCR *sp;

        /* If there are any remaining screens, kill them off. */
        if (gp->ccl_sp != NULL) {
                (void)file_end(gp->ccl_sp, NULL, 1);
                (void)screen_end(gp->ccl_sp);
        }
        while ((sp = TAILQ_FIRST(&gp->dq)))
                (void)screen_end(sp);   /* Removes sp from the queue. */
        while ((sp = TAILQ_FIRST(&gp->hq)))
                (void)screen_end(sp);   /* Removes sp from the queue. */

#if defined(DEBUG) || defined(PURIFY)
        { FREF *frp;
                /* Free FREF's. */
                while ((frp = TAILQ_FIRST(&gp->frefq))) {
                        TAILQ_REMOVE(&gp->frefq, frp, q);
                        free(frp->name);
                        free(frp->tname);
                        free(frp);
                }
        }

        /* Free key input queue. */
        free(gp->i_event);

        /* Free cut buffers. */
        cut_close(gp);

        /* Free map sequences. */
        seq_close(gp);

        /* Free default buffer storage. */
        (void)text_lfree(&gp->dcb_store.textq);
#endif

        /* Ring the bell if scheduled. */
        if (F_ISSET(gp, G_BELLSCHED))
                (void)fprintf(stderr, "\07");           /* \a */

        /*
         * Flush any remaining messages.  If a message is here, it's almost
         * certainly the message about the event that killed us (although
         * it's possible that the user is sourcing a file that exits from the
         * editor).
         */
        while ((mp = LIST_FIRST(&gp->msgq)) != NULL) {
                (void)fprintf(stderr, "%s%.*s",
                    mp->mtype == M_ERR ? "ex/vi: " : "", (int)mp->len, mp->buf);
                LIST_REMOVE(mp, q);
#if defined(DEBUG) || defined(PURIFY)
                free(mp->buf);
                free(mp);
#endif
        }

#if defined(DEBUG) || defined(PURIFY)
        /* Free any temporary space. */
        free(gp->tmp_bp);

#if defined(DEBUG)
        /* Close debugging file descriptor. */
        if (gp->tracefp != NULL)
                (void)fclose(gp->tracefp);
#endif
#endif
}

/*
 * v_obsolete --
 *      Convert historic arguments into something getopt(3) will like.
 */
static int
v_obsolete(char *argv[])
{
        size_t len;
        char *p;

        /*
         * Translate old style arguments into something getopt will like.
         * Make sure it's not text space memory, because ex modifies the
         * strings.
         *      Change "+" into "-c$".
         *      Change "+<anything else>" into "-c<anything else>".
         *      Change "-" into "-s"
         *      The c, T, t and w options take arguments so they can't be
         *          special arguments.
         *
         * Stop if we find "--" as an argument, the user may want to edit
         * a file named "+foo".
         */
        while (*++argv && strcmp(argv[0], "--"))
                if (argv[0][0] == '+') {
                        if (argv[0][1] == '\0') {
                                argv[0] = strdup("-c$");
                                if (argv[0] == NULL)
                                        goto nomem;
                        } else  {
                                p = argv[0];
                                len = strlen(argv[0]);
                                if ((argv[0] = malloc(len + 2)) == NULL)
                                        goto nomem;
                                argv[0][0] = '-';
                                argv[0][1] = 'c';
                                (void)strlcpy(argv[0] + 2, p + 1, len);
                        }
                } else if (argv[0][0] == '-') {
                        if (argv[0][1] == '\0') {
                                argv[0] = strdup("-s");
                                if (argv[0] == NULL) {
nomem:                                  warn(NULL);
                                        return (1);
                                }
                        } else
                                if ((argv[0][1] == 'c' || argv[0][1] == 'T' ||
                                    argv[0][1] == 't' || argv[0][1] == 'w') &&
                                    argv[0][2] == '\0')
                                        ++argv;
                }
        return (0);
}

#ifdef DEBUG
static void
attach(GS *gp)
{
        int fd;
        char ch;

        if ((fd = open(_PATH_TTY, O_RDONLY)) < 0) {
                warn("%s", _PATH_TTY);
                return;
        }

        (void)printf("process %ld waiting, enter <CR> to continue: ",
            (long)getpid());
        (void)fflush(stdout);

        do {
                if (read(fd, &ch, 1) != 1) {
                        (void)close(fd);
                        return;
                }
        } while (ch != '\n' && ch != '\r');
        (void)close(fd);
}
#endif