/*
 * Copyright (C) 1984-2012  Mark Nudelman
 * Modified for use with illumos by Garrett D'Amore.
 * Copyright 2014 Garrett D'Amore <garrett@damore.org>
 *
 * You may distribute under the terms of either the GNU General Public
 * License or the Less License, as specified in the README file.
 *
 * For more information, see the README file.
 */

/*
 * Entry point, initialization, miscellaneous routines.
 */

#include <sys/types.h>

#include <libgen.h>
#include <stdarg.h>

#include "less.h"

char    *every_first_cmd = NULL;
int     new_file;
int     is_tty;
IFILE   curr_ifile = NULL;
IFILE   old_ifile = NULL;
struct scrpos initial_scrpos;
int     any_display = FALSE;
off_t   start_attnpos = -1;
off_t   end_attnpos = -1;
int     wscroll;

static char     *progname;

int     quitting;
int     secure;
int     dohelp;

int logfile = -1;
int force_logfile = FALSE;
char *namelogfile = NULL;
char *editor;
char *editproto;

extern char     *tags;
extern char     *tagoption;
extern int      jump_sline;
extern int      less_is_more;
extern int      missing_cap;
extern int      know_dumb;
extern int      quit_if_one_screen;
extern int      quit_at_eof;
extern int      pr_type;
extern int      hilite_search;
extern int      no_init;
extern int      top_scroll;
extern int      errmsgs;


/*
 * Entry point.
 */
int
main(int argc, char *argv[])
{
        IFILE ifile;
        char *s;

        progname = basename(argv[0]);
        argv++;
        argc--;

        /*
         * If the name of the executable program is "more",
         * act like LESS_IS_MORE is set.  We have to set this as early
         * as possible for POSIX.
         */
        if (strcmp(progname, "more") == 0)
                less_is_more = 1;
        else {
                s = lgetenv("LESS_IS_MORE");
                if (s != NULL && *s != '\0')
                        less_is_more = 1;
        }

        secure = 0;
        s = lgetenv("LESSSECURE");
        if (s != NULL && *s != '\0')
                secure = 1;

        if (secure) {
                if (pledge("stdio rpath tty", NULL) == -1) {
                        perror("pledge");
                        exit(1);
                }
        } else {
                if (pledge("stdio rpath wpath cpath fattr proc exec tty", NULL) == -1) {
                        perror("pledge");
                        exit(1);
                }
        }

        /*
         * Process command line arguments and LESS environment arguments.
         * Command line arguments override environment arguments.
         */
        is_tty = isatty(1);
        get_term();
        init_cmds();
        init_charset();
        init_line();
        init_cmdhist();
        init_option();
        init_search();


        init_prompt();

        if (less_is_more) {
                /* this is specified by XPG */
                quit_at_eof = OPT_ON;

                /* more users don't like the warning */
                know_dumb = OPT_ON;

                /* default prompt is medium */
                pr_type = OPT_ON;

                /* do not highlight search terms */
                hilite_search = OPT_OFF;

                /* do not set init strings to terminal */
                no_init = OPT_ON;

                /* repaint from top of screen */
                top_scroll = OPT_OFF;
        }

        s = lgetenv(less_is_more ? "MORE" : "LESS");
        if (s != NULL)
                scan_option(estrdup(s), 1);

#define isoptstring(s)  (((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
        while (argc > 0 && (isoptstring(*argv) || isoptpending())) {
                s = *argv++;
                argc--;
                if (strcmp(s, "--") == 0)
                        break;
                scan_option(s, 0);
        }
#undef isoptstring

        if (isoptpending()) {
                /*
                 * Last command line option was a flag requiring a
                 * following string, but there was no following string.
                 */
                nopendopt();
                quit(QUIT_OK);
        }

        if (errmsgs) {
                quit(QUIT_ERROR);
        }
        if (less_is_more && quit_at_eof == OPT_ONPLUS) {
                extern int no_init;
                no_init = OPT_ON;
        }
        if (less_is_more && pr_type == OPT_ONPLUS) {
                extern int quiet;
                quiet = VERY_QUIET;
        }

        editor = lgetenv("VISUAL");
        if (editor == NULL || *editor == '\0') {
                editor = lgetenv("EDITOR");
                if (editor == NULL || *editor == '\0')
                        editor = EDIT_PGM;
        }
        editproto = lgetenv("LESSEDIT");
        if (editproto == NULL || *editproto == '\0')
                editproto = "%E ?lm+%lm. %f";

        /*
         * Call get_ifile with all the command line filenames
         * to "register" them with the ifile system.
         */
        ifile = NULL;
        if (dohelp)
                ifile = get_ifile(helpfile(), ifile);
        while (argc-- > 0) {
                char *filename;
                filename = shell_quote(*argv);
                if (filename == NULL)
                        filename = *argv;
                argv++;
                (void) get_ifile(filename, ifile);
                ifile = prev_ifile(NULL);
                free(filename);
        }
        /*
         * Set up terminal, etc.
         */
        if (!is_tty) {
                /*
                 * Output is not a tty.
                 * Just copy the input file(s) to output.
                 */
                if (nifile() == 0) {
                        if (edit_stdin() == 0)
                                cat_file();
                } else if (edit_first() == 0) {
                        do {
                                cat_file();
                        } while (edit_next(1) == 0);
                }
                quit(QUIT_OK);
        }

        if (missing_cap && !know_dumb)
                error("WARNING: terminal is not fully functional", NULL);
        init_mark();
        open_getchr();

        if (secure)
                if (pledge("stdio rpath tty", NULL) == -1) {
                        perror("pledge");
                        exit(1);
                }

        raw_mode(1);
        init_signals(1);

        /*
         * Select the first file to examine.
         */
        if (tagoption != NULL || strcmp(tags, "-") == 0) {
                /*
                 * A -t option was given.
                 * Verify that no filenames were also given.
                 * Edit the file selected by the "tags" search,
                 * and search for the proper line in the file.
                 */
                if (nifile() > 0) {
                        error("No filenames allowed with -t option", NULL);
                        quit(QUIT_ERROR);
                }
                findtag(tagoption);
                if (edit_tagfile())  /* Edit file which contains the tag */
                        quit(QUIT_ERROR);
                /*
                 * Search for the line which contains the tag.
                 * Set up initial_scrpos so we display that line.
                 */
                initial_scrpos.pos = tagsearch();
                if (initial_scrpos.pos == -1)
                        quit(QUIT_ERROR);
                initial_scrpos.ln = jump_sline;
        } else if (nifile() == 0) {
                if (edit_stdin())  /* Edit standard input */
                        quit(QUIT_ERROR);
        } else {
                if (edit_first())  /* Edit first valid file in cmd line */
                        quit(QUIT_ERROR);
        }

        init();
        commands();
        quit(QUIT_OK);
        return (0);
}

/*
 * Allocate memory.
 * Like calloc(), but never returns an error (NULL).
 */
void *
ecalloc(int count, unsigned int size)
{
        void *p;

        p = calloc(count, size);
        if (p != NULL)
                return (p);
        error("Cannot allocate memory", NULL);
        quit(QUIT_ERROR);
        return (NULL);
}

char *
easprintf(const char *fmt, ...)
{
        char *p = NULL;
        int rv;
        va_list ap;

        va_start(ap, fmt);
        rv = vasprintf(&p, fmt, ap);
        va_end(ap);

        if (rv == -1) {
                error("Cannot allocate memory", NULL);
                quit(QUIT_ERROR);
        }
        return (p);
}

char *
estrdup(const char *str)
{
        char *n;

        n = strdup(str);
        if (n == NULL) {
                error("Cannot allocate memory", NULL);
                quit(QUIT_ERROR);
        }
        return (n);
}

/*
 * Skip leading spaces in a string.
 */
char *
skipsp(char *s)
{
        while (*s == ' ' || *s == '\t')
                s++;
        return (s);
}

/*
 * See how many characters of two strings are identical.
 * If uppercase is true, the first string must begin with an uppercase
 * character; the remainder of the first string may be either case.
 */
int
sprefix(char *ps, char *s, int uppercase)
{
        int c;
        int sc;
        int len = 0;

        for (; *s != '\0'; s++, ps++) {
                c = *ps;
                if (uppercase) {
                        if (len == 0 && islower(c))
                                return (-1);
                        c = tolower(c);
                }
                sc = *s;
                if (len > 0)
                        sc = tolower(sc);
                if (c != sc)
                        break;
                len++;
        }
        return (len);
}

/*
 * Exit the program.
 */
void
quit(int status)
{
        static int save_status;

        /*
         * Put cursor at bottom left corner, clear the line,
         * reset the terminal modes, and exit.
         */
        if (status < 0)
                status = save_status;
        else
                save_status = status;
        quitting = 1;
        edit(NULL);
        if (!secure)
                save_cmdhist();
        if (any_display && is_tty)
                clear_bot();
        deinit();
        flush(1);
        raw_mode(0);
        exit(status);
}

char *
helpfile(void)
{
        return (less_is_more ? HELPDIR "/more.help" : HELPDIR "/less.help");
}