/*
 * Copyright (C) 1984-2011  Mark Nudelman
 *
 * 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 about less, or for information on how to 
 * contact the author, see the README file.
 */


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

#include "less.h"
#if MSDOS_COMPILER==WIN32C
#include <windows.h>
#endif

public char *	every_first_cmd = NULL;
public int	new_file;
public int	is_tty;
public IFILE	curr_ifile = NULL_IFILE;
public IFILE	old_ifile = NULL_IFILE;
public struct scrpos initial_scrpos;
public int	any_display = FALSE;
public POSITION	start_attnpos = NULL_POSITION;
public POSITION	end_attnpos = NULL_POSITION;
public int	wscroll;
public char *	progname;
public int	quitting;
public int	secure;
public int	dohelp;

#if LOGFILE
public int	logfile = -1;
public int	force_logfile = FALSE;
public char *	namelogfile = NULL;
#endif

#if EDITOR
public char *	editor;
public char *	editproto;
#endif

#if TAGS
extern char *	tags;
extern char *	tagoption;
extern int	jump_sline;
#endif

#ifdef WIN32
static char consoleTitle[256];
#endif

extern int	less_is_more;
extern int	missing_cap;
extern int	know_dumb;
extern int	quit_if_one_screen;
extern int	pr_type;


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

#ifdef __EMX__
	_response(&argc, &argv);
	_wildcard(&argc, &argv);
#endif

	progname = *argv++;
	argc--;

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

#ifdef WIN32
	if (getenv("HOME") == NULL)
	{
		/*
		 * If there is no HOME environment variable,
		 * try the concatenation of HOMEDRIVE + HOMEPATH.
		 */
		char *drive = getenv("HOMEDRIVE");
		char *path  = getenv("HOMEPATH");
		if (drive != NULL && path != NULL)
		{
			size_t len = strlen(drive) + strlen(path) + 6;
			char *env = (char *) ecalloc(len, sizeof(char));
			strlcpy(env, "HOME=", len);
			strlcat(env, drive, len);
			strlcat(env, path, len);
			putenv(env);
		}
	}
	GetConsoleTitle(consoleTitle, sizeof(consoleTitle)/sizeof(char));
#endif /* WIN32 */

	/*
	 * 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();

	/*
	 * If the name of the executable program is "more",
	 * act like LESS_IS_MORE is set.
	 */
	for (s = progname + strlen(progname);  s > progname;  s--)
	{
		if (s[-1] == PATHNAME_SEP[0])
			break;
	}
	if (strcmp(s, "more") == 0)
		less_is_more = 1;

	init_prompt();

	if (less_is_more) {
		scan_option("-G");
		scan_option("-L");
		scan_option("-X");
		scan_option("-c");
	}

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

#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);
	}
#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 (less_is_more && get_quit_at_eof())
		quit_if_one_screen = TRUE;

#if EDITOR
	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";
#endif

	/*
	 * Call get_ifile with all the command line filenames
	 * to "register" them with the ifile system.
	 */
	ifile = NULL_IFILE;
#if !SMALL
	if (dohelp)
		ifile = get_ifile(HELPFILE, ifile);
#endif /* !SMALL */
	while (argc-- > 0)
	{
		char *filename;
#if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
		/*
		 * Because the "shell" doesn't expand filename patterns,
		 * treat each argument as a filename pattern rather than
		 * a single filename.  
		 * Expand the pattern and iterate over the expanded list.
		 */
		struct textlist tlist;
		char *gfilename;
		
		gfilename = lglob(*argv++);
		init_textlist(&tlist, gfilename);
		filename = NULL;
		while ((filename = forw_textlist(&tlist, filename)) != NULL)
		{
			(void) get_ifile(filename, ifile);
			ifile = prev_ifile(NULL_IFILE);
		}
		free(gfilename);
#else
		filename = shell_quote(*argv);
		if (filename == NULL)
			filename = *argv;
		argv++;
		(void) get_ifile(filename, ifile);
		ifile = prev_ifile(NULL_IFILE);
#endif
	}
	/*
	 * Set up terminal, etc.
	 */
	if (!is_tty)
	{
		/*
		 * Output is not a tty.
		 * Just copy the input file(s) to output.
		 */
		SET_BINARY(1);
		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 && !less_is_more)
		error("WARNING: terminal is not fully functional", NULL_PARG);
	init_mark();
	open_getchr();
	raw_mode(1);
	init_signals(1);

	/*
	 * Select the first file to examine.
	 */
#if TAGS
	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_PARG);
			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 == NULL_POSITION)
			quit(QUIT_ERROR);
		initial_scrpos.ln = jump_sline;
	} else
#endif
	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);
	/*NOTREACHED*/
	return (0);
}

/*
 * Copy a string to a "safe" place
 * (that is, to a buffer allocated by calloc).
 */
	public char *
save(s)
	char *s;
{
	register char *p;
	size_t len = strlen(s) + 1;

	p = (char *) ecalloc(len, sizeof(char));
	strlcpy(p, s, len);
	return (p);
}

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

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

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

#if GNU_OPTIONS
/*
 * 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.
 */
	public int
sprefix(ps, s, uppercase)
	char *ps;
	char *s;
	int uppercase;
{
	register int c;
	register int sc;
	register int len = 0;

	for ( ;  *s != '\0';  s++, ps++)
	{
		c = *ps;
		if (uppercase)
		{
			if (len == 0 && ASCII_IS_LOWER(c))
				return (-1);
			if (ASCII_IS_UPPER(c))
				c = ASCII_TO_LOWER(c);
		}
		sc = *s;
		if (len > 0 && ASCII_IS_UPPER(sc))
			sc = ASCII_TO_LOWER(sc);
		if (c != sc)
			break;
		len++;
	}
	return (len);
}
#endif /* GNU_OPTIONS */

/*
 * Exit the program.
 */
	public void
quit(status)
	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((char*)NULL);
	save_cmdhist();
	if (any_display && is_tty)
		clear_bot();
	deinit();
	flush();
	raw_mode(0);
#if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
	/* 
	 * If we don't close 2, we get some garbage from
	 * 2's buffer when it flushes automatically.
	 * I cannot track this one down  RB
	 * The same bug shows up if we use ^C^C to abort.
	 */
	close(2);
#endif
#ifdef WIN32
	SetConsoleTitle(consoleTitle);
#endif
	close_getchr();
	exit(status);
}