/* $FreeBSD$ */

#include <paths.h>

#include "EXTERN.h"
#include "common.h"
#include "INTERN.h"
#include "util.h"
#include "backupfile.h"

void	my_exit(int _status);		/* in patch.c */

#ifndef HAVE_STRERROR
static char *
private_strerror (errnum)
     int errnum;
{
  extern char *sys_errlist[];
  extern int sys_nerr;

  if (errnum > 0 && errnum <= sys_nerr)
    return sys_errlist[errnum];
  return "Unknown system error";
}
#define strerror private_strerror
#endif /* !HAVE_STRERROR */

/*
 * Rename a file, copying it if necessary.
 */
int
move_file(char *from, char *to)
{
	char bakname[512];
	Reg1 char *s;
	Reg2 int i;
	Reg3 int fromfd;

	/* to stdout? */

	if (strEQ(to, "-")) {
#ifdef DEBUGGING
		if (debug & 4)
			say2("Moving %s to stdout.\n", from);
#endif
		fromfd = open(from, 0);
		if (fromfd < 0)
			pfatal2("internal error, can't reopen %s", from);
		while ((i = read(fromfd, buf, buf_size)) > 0)
			if (write(1, buf, i) != 1)
				pfatal1("write failed");
		Close(fromfd);
		return 0;
	}

	if (origprae) {
		Strcpy(bakname, origprae);
		Strcat(bakname, to);
	} else {
#ifndef NODIR
		char *backupname = find_backup_file_name(to);
		if (backupname == (char *) 0)
		    fatal1("out of memory\n");
		Strcpy(bakname, backupname);
		free(backupname);
#else /* NODIR */
		Strcpy(bakname, to);
		Strcat(bakname, simple_backup_suffix);
#endif /* NODIR */
	}

	if (stat(to, &filestat) == 0) {	/* output file exists */
		dev_t to_device = filestat.st_dev;
		ino_t to_inode  = filestat.st_ino;
		char *simplename = bakname;

		for (s = bakname; *s; s++) {
			if (*s == '/')
				simplename = s + 1;
		}
		/*
		 * Find a backup name that is not the same file.
		 * Change the first lowercase char into uppercase;
		 * if that isn't sufficient, chop off the first char
		 * and try again.
		 */
		while (stat(bakname, &filestat) == 0 &&
		    to_device == filestat.st_dev &&
		    to_inode == filestat.st_ino) {
			/* Skip initial non-lowercase chars.  */
			for (s=simplename; *s && !islower((unsigned char)*s);
			    s++)
				;
			if (*s)
				*s = toupper((unsigned char)*s);
			else
				Strcpy(simplename, simplename + 1);
		}
		while (unlink(bakname) >= 0)
			;	/* while() is for benefit of Eunice */
#ifdef DEBUGGING
		if (debug & 4)
			say3("Moving %s to %s.\n", to, bakname);
#endif
		if (rename(to, bakname) < 0) {
			say4("Can't backup %s, output is in %s: %s\n", to, from,
			    strerror(errno));
			return -1;
		}
		while (unlink(to) >= 0)
			;
	}
#ifdef DEBUGGING
	if (debug & 4)
		say3("Moving %s to %s.\n", from, to);
#endif
	if (rename(from, to) < 0) {	/* different file system? */
		Reg4 int tofd;

		tofd = creat(to, 0666);
		if (tofd < 0) {
			say4("Can't create %s, output is in %s: %s\n",
			    to, from, strerror(errno));
			return -1;
		}
		fromfd = open(from, 0);
		if (fromfd < 0)
			pfatal2("internal error, can't reopen %s", from);
		while ((i = read(fromfd, buf, buf_size)) > 0)
			if (write(tofd, buf, i) != i)
				pfatal1("write failed");
		Close(fromfd);
		Close(tofd);
	}
	Unlink(from);
	return 0;
}

/*
 * Copy a file.
 */
void
copy_file(char *from, char *to)
{
	Reg3 int tofd;
	Reg2 int fromfd;
	Reg1 int i;

	tofd = creat(to, 0666);
	if (tofd < 0)
		pfatal2("can't create %s", to);
	fromfd = open(from, 0);
	if (fromfd < 0)
		pfatal2("internal error, can't reopen %s", from);
	while ((i = read(fromfd, buf, buf_size)) > 0)
		if (write(tofd, buf, i) != i)
			pfatal2("write to %s failed", to);
	Close(fromfd);
	Close(tofd);
}

/*
 * Allocate a unique area for a string.
 */
char *
savestr(char *s)
{
	Reg3 char *rv;
	Reg2 char *t;

	if (!s)
		s = "Oops";
	t = s;
	while (*t++)
		;
	rv = malloc((MEM) (t - s));
	if (rv == Nullch) {
		if (using_plan_a)
			out_of_mem = TRUE;
		else
			fatal1("out of memory\n");
	} else {
		t = rv;
		while ((*t++ = *s++));
	}
	return rv;
}

#if defined(lint) && defined(CANVARARG)

/*VARARGS ARGSUSED*/
say(pat) char *pat; { ; }
/*VARARGS ARGSUSED*/
fatal(pat) char *pat; { ; }
/*VARARGS ARGSUSED*/
pfatal(pat) char *pat; { ; }
/*VARARGS ARGSUSED*/
ask(pat) char *pat; { ; }

#else

/*
 * Vanilla terminal output (buffered).
 */
void
say(pat,arg1,arg2,arg3)
char *pat;
long arg1,arg2,arg3;
{
	fprintf(stderr, pat, arg1, arg2, arg3);
	Fflush(stderr);
}

/*
 * Terminal output, pun intended.
 */
void				/* very void */
fatal(pat,arg1,arg2,arg3)
char *pat;
long arg1,arg2,arg3;
{
	fprintf(stderr, "patch: **** ");
	fprintf(stderr, pat, arg1, arg2, arg3);
	my_exit(1);
}

/*
 * Say something from patch, something from the system, then silence...
 */
void				/* very void */
pfatal(pat,arg1,arg2,arg3)
char *pat;
long arg1,arg2,arg3;
{
	int errnum = errno;

	fprintf(stderr, "patch: **** ");
	fprintf(stderr, pat, arg1, arg2, arg3);
	fprintf(stderr, ": %s\n", strerror(errnum));
	my_exit(1);
}

/*
 * Get a response from the user, somehow or other.
 */
int
ask(pat,arg1,arg2,arg3)
char *pat;
long arg1,arg2,arg3;
{
	int ttyfd;
	int r;
	bool tty2 = isatty(2);

	Sprintf(buf, pat, arg1, arg2, arg3);
	Fflush(stderr);
	write(2, buf, strlen(buf));
	if (tty2) {			/* might be redirected to a file */
		r = read(2, buf, buf_size);
	} else if (isatty(1)) {		/* this may be new file output */
		Fflush(stdout);
		write(1, buf, strlen(buf));
		r = read(1, buf, buf_size);
	} else if ((ttyfd = open(_PATH_TTY, 2)) >= 0 && isatty(ttyfd)) {
					/* might be deleted or unwriteable */
		write(ttyfd, buf, strlen(buf));
		r = read(ttyfd, buf, buf_size);
		Close(ttyfd);
	} else if (isatty(0)) {		/* this is probably patch input */
		Fflush(stdin);
		write(0, buf, strlen(buf));
		r = read(0, buf, buf_size);
	} else {			/* no terminal at all--default it */
		buf[0] = '\n';
		buf[1] = 0;
		say1(buf);
		return 0;		/* signal possible error */
	}
	if (r <= 0)
		buf[0] = 0;
	else
		buf[r] = '\0';
	if (!tty2)
		say1(buf);

	if (r <= 0)
		return 0;		/* if there was an error, return it */
	else
		return 1;
}
#endif /* lint */

/*
 * How to handle certain events when not in a critical region.
 */
void
set_signals(int reset)
{
#ifndef lint
	static RETSIGTYPE (*hupval)(),(*intval)();

	if (!reset) {
		hupval = signal(SIGHUP, SIG_IGN);
		if (hupval != SIG_IGN)
			hupval = (RETSIGTYPE(*)())my_exit;
		intval = signal(SIGINT, SIG_IGN);
		if (intval != SIG_IGN)
			intval = (RETSIGTYPE(*)())my_exit;
	}
	Signal(SIGHUP, hupval);
	Signal(SIGINT, intval);
#endif
}

/*
 * How to handle certain events when in a critical region.
 */
void
ignore_signals(void)
{
#ifndef lint
	Signal(SIGHUP, SIG_IGN);
	Signal(SIGINT, SIG_IGN);
#endif
}

/*
 * Make sure we'll have the directories to create a file.
 * If `striplast' is TRUE, ignore the last element of `filename'.
 */
void
makedirs(filename,striplast)
Reg1 char *filename;
bool striplast;
{
	char tmpbuf[256];
	Reg2 char *s = tmpbuf;
	char *dirv[20];		/* Point to the NULs between elements.  */
	Reg3 int i;
	Reg4 int dirvp = 0;	/* Number of finished entries in dirv. */

	/*
	 * Copy `filename' into `tmpbuf' with a NUL instead of a slash
	 * between the directories.
	 */
	while (*filename) {
		if (*filename == '/') {
			filename++;
			dirv[dirvp++] = s;
			*s++ = '\0';
		} else {
			*s++ = *filename++;
		}
	}
	*s = '\0';
	dirv[dirvp] = s;
	if (striplast)
		dirvp--;
	if (dirvp < 0)
		return;

	strcpy(buf, "mkdir");
	s = buf;
	for (i = 0; i <= dirvp; i++) {
		struct stat sbuf;

		if (stat(tmpbuf, &sbuf) && errno == ENOENT) {
			while (*s)
				s++;
			*s++ = ' ';
			strcpy(s, tmpbuf);
		}
		*dirv[i] = '/';
	}
	if (s != buf)
		system(buf);
}

/*
 * Make filenames more reasonable.
 */
char *
fetchname(char *at, int strip_leading, int assume_exists)
{
	char *fullname;
	char *name;
	Reg1 char *t;
	char tmpbuf[200];
	int sleading = strip_leading;

	if (!at)
		return Nullch;
	while (isspace((unsigned char)*at))
		at++;
#ifdef DEBUGGING
	if (debug & 128)
		say4("fetchname %s %d %d\n",at,strip_leading,assume_exists);
#endif
	if (strnEQ(at, _PATH_DEVNULL, sizeof _PATH_DEVNULL - 1))
		/* So files can be created by diffing against /dev/null. */
		return Nullch;
	name = fullname = t = savestr(at);

	/* Strip off up to `sleading' leading slashes and null terminate. */
	for (; *t && !isspace((unsigned char)*t); t++)
		if (*t == '/')
			if (--sleading >= 0)
				name = t + 1;
	*t = '\0';

	/*
	 * If no -p option was given (957 is the default value!),
	 * we were given a relative pathname,
	 * and the leading directories that we just stripped off all exist,
	 * put them back on. 
	 */
	if (strip_leading == 957 && name != fullname && *fullname != '/') {
		name[-1] = '\0';
		if (stat(fullname, &filestat) == 0 &&
		    S_ISDIR(filestat.st_mode)) {
			name[-1] = '/';
			name = fullname;
		}
	}

	name = savestr(name);
	free(fullname);

	if (stat(name, &filestat) && !assume_exists) {
		char *filebase = basename(name);
		int pathlen = filebase - name;

		/* Put any leading path into `tmpbuf'. */
		strncpy(tmpbuf, name, pathlen);

#define try(f, a1, a2) \
    (Sprintf(tmpbuf + pathlen, f, a1, a2), stat(tmpbuf, &filestat) == 0)
		if (try("RCS/%s%s", filebase, RCSSUFFIX) ||
		    try("RCS/%s%s", filebase,        "") ||
		    try(    "%s%s", filebase, RCSSUFFIX) ||
		    try("SCCS/%s%s", SCCSPREFIX, filebase) ||
		    try(     "%s%s", SCCSPREFIX, filebase))
			return name;
		free(name);
		name = Nullch;
	}

	return name;
}

char *
xmalloc(unsigned int size)
{
	register char *p = (char *) malloc (size);
	if (!p)
		fatal("out of memory");
	return p;
}