#! /usr/bin/perl -w
#
# zip file archive Virtual File System for Midnight Commander
# Version 1.4.0 (2001-08-07).
#
# (C) 2000-2001  Oskar Liljeblad <osk@hem.passagen.se>.
#

use POSIX;
use File::Basename;
use strict;

#
# Configuration options
#

# Location of the zip program
my $app_zip = "/usr/bin/zip";
# Location of the unzip program
my $app_unzip = "/usr/local/bin/unzip";
# Set this to 1 if zipinfo (unzip -Z) is to be used (recommended), otherwise 0.
my $op_has_zipinfo = 1;

# Command used to list archives (zipinfo mode)
my $cmd_list_zi = "$app_unzip -Z -l -T";
# Command used to list archives (non-zipinfo mode)
my $cmd_list_nzi = "$app_unzip -qq -v";
# Command used to add a file to the archive
my $cmd_add = "$app_zip -g";
# Command used to add a link file to the archive (unused)
my $cmd_addlink = "$app_zip -g -y";
# Command used to delete a file from the archive
my $cmd_delete = "$app_zip -d";
# Command used to extract a file to standard out
my $cmd_extract = "$app_unzip -p";

#
# Main code
#

die "uzip: missing command and/or archive arguments\n" if ($#ARGV < 1);

# Initialization of some global variables
my $cmd = shift;
my %known = ( './' => 1 );
my %pending = ();
my $oldpwd = POSIX::getcwd();
my $archive = shift;
my $aarchive = absolutize($archive, $oldpwd);
my $cmd_list = ($op_has_zipinfo ? $cmd_list_zi : $cmd_list_nzi);
my ($qarchive, $aqarchive) = map (quotemeta, $archive, $aarchive);

if ($cmd eq 'list')    { &mczipfs_list(@ARGV); }
if ($cmd eq 'rm')      { &mczipfs_rm(@ARGV); }
if ($cmd eq 'rmdir')   { &mczipfs_rmdir(@ARGV); }
if ($cmd eq 'mkdir')   { &mczipfs_mkdir(@ARGV); }
if ($cmd eq 'copyin')  { &mczipfs_copyin(@ARGV); }
if ($cmd eq 'copyout') { &mczipfs_copyout(@ARGV); }
if ($cmd eq 'run')		 { &mczipfs_run(@ARGV); }
#if ($cmd eq 'mklink')  { &mczipfs_mklink(@ARGV); }		# Not supported by MC extfs
#if ($cmd eq 'linkout') { &mczipfs_linkout(@ARGV); }	# Not supported by MC extfs
exit 1;

# Remove a file from the archive.
sub mczipfs_rm {
	my ($qfile) = map { &zipquotemeta($_) } @_;
	&checkargs(1, 'archive file', @_);
	&safesystem("$cmd_delete $qarchive $qfile >/dev/null");
	exit;
}

# Remove an empty directory from the archive.
# The only difference from mczipfs_rm is that we append an 
# additional slash to the directory name to remove. I am not
# sure this is absolutely necessary, but it doesn't hurt.
sub mczipfs_rmdir {
	my ($qfile) = map { &zipquotemeta($_) } @_;
	&checkargs(1, 'archive directory', @_);
	&safesystem("$cmd_delete $qarchive $qfile/ >/dev/null", 12);
  exit;
}

# Extract a file from the archive.
# Note that we don't need to check if the file is a link,
# because mc apparently doesn't call copyout for symbolic links.
sub mczipfs_copyout {
	my ($qafile, $qfsfile) = map { &zipquotemeta($_) } @_;
	&checkargs(1, 'archive file', @_);
	&checkargs(2, 'local file', @_);
	&safesystem("$cmd_extract $qarchive $qafile > $qfsfile", 11);
  exit;
}

# Add a file to the archive.
# This is done by making a temporary directory, in which
# we create a symlink the original file (with a new name).
# Zip is then run to include the real file in the archive,
# with the name of the symbolic link.
# Here we also doesn't need to check for symbolic links,
# because the mc extfs doesn't allow adding of symbolic
# links.
sub mczipfs_copyin {
	my ($afile, $fsfile) = @_;
	&checkargs(1, 'archive file', @_);
	&checkargs(2, 'local file', @_);
	my ($qafile) = quotemeta $afile;
	$fsfile = &absolutize($fsfile, $oldpwd);
	my $adir = File::Basename::dirname($afile);

	my $tmpdir = &mktmpdir();
	chdir $tmpdir || &croak("chdir $tmpdir failed");
	&mkdirs($adir, 0700);
	symlink ($fsfile, $afile) || &croak("link $afile failed");
	&safesystem("$cmd_add $aqarchive $qafile >/dev/null");
	unlink $afile || &croak("unlink $afile failed");
	&rmdirs($adir);
	chdir $oldpwd || &croak("chdir $oldpwd failed");
	rmdir $tmpdir || &croak("rmdir $tmpdir failed");
  exit;
}

# Add an empty directory the the archive.
# This is similar to mczipfs_copyin, except that we don't need
# to use symlinks.
sub mczipfs_mkdir {
	my ($dir) = @_;
	&checkargs(1, 'directory', @_);
	my ($qdir) = quotemeta $dir;

	my $tmpdir = &mktmpdir();
	chdir $tmpdir || &croak("chdir $tmpdir failed");
	&mkdirs($dir, 0700);
	&safesystem("$cmd_add $aqarchive $qdir >/dev/null");
	&rmdirs($dir);
	chdir $oldpwd || &croak("chdir $oldpwd failed");
	rmdir $tmpdir || &croak("rmdir $tmpdir failed");
  exit;
}

# Add a link to the archive. This operation is not used yet,
# because it is not supported by the MC extfs.
sub mczipfs_mklink {
	my ($linkdest, $afile) = @_;
	&checkargs(1, 'link destination', @_);
	&checkargs(2, 'archive file', @_);
	my ($qafile) = quotemeta $afile;
	my $adir = File::Basename::dirname($afile);

	my $tmpdir = &mktmpdir();
	chdir $tmpdir || &croak("chdir $tmpdir failed");
	&mkdirs($adir, 0700);
	symlink ($linkdest, $afile) || &croak("link $afile failed");
	&safesystem("$cmd_addlink $aqarchive $qafile >/dev/null");
	unlink $afile || &croak("unlink $afile failed");
	&rmdirs($adir);
	chdir $oldpwd || &croak("chdir $oldpwd failed");
	rmdir $tmpdir || &croak("rmdir $tmpdir failed");
  exit;
}

# This operation is not used yet, because it is not
# supported by the MC extfs.
sub mczipfs_linkout {
	my ($afile, $fsfile) = @_;
	&checkargs(1, 'archive file', @_);
	&checkargs(2, 'local file', @_);
	my ($qafile) = map { &zipquotemeta($_) } $afile;

	my $linkdest = &get_link_destination($afile);
	symlink ($linkdest, $fsfile) || &croak("link $fsfile failed");
  exit;
}

# Use unzip to find the link destination of a certain file in the
# archive.
sub get_link_destination {
	my ($afile) = @_;
	my ($qafile) = map { &zipquotemeta($_) } $afile;
	my $linkdest = safeticks("$cmd_extract $qarchive $qafile");
	&croak ("extract failed", "link destination of $afile not found")
			if (!defined $linkdest || $linkdest eq '');
	return $linkdest;
}

# List files in the archive.
# Because mc currently doesn't allow a file's parent directory
# to be listed after the file itself, we need to do some
# rearranging of the output. Most of this is done in
# checked_print_file.
sub mczipfs_list {
	open (PIPE, "$cmd_list $qarchive |") || &croak("$app_unzip failed");
	if ($op_has_zipinfo) {
		while (<PIPE>) {
			chomp;
			next if /^Archive:/;
			next if /^\d+ file/;
			next if /^Empty zipfile\.$/;
			my @match = /^(.{10}) +([\d.]+) +([a-z\d]+) +(\d+) +([^ ]{2}) +(\d+) +([^ ]{4}) +(\d{4})(\d\d)(\d\d)\.(\d\d)(\d\d)(\d\d) +(.*)$/;
			next if ($#match != 13);
			&checked_print_file(@match);
		}
	} else {
		while (<PIPE>) {
			chomp;
			my @match = /^ +(\d+) +([^ ]+) +(\d+) +(\d+\%) +(\d?\d)-(\d?\d)-(\d\d) (\d?\d):(\d\d) +([0-9a-f]+) +(.*)$/;
			next if ($#match != 10);
			my @rmatch = ('', '', 'unknown', $match[0], '', $match[2], $match[1],
					$match[6] + ($match[6] < 70 ? 2000 : 1900), $match[4], $match[5],
					$match[7], $match[8], "00", $match[10]);
			&checked_print_file(@rmatch);
		}
	}
	if (!close (PIPE)) {
		&croak("$app_unzip failed") if ($! != 0);
		&croak("$app_unzip failed", 'non-zero exit status ('.($? >> 8).')') 
	}

	foreach my $key (sort keys %pending) {
		foreach my $file (@{ $pending{$key} }) {
			&print_file(@{ $file });
		}
	}

  exit;
}

# Execute a file in the archive, by first extracting it to a
# temporary directory. The name of the extracted file will be
# the same as the name of it in the archive.
sub mczipfs_run {
	my ($afile) = @_;
	&checkargs(1, 'archive file', @_);
	my $qafile = &zipquotemeta($afile);
	my $tmpdir = &mktmpdir();
	my $tmpfile = File::Basename::basename($afile);

	chdir $tmpdir || &croak("chdir $tmpdir failed");
	&safesystem("$cmd_extract $aqarchive $qafile > $tmpfile");
  chmod 0700, $tmpfile;
	&safesystem("./$tmpfile");
	unlink $tmpfile || &croak("rm $tmpfile failed");
	chdir $oldpwd || &croak("chdir $oldpwd failed");
	rmdir $tmpdir || &croak("rmdir $tmpdir failed");
  exit;
}

# This is called prior to printing the listing of a file.
# A check is done to see if the parent directory of the file has already
# been printed or not. If it hasn't, we must cache it (in %pending) and
# print it later once the parent directory has been listed. When all
# files have been processed, there may still be some that haven't been 
# printed because their parent directories weren't listed at all. These
# files are dealt with in mczipfs_list.
sub checked_print_file {
	my @waiting = ([ @_ ]);

	while ($#waiting != -1) {
		my $item = shift @waiting;
		my $filename = ${$item}[13];
		my $dirname = File::Basename::dirname($filename) . '/';

		if (exists $known{$dirname}) {
			&print_file(@{$item});
			if ($filename =~ /\/$/) {
				$known{$filename} = 1;
				if (exists $pending{$filename}) {
					push @waiting, @{ $pending{$filename} };
					delete $pending{$filename};
				}
			}
		} else {
			push @{$pending{$dirname}}, $item;
		}
	}
}

# Print the mc extfs listing of a file from a set of parsed fields.
# If the file is a link, we extract it from the zip archive and
# include the output as the link destination. Because this output
# is not newline terminated, we must execute unzip once for each
# link file encountered.
sub print_file {
	my ($perms,$zipver,$platform,$realsize,$format,$cmpsize,$comp,$year,$mon,$day,$hours,$mins,$secs,$filename) = @_;
	$mon = (qw/Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec/)[$mon-1];
	if ($platform ne 'unx') {
		$perms = ($filename =~ /\/$/ ? 'drwxr-xr-x' : '-rw-r--r--');
	}
	printf "%-10s    1 %-8d %-8d %8d %s %s %s %s:%s %s", $perms, $<,
		$(, $realsize, $mon, $day, $year, $hours, $mins, $filename;
	if ($platform eq 'unx' && $perms =~ /^l/) {
		my $linkdest = &get_link_destination($filename);
		print " -> $linkdest";
	}
	print "\n";
}

# Die with a reasonable error message.
sub croak {
	my ($command, $desc) = @_;
	die "uzip ($cmd): $command - $desc\n" if (defined $desc);
	die "uzip ($cmd): $command - $!\n";
}

# Make a set of directories, like the command `mkdir -p'.
# This subroutine has been tailored for this script, and
# because of that, it ignored the directory name '.'.
sub mkdirs {
	my ($dirs, $mode) = @_;
	$dirs = &cleandirs($dirs);
	return if ($dirs eq '.');

	my $newpos = -1;
	while (($newpos = index($dirs, '/', $newpos+1)) != -1) {
		my $dir = substr($dirs, 0, $newpos);
		mkdir ($dir, $mode) || &croak("mkdir $dir failed");
	}
	mkdir ($dirs, $mode) || &croak("mkdir $dirs failed");
}

# Remove a set of directories, failing if the directories
# contain other files.
# This subroutine has been tailored for this script, and
# because of that, it ignored the directory name '.'.
sub rmdirs {
	my ($dirs) = @_;
	$dirs = &cleandirs($dirs);
	return if ($dirs eq '.');

	rmdir $dirs || &croak("rmdir $dirs failed");
	my $newpos = length($dirs);
	while (($newpos = rindex($dirs, '/', $newpos-1)) != -1) {
		my $dir = substr($dirs, 0, $newpos);
		rmdir $dir || &croak("rmdir $dir failed");
	}
}

# Return a semi-canonical directory name.
sub cleandirs {
	my ($dir) = @_;
	$dir =~ s:/+:/:g;
	$dir =~ s:/*$::;
	return $dir;
}

# Make a temporary directory with mode 0700.
sub mktmpdir {
	while (1) {
		my $dir = POSIX::tmpnam();
		return $dir if mkdir ($dir, 0700);
	}
}

# Make a filename absolute and return it.
sub absolutize {
	my ($file, $pwd) = @_;
	return "$pwd/$file" if ($file !~ /^\//);
	return $file;
}

# Like the system built-in function, but with error checking.
# The other argument is an exit status to allow.
sub safesystem {
	my ($command, @allowrc) = @_;
	my ($desc) = ($command =~ /^([^ ]*) */);
	$desc = File::Basename::basename($desc);
	system $command;
	my $rc = $?;
	&croak("`$desc' failed") if (($rc & 0xFF) != 0);
	if ($rc != 0) {
		$rc = $rc >> 8;
		foreach my $arc (@allowrc) {
			return if ($rc == $arc);
		}
		&croak("`$desc' failed", "non-zero exit status ($rc)");
	}
}

# Like backticks built-in, but with error checking.
sub safeticks {
	my ($command, @allowrc) = @_;
	my ($desc) = ($command =~ /^([^ ]*) /);
	$desc = File::Basename::basename($desc);
	my $out = `$command`;
	my $rc = $?;
	&croak("`$desc' failed") if (($rc & 0xFF) != 0);
	if ($rc != 0) {
		$rc = $rc >> 8;
		foreach my $arc (@allowrc) {
			return if ($rc == $arc);
		}
		&croak("`$desc' failed", "non-zero exit status ($rc)");
	}
	return $out;
}

# Make sure enough arguments are supplied, or die.
sub checkargs {
	my $count = shift;
	my $desc = shift;
	&croak('missing argument', $desc) if ($count-1 > $#_);
}

# Quote zip wildcard metacharacters. Unfortunately Info-ZIP zip and unzip
# on unix interpret some wildcards in filenames, despite the fact that
# the shell already does this. Thus this function.
sub zipquotemeta {
	my ($name) = @_;
	my $out = '';
	for (my $c = 0; $c < length $name; $c++) {
		my $ch = substr($name, $c, 1);
		$out .= '\\' if (index('*?[]\\', $ch) != -1);
		$out .= $ch;
	}
	return quotemeta($out);
}