#!/usr/local/bin/perl -w

#
# Library with definitions and common routines for MPIWG storage system
# scripts
#

package MPIWGlib;

use strict;
use vars qw(@ISA @EXPORT $VERSION
	    $debug %junk_files $file_perm $index_file_perm);
use Exporter;

$VERSION = 0.1; #  ROC 19.2.2004

@ISA = qw(Exporter);

@EXPORT = qw($debug %junk_files $file_perm $index_file_perm 
	     &parseargs &logger &stime &ymd_date &split_file_path &sstrip &valid_file_name
	     &valid_dir_name &read_xml &write_xml);

# debug level
$debug = 0;

# junk files
%junk_files = (
		  '.HSResource' => '.HSResource',
		  '.HSancillary' => '.HSancillary',
		  '.HSicon' => '.HSicon',
		  'Network Trash Folder' => 'Network Trash Folder',
		  'TheVolumeSettingsFolder' => 'TheVolumeSettingsFolder',
		  '.DS_Store' => '.DS_Store'
		  );

# default permissions for normal index files (rw-rw-r--)
$index_file_perm = 0664;
# default permissions for other files (rw-rw-r--)
$file_perm = 0664;


#
# $param_hash = parseargs;
#
# reads @ARGV and returns a hash with all options like "-option=value"
# and the last part of the string as "path"
#
sub parseargs {
    my %opts;
    foreach my $s (@ARGV) {
	if ($s =~ /^-([^=]+)=*(.*)$/) {
	    $opts{$1} = ($2) ? $2 : $1;
	} else {
	    $opts{'path'} = $s;
	}
    }
    return \%opts;
}


#
# logger($level, $message)
#
# logs the $message (mostly to stdout)
# Messages with the level DEBUG will be suppressed if $debug is false.
#
sub logger {
    my ($level, $message) = @_;
    if ($debug || ($level ne "DEBUG")) {
	print "$level: $message\n";
    }
}

#
# $stime = stime($utime)
#
# format utime (seconds since epoch) into string 
# representation: "YYYY/MM/DD HH:MM:SS"
#
sub stime {
    my ($utime) = @_;
    my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
	localtime($utime);
    my $yy = $year + 1900;
    my $mm = $mon + 1;
    my $stime = sprintf("%d/%02d/%02d %02d:%02d:%02d", 
			$yy, $mm, $mday, $hour, $min, $sec);
    return $stime;
}

#
# $date = ymd_date($olddate)
#
# converts a date string in mm/dd/yy format to yyyy/mm/dd format
#
sub ymd_date {
    my ($mdy) = @_;
    my $ydm;
    if ($mdy =~ /(\d+)\/(\d+)\/(\d+)/) {
	my $m = $1;
	my $d = $2;
	my $y = $3;
	# extend yy to yyyy
	$y = ($y < 70) ? (2000 + $y) : (($y < 100) ? ($y + 1900) : $y);
	$ydm = sprintf "%d/%02d/%02d", $y, $m, $d;
    }
    return $ydm;
}

#
# ($name, $path) = split_file_path($fn)
#
# splits the file path $fn into
# file name (the last path element) and path
#
sub split_file_path {
    my ($fn) = @_;

    if ($fn =~ /^(.*)\/([^\/]+)$/) {
        return ($2, $1);
    }
    return $fn;
}


#
# $name = sstrip($name)
#
# strips leading and trailing whitespace from $name
#
sub sstrip {
    my ($name) = @_;
    
    if ($name =~ /\s*(.*)\s*/) {
	return $1;
    }
    return $name;
}


#
# $valid = valid_file_name($name)
#
# checks if $name is a valid file name
#
sub valid_file_name {
    return valid_name($_[0], 0);
}


#
# $valid = valid_dir_name($name)
#
# checks if $name is a valid directory name
#
sub valid_dir_name {
    return valid_name($_[0], 1);
}


#
# $valid = valid_name($name, $mode)
#
# checks if $name is a valid file ($mode=0) or directory name (mode=1)
#
sub valid_name {
    my ($name, $mode) = @_;

    # whitespace?
    if ($name =~ /\s+/) {
	return 0;
    }
    # invalid characters
    if ($name !~ /^[-\w.\/]+$/) {
	return 0;
    }
    # files have extension
    if ($mode == 0) {
	if ($name !~ /\.[-\w]+$/) {
	    return 0;
	}
    }
    return 1;
}


#
# ($document, $rootnode) = read_xml($file)
#
# reads xml meta file $file
# returns root node element
#
sub read_xml {
    my ($file) = @_;
    my $document;

    my $parser = XML::LibXML->new();
    if (! $parser) {
	logger("ABORT", "unable to create parser for metadata index file!!");
	exit 1;
    }

    logger("INFO", "index file: $file");
    eval { $document = $parser->parse_file($file) };
    # catch parsing errors
    if ($@) {
	logger("ABORT", "XML syntax error in index file!!");
	exit 1;
    }
    my $rootnode = $document->documentElement;
    logger("INFO", "root element: \'" . $rootnode->nodeName . "\'");

    return ($document, $rootnode);
}


#
# write_xml($document, $file)
#
# saves the XML tree of $document to the file $file
#
sub write_xml {
    my ($document, $filename) = @_;
    # keep backup copy
    if (-f $filename) {
	if (! rename $filename, "$filename.old") {
	    logger("ABORT", "unable to change file $filename!");
	    exit 1;
	}
    }
    # write new file
    if ($document->toFile($filename)) {
	logger("INFO", "written new file $filename");
	chmod $index_file_perm, $filename;
    } else {
	logger("ABORT", "unable to write file $filename!");
	exit 1;
    }
}


# module init
return 1;