#!/usr/bin/perl 

# Author:	Avalon Johnson
# Date:		Aug 21st 2006
# Version:	0.1 beta
# Notes:	Needs to be tested
#               it may be faster to use pvfs2-ls rather
#               than perl's "opendir/readdir" combo
# 		should we comment out the debug statements
#		to try and speed up the code (no extra "tests")

use strict;
use Getopt::Std;

sub SetGlobals()
{
    my $hostname = `hostname`;
    
    if ($hostname =~ /^shc/) {
        $main::LINUX_MKDIR="/bin/mkdir";
        $main::PVFS_COPY="/usr/local/pvfs2/bin/pvfs2-cp";
        $main::PVFS_MKDIR="/usr/local/pvfs2/bin/pvfs2-mkdir";
        $main::PVFS_STAT="/usr/local/pvfs2/bin/pvfs2-stat";
        $main::MOUNT="/bin/mount";
    }elsif ($hostname =~ /^tg/) {    
        $main::PVFS_COPY="/usr/bin/pvfs2-cp";
        $main::PVFS_MKDIR="/usr/bin/pvfs2-mkdir";
        $main::PVFS_STAT="/usr/bin/pvfs2-stat";
    }else {
	return 0;
    }
}

# test
# $main::PVFS_COPY="/bin/cp";
# $main::PVFS_MKDIR="/bin/mkdir";

$main::DEBUG       = 5;
$main::DebugLevel  = 0;
$main::MKDIR	   = "";

# Should we follow symbolic links
$main::Dereference = 1;

sub Debug($)
{
    my $str = shift;

    printf STDERR "\n" . $str . "\n" if $main::DebugLevel > $main::DEBUG;
}


sub Error($)
{
    my $str = shift;

    printf STDERR "\n\t" . $str . "\n\n";
    exit 1;

}

sub Usage()
{
    printf "\n\tUsage: $0 [-dhLP] <source> <dest>\n\n";
    printf "\t\t-d: Turn debugging on\n";
    printf "\t\t-L: Always de-reference symbolic links (default)\n";
    printf "\t\t-P: Never de-reference symbolic links\n\n";
    exit 1;
}


sub ToPvfs($) {
    my $to = shift;
    my $is_pvfs = 0;
    my @mount;
    my $mount_pt;
    my $type;
    my %pvfs_filesystems;
    my $line;

    Debug "ToPvfs ($to)";

    @mount = `$main::MOUNT`;
    foreach $line (@mount) {
        ($mount_pt, $type) = $line =~ /.*\s+on\s+([\w\/\:0-9\-]+)\s+type\s+(\w+).*/;
        $pvfs_filesystems{$mount_pt} = $mount_pt if $type =~ /^pvfs/i;
    }
    foreach $mount_pt (keys %pvfs_filesystems) {
        $is_pvfs = 1 and last if ($to =~ /$mount_pt/);
    }
    return $is_pvfs;
}


sub DoCopy($$)
{
    my $from = shift;
    my $to   = shift;

    Debug "DoCopy ($from, $to)";

    (-f $from ) || return -1;
    if ((-e $to) and !(-d $to  or -f $to)) {
        warn "$to exists and is not a directory or file";
	return 0;
    }

    if (system ($main::PVFS_COPY, $from, $to) != 0) {
	warn "Failed to copy $from to $to\n";
	return 0;
    }
    return 1;

}


sub PvfsCopy($$)
{
    my $from = shift;
    my $to   = shift;
    my $from_file;
    my $to_file;
    my $fn;
    my @files;    

    Debug "PvfsCopy ($from, $to)";

    Debug "Dereferencing" if $main::Dereference;

    if (-f $from) {

        if ( $main::Dereference || !(-l $from)){
            DoCopy ($from, $to);
        }elsif ( -l $from ){
    	    my $towhat;
            if ( defined($towhat = readlink $from)){
    	        if ( ! symlink $towhat, $to ) { 
    	    	    warn "Can\'t create symlink from: $to to $towhat";
    		    return 0;
    	        }
    	    } else {
    	        warn "Can't readlink $from: $!";
    	        return 0;
            } 
        }else {
            warn "Copy failed: Can't determine filetype of $from";
        }

    }elsif ( -d $from ) {
        if ( !(-d $to) ) {
    	    if (system ($main::MKDIR, $to) != 0) {
	        warn "Failed to copy make dest directory $to\n";
		return 0;
            }
	    Debug "Created Directory $to";
	}

        opendir(DIR, $from) || Error ("Can\'t open directory: $from");
	@files = readdir(DIR);   # do this so that we don't have too many open directories
	closedir(DIR) || Error ("Whoa Nelly: Can\'t close directory $from!!!");
        foreach $fn (@files) {
            next if ($fn =~ /^\.$/ or $fn =~ /^\.\.$/);
   	    $from_file = ${from} . "/" . $fn;
	    $to_file   = ${to} . "/" . $fn;
	    PvfsCopy ($from_file, $to_file);
	}
    }else {
        warn "Can\'t copy. \"$from\" must be a file,directory of symlink";
	return 0;
    }
    return 1;
}


sub Main()
{
    my $from;
    my $to;

    Getopt::Std::getopts ('dhPL');

    SetGlobals() or die "\nCan't set global parameters. Runnable only on shc/tg clusters\n\n";

    Usage if $Getopt::Std::opt_d;
    $main::DebugLevel = 10 if $Getopt::Std::opt_d;
    $main::Dereference = 0 if $Getopt::Std::opt_P; # ignore -L we dereference by default
    
    Usage() if $#ARGV != 1;

    $from = $ARGV[0];
    $to   = $ARGV[1];

    if ( -d $to) { 
        $to = $from;
	$to =~ s/.*\///;
        $to  = $ARGV[1] . '/' . $to;
    }
 
    printf STDERR "\nCopying files from \"$from\" to \"$to\" using pvfs2-cp\n";
    printf "\n";

    $main::MKDIR = ToPvfs($to) ?  $main::PVFS_MKDIR : $main::LINUX_MKDIR ;

    PvfsCopy ($from, $to);

}


Main();