#!/usr/bin/perl -w
#Copyright (c) Members of the EGEE Collaboration. 2004. 
#See http://www.eu-egee.org/partners/ for details on the copyright holders.
#
#Licensed under the Apache License, Version 2.0 (the "License"); 
#you may not use this file except in compliance with the License. 
#You may obtain a copy of the License at 
#
#  http://www.apache.org/licenses/LICENSE-2.0 
#
#Unless required by applicable law or agreed to in writing, software 
#distributed under the License is distributed on an "AS IS" BASIS, 
#WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
#See the License for the specific language governing permissions and 
#limitations under the License

use strict;
use LWP::Simple;
use POSIX;
use IO::Handle;
use Getopt::Std;
use File::Basename;
use File::Path;
use File::stat;
use File::Copy;

use vars qw( $debug );

# Print the usage message
sub usage(){
    print STDERR "Usage: $0 -c <config file> [-m <mds-vo-name>] [-v validity]"
               . " -[d dynamic] [-t timeout] [-s size] [-g site/region]\n";
    print STDERR '
This information provider takes a list of LDAP urls from the configuration
file and queries the LDAP sources. It then merges the results and modifies
the dn to append the mds-vo-name as specified on the command line.
The configuration file has lines typically with the following format:

entity  ldap://host.domain:2170/mds-vo-name=something,o=grid

Comments start with "#" and are ignored.

Options:

    -c  The configuration file listing all the LDAP URLs.

    -m  The mds-vo-name which should be used.

    -h  Displays this helpful message.

    -d  This option will change the search filter to only
        retrieve the dynamic information. (currently not supported)

    -g  This option will modify the search endpoint to obtain glue 2.0 
        information and dynamically modify the dn if value is not "none".

    -t  The timeout of the ldapsearch in seconds.

    -v  The validity of the cache files in seconds.

    -s  Maximum file size in megabytes for a single source.

';
    exit 1;
}

# Parse the command line options
my %options=();
getopts("v:dg:hm:c:t:s:",\%options) or usage();

# Set configuration file
my $config;
if ($options{c}){
    $config=$options{c};
}else{
    usage();
    exit 1;
}

# Set value for mds-vo-name
my $name;
if ($options{m}){
    $name=$options{m};
}elsif ($options{g}){
    $name=$options{g};
}

if ($options{h}){
    usage();
    exit 1;
}

# Select Filter, all Glue entries or only dynamic CE entries
my $filter;
if ($options{d}) {
    $filter = "'(|(objectClass=GlueVOView)(objectClass=GlueCE))'"
            . " GlueCEStateRunningJobs GlueCEStateWaitingJobs"
	    . " GlueCEStateTotalJobs GlueCEStateFreeJobSlots"
	    . " GlueCEStateEstimatedResponseTime GlueCEStateWorstResponseTime";
}else{
    $filter = "'(|(objectClass=GlueTop)(objectClass=MDS)"
	. "(objectClass=GlueClusterTop)(objectClass=GlueCETop)"
	. "(objectClass=GlueGeneralTop)(objectClass=GlueSETop)"
	. "(objectClass=GlueSATop))'";
}

# Set ttl for cache or set ttl to 0 if using dynamic option
my $ttl;
if ($options{v}){
    if ( ! int($options{v})){
	usage();
    };
    $ttl=int($options{v});
    if ($options{d}){
	print STDERR "Error: Can not use ttl option with dynamic option\n";
	exit 1;
    }
}else{
    $ttl=600;
}

# Set timeout for the ldapsearch
my $timeout=30;
if ($options{t}){
    if ( ! int($options{t})){
	usage();
    };
    $timeout=int($options{t});
}


# Set the maximum file size.
my $max_file_size=10;

if ($options{s}){
    if ( ! int($options{s})){
	usage();
    };
    $max_file_size=int($options{s});
}

# Figure out the location of the glite var directory
my $var_dir;
if (exists($ENV{GLITE_LOCATION_VAR})) {
    $var_dir = "$ENV{GLITE_LOCATION_VAR}";
} elsif (exists($ENV{GLITE_LOCATION})) {
    $var_dir = "$ENV{GLITE_LOCATION}/var";
} else {
    $var_dir = "/opt/glite/var";
}

# Figure out the location of the glite etc directory
my $etc_dir;
if (exists($ENV{GLITE_LOCATION})) {
    $etc_dir = "$ENV{GLITE_LOCATION}/etc";
} else {
    $etc_dir = "/opt/glite/etc";
}

my @ldif;

# Get the ldap urls from the configuration file.
my @urls;
open (CONFIG, "$config" ) ||
    die "Couldn't open config file $config $!\n";
while (<CONFIG>) {
    s/\#.*//;
    if (m/\s+ldap:\/\//){
	push @urls, $_;
    }
}
close (CONFIG);

# Prepare the temporary directory
my $file_name=fileparse($config);
if ($options{g}){
    $file_name=$file_name . '-glue2'
}
my $tmp_dir = "$var_dir/tmp/gip/$file_name";
my $cache_dir = "$var_dir/cache/gip/$file_name";

if( -d $tmp_dir ){
    my @files=glob("$tmp_dir/*.ldif");
    foreach my $file (@files) {
	unlink($file);
    }
}else{
    mkpath($tmp_dir);
}

if( ! -d $cache_dir ){
    mkpath($cache_dir);
}

my $date = `date +\%Y-\%m-\%d`;  chomp $date;
my $log_dir  = "$var_dir/tmp/gip/log/$file_name";
my $log_file = "$log_dir/$file_name-$date.log";

if( ! -d $log_dir ){
    mkpath($log_dir);
}


# Remove old log files
my $log_file_retention=60; # in number of days
my @log_files=glob("$log_dir/$file_name*.log");
my $current_time=time;
my $file_info;
my $file_time;
foreach(@log_files){
    $file_info =  stat($_);
    if($file_info){
	$file_time=$file_info->mtime;
	if ( $current_time > ($file_time + 
			      ($log_file_retention * 24 * 3600)) ){   
	    
	    unlink($_);
	}
    }
}


open(LOGFILE, ">> $log_file") or die "$0: cannot open '$log_file': $!\n";
my $fh = select(LOGFILE); $| = 1; select($fh);

my $start_time = `date '+\%Y-\%m-\%d \%T'`; chomp $start_time;
my $t0 = time;
print LOGFILE "=== $start_time START\n";

my @pid;      # The pids of the forked processes.
my $pid;      # A pid for one process.
my $region;   # A region name for the ldif source.
my $bind;     # The bind point for the search.
my $command;  # A command that will return ldif.
my $bunch=10;
my $delay=5;
my $n=0;

#Loop through for each ldif source
foreach(@urls){

    if ($n++ >= $bunch) {
	my $child = 0;
	eval {
	    local $SIG{ALRM} = sub { die "timeout" };
	    alarm($delay);
	    $child = wait();
	    alarm(0);
	};
	if (!$child) {
	    # The active commands may all be hanging,
	    # so launch another bunch...
	    $n = 0;
	} else {
	    $n--;
	}
    }

    # Split the information from the url.
    if (m|^([-.\w]+)\s+ldap://(.+):([0-9]+)/(.+)|) {
	$region  = $1;

	if ($options{g}){
	    my $site = $4;
	    $site =~s/,o=grid$//;
	    $site =~s/^.*=//;
	    if ( $site eq 'resource'){
		$bind = 'GLUE2GroupID=resource,o=glue';
	    }else{
		$bind = "GLUE2DomainId=$site,o=glue";
	    }
	    $filter = ''
	}else{
	    $bind = $4;
	}
	
	$command = "ldapsearch -x -LLL -h $2 -p $3 -b $bind "
	    . $filter
	    . "> $tmp_dir/$region.ldif 2>$tmp_dir/$region.err";
    } else {
	chomp;
	print LOGFILE "ignoring badly formatted line: '$_'\n";
	next;
    }

    # Fork the search.
    if (!defined($pid=fork)) {
	print LOGFILE "cannot fork: $!\n";
	next;
    }

    unless ($pid) {
	# Set our process group to a distinct value.
	setpgrp();
	my $msg = "GOT TIRED OF WAITING";

	# Eval will kill the process if it times out.
	eval {
	    local $SIG{ALRM} = sub { die "$msg" };
	    alarm ($timeout);  #Will call alarm after the timeout.

	    if (system("$command") != 0) {
		unlink("$tmp_dir/$region.ldif");
	    }else{
		unlink("$tmp_dir/$region.err");
	    }
	    alarm(0); # Cancel the pending alarm if responds.
	};

	# This section is executed if the process times out.
	if ($@ =~ /$msg/) {
	    unlink("$tmp_dir/$region.ldif");
	    system("echo Search timed out >> $tmp_dir/$region.err");
	    my $PGRP=getpgrp();
	    kill (-SIGKILL(), $PGRP);
	    exit 1;
	}
	exit 0;
    }
    push @pid, $pid;
}

foreach(@pid){
    waitpid($_, 0);
}

my $end_time = `date '+\%Y-\%m-\%d \%T'`; chomp $end_time;
my $dt = sprintf "%4d", time - $t0;
print LOGFILE "=== $end_time END - elapsed: $dt\n";

for (<$tmp_dir/*.err>){
    $region=$_;
    $region=~s/.*\///;
    $region=~s/\.err$//;
    print LOGFILE "--> $region:\n";
    system("cat $_ >> $log_file");
    print LOGFILE "\n";
    unlink($_);
}

my $file_size;
for (<$tmp_dir/*.ldif>){
    $file_info =  stat($_);
    if($file_info){
	$region=$_;
	$region=~s/.*\///;
	$region=~s/\.ldif$//;
	$file_size = $file_info->size;
	# Protection for too much data coming from a site.
	if ( $file_size > ($max_file_size * 1000000) ){
	    print LOGFILE "ERROR: $region is producing too much data!\n";
	    unlink($_);
	}else{
	    move($_, "$cache_dir/$region.ldif");
	}
    }
}

# Delete old files from the cache
for (<$cache_dir/*.ldif>){
    $file_info =  stat($_);
    $file_time=$file_info->mtime;
    if ( $current_time > ($file_time + $ttl) ){
	$region=$_;
	$region=~s/.*\///;
	$region=~s/\.ldif$//;
	print LOGFILE "NOTICE: deleting stale cache file for $region.\n";
	unlink($_);
    }
}

my $rs = $/;
$/ = "";

for (<$cache_dir/*.ldif>) {
    open(LDIF, $_) || warn "Cannot open '$_': $!\n";
    while (<LDIF>) {
	s/\n //g; # Remove line wrapping

	next if /^\s*$/;

	unless (/^dn:/) {
	    chomp;
	    s/(.{900}).*/$1\[...]/s;
	    print LOGFILE "ERROR: Skipping junk:\n"
		. ('-' x 70) . "\n$_\n" . ('-' x 70) . "\n";
	    next;
	}

	my $dn = $_;
	$dn =~ s/\n.*//s;
	$dn =~ s/,\s+/,/g;

	if ($options{m}){
	    if ($dn =~ m/mds-vo-name=$name,/i) {
		print LOGFILE "ERROR: Skipping recursive entry '$dn'\n";
		next;
	    }

	    $dn =~ s/mds-vo-name=(local|resource),o=grid\s*$/o=grid/i;
	    $dn =~ s/o=grid\s*$/mds-vo-name=$name,o=grid/i;

	}
	if ($options{g}){
	    if ($dn =~ m/GLUE2DomainId=$name,/i) {
		print LOGFILE "ERROR: Skipping recursive entry '$dn'\n";
		next;
	    }

	    if ( $name ne "none"){
		$dn =~ s/o=glue/GLUE2DomainId=$name,o=glue/i;
	    }
	}

	s/[^\n]*/$dn/;

	if ($name ne "local" ){
	    s/mds-vo-name:[^\n]*\n/mds-vo-name: $name\n/i;
	}

	print;
    }
    close LDIF;
}

$/ = $rs;