#!/usr/bin/perl
# 
# This walks through all installed fence agents, parses their man page, and records their description and 
# STDIN parameters.
# 
# TODO: 
# - Look at the mtime of the fence agents and record them as variables. Only process if an agenti is new or 
#   the mtime has changed.
# 

use strict;
use warnings;
use Anvil::Tools;
use Data::Dumper;

# Turn off buffering so that the pinwheel will display while waiting for the SSH call(s) to complete.
$| = 1;

my $THIS_FILE           =  ($0 =~ /^.*\/(.*)$/)[0];
my $running_directory   =  ($0 =~ /^(.*?)\/$THIS_FILE$/)[0];
if (($running_directory =~ /^\./) && ($ENV{PWD}))
{
	$running_directory =~ s/^\./$ENV{PWD}/;
}

my $anvil = Anvil::Tools->new();

$anvil->data->{switches}{refresh} = 0;
$anvil->Get->switches;
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 3, secure => 0, key => "log_0115", variables => { program => $THIS_FILE }});
$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
	"switches::refresh" => $anvil->data->{switches}{refresh}, 
}});

refresh_unified_metadata($anvil);

$anvil->nice_exit({exit_code => 0});


#############################################################################################################
# Functions                                                                                                 #
#############################################################################################################

# See if the unified fence metadata need to be (re)generated.
sub refresh_unified_metadata
{
	my ($anvil) = @_;
	
	my $refresh = 0;
	if (not -e $anvil->data->{path}{data}{fences_unified_metadata})
	{
		$refresh = 1;
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, 'print' => 1, key => "log_0472"});
	}
	elsif ($anvil->data->{switches}{refresh})
	{
		$refresh = 1;
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, 'print' => 1, key => "log_0473"});
	}
	else
	{
		# How old is the file?
		my $modified_time = (stat($anvil->data->{path}{data}{fences_unified_metadata}))[9];
		my $age           = time - $modified_time;
		my $maximum_age   = ((60 * 60) * 24);
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
			modified_time => $modified_time, 
			age           => $age,
			maximum_age   => $maximum_age,  
		}});
		if ($age > $maximum_age)
		{
			$refresh = 1;
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, 'print' => 1, key => "log_0474"});
		}
	}
	
	if ($refresh)
	{
		# This will store the new unified XML, when regenerating the output.
		$anvil->data->{fences}{unified_xml} =  "<\?xml version=\"1.0\" \?>\n\n";
		$anvil->data->{fences}{unified_xml} .= "<unified>\n";

		# Get a list of fence agents on this system.
		get_fences_metadata($anvil);

		$anvil->data->{fences}{unified_xml} .= "</unified>\n";

		$anvil->Storage->write_file({
			overwrite => 1,
			backup    => 0,
			file      => $anvil->data->{path}{data}{fences_unified_metadata}, 
			body      => $anvil->data->{fences}{unified_xml}, 
			user      => "apache", 
			group     => "apache", 
			mode      => "0666",
		});
	}

	if (not -e $anvil->data->{path}{data}{fences_unified_metadata})
	{
		# Failed...
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, 'print' => 1, priority => "err", key => "error_0113"});
		$anvil->nice_exit({exit_code => 1});
	}
	
	return(0);
}

# The walks through the found fence_X files and reads their metadata.
sub get_fences_metadata
{
	my ($anvil) = @_;
	
	my ($ethtool, $return_code) = $anvil->System->call({shell_call => $anvil->data->{path}{exe}{ls}." ".$anvil->data->{path}{directories}{fence_agents}."/fence_*"});
	foreach my $line (split/\n/, $ethtool)
	{
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { line => $line }});
		
		# fence_pacemaker is out fence handler for DRBD 9 and it isn't a fence agent, skip it.
		next if $line eq $anvil->data->{path}{directories}{fence_agents}."/fence_pacemaker";
		
		# fence_virtd is the host daemon component of 'fence_virt', ignore it
		next if $line eq $anvil->data->{path}{directories}{fence_agents}."/fence_virtd";
		
		my $fence_agent_path = $line;
		my $fence_agent_file = ($fence_agent_path =~ /^.*\/(.*)$/)[0];
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
			fence_agent_path => $fence_agent_path,
			fence_agent_file => $fence_agent_file, 
		}});
		
		# Add it's metadata to the unify XML.
		unify_metadata($anvil, $fence_agent_path, $fence_agent_file);
	}
	
	return(0);
}

# This does the actual call to collect the agent's metadata.
sub unify_metadata
{
	my ($anvil, $fence_agent_path, $fence_agent_file) = @_;
	
	my ($metadata, $return_code) = $anvil->System->call({debug => 3, shell_call => $fence_agent_path." -o metadata"});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { 
		metadata    => $metadata, 
		return_code => $return_code,
	}});
	
	# Test that the metadata is valid XML.
	local $@;
	my $dom = eval { XML::LibXML->load_xml(string => $metadata); };
	if ($@)
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, key => "warning_0128", variables => { 
			agent    => $fence_agent_file, 
			metadata => $metadata,
			error    => $@,
		}});
		return(1);
	}
	
	if ($metadata =~ /<\?xml version="1.0" \?>/gs)
	{
		$metadata                           =~ s/<\?xml version="1.0" \?>/<agent name="$fence_agent_file">/gs;
		$anvil->data->{fences}{unified_xml} .= $metadata."\n";
		$anvil->data->{fences}{unified_xml} .= "</agent>\n";
	}
	else
	{
		# Bad, ignore it.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, 'print' => 1, priority => "alert", key => "warning_0028", variables => { agent => $fence_agent_file }});
		return(1);
	}
	
	return(0);
}