#!/usr/bin/perl
# 
# This is the main ScanCore program. It is started/killed/recovered by anvil-daemon.
# 
# Examples;
# 
# Exit codes;
# 0 = Normal exit.
# 1 = No database connections available.
# 
# TODO: 
# - Decide if it's worth having a separate ScanCore.log file or just feed into anvil.log.
# 

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

# Disable buffering
$| = 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({log_level => 2, log_secure => 1});

$anvil->Storage->read_config();
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "log_0115", variables => { program => $THIS_FILE }});

# Read switches
$anvil->data->{switches}{'run-once'} = "";
$anvil->Get->switches;

# Calculate my sum so that we can exit if it changes later.
$anvil->Storage->record_md5sums;

# Connect to DBs.
wait_for_database($anvil);

# If we're not configured, sleep.
wait_until_configured($anvil);

# Disconnect. We'll reconnect inside the loop
$anvil->Database->disconnect();
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 2, key => "log_0203"});

# The main loop
while(1)
{
	# Reload defaults, re-read the config and then connect to the database(s)
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 2, key => "log_0248"});
	$anvil->_set_paths();
	$anvil->_set_defaults();
	$anvil->Storage->read_config();
	$anvil->Database->connect();
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "log_0132"});
	
	if ($anvil->data->{sys}{database}{connections})
	{
		# Run the normal tasks
		call_agents($anvil);
	}
	else
	{
		# No databases available, we can't do anything this run. Sleep for a couple of seconds and 
		# then try again.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 0, key => "log_0202"});
		
		my $db_retry_interval = 2;
 		if ((exists $anvil->data->{scancore}{timing}{db_retry_interval}) && ($anvil->data->{scancore}{timing}{db_retry_interval} =~ /^\d+$/))
		{
			$db_retry_interval = $anvil->data->{scancore}{timing}{db_retry_interval};
		}
		sleep($db_retry_interval);
		next;
	}
	
	# Exit if 'run-once' selected.
	if ($anvil->data->{switches}{'run-once'})
	{
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 0, key => "message_0055"});
		$anvil->nice_exit({code => 0});
	}
	
	# Disconnect from the database(s) and sleep now.
	$anvil->Database->disconnect();
	my $run_interval = 30;
	if ((exists $anvil->data->{scancore}{timing}{run_interval}) && ($anvil->data->{scancore}{timing}{run_interval} =~ /^\d+$/))
	{
		$run_interval = $anvil->data->{scancore}{timing}{run_interval};
	}
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 2, key => "log_0249", variables => { run_interval => $run_interval }});
	sleep($run_interval);
	
	# In case something has changed, exit.
	exit_if_sums_changed($anvil);
}

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


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

# This invokes all scan agents found in 'path::directories::scan_agents'
sub call_agents
{
	my ($anvil) = @_;
	
	# Get the list of scan agents on this system.
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
		"path::directories::scan_agents" => $anvil->data->{path}{directories}{scan_agents},
	}});
	scan_directory($anvil, $anvil->data->{path}{directories}{scan_agents});
	
	return(0);
}

# This checks to see if any files on disk have changed and, if so, exits.
sub exit_if_sums_changed
{
	my ($anvil) = @_;
	
	if ($anvil->Storage->check_md5sums)
	{
		# NOTE: We exit with '0' to prevent systemctl from showing a scary red message.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 0, priority => "warn", key => "message_0014"});
		$anvil->nice_exit({code => 0});
	}
	
	return(0);
}

# This looks in the passed-in directory for scan agents or sub-directories (which will in turn be scanned).
sub scan_directory
{
	my ($anvil, $directory) = @_;
	
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { directory => $directory }});
	local(*DIRECTORY);
	opendir(DIRECTORY, $directory);
	while(my $file = readdir(DIRECTORY))
	{
		next if $file eq ".";
		next if $file eq "..";
		my $full_path = $directory."/".$file;
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
			file      => $file,
			full_path => $full_path,
		}});
		# If we're looking at a directory, scan it. Otherwise, see if it's an executable and that it
		# starts with 'scan-*'.
		if (-d $full_path)
		{
			# This is a directory, dive into it.
			scan_directory($anvil, $full_path);
		}
		elsif (-x $full_path)
		{
			# Now I only want to know if the file starts with 'scan-'
			next if $file !~ /^scan-/;
			
			# If I am still alive, I am looking at a scan agent!
			$anvil->data->{scancore}{agent}{$file} = $full_path;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
				"scancore::agent::${file}" => $anvil->data->{scancore}{agent}{$file},
			}});
		}
	}
	closedir(DIRECTORY);
	
	return(0);
}

# This loops until it can connect to at least one database.
sub wait_for_database
{
	my ($anvil) = @_;
	
	$anvil->Database->connect;
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 2, key => "log_0132"});
	if (not $anvil->data->{sys}{database}{connections})
	{
		# No databases, sleep until one comes online.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "log_0244"});
		
		until($anvil->data->{sys}{database}{connections})
		{
			# Disconnect, Sleep, then check again.
			$anvil->Database->disconnect();
			sleep 60;
			
			$anvil->_set_paths();
			$anvil->_set_defaults();
			$anvil->Storage->read_config();
			$anvil->Database->connect;
			if ($anvil->data->{sys}{database}{connections})
			{
				# We're good
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "log_0245"});
			}
			else
			{
				# Not yet...
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 2, key => "log_0244"});
			}
			
			# In case something has changed, exit.
			exit_if_sums_changed($anvil);
		}
	}
	
	return(0);
}

# Wait until the local system has been configured.
sub wait_until_configured
{
	my ($anvil) = @_;
	
	my $configured = $anvil->System->check_if_configured;
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 3, list => { configured => $configured }});
	if (not $configured)
	{
		# Sleep for a minute and check again.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0246"});
		until ($configured)
		{
			# Sleep, then check.
			sleep 60;
			
			$configured = $anvil->System->check_if_configured;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { configured => $configured }});
			if ($configured)
			{
				# We're good
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "log_0247"});
			}
			else
			{
				# Not yet...
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 2, key => "log_0246"});
			}
			
			# In case something has changed, exit.
			exit_if_sums_changed($anvil);
		}
	}
	
	return(0);
}