anvil/Anvil/Tools/Log.pm

package Anvil::Tools::Log;
# 
# This module contains methods used to handle logging related tasks
# 

use strict;
use warnings;
use Data::Dumper;
use Scalar::Util qw(weaken isweak);
use Log::Journald;
use Sys::Syslog qw/:macros/;


our $VERSION  = "3.0.0";
my $THIS_FILE = "Log.pm";

### Methods;
# entry
# language
# level
# secure
# switches
# variables
# _adjust_log_level

=pod

=encoding utf8

=head1 NAME

Anvil::Tools::Log

Provides all methods related to logging.

=head1 SYNOPSIS

 use Anvil::Tools;

 # Get a common object handle on all Anvil::Tools modules.
 my $anvil = Anvil::Tools->new();
 
 # Access to methods using '$anvil->Log->X'. 
 # 
 # Example using 'entry()';
 my $foo_path = $anvil->Log->entry({...});

=head1 METHODS

Methods in this module;

=cut
sub new
{
	my $class = shift;
	my $self  = {
		LOG	=>	{
			LANGUAGE	=>	"",
		},
	};
	
	bless $self, $class;
	
	return ($self);
}

# Get a handle on the Anvil::Tools object. I know that technically that is a sibling module, but it makes more 
# sense in this case to think of it as a parent.
sub parent
{
	my $self   = shift;
	my $parent = shift;
	
	$self->{HANDLE}{TOOLS} = $parent if $parent;
	
	# Defend against memory leads. See Scalar::Util'.
	if (not isweak($self->{HANDLE}{TOOLS}))
	{
		weaken($self->{HANDLE}{TOOLS});
	}
	
	return ($self->{HANDLE}{TOOLS});
}


#############################################################################################################
# Public methods                                                                                            #
#############################################################################################################

=head2 entry

This method writes an entry to either the log files or to the journald logs, provided the log entry's level is equal to or higher than the active log level. The exception is if the log entry contains sensitive data, like a password, and 'C<< log::secure >> is set to 'C<< 0 >>' (the default). In this case, the sensitive log / data will be listed as suppressed. 

B<< NOTE >>: Deciding if the logs go to a file or journald is determined by checking to see if C<< path::log::main >> is set. If it isn't, journald is used. If it is (default), the file is used. If writing to a log file, and if C<< path::log::alert >> is also set, any entry with a set C<< priority >> (see below) is logged to both files.

Here is a simple example of writing a simple log entry at log log level 1.

 $anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 1, key => "log_0001"});

In the example above, the string will be written to the log file if the active log level is 'C<< 1 >>' or higher and it will use the 'C<< log::language >>' language to translate the string key.

Now a more complex example;

 $anvil->Log->entry({
 	source    => $THIS_FILE, 
 	line      => __LINE__, 
 	level     => 2,
 	secure    => 1,
 	language  => "jp",
 	key       => "log_0002",
 	variables => {
 		password => "foo",
 	},
 });

In the above example, the log level is set to 'C<< 2 >>' and the 'C<< secure >>' flag is set. We're also logging in Japanese and we are passing a variable into the string key. With the secure flag set, even if the user's log level is 2 or higher, the log entry will only be recorded if the user has set 'C<< log::secure >>' to '1'.

Finally, it is possible to log pre-processed strings (as is done in 'Alert->warning()' and 'Alert->error()'). In this case, the 'C<< raw >>' parameter is used and it contains the processed string. Note that the source file and line number are still pre-pended to the raw message.

 $anvil->Log->entry({
 	source    => $THIS_FILE, 
 	line      => __LINE__, 
 	level     => 2,
 	raw       => "This error can't be translated",
 });

The above should be used very sparingly, and generally only in places where string processing itself is being logged.

Parameters;

=head3 facility (optional)

This is an optional log facility to log the message with. By default, 'C<< local0 >>' is used.

If the 'C<< secure >>' flag is set, the facility is changed to 'C<< authpriv >>' and this is ignored.

See 'C<< man logger >>' for a full list of valid priorities.

=head3 key (required)

NOTE: This is not required *if* 'C<< raw >>' is used instead.

This is the string key to use for the log entry. By default, it will be translated into the 'C<< log::language >> language. If the string contains replacement variables, be sure to also use 'C<< variables >>'.

=head3 language (optional)

This is the ISO code for the language you wish to use for the log message. For example, 'en_CA' to get the Canadian English string, or 'jp' for the Japanese string.

When no language is passed, 'C<< defaults::log::languages >>' is used. 

=head3 level (required)

This is the numeric log level of this log entry. It determines if the message is of interest to the user. An entry is only recorded if the user's 'C<< log::level >>' is equal to or higher than this number. This is required, but if it is not passed, 'C<< 2 >>' will be used.

NOTE: The 'C<< log::level >>' might be changed inside certain programs. For example, in ScanCore, the user may set 'C<< scancore::log::level >>' and that will be used to set 'C<< log::level >>'.

Log levels are:

=head4 C<< 0 >>

Critical messages. These will always be logged, and so this log level should very rarely be used. Generally it will be used only by Alert->warning() and Alert->error().

=head4 C<< 1 >>

Important messages. The default log level is 'C<< 1 >>', so anything at this log level will usually be logged under normal conditions.

=head4 C<< 2 >>

This is the 'debug' log level. It is used by developers while working on a section of code, or in places where the log entries can help in general debugging.

=head4 C<< 3 >>

This is the 'verbose' log level. It will generally generate a significant amount of output and is generally used for most logging. A user will generally only set this log level when trying to debug a problem with an unknown source.

=head4 C<< 4 >>

This is the highest log level, and it will generate a tremendous amount of log entries. This is generally used is loops or recursive functions where the output is significant, but the usefulness of the output is not.

=head3 line (optional)

When set, the string is prepended to the log entry, after 'C<< file >> if set, and should be set to C<< __LINE__ >>. It is used to show where in 'C<< file >>' the log entry was made and can assist with debugging.

=head3 print (optional, default '0')

When set to '1', the log entry is also printed to STDOUT. The prefix (source file and timestamp) is NOT printed, and a newline is added to the end of the string.

B<< NOTE >>: This honours the log level. That is to say, it will only print the string to STDOUT if it also logs it to a file. 

=head3 priority (optional)

What this does depends on if we're logging to a file or not. 

=head4 File

If set, the log entry will also be written to the C<< path::log::alert >> log file, with a prefix indicating 'Error', 'Warning' or 'Note'. This is meant to make it easier to filter out important messages from general log entries. Note that these log entries are also still written to C<< path::log::main >>, so that these messages can be seen in context.

=head4 Journald

This is an optional log priority (level) name. By default, the following priorities will be used based on the log level of the message.

* 0 = notice
* 1 = info
* 2 = info
* 3 = debug
* 4 = debug

See 'C<< man logger >>' for a full list of valid priorities. Most notably, setting 'C<< crit >>' for critical events, 'C<< err >>' for errors, 'C<< alert >>' for alerts and 'C<< emerg >>' for emergencies are used.

WARNING: Using 'C<< emerg >>' will spam all terminals. Only use it in true emergencies, like when about to shut down.

=head3 raw (optional)

NOTE: This *or* C<< key >> must be passed.

This can contain a string to record to the log file. It is treated as a raw string and is not translated, altered or processed in any way. It will be recorded exactly as-is, provided the log level and secure settings allow for it.

=head3 secure (optional)

When set, this indicates that the log entry might contain sensitive data, like a password. When set, the log entry will only be recorded if 'C<< log::secure >>' is set to '1' *and* the log level is equal to or higher than 'C<< log::level >>'.

=head3 server (optional)

This controls which log server the log entries are recorded. By default, this is blank (and logs are recorded locally).

=head3 source (optional)

When set, the string is pre-pended to the log entry. This is generally set to 'C<< $THIS_FILE >>', which itself should contain the file name requesting the log entry.

=head3 tag (optional)

This is the tag given to the log entry. By default, it will be 'C<< anvil >>'.

=head3 variables (optional)

This is a hash reference containing replacement variables to inject into the 'C<< key >>' string.

=cut
sub entry
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	my $test      = defined $parameter->{test}  ? $parameter->{test}  : 0;
	
	# If logging is disabled, return immediately.
	return(0) if $anvil->data->{sys}{'log'}{disable};
	
	# If we're called before $anvil->_set_defaults, this will be undefined.
	$anvil->data->{defaults}{'log'}{level} = 1 if not defined $anvil->data->{defaults}{'log'}{level};
	
	my $key       = defined $parameter->{key}       ? $parameter->{key}       : "";
	my $language  = defined $parameter->{language}  ? $parameter->{language}  : $anvil->Log->language;
	my $level     = defined $parameter->{level}     ? $parameter->{level}     : 2;
	my $line      = defined $parameter->{line}      ? $parameter->{line}      : "";
	my $facility  = defined $parameter->{facility}  ? $parameter->{facility}  : $anvil->data->{defaults}{'log'}{facility};
	my $print     = defined $parameter->{'print'}   ? $parameter->{'print'}   : "";
	my $priority  = defined $parameter->{priority}  ? $parameter->{priority}  : "";
	my $raw       = defined $parameter->{raw}       ? $parameter->{raw}       : "";
	my $secure    = defined $parameter->{secure}    ? $parameter->{secure}    : 0;
	my $server    = defined $parameter->{server}    ? $parameter->{server}    : $anvil->data->{defaults}{'log'}{server};
	my $source    = defined $parameter->{source}    ? $parameter->{source}    : "";
	my $tag       = defined $parameter->{tag}       ? $parameter->{tag}       : $anvil->data->{defaults}{'log'}{tag};
	my $variables = defined $parameter->{variables} ? $parameter->{variables} : "";
	
	$anvil->data->{loop}{count} = 0 if not defined $anvil->data->{loop}{count};
	$anvil->data->{loop}{count}++;
	print $THIS_FILE." ".__LINE__."; [ Debug ] - level: [".$level."], defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."], logging secure? [".$anvil->Log->secure."], priority: [".$priority."], source: [".$source."], line: [".$line."], key: [".$key."], variables: [".$variables."]\n" if $test;
	if (($test) && (ref($variables) eq "HASH"))
	{
		foreach my $key (sort {$a cmp $b} keys %{$variables})
		{
			print $THIS_FILE." ".__LINE__.";           - key: [".$key."] -> [".$variables->{$key}."]\n";
		}
	}
	# The counter needs to be longer than any conceivable file line count we might read.
	if ($anvil->data->{loop}{count} > 5000000)
	{
		if ($anvil->environment eq "html")
		{
			### NOTE: Don't use the template, it could be part of the infinite loop problem.
			print "Content-type: text/html; charset=utf-8\n\n";
			print "<pre>\n";
		}
		print $THIS_FILE." ".__LINE__."; Infinite loop detected trying to log:\n";
		print $THIS_FILE." ".__LINE__."; - key: ..... [".$key."]:\n";
		print $THIS_FILE." ".__LINE__."; - language:  [".$language."]:\n";
		print $THIS_FILE." ".__LINE__."; - level: ... [".$level."]:\n";
		print $THIS_FILE." ".__LINE__."; - line: .... [".$line."]:\n";
		print $THIS_FILE." ".__LINE__."; - print: ... [".$print."]:\n";
		print $THIS_FILE." ".__LINE__."; - priority:  [".$priority."]:\n";
		print $THIS_FILE." ".__LINE__."; - raw: ..... [".$raw."]:\n";
		print $THIS_FILE." ".__LINE__."; - secure: .. [".$secure."]:\n";
		print $THIS_FILE." ".__LINE__."; - server: .. [".$server."]:\n";
		print $THIS_FILE." ".__LINE__."; - source: .. [".$source."]:\n";
		print $THIS_FILE." ".__LINE__."; - tag: ..... [".$tag."]:\n";
		print $THIS_FILE." ".__LINE__."; - variables: [".$variables."]:\n";
		if (ref($variables) eq "HASH")
		{
			print $THIS_FILE." ".__LINE__."; - variable hash dump:\n";
			print $THIS_FILE." ".__LINE__."; =====================\n";
			use Data::Dumper;
			print Dumper $variables;
			print $THIS_FILE." ".__LINE__."; =====================\n";
		}
		# Don't use nice_exit, it might be part of the problem.
		if ($anvil->environment eq "html")
		{
			print "</pre>\n";
		}
		exit (1);
	}
	
	# Exit immediately if this isn't going to be logged
	if ($level > $anvil->Log->level)
	{
		$anvil->data->{loop}{count}--;
		return(1);
	}
	if (($secure) && (not $anvil->Log->secure))
	{
		$anvil->data->{loop}{count}--;
		return(2);
	}
	
	# Build the priority, if not set by the user.
	my $log_to_alert = "";
	my $priority_string = $secure ? "authpriv" : $facility;
	if ($priority)
	{
		$priority_string .= ".$priority";
		if ($priority =~ /^err/i)
		{
			$log_to_alert = $anvil->Words->string({test => $test, language => $language, key => "prefix_0001"});
		}
		elsif ($priority =~ /^alert/i)
		{
			$log_to_alert = $anvil->Words->string({test => $test, language => $language, key => "prefix_0002"});;
		}
		elsif ($priority =~ /^info/i)
		{
			$log_to_alert = $anvil->Words->string({test => $test, language => $language, key => "prefix_0003"});;
		}
		print $THIS_FILE." ".__LINE__."; priority_string: [".$priority_string."], log_to_alert: [".$log_to_alert."]\n" if $test;
	}
	elsif ($level eq "0")
	{
		$priority_string .= ".notice";
	}
	elsif (($level eq "1") or ($level eq "2"))
	{
		$priority_string .= ".info";
	}
	else
	{
		$priority_string .= ".debug";
	}
	print $THIS_FILE." ".__LINE__."; priority string: [".$priority_string."]\n" if $test;
	
	# Log the file and line, if passed.
	my $job_uuid     = "";
	my $string       = "";
	my $print_string = "";
	if ($anvil->data->{sys}{'log'}{date})
	{
		# Keep the debug level super high to avoid Get->date_and_time() going into an infinite loop.
		$string .= $anvil->Get->date_and_time({debug => 99}).":";
		print $THIS_FILE." ".__LINE__."; string: [".$string."]\n" if $test;
	}
	if ((exists $anvil->data->{switches}{'job-uuid'}) && ($anvil->Validate->uuid({uuid => $anvil->data->{switches}{'job-uuid'}})))
	{
		$job_uuid =  $anvil->data->{switches}{'job-uuid'};
		$job_uuid =~ s/^(\w+?)-.*$/$1/;
		$string   .= "[".$job_uuid."]:";
	}
	if (exists $anvil->data->{'log'}{scan_agent})
	{
		$string   .= "[".$anvil->data->{'log'}{scan_agent}."]:";
	}
	if (($source) && ($line))
	{
		$string .= $source.":".$line."; ";
		print $THIS_FILE." ".__LINE__."; string: [".$string."]\n" if $test;
	}
	elsif ($source)
	{
		$string .= $source."; ";
		print $THIS_FILE." ".__LINE__."; string: [".$string."]\n" if $test;
	}
	elsif ($line)
	{
		$string .= $line."; ";
		print $THIS_FILE." ".__LINE__."; string: [".$string."]\n" if $test;
	}
	print $THIS_FILE." ".__LINE__."; loop::count: [".$anvil->data->{loop}{count}."] " if $test;
	
	if ($log_to_alert)
	{
		$log_to_alert = $string.$log_to_alert;
		print $THIS_FILE." ".__LINE__."; log_to_alert: [".$log_to_alert."]\n" if $test;
	}
	
	# If I have a raw string, do no more processing.
	print $THIS_FILE." ".__LINE__."; raw: [".$raw."], key: [".$key."]\n" if $test;
	if ($raw)
	{
		$string       .= $raw;
		$print_string .= $raw;
		print $THIS_FILE." ".__LINE__."; string: ..... [".$string."]\n" if $test;
		print $THIS_FILE." ".__LINE__."; print_string: [".$print_string."]\n" if $test;
		
		if ($log_to_alert)
		{
			$log_to_alert .= $raw;
			print $THIS_FILE." ".__LINE__."; log_to_alert: [".$log_to_alert."]\n" if $test;
		}
	}
	elsif ($key)
	{
		# Build the string from the key/variables.
		print $THIS_FILE." ".__LINE__."; debug: [".$debug."], language: [".$language."], key: [".$key."], variables: [".$variables."]\n" if $test;
		my $message .= $anvil->Words->string({
			test      => $test,
			debug     => $debug, 
			language  => $language,
			key       => $key,
			variables => $variables,
		});
		print $THIS_FILE." ".__LINE__."; [ Debug ] - message: [$message]\n" if $test;
		
		$string       .= $message;
		$print_string .= $message;
		print $THIS_FILE." ".__LINE__."; string: ..... [".$string."]\n" if $test;
		print $THIS_FILE." ".__LINE__."; print_string: [".$print_string."]\n" if $test;
		
		if ($log_to_alert)
		{
			$log_to_alert .= $message;
			print $THIS_FILE." ".__LINE__."; log_to_alert: [".$log_to_alert."]\n" if $test;
		}
	}
	
	### TODO: Left off here - check priority and switch to 'anvil.errors' if set to 'warn' or 'err'. All 
	###       logs go to main still (so they can be seen in context).
	# If the user set a log file, log to that. Otherwise, log via Log::Journald.
	print $THIS_FILE." ".__LINE__."; path::log::main: [".$anvil->data->{path}{'log'}{main}."]\n" if $test;
	if ($anvil->data->{path}{'log'}{main})
	{
		# TODO: Switch back to journald later, using a file for testing for now
		if ($string !~ /\n$/)
		{
			$string .= "\n";
			print $THIS_FILE." ".__LINE__."; string: [".$string."]\n" if $test;
		}
		if ($log_to_alert !~ /\n$/)
		{
			$log_to_alert .= "\n";
			print $THIS_FILE." ".__LINE__."; log_to_alert: [".$log_to_alert."]\n" if $test;
		}
		
		### TODO: Periodically check the log file size. If it's over a gigabyte, archive it
		
		# Open the file?
		$anvil->data->{HANDLE}{'log'}{main} = "" if not defined $anvil->data->{HANDLE}{'log'}{main};
		print $THIS_FILE." ".__LINE__."; HANDLE::log::main: [".$anvil->data->{HANDLE}{'log'}{main}."]\n" if $test;
		if (not $anvil->data->{HANDLE}{'log'}{main})
		{
			# If the file doesn't start with a '/', we'll put it under /var/log.
			my $log_file           = $anvil->data->{path}{'log'}{main} =~ /^\// ? $anvil->data->{path}{'log'}{main} : "/var/log/".$anvil->data->{path}{'log'}{main};
			my ($directory, $file) = ($log_file =~ /^(\/.*)\/(.*)$/);
			print $THIS_FILE." ".__LINE__."; log_file: [".$log_file."]. directory: [".$directory."], file: [".$file."]\n" if $test;
			
			### WARNING: We MUST set the debug level really high, or else we'll go into a deep 
			###          recursion!
			# Make sure the log directory exists.
			$anvil->data->{sys}{'log'}{disable} = 1;
			$anvil->Storage->make_directory({test => $test, debug => 99, directory => $directory, mode => 755});
			$anvil->data->{sys}{'log'}{disable} = 0;
			
			# Now open the log
			my $shell_call = $log_file;
			print $THIS_FILE." ".__LINE__."; shell_call: [".$shell_call."]\n" if $test;
			# NOTE: Don't call '$anvil->Log->entry()' here, it will cause a loop!
			open (my $file_handle, ">>", $shell_call) or die "Failed to open: [".$shell_call."] for writing. The error was: $!\n";
			$file_handle->autoflush(1);
			$anvil->data->{HANDLE}{'log'}{main} = $file_handle;
			binmode($anvil->data->{HANDLE}{'log'}{main}, ':encoding(utf-8)');
			print $THIS_FILE." ".__LINE__."; HANDLE::log::main: [".$anvil->data->{HANDLE}{'log'}{main}."]\n" if $test;
			
			# Make sure it can be written to by apache.
			$anvil->Storage->change_mode({test => $test, debug => $debug, path => $log_file, mode => "0666"});
		}
		
		if (not $anvil->data->{HANDLE}{'log'}{main})
		{
			# NOTE: This can't be a normal error because we can't write to the logs.
			print $THIS_FILE." ".__LINE__."; log main file handle doesn't exist, but it should by now.\n";
			exit 1;
		}
		
		# The handle has to be wrapped in a block to make 'print' happy as it doesn't like non-scalars for file handles
		print { $anvil->data->{HANDLE}{'log'}{main} } $string;
		
		# Does this need to be logged to 'notice' as well?
		if (($log_to_alert) && ($anvil->data->{path}{'log'}{alert}))
		{
			$anvil->data->{HANDLE}{'log'}{alert} = "" if not defined $anvil->data->{HANDLE}{'log'}{alert};
			print $THIS_FILE." ".__LINE__."; HANDLE::log::alert: [".$anvil->data->{HANDLE}{'log'}{alert}."]\n" if $test;
			if (not $anvil->data->{HANDLE}{'log'}{alert})
			{
				# If the file doesn't start with a '/', we'll put it under /var/log.
				my $log_file           = $anvil->data->{path}{'log'}{alert} =~ /^\// ? $anvil->data->{path}{'log'}{alert} : "/var/log/".$anvil->data->{path}{'log'}{alert};
				my ($directory, $file) = ($log_file =~ /^(\/.*)\/(.*)$/);
				print $THIS_FILE." ".__LINE__."; log_file: [".$log_file."]. directory: [".$directory."], file: [".$file."]\n" if $test;
				
				### WARNING: We MUST set the debug level really high, or else we'll go into a deep 
				###          recursion!
				# Make sure the log directory exists.
				$anvil->Storage->make_directory({test => $test, debug => 99, directory => $directory, mode => 755});
				
				# Now open the log
				my $shell_call = $log_file;
				print $THIS_FILE." ".__LINE__."; shell_call: [".$shell_call."]\n" if $test;
				# NOTE: Don't call '$anvil->Log->entry()' here, it will cause a loop!
				open (my $file_handle, ">>", $shell_call) or die "Failed to open: [$shell_call] for writing. The error was: $!\n";
				$file_handle->autoflush(1);
				$anvil->data->{HANDLE}{'log'}{alert} = $file_handle;
				print $THIS_FILE." ".__LINE__."; HANDLE::log::alert: [".$anvil->data->{HANDLE}{'log'}{alert}."]\n" if $test;
				
				# Make sure it can be written to by apache.
				$anvil->Storage->change_mode({test => $test, debug => $debug, path => $log_file, mode => "0666"});
			}
			
			if (not $anvil->data->{HANDLE}{'log'}{alert})
			{
				# NOTE: This can't be a normal error because we can't write to the logs.
				print $THIS_FILE." ".__LINE__."; log alert file handle doesn't exist, but it should by now.\n";
				exit 1;
			}
			
			# The handle has to be wrapped in a block to make 'print' happy as it doesn't like non-scalars for file handles
			print { $anvil->data->{HANDLE}{'log'}{alert} } $log_to_alert;
		}
		$anvil->data->{loop}{count} = 0;
	}
	else
	{
		Log::Journald::send(
			PRIORITY          => $priority, 
			MESSAGE           => $string, 
			CODE_FILE         => $source, 
			CODE_LINE         => $line, 
			SYSLOG_FACILITY   => $secure ? "authpriv" : $facility,
			SYSLOG_IDENTIFIER => $tag,
		);
		
		# Reset the loop counter
		$anvil->data->{loop}{count} = 0;
	}
	
	if ($print)
	{
		print $print_string."\n";
	}
	
	$anvil->data->{loop}{count}--;
	return(0);
}

=head2 is_secure

This method takes a password string. If C<< Log->secure >> is C<< 1 >>, the same string is returned. If not, C<< #!string!log_0186!# >> is returned. 

 $anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
 	user     => $user,
 	host     => $host, 
 	password => $anvil->Log->is_secure($password),
 }});

B<< NOTE >>: Unlike most methods, this one does not take a hash reference for the parameters. It takes the string directly.

=cut
sub is_secure
{
	my $self     = shift;
	my $password = shift;
	my $anvil    = $self->parent;
	
	if (not $anvil->Log->secure)
	{
		$password = $anvil->Words->string({key => "log_0186"});
	}
	
	return($password);
}

=head2 language

This sets or returns the log language ISO code.

Get the current log language;

 my $language = $anvil->Log->language;
 
Set the log langauge to Japanese;

 $anvil->Log->language({set => "jp"});

=cut
sub language
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 0;
	
	my $set   = defined $parameter->{set} ? $parameter->{set} : "";
	print $THIS_FILE." ".__LINE__."; set: [$set]\n" if $debug;
	
	if ($set)
	{
		$self->{LOG}{LANGUAGE} = $set;
		print $THIS_FILE." ".__LINE__."; LOG::LANGUAGE: [".$self->{LOG}{LANGUAGE}."]\n" if $debug;
	}
	
	print $THIS_FILE." ".__LINE__."; LOG::LANGUAGE: [".$self->{LOG}{LANGUAGE}."], defaults::log::language: [".$anvil->data->{defaults}{'log'}{language}."]\n" if $debug;
	if (not $self->{LOG}{LANGUAGE})
	{
		$self->{LOG}{LANGUAGE} = $anvil->data->{defaults}{'log'}{language};
		print $THIS_FILE." ".__LINE__."; LOG::LANGUAGE: [".$self->{LOG}{LANGUAGE}."]\n" if $debug;
	}
	
	print $THIS_FILE." ".__LINE__."; LOG::LANGUAGE: [".$self->{LOG}{LANGUAGE}."]\n" if $debug;
	return($self->{LOG}{LANGUAGE});
}

=head2 level

This sets or returns the active log level. Valid values are 0 to 4. See the 'entry()' method docs for more details.

Check the current log level:

 print "Current log level: [".$anvil->Log->level."]\n";
 
Change the current log level to 'C<< 2 >>';

 $anvil->Log->level({set => 2});

=cut
sub level
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 0;
	
	my $set   = defined $parameter->{set} ? $parameter->{set} : "";
	print $THIS_FILE." ".__LINE__."; set: [".$set."]\n" if $debug;
	
	if (($set =~ /^\d$/) && ($set >= 0) && ($set <= 4))
	{
		if ($set == 0)
		{
			$anvil->data->{defaults}{'log'}{level} = 0;
			print $THIS_FILE." ".__LINE__."; defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."]\n" if $debug;
		}
		elsif ($set == 1)
		{
			$anvil->data->{defaults}{'log'}{level} = 1;
			print $THIS_FILE." ".__LINE__."; defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."]\n" if $debug;
		}
		elsif ($set == 2)
		{
			$anvil->data->{defaults}{'log'}{level} = 2;
			print $THIS_FILE." ".__LINE__."; defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."]\n" if $debug;
		}
		elsif ($set == 3)
		{
			$anvil->data->{defaults}{'log'}{level} = 3;
			print $THIS_FILE." ".__LINE__."; defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."]\n" if $debug;
		}
		elsif ($set == 4)
		{
			$anvil->data->{defaults}{'log'}{level} = 4;
			print $THIS_FILE." ".__LINE__."; defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."]\n" if $debug;
		}
	}
	elsif ($set ne "")
	{
		# Invalid value passed.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, level => 0, priority => "err", key => "log_0047", variables => { set => $set }});
	}

	if ((not defined $anvil->data->{defaults}{'log'}{level}) or ($anvil->data->{defaults}{'log'}{level} !~ /^\d$/) or ($anvil->data->{defaults}{'log'}{level} < 0) or ($anvil->data->{defaults}{'log'}{level} > 4))
	{
		$anvil->data->{defaults}{'log'}{level} = 1;
		print $THIS_FILE." ".__LINE__."; defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."]\n" if $debug;
	}
	
	print $THIS_FILE." ".__LINE__."; defaults::log::level: [".$anvil->data->{defaults}{'log'}{level}."]\n" if $debug;
	return($anvil->data->{defaults}{'log'}{level});
}

=head2 secure

This sets or returns whether logging of sensitive log strings is enabled. 

It returns 'C<< 0 >>' if sensitive entries are *not* being logged (default). It returns 'C<< 1 >>' if they are.

Passing 'C<< 0 >>' disables recording sensitive logs. Passing 'C<< 1 >>' enables logging sensitive entries.
 
Enable logging of secure data;

 $anvil->Log->secure({set => 1});
 
 if ($anvil->Log->secure)
 {
	# Sensitive data logging is enabled.
 }
 
Disable sensitive log entry recording.

 $anvil->Log->secure({set => 0});

=cut
sub secure
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 0;
	
	my $set = defined $parameter->{set} ? $parameter->{set} : "";
	
	if (defined $set)
	{
		if ($set eq "0")
		{
			$anvil->data->{defaults}{'log'}{secure} = 0;
		}
		elsif ($set eq "1")
		{
			$anvil->data->{defaults}{'log'}{secure} = 1;
		}
	}
	
	return($anvil->data->{defaults}{'log'}{secure});
}


=head2 switches

This method returns switches to append to Alteeve tools to pass the active log level (and log secure) to our tools we call as shell calls.

Examples;

If the active log level is 1, and we're not logging secure messages;

 my $switches = $anvil->Log->switches();
 
In this case, C<< $switches >> would contain C<< -v >>.

If the active log level is 2, and we are logging secure messages;

 my $switches = $anvil->Log->switches();
 
In this case, C<< $switches >> would contain C<< -vv --log-secure >>.

B<< Note >>: The string returned is padded with a leading space so that this method can be called directly after the executable. Example;

 my $shell_call = $anvil->data->{path}{exe}{'anvil-provision-server'}.$anvil->Log->switches();

This method takes no parameters.

=cut
sub switches
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 0;
	
	my $log_level  = $anvil->Log->level;
	my $log_secure = $anvil->Log->secure;
	my $switches   = "";
	if ($log_level)
	{
		$switches .= " -";
		for (1..$log_level)
		{
			$switches .= "v";
		}
	}
	if ($log_secure)
	{
		$switches .= " --log-secure";
	}
	
	return($switches);
}


=head2 variables

This is a special method used in testing and debugging for logging a certain number of variables. It takes a hash reference via the 'C<< variables >>' parameter and creates a raw log entry showing the variables as 'C<< variable: [value] >>' pairs.

parameters;

NOTE: It takes all of the same parameters as 'C<< Log->entry >>', minus 'C<< raw >>', 'C<< key >>' and 'C<< variables >>':

head3 list (required)

This is a hash reference containing the variables to record.

If the passed in number of entries is 5 or less, the output will all be on one line. If more entries are passed, the variable/value pairs will be presented as one entry per line.

To allow for sorting, if the key starts with 's#:', that part of the key will be removed in the log. For example;

 $anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
 	"s1:i"            => $i,
 	"s2:column_name"  => $column_name, 
 	"s3:column_value" => $column_value,
 	"s4:not_null"     => $not_null,
 	"s5:data_type"    => $data_type, 
 }});
 
Would generate a sorted log entry that looks like:
 
 Aug 20 13:10:28 m3-striker01.alteeve.com anvil[9445]: Database.pm:2604; Variables:
                                                       |- i: [0]
                                                       |- column_name: [host_name]
                                                       |- column_value: [m3-striker01.alteeve.com]
                                                       |- not_null: [1]
                                                       \- data_type: [text]

All other key names are left alone and output is sorted alphabetically.

=head3 prefix (optional)

If set, this string will be prefixed to all variable names. The string passed will be separated from variable names by a space-padded hyphen. 

For example, if C<< prefix >> is set to C<< foo >>, and the variables in the list are C<< bar >> and C<< baz >>, the logged variables will be C<< foo - bar >> and C<< foo - baz >>.

B<< Note >>: If the list is short enough to be displayed on one line (three or less keys), the prefix is prepended to the list, not each variable name.

=cut
sub variables
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	my $test      = defined $parameter->{test}  ? $parameter->{test}  : 0;
	
	# Return immediately if logging is disabled globally.
	return(0) if $anvil->data->{sys}{'log'}{disable};
	
	my $language  = defined $parameter->{language}  ? $parameter->{language}  : $anvil->data->{defaults}{'log'}{language};
	my $level     = defined $parameter->{level}     ? $parameter->{level}     : 2;
	my $line      = defined $parameter->{line}      ? $parameter->{line}      : "";
	my $list      = defined $parameter->{list}      ? $parameter->{list}      : {};
	my $facility  = defined $parameter->{facility}  ? $parameter->{facility}  : $anvil->data->{defaults}{'log'}{facility};
	my $prefix    = defined $parameter->{prefix}    ? $parameter->{prefix}    : "";
	my $print     = defined $parameter->{'print'}   ? $parameter->{'print'}   : "";
	my $priority  = defined $parameter->{priority}  ? $parameter->{priority}  : "";
	my $secure    = defined $parameter->{secure}    ? $parameter->{secure}    : 0;
	my $server    = defined $parameter->{server}    ? $parameter->{server}    : $anvil->data->{defaults}{'log'}{server};
	my $source    = defined $parameter->{source}    ? $parameter->{source}    : "";
	my $tag       = defined $parameter->{tag}       ? $parameter->{tag}       : $anvil->data->{defaults}{'log'}{tag};
	
	# Exit immediately if this isn't going to be logged
	print $THIS_FILE." ".__LINE__."; debug: [".$debug."], level: [".$level."], Log->level: [".$anvil->Log->level."]\n" if $test;
	#die if $test;
	if (not defined $level)
	{
		warn $THIS_FILE." ".__LINE__."; Log->variables() called without 'level': [".$level."] defined from: [$source : $line]\n";
		$anvil->nice_exit({exit_code => 1});
	}
	elsif (not defined $anvil->Log->level)
	{
		warn $THIS_FILE." ".__LINE__."; Log->variables() called without Log->level: [".$anvil->Log->level."] defined from: [$source : $line]\n";
		$anvil->nice_exit({exit_code => 1});
	}
	print "level: [$level], logging: [".$anvil->Log->level."], secure: [$secure], logging secure: [".$anvil->Log->secure."]\n" if $test;
	if ($level > $anvil->Log->level)
	{
		return(1);
	}
	print $THIS_FILE." ".__LINE__."; secure: [".$secure."], Log->secure: [".$anvil->Log->secure."]\n" if $test;
	if (($secure) && (not $anvil->Log->secure))
	{
		return(2);
	}
	
	# If I don't have a list, or the list is empty, return.
	my $entry   = 1;
	my $entries = keys %{$list};
	print $THIS_FILE." ".__LINE__."; entries: [".$entries."]\n" if $test;
	if ($entries)
	{
		# If the key points to an undefined value, convert it to '!!undef!!' so that we don't scare
		# the user with 'undefined variable' warnings.
		foreach my $key (sort {$a cmp $b} keys %{$list})
		{
			print $THIS_FILE." ".__LINE__."; key: [".$key."]\n" if $test;
			if (not defined $list->{$key})
			{
				$list->{$key} = "!!undef!!";
				print $THIS_FILE." ".__LINE__."; list->{$key}: [".$list->{$key}."]\n" if $test;
			}
		}
		my $raw = "";
		# NOTE: If you change this, be sure to update Tools.t
		if ($entries <= 3)
		{
			# Put all the entries on one line.
			if ($prefix)
			{
				$raw = $prefix." - ";
			}
			foreach my $key (sort {$a cmp $b} keys %{$list})
			{
				print $THIS_FILE." ".__LINE__."; key: [".$key."]\n" if $test;
				# Strip a leading 'sX:' in case the user is sorting the output.
				my $say_key =  $key;
				   $say_key =~ s/^s(\d+)://;
				$raw .= "$say_key: [".$list->{$key}."], ";
				print $THIS_FILE." ".__LINE__."; raw: [".$raw."]\n" if $test;
			}
			$raw =~ s/, $//;
			print $THIS_FILE." ".__LINE__."; raw: [".$raw."]\n" if $test;
		}
		else
		{
			# Put all the entries on their own line. We'll loop twice; the first time to get the 
			# longest variable, and the second loop to print them (with dots to make the values 
			# all line up).
			my $length = 0;
			foreach my $key (sort {$a cmp $b} keys %{$list})
			{
				print $THIS_FILE." ".__LINE__."; key: [".$key."]\n" if $test;
				if (length($key) > $length)
				{
					$length = length($key);
					print $THIS_FILE." ".__LINE__."; length: [".$length."]\n" if $test;
				}
			}
			# We add '1' to account for the colon we append.
			$length++;
			print $THIS_FILE." ".__LINE__."; length: [".$length."]\n" if $test;
			
			$raw .= $anvil->Words->string({key => "log_0019"})."\n";
			print $THIS_FILE." ".__LINE__."; raw: [".$raw."]\n" if $test;
			foreach my $key (sort {$a cmp $b} keys %{$list})
			{
				print $THIS_FILE." ".__LINE__."; key: [".$key."]\n" if $test;
				# Strip a leading 'sX:' in case the user is sorting the output.
				my $say_key =  $key;
				   $say_key =~ s/^s(\d+)://;
				if ($prefix)
				{
					$say_key = $prefix." - ".$say_key;
				}
				$say_key .= ":";
				my $difference = $length - length($say_key);
				print $THIS_FILE." ".__LINE__."; say_key: [".$say_key."], difference: [".$difference."]\n" if $test;
				if ($difference)
				{
					$say_key .= " ";
					for (2..$difference)
					{
						$say_key .= ".";
					}
				}
				
				print $THIS_FILE." ".__LINE__."; entry: [".$entry."], entries: [".$entries."]\n" if $test;
				if ($entry ne $entries)
				{
					$raw .= "|- $say_key [".$list->{$key}."]\n";
					print $THIS_FILE." ".__LINE__."; raw: [".$raw."]\n" if $test;
				}
				else
				{
					$raw .= "\\- $say_key [".$list->{$key}."]\n";
					print $THIS_FILE." ".__LINE__."; raw: [".$raw."]\n" if $test;
				}
				$entry++;
				print $THIS_FILE." ".__LINE__."; entry: [".$entry."]\n" if $test;
			}
		}
		
		# Do the raw log entry.
		$anvil->Log->entry({
			test     => $test, 
			language => $language,
			level    => $level,
			line     => $line,
			facility => $facility,
			'print'  => $print, 
			priority => $priority,
			raw      => $raw,
			secure   => $secure,
			server   => $server,
			source   => $source,
			tag      => $tag,
		})
	}
	
	return(0);
}


# =head3
# 
# Private Functions;
# 
# =cut

#############################################################################################################
# Private functions                                                                                         #
#############################################################################################################

=head2 _adjust_log_level

This is a private method used by 'C<< $anvil->Get->switches >>' that automatically adjusts the active log level to 0 ~ 4. See 'C<< perldoc Anvil::Tools::Get >>' for more information.

=cut 
sub _adjust_log_level
{
	my $self      = shift;
	my $parameter = shift;
	my $anvil     = $self->parent;
	my $debug     = defined $parameter->{debug} ? $parameter->{debug} : 3;
	
	### TODO: Support '--secure' and '--no-secure' 
	if ($anvil->data->{switches}{V})
	{
		$anvil->Log->level({set => 0});
		$anvil->data->{sys}{'log'}{level} = "-V";
	}
	elsif ($anvil->data->{switches}{v})
	{
		$anvil->Log->level({set => 1});
		$anvil->data->{sys}{'log'}{level} = "-v";
	}
	elsif ($anvil->data->{switches}{vv})
	{
		$anvil->Log->level({set => 2});
		$anvil->data->{sys}{'log'}{level} = "-vv";
	}
	elsif ($anvil->data->{switches}{vvv})
	{
		$anvil->Log->level({set => 3});
		$anvil->data->{sys}{'log'}{level} = "-vvv";
	}
	elsif ($anvil->data->{switches}{vvvv})
	{
		$anvil->Log->level({set => 4});
		$anvil->data->{sys}{'log'}{level} = "-vvvv";
	}
	
	if ($anvil->data->{switches}{'log-secure'})
	{
		$anvil->Log->secure({set => 1});
	}
	if (($anvil->data->{switches}{'log-db'}) or ($anvil->data->{switches}{'log-db-transactions'}))
	{
		$anvil->data->{sys}{database}{log_transactions} = 1;
	}
	
	return(0);
}