package Smokeping::probes::base;

=head1 301 Moved Permanently

This is a Smokeping probe module. Please use the command 

C<smokeping -man Smokeping::probes::base>

to view the documentation or the command

C<smokeping -makepod Smokeping::probes::base>

to generate the POD document.

=cut

use vars qw($VERSION);
use Carp;
use lib qw(..);
use Smokeping;

$VERSION = 1.0;

use strict;

sub pod_hash {
    return {
    	name => <<DOC,
Smokeping::probes::base - Base Class for implementing SmokePing Probes
DOC
	overview => <<DOC,
For the time being, please use the L<Smokeping::probes::FPing|Smokeping::probes::FPing> for
inspiration when implementing your own probes.
DOC
	authors => <<'DOC',
Tobias Oetiker <tobi@oetiker.ch>
DOC
    };
}

sub pod {
	my $class = shift;
	my $pod = "";
	my $podhash = $class->pod_hash;
	$podhash->{synopsis} = $class->pod_synopsis;
	$podhash->{variables} = $class->pod_variables;
	for my $what (qw(name overview synopsis description variables authors notes bugs see_also)) {
		my $contents = $podhash->{$what};
		next if not defined $contents or $contents eq "";
		my $headline = uc $what;
		$headline =~ s/_/ /; # see_also => SEE ALSO
		$pod .= "=head1 $headline\n\n";
		$pod .= $contents;
		chomp $pod;
		$pod .= "\n\n";
	}
	$pod .= "=cut";
	return $pod;
}

sub new($$)
{
    my $this   = shift;
    my $class   = ref($this) || $this;
    my $self = { properties => shift, cfg => shift, 
    name => shift,
    targets => {}, rtts => {}, addrlookup => {}, rounds_count => 0};
    bless $self, $class;
    return $self;
}

sub add($$)
{
    my $self = shift;
    my $tree = shift;
    
    $self->{targets}{$tree} = shift;
}

sub ping($)
{
    croak "this must be overridden by the subclass";
}

sub round ($) {
    return sprintf "%.0f", $_[0];
}

sub ProbeDesc ($) {
    return "Probe which does not override the ProbeDesc method";
}    

sub ProbeUnit ($) {
    return "Seconds";
}    

# this is a read-only variable that should get incremented by
# the ping() method
sub rounds_count ($) {
    my $self = shift;
    return $self->{rounds_count};
}

sub increment_rounds_count ($) {
    my $self = shift;
    $self->{rounds_count}++;
}

sub target2dynfile ($$) {
    # the targets are stored in the $self->{targets}
    # hash as filenames pointing to the RRD files
    #
    # now that we use a (optionally) different dir for the
    # . adr files, we need to derive the .adr filename
    # from the RRD filename with a simple substitution

    my $self = shift;
    my $target = shift; # filename with <datadir> embedded
    my $dyndir =  $self->{cfg}{General}{dyndir};
    return $target unless defined $dyndir; # nothing to do
    my $datadir = $self->{cfg}{General}{datadir};
    $target =~ s/^\Q$datadir\E/$dyndir/;
    return $target;
}

sub rrdupdate_string($$)
{   my $self = shift;
    my $tree = shift;
#    print "$tree -> ", join ",", @{$self->{rtts}{$tree}};print "\n";    
    # skip invalid addresses
    my $pings = $self->_pings($tree);
    return "U:${pings}:".(join ":", map {"U"} 1..($pings+1)) 
        unless defined $self->{rtts}{$tree} and @{$self->{rtts}{$tree}} > 0;
    my $entries = scalar @{$self->{rtts}{$tree}};
    my @times = @{$self->{rtts}{$tree}};
    my $loss = $pings - $entries;
    my $median = $times[int($entries/2)] || 'U';
    # shift the data into the middle of the times array
    my $lowerloss = int($loss/2);
    my $upperloss = $loss - $lowerloss;
    @times = ((map {'U'} 1..$lowerloss),@times, (map {'U'} 1..$upperloss));
    my $age;
    my $dynbase = $self->target2dynfile($self->{targets}{$tree});
    if ( -f $dynbase.".adr" ) {
      $age =  time - (stat($dynbase.".adr"))[9];
    } else {
      $age = 'U';
    }
    if ( $entries == 0 ){
      $self->do_log("Warning: got zero answers from $tree->{addr}($tree->{probe}) $self->{targets}{$tree}");
      $age = 'U';
      $loss = 'U';
      if ( -f $dynbase.".adr"
	   and not -f $dynbase.".snmp" ){
	unlink $dynbase.".adr";
      }
    } ;
    return "${age}:${loss}:${median}:".(join ":", @times);
}

sub addresses($)
{
    my $self = shift;
    my $addresses = [];
    $self->{addrlookup} = {};
    foreach my $tree (keys %{$self->{targets}}){
        my $target = $self->{targets}{$tree};
        if ($target =~ m|/|) {
	   my $dynbase = $self->target2dynfile($target);
	   if ( open D, "<$dynbase.adr" ) {
	       my $ip;
	       chomp($ip = <D>);
	       close D;
	       
	       if ( open D, "<$dynbase.snmp" ) {
		   my $snmp = <D>;
		   chomp($snmp);
		   if ($snmp ne Smokeping::snmpget_ident $ip) {
		       # something fishy snmp properties do not match, skip this address
		       next;
		   }
                   close D;
	       }
	       $target = $ip;
	   } else {
	       # can't read address file skip
	       next;
	   }
	}
        $self->{addrlookup}{$target} = () 
                unless defined $self->{addrlookup}{$target};
        push @{$self->{addrlookup}{$target}}, $tree;
	push @{$addresses}, $target;
    };    
    return $addresses;
}

sub debug {
        my $self = shift;
        my $newval = shift;
        $self->{debug} = $newval if defined $newval;
        return $self->{debug};
}

sub do_debug {
        my $self = shift;
        return unless $self->debug;
        $self->do_log(@_);
}

sub do_fatal {
        my $self = shift;
        $self->do_log("Fatal:", @_);
        croak(@_);
}

sub do_log {
        my $self = shift;
        Smokeping::do_log("$self->{name}:", @_);
}

sub report {
	my $self = shift;
	my $count = $self->target_count;
	my $offset = $self->offset_in_seconds;
	my $step = $self->step;
	$self->do_log("probing $count targets with step $step s and offset $offset s.");
}

sub step {
	my $self = shift;
	my $rv = $self->{cfg}{Database}{step};
	unless (defined $self->{cfg}{General}{concurrentprobes}
	    and $self->{cfg}{General}{concurrentprobes} eq 'no') {
		$rv = $self->{properties}{step} if defined $self->{properties}{step};
	}
	return $rv;
}

sub offset {
	my $self = shift;
	my $rv = $self->{cfg}{General}{offset};
	unless (defined $self->{cfg}{General}{concurrentprobes}
	    and $self->{cfg}{General}{concurrentprobes} eq 'no') {
		$rv = $self->{properties}{offset} if defined $self->{properties}{offset};
	}
	return $rv;
}

sub offset_in_seconds {
	# returns the offset in seconds rather than as a percentage
	# this is filled in from the initialization in Smokeping::main
	my $self = shift;
	my $newval = shift;
	$self->{offset_in_seconds} = $newval if defined $newval;
	return $self->{offset_in_seconds};
}

# the "public" method that takes a "target" argument is used by the probes
# the "private" method that takes a "tree" argument is used by Smokeping.pm
# there's no difference between them here, but we have to provide both

sub pings {
	my $self = shift;
	my $target = shift;
	# $target is not used; basefork.pm overrides this method to provide a target-specific parameter
	my $rv = $self->{cfg}{Database}{pings};
	$rv = $self->{properties}{pings} if defined $self->{properties}{pings};
	return $rv;
}


sub _pings {
	my $self = shift;
	my $tree = shift;
	# $tree is not used; basefork.pm overrides this method to provide a target-specific parameter
	my $rv = $self->{cfg}{Database}{pings};
	$rv = $self->{properties}{pings} if defined $self->{properties}{pings};
	return $rv;
}

sub target_count {
	my $self = shift;
	return scalar keys %{$self->{targets}};
}

sub probevars {
	return {
		step => {
			_re => '\d+',
			_example => 300,
			_doc => <<DOC,
Duration of the base interval that this probe should use, if different
from the one specified in the 'Database' section. Note that the step in
the RRD files is fixed when they are originally generated, and if you
change the step parameter afterwards, you'll have to delete the old RRD
files or somehow convert them. (This variable is only applicable if
the variable 'concurrentprobes' is set in the 'General' section.)
DOC
		},
		offset => {
			_re => '(\d+%|random)',
			_re_error =>
			  "Use offset either in % of operation interval or 'random'",
			_example => '50%',
			_doc => <<DOC,
If you run many probes concurrently you may want to prevent them from
hitting your network all at the same time. Using the probe-specific
offset parameter you can change the point in time when each probe will
be run. Offset is specified in % of total interval, or alternatively as
'random', and the offset from the 'General' section is used if nothing
is specified here. Note that this does NOT influence the rrds itself,
it is just a matter of when data acqusition is initiated.
(This variable is only applicable if the variable 'concurrentprobes' is set
in the 'General' section.)
DOC
		},
		pings => {
			_re => '\d+',
           		_sub => sub {
                		my $val = shift;
                		return "ERROR: The pings value must be at least 3."
                        		if $val < 3;
                		return undef;
           		},
			_example => 20,
			_doc => <<DOC,
How many pings should be sent to each target, if different from the global
value specified in the Database section. Note that the number of pings in
the RRD files is fixed when they are originally generated, and if you
change this parameter afterwards, you'll have to delete the old RRD
files or somehow convert them.
DOC
		},
		_mandatory => [],
	};
}

sub targetvars {
	return {_mandatory => []};
}

# a helper method that combines two var hash references
# and joins their '_mandatory' lists.
sub _makevars {
	my ($class, $from, $to) = @_;
	for (keys %$from) {
		if ($_ eq '_mandatory') {
			push @{$to->{_mandatory}}, @{$from->{$_}};
			next;
		}
		$to->{$_} = $from->{$_};
	}
	return $to;
}

sub pod_synopsis {
	my $class = shift;
	my $classname = ref $class||$class;
	$classname =~ s/^Smokeping::probes:://;

	my $probevars = $class->probevars;
	my $targetvars = $class->targetvars;
	my $pod = <<DOC;
 *** Probes ***

 +$classname

DOC
	$pod .= $class->_pod_synopsis($probevars);
	my $targetpod = $class->_pod_synopsis($targetvars);
        $pod .= "\n # The following variables can be overridden in each target section\n$targetpod"
		if defined $targetpod and $targetpod ne "";
        $pod .= <<DOC;

 # [...]

 *** Targets ***

 probe = $classname # if this should be the default probe

 # [...]

 + mytarget
 # probe = $classname # if the default probe is something else
 host = my.host
DOC
        $pod .= $targetpod
		if defined $targetpod and $targetpod ne "";

	return $pod;
}

# synopsis for one hash ref
sub _pod_synopsis {
	my $class = shift;
	my $vars = shift;
	my %mandatory;
	$mandatory{$_} = 1 for (@{$vars->{_mandatory}});
	my $pod = "";
	for (sort keys %$vars) {
		next if /^_mandatory$/;
		my $val = $vars->{$_}{_example};
		$val = $vars->{$_}{_default}
			if exists $vars->{$_}{_default}
			and not defined $val;
		$pod .= " $_ = $val";
		$pod .= " # mandatory" if $mandatory{$_};
		$pod .= "\n";
	}
	return $pod;
}

sub pod_variables {
	my $class = shift;
	my $probevars = $class->probevars;
	my $pod = "Supported probe-specific variables:\n\n";
	$pod .= $class->_pod_variables($probevars);
	return $pod;
}

sub _pod_variables {
	my $class = shift;
	my $vars = shift;
	my $pod = "=over\n\n";
	my %mandatory;
	$mandatory{$_} = 1 for (@{$vars->{_mandatory}});
	for (sort keys %$vars) {
		next if /^_mandatory$/;
		$pod .= "=item $_\n\n";
		$pod .= $vars->{$_}{_doc};
		chomp $pod;
		$pod .= "\n\n";
		$pod .= "Example value: " . $vars->{$_}{_example} . "\n\n"
			if exists $vars->{$_}{_example};
		$pod .= "Default value: " . $vars->{$_}{_default} . "\n\n"
			if exists $vars->{$_}{_default};
		$pod .= "This setting is mandatory.\n\n"
			if $mandatory{$_};
	}
	$pod .= "=back\n\n";
	return $pod;
}
1;