# global variables
our $dsl_cache_basicstats_time=0; 	# last time we got real data from device
our $dsl_cache_basicstats_cache=10; 	# cache time, data older than this
					# is considered outdated (300 seconds)

our @dsl_cache_basicstats_data=(	# our array of basic stats
				0,	# time (last retrieved basic stats)
				0,	# snr_dn - signal noise margin
				0,	# snr_up
				0,	# att_dn - attenuation
				0,	# att_up
				0,	# pwr_dn - power (dBm)
				0,	# pwr_up
				0,	# capa_dn - line capacity
				0,	# capa_up
				0,	# rate_dn - actual rate
				0,	# rate_dn
				0,	# perc_dn
				0,	# perc_up
				);

sub dsl_cache_basicstats ($)
{
    # making a new telnet connection each time a value is requested is a waste
    # of ressources and puts a significant load onto the device.
    # we retrieve all of the basic data at once, cache them and return 
    # cached values instead of the real data if cached data is not older than 
    # five minutes
    debug("dsl basicstats cache controller\n");
    
    $current_time=time();
    debug("current time: $current_time\n");
    
    if ( ($dsl_cache_basicstats_time + $dsl_cache_basicstats_cache) > $current_time )
    {
	debug("basic stats are not outdated - returning cached data\n");
    }
    else
    {
	debug("basic stats are quite old - refreshing now...\n");
	$comm=open_telnet();
	if ( $commstatus == 9 ) 
	{
	    debug ("retrieving data from device\n");
	    @output=$comm->cmd("adsl info --stats");
	    if ( $commstatus == 9 ) 
	    {
    		close_telnet($comm);
    	        $snr_dn=rwhite(substr(substr(@output[12],16),0,-5));
		$snr_up=rwhite(substr(@output[12],25));
    	    	$att_dn=rwhite(substr(substr(@output[13],16),0,-5));
        	$att_up=rwhite(substr(@output[13],25));
		$pwr_dn=rwhite(substr(substr(@output[14],16),0,-5));
    	    	$pwr_up=rwhite(substr(@output[14],25));
    		$capa_dn=rwhite(substr(substr(@output[15],16),0,-5));
    		$capa_up=rwhite(substr(@output[15],25));
    		$rate_dn=rwhite(substr(substr(@output[16],16),0,-5));
    		$rate_up=rwhite(substr(@output[16],25));
    		$perc_dn=100 * $rate_dn / $capa_dn;
		$perc_up=100 * $rate_up / $capa_up;
		our @dsl_cache_basicstats_data=(	# our array of basic stats
					time(),		# time 
					$snr_dn,	# snr_dn
					$snr_up,	# snr_up
					$att_dn,	# att_dn
					$att_up,	# att_up
					$pwr_dn,	# pwr_dn
					$pwr_up,	# pwr_up
					$capa_dn,	# capa_dn
					$capa_up,	# capa_up
					$rate_dn,	# rate_dn
					$rate_up,	# rate_dn
					$perc_dn,	# perc_dn
					$perc_up,	# perc_up
					);	
		$dsl_cache_basicstats_time=time();
		debug (@dsl_cache_basicstats_data."\n");
		debug ("
	    $dsl_cache_basicstats_data[0]
	    $dsl_cache_basicstats_data[1]
	    $dsl_cache_basicstats_data[2]
	    $dsl_cache_basicstats_data[3]
	    $dsl_cache_basicstats_data[4]
	    $dsl_cache_basicstats_data[5]
	    $dsl_cache_basicstats_data[6]
	    $dsl_cache_basicstats_data[7]
	    $dsl_cache_basicstats_data[8]
	    $dsl_cache_basicstats_data[9]
	    $dsl_cache_basicstats_data[10]
	    $dsl_cache_basicstats_data[11]
	    $dsl_cache_basicstats_data[12]\n");
	    }
	    else
	    {
		debug ("eeek! while retrieving data from device:\n");
		debug ("connection problem. can't refresh, failing back to cached data\n");
	    }
	}
	else
	{
	    debug ("eeek! while connecting to device:\n");
	    debug ("eeek! connection problem. can't refresh, failing back to cached data\n");
	}
    }
    debug ("begin request processing\n");
    $request=shift;
    debug ("request as given in argument 1: $request\n");
    if ( $request == "snr" ) 
    { 
	debug("reqest: snr/$request\n"); 
	my ($retval1,$retval2) = ($dsl_cache_basicstats_data[1],$dsl_cache_basicstats_data[2]); 
    }
    elsif ( $request == "att" ) 
    { 
	debug("reqest: att/$request\n"); 
	my ($retval1,$retval2) = ($dsl_cache_basicstats_data[3],$dsl_cache_basicstats_data[4]); 
    }    
    elsif ( $request == "pwr" ) 
    { 
	debug("reqest: pwr/$request\n"); 
	my ($retval1,$retval2) = ($dsl_cache_basicstats_data[5],$dsl_cache_basicstats_data[6]); 
    }
    elsif ( $request == "capa" ) 
    { 
	debug("reqest: capa/$request\n"); 
	my ($retval1,$retval2) = ($dsl_cache_basicstats_data[7],$dsl_cache_basicstats_data[8]); 
    }    
    elsif ( $request == "rate" ) 
    { 
	debug("reqest: rate/$request\n"); 
	my ($retval1,$retval2) = ($dsl_cache_basicstats_data[9],$dsl_cache_basicstats_data[10]); 
    }
    elsif ( $request == "perc" ) 
    { 
	debug("reqest: perc/$request\n"); 
	my ($retval1,$retval2) = ($dsl_cache_basicstats_data[11],$dsl_cache_basicstats_data[12]); 
    }    
    else 
    { 
	debug ("fall through... oh my dear\n"); 
	my ($retval1,$retval2) = ("error","unspecified request: $request"); 
    }
    debug ("end request processing\n");
    return ($retval1,$retval2);
}