#!/usr/bin/perl
use strict;
use warnings;

my @FILENAMES_ARP = <./*arp*.txt>;
my @FILENAMES_MAC = <./*mac*.txt>;
# use File::Slurp;	this way this works:  my @LINES =read_file($FILE );
my %MACS;
my $FILE;


my $CLEAN_ARP_REC = './clean_arp.tmp';
open (OUTPUT, ">", $CLEAN_ARP_REC) or die "Could not open $CLEAN_ARP_REC because $!"; 

for $FILE (@FILENAMES_MAC){
	print "processing $FILE...\n";
	if( open(FH, "<", $FILE) ){
		while(<FH>){
			chomp;
			next unless /^\*/; # skip if line does not start with "*", for example, empty lines
			next if /static/; # skip static entries
			my @F = split(/\s+/, $_);
			my $VLAN = $F[1];
			my $MAC =$F[2];
			my $INT = $F[7];
			next unless $MAC=~/^[0-9a-f]{4}\.[0-9a-f]{4}\.[0-9a-f]{4}$/;
			if($MACS{$MAC}){
				warn "$MAC already defined, skipping entry at line $.\n";
			}else{
				$MACS{$MAC}{VLAN}=$VLAN;
				$MACS{$MAC}{INT}=$INT;
			}
		}
		close FH;
	}else{
		warn "Could not open $FILE, skipping. Errormsg=$!\n";
	}
}	

for $FILE (@FILENAMES_ARP){
	print "Processing $FILE...\n";
	if( open(FH, "<", $FILE) ){
		while(<FH>){
			chomp;
			my @F = split(/\s+/, $_);
			my $MAC = $F[3];
			my $VLAN = $F[5];
			my $IP = $F[1];
			next unless $IP; # must be defined?
			if($MACS{$MAC}){
				$MACS{$MAC}{IP}=$IP; # add this extra data
				$MACS{$MAC}{_}=1; # have to "merge"
			}
		}
		close FH;
	}else{
		warn "Could not open $FILE, skipping. Errormsg=$!\n";
	}
}

for my $MAC (sort keys %MACS){
	if( defined $MACS{$MAC}{_} ){
		print OUTPUT $MAC 
			. ", " . $MACS{$MAC}{IP}
			. ", " . $MACS{$MAC}{VLAN}
			. ", " . $MACS{$MAC}{INT}
			."\n";
	}else{
		# normal line, do not print ?	
	}
}

close OUTPUT;