#!/bin/env perl
use strict;
use warnings;
use List::Util qw(min max);
use Math::BigInt;

my @filenames = @ARGV;

#Define empty hash. This will be a hash of all the filenames. Within the hash each filename points to an array containing the entire contents of the file, and an array of timestamps.
my %all_files=();

#>32 hex to dec function
sub hex2dec {
  my $hex = shift;
  return Math::BigInt->from_hex("0x$hex");
}

#For each file on the command line, create a new hash entry indexed by the filename. Each entry is an array containing the contents of the file.
foreach my $filename (@filenames) {
  open(my $handle, "<", "$filename") or die "Failed to open file $filename: $!\n";
  while(<$handle>) {
    chomp;
    my $fullline = $_;
    if($fullline =~ m/(\w+).*/) {
	    #Store contents of line
	    my $timestamp = $1;
      push @{$all_files{$filename}}, $fullline;
      push @{$all_files{"${filename}.timestamp"}}, $timestamp;
    } else {
	    print "Unexpected line format: $fullline in $filename\n";
	    exit;
    }
  }
  close $handle;
  $all_files{"${filename}.neof"} = 1;
}

my $neofs = 1;
my @minarray = ();
my $min = 0;
my $storeline = "";
my @mergedlogs = ();
my $matchmin=0;
my $line=0;
while ($neofs == 1) {
  print "$line\n";
  $line++;
  $neofs = 0;
  #First find the lowest count
  foreach my $filename (@filenames) {
    print "@{$all_files{\"${filename}.timestamp\"}}[0]\n";
    my $tmpdec=hex2dec(@{$all_files{"${filename}.timestamp"}}[0]);
    print "$tmpdec\n";
    push @minarray, hex2dec(@{$all_files{"${filename}.timestamp"}}[0]);
  }
  $min = min @minarray;
  @minarray = ();
  #For each file matching the lowest count, shift out the current line
  foreach my $filename (@filenames) {
    print "$filename $min";
    $matchmin=0;
    if(hex2dec(@{$all_files{"${filename}.timestamp"}}[0]) == $min && $all_files{"${filename}.neof"} == 1) {
      $matchmin=1;
      $storeline = shift @{$all_files{$filename}};
      shift @{$all_files{"${filename}.timestamp"}};
      #Check if array is empty (i.e. file completed)
      if ( ! @{$all_files{$filename}}) {
        #If so, set not end of file to 0
        $all_files{"${filename}.neof"} = 0;
        #Force count value to max so that it loses all future min battles
        push @{$all_files{"${filename}.timestamp"}}, "10000000000";
      }
      #Push the line to the merged file.
      push @mergedlogs, "$storeline $filename";
    }
    $neofs = $neofs || $all_files{"${filename}.neof"};
  }
}

unlink "mergedlogs.txt";
foreach (@mergedlogs)
{
  open FH, ">>mergedlogs.txt" or die "can't open mergedlogs.txt: $!";
  print FH "$_\n";
  close FH
}