#!/usr/bin/perl
#
# Shows the route of an Internet mail message
# Copyright (c) 1999 Marius Gedminas <mgedmin@takas.lt>
#           (c) 2000-2011 Roland Rosenfeld <roland@spinnaker.de>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# Based on Version 0.0.1pre-alpha by Marius Gedminas.
# Patched by Roland Rosenfeld <roland@spinnaker.de>
#
# $Id: mailhops,v 1.4 2011/08/04 13:13:35 roland Exp roland $

use warnings;
use strict;
use Date::Parse;

my $verbose = 0;

# Read headers
$/ = '';
my $head = <>;
$head =~ s/\n\s+/ /g;
my @headers = split("\n", $head);

# Parse headers
my @hops;
for (@headers) {
  next unless /^(>?Received|Date):/;
  my $time;
  my $host;
  my $from;
  if (/^Date:\s+(.*)/) {
    $host = "Date:";
    $time = $1;
    $from = "";
  } else {
    $host = "(unknown)";
    $host = $1 if /\sby\s+([a-z0-9\-_+.]+)\s/ && $1 ne "uid";
    $from = "(unknown)";
    $from = $1 if /\sfrom\s+([a-z0-9\-_+.]+(?:\s+[(].+?[)]))\s/;
    $time = "(unknown)";
    $time = $1 if /;\s+(.+)$/;
    $time =~ s/using.*//;
  }

  my $epoch = str2time ($time);

  unshift @hops, { HOST => $host, FROM => $from, TIME => $epoch};
}

# Print output
print "    Host                            Date received (local)   Lag       Total lag\n";
my $nr = 0;
my ($first, $prev);
for (@hops) {
  my $host = $_->{HOST};
  my $from = $_->{FROM};
  my $time = $_->{TIME};
  $first = $prev = $time unless defined $first;
  printf "%2d. %-31.31s", ++$nr, $host;
  do { print "\n"; next } unless defined $time;

  my $delta = $time - $prev;
  my $neg = $delta < 0; $delta = abs($delta);
  my $delta_h = int($delta / 3600);
  my $delta_m = int(($delta - $delta_h * 3600) / 60);
  my $delta_s = ($delta - $delta_h * 3600 - $delta_m * 60);

  my ($sec,$min,$hour,$day,$mon,$year,undef,undef,$dst) = localtime($time);

  printf "  %4d-%02d-%02d  %02d:%02d:%02d  %s%02d:%02d:%02d",
         1900+$year, $mon+1, $day, $hour, $min, $sec,
	 $neg ? '-' : ' ', $delta_h, $delta_m, $delta_s;

  $delta = $time - $first;
  $neg = $delta < 0; $delta = abs($delta);
  $delta_h = int($delta / 3600);
  $delta_m = int(($delta - $delta_h * 3600) / 60);
  $delta_s = ($delta - $delta_h * 3600 - $delta_m * 60);
  printf "  %s%02d:%02d:%02d\n",
	 $neg ? '-' : ' ', $delta_h, $delta_m, $delta_s;
  print  "     from $from\n" if $verbose;
  $prev = $time;
}