#!/usr/bin/perl

use strict;
use warnings;

# The following statistics are from
# http://www.fifa.com/en/mens/statistics/index/0,2548,All-May-2006,00.html

my %FIFA_points =
  ("Brazil"              => 827,
   "Czech Republic"      => 772,
   "Holland"             => 768,
   "Mexico"              => 758,
   "Spain"               => 756,
   "USA"                 => 756,
   "Portugal"            => 750,
   "France"              => 749,
   "Argentina"           => 746,
   "England"             => 741,
   "Italy"               => 728,
   "Sweden"              => 709,
   "Japan"               => 705,
   "Germany"             => 696,
   "Tunisia"             => 693,
   "Iran"                => 686,
   "Croatia"             => 686,
   "Costa Rica"          => 683,
   "Poland"              => 677,
   "South Korea"         => 677,
   "Ivory Coast"         => 669,
   "Paraguay"            => 653,
   "Saudi Arabia"        => 651,
   "Switzerland"         => 648,
   "Ecuador"             => 631,
   "Australia"           => 612,
   "Serbia & Montenegro" => 610,
   "Ukraine"             => 609,
   "Trinidad & Tobago"   => 604,
   "Ghana"               => 600,
   "Angola"              => 581,
   "Togo"                => 569
  );

my %groups =
 (A => ["Germany",     "Costa Rica",     "Poland",              "Ecuador"],
  B => ["England",     "Paraguay",       "Trinidad & Tobago",   "Sweden"],
  C => ["Argentina",   "Ivory Coast",    "Serbia & Montenegro", "Holland"],
  D => ["Mexico",      "Iran",           "Angola",              "Portugal"],
  E => ["USA",         "Czech Republic", "Italy",               "Ghana"],
  F => ["Australia",   "Japan",          "Brazil",              "Croatia"],
  G => ["South Korea", "Togo",           "France",              "Switzerland"],
  H => ["Spain",       "Ukraine",        "Tunisia",             "Saudi Arabia"]
 );

my @combinations = ([0, 1], [2, 3], [0, 2], [3, 1], [3, 0], [1, 2]);

for ("A" .. "H") {
  print STDERR "\nGroup $_:\n";
  my $group = $groups{$_};
  foreach (@combinations) {
    my $a = $group->[$_->[0]];
    my $b = $group->[$_->[1]];
    my $home_advantage = $FIFA_points{$a} - $FIFA_points{$b};
    my $score = get_score($home_advantage);
    print STDERR "$a vs $b ($score)\n";
  }
}

sub get_score {
  my ($points_diff) = @_;
  my $score = 0;
  my $other = 0;
  if (abs $points_diff <= 30) {
    $score = 0;
  }
  elsif (abs $points_diff <= 80) {
    $score = 1;
  }
  elsif (abs $points_diff <= 130) {
    $score = 2;
  }
  elsif (abs $points_diff <= 200) {
    $score = 3;
  }
  else {
    $score = 4;
  }

  my $random_factor = rand;
  if ($random_factor > 0.9) {
    $score += 2;
    $other += 2;
  }
  elsif ($random_factor <= 0.9 and $random_factor > 0.75) {
    $score += 1;
    $other += 1;
  }

  if ($points_diff == abs $points_diff) {
    return "${score}-${other}";
  }
  else {
    return "${other}-${score}";
  }
}