#! /usr/bin/perl
use strict;
use warnings;
no warnings qw(once);
use CGI;
use CGI::Carp qw( fatalsToBrowser );
use DBI;
use POSIX;
use Devel::Peek;
use HTML::Entities;
use Encode;
use utf8;
use locale;
require '../config.pm';
require '../common.pm';

my $cgi = CGI->new;

my $dbh = DBI->connect($config::local_connstr, $config::local_username, $config::local_password)
	or die "connect: " . $DBI::errstr;
$dbh->{AutoCommit} = 0;
$dbh->{RaiseError} = 1;

my $trials = 25_000;

binmode STDOUT, ':utf8';

my %players = ();
my %ratings = ();
my %ratings_stddev = ();
my @matches = ();

sub sanitize {
	return HTML::Entities::encode_entities(shift);
}

sub color {
	my $x = shift;
	return int(255.0 * ($x ** (1.80)));
}

sub get_max_season {
	my $dbh = shift;
	my $ref = $dbh->selectrow_hashref('SELECT MAX(sesong) AS max_sesong FROM fotballserier');
	return $ref->{'max_sesong'};
}

sub get_divisions {
	my ($dbh, $season) = @_;

	my @divisions = ();

	my $q = $dbh->prepare('SELECT DISTINCT(divisjon) FROM fotballserier WHERE sesong=? ORDER BY divisjon');
	$q->execute($season);

	while (my $ref = $q->fetchrow_hashref) {
		push @divisions, $ref->{'divisjon'};
	}

	return @divisions;
}

sub get_subdivisions {
	my ($dbh, $season, $division) = @_;

	my @subdivisions = ();

	my $q = $dbh->prepare('SELECT DISTINCT(avdeling) FROM fotballserier WHERE sesong=? AND divisjon=? ORDER BY avdeling');
	$q->execute($season, $division);

	while (my $ref = $q->fetchrow_hashref) {
		push @subdivisions, $ref->{'avdeling'};
	}

	return @subdivisions;
}

sub print_division_selector {
	my ($dbh, $divisions, $subdivisions, $division, $subdivision) = @_;

	print <<"EOF";
    <form method="get" action="/">
EOF

	my $max_division = $divisions->[(scalar @$divisions) - 1];

	print <<"EOF";
     <p>Divisjon:
        <select name="divisjon" onchange="form.submit();">
EOF

	for my $d (@$divisions) {
		if ($d == $division) {
			print "        <option value=\"$d\" selected=\"selected\">$d</option>\n";
		} else {
			print "        <option value=\"$d\">$d</option>\n";
		}
	}

	print <<"EOF";
        </select>
        Avdeling:
        <select name="avdeling" onchange="form.submit();">
EOF

	for my $sd (@$subdivisions) {
		if ($sd == $subdivision) {
			print "        <option value=\"$sd\" selected=\"selected\">$sd</option>\n";
		} else {
			print "        <option value=\"$sd\">$sd</option>\n";
		}
	}

	print <<"EOF";
        </select>
        <input type="submit" value="Vis" />
      </p>
    </form>
EOF
}

sub get_players_and_ratings {
	my ($dbh, $season, $division, $subdivision) = @_;

	my $q = $dbh->prepare('SELECT fotballdeltagere.id,fotballdeltagere.navn,rating,rating_stddev FROM fotballdeltagere JOIN fotballserier ON fotballdeltagere.serie=fotballserier.nr LEFT JOIN ratings ON fotballdeltagere.id=ratings.id WHERE sesong=? AND divisjon=? AND avdeling=?');
	$q->execute($season, $division, $subdivision);

	while (my $ref = $q->fetchrow_hashref) {
		my $id = $ref->{'id'};
		$players{$id} = sanitize(Encode::decode_utf8($ref->{'navn'}));
		$ratings{$id} = $ref->{'rating'};
		$ratings_stddev{$id} = $ref->{'rating_stddev'};
	}
	$q->finish;
}

sub get_matches {
	my ($dbh, $season, $division, $subdivision) = @_;

	my @matches = ();
	my $q = $dbh->prepare('
	SELECT
	  d1.id AS p1, d2.id AS p2, maalfor AS score1, maalmot AS score2
	FROM fotballresultater r
	  JOIN fotballserier s ON r.serie=s.nr
	  JOIN fotballdeltagere d1 ON r.lagrecno=d1.nr AND r.serie=d1.serie
	  JOIN fotballdeltagere d2 ON r.motstander=d2.nr AND r.serie=d2.serie
	WHERE
	  sesong=? AND divisjon=? AND avdeling=?
	  AND lagrecno > motstander
	');
	$q->execute($season, $division, $subdivision);

	while (my $ref = $q->fetchrow_hashref) {
		push @matches, [ $ref->{'p1'}, $ref->{'p2'}, $ref->{'score1'}, $ref->{'score2'} ];
	}
	$q->finish;

	return @matches;
}

sub get_covariance_matrix {
	my ($dbh, @players) = @_;

	my $player_sql = '{' . join(',', @players ) . '}';
	my $q = $dbh->prepare('SELECT * FROM covariance WHERE player1=ANY(?::smallint[]) AND player2=ANY(?::smallint[])', { pg_prepare_now => 0 });
	$q->execute($player_sql, $player_sql);

	my $cov = {};
	while (my $ref = $q->fetchrow_hashref) {
		$cov->{$ref->{'player1'}}{$ref->{'player2'}} = $ref->{'cov'};
	}

	return $cov;
}

sub write_parms_to_file {
	my ($aux_parms, $match_stddev, $used_ratings, $used_cov) = @_;

	POSIX::setlocale(&POSIX::LC_ALL, 'C');

	my $tmpnam = POSIX::tmpnam();
	open MCCALC, ">", $tmpnam
		or die "$tmpnam: $!";

	printf MCCALC "%f\n", $match_stddev;
	printf MCCALC "%d\n", scalar keys %players;

	for my $id (keys %players) {
		my $rating = $used_ratings->{$id} // 500.0;
		printf MCCALC "%s %f\n", $id, $rating;
	}

	# covariance matrix
	for my $id1 (keys %players) {
		for my $id2 (keys %players) {
			if ($id1 == $id2) {
				printf MCCALC "%f ", ($used_cov->{$id1}{$id2} // $aux_parms->{-3});
			} else {
				printf MCCALC "%f ", ($used_cov->{$id1}{$id2} // 0.0);
			}
		}
		printf MCCALC "\n";
	}

	for my $match (@matches) {
		printf MCCALC "%s %s %d %d\n", $match->[0], $match->[1], $match->[2], $match->[3];
	}
	close MCCALC;

	POSIX::setlocale(&POSIX::LC_ALL, 'nb_NO.UTF-8');

	return $tmpnam;
}

sub make_table {
	my ($aux_parms, $match_stddev, $lowest_division, $used_ratings, $used_cov) = @_;

	print <<"EOF";

    <table>
      <tr>
        <th></th>
EOF

	my $tmpnam = write_parms_to_file($aux_parms, $match_stddev, $used_ratings, $used_cov);
	my %prob = ();

	open MCCALC, "$config::base_dir/mcwordfeud $trials < $tmpnam |"
		or die "mccalc: $!";
	while (<MCCALC>) {
		chomp;
		my @x = split /\s+/;
		my $id = $x[0];
		my $player = sprintf "%s (%.0f ± %.0f)", $players{$id}, ($ratings{$id} // 500.0), ($ratings_stddev{$id} // $aux_parms->{-3});
		$prob{$player} = [ @x[1..$#x] ];
	}
	close MCCALC;
	#unlink $tmpnam;

	my $num_games = scalar keys %prob;
	for my $i (1..$num_games) {
		print "        <th>$i.</th>\n";
	}
	print "        <th>NEDRYKK</th>\n" unless ($lowest_division);
	print "      </tr>\n";

	for my $player (sort { $a cmp $b } keys %prob) {
		print "      <tr>\n";
		print "        <th>$player</th>\n";

		for my $i (1..$num_games) {
			my $pn = $prob{$player}->[$i - 1] / $trials;

			my $r = color(1.0 - $pn / 3);
			my $g = color(1.0 - $pn / 3);
			my $b = color(1.0);

			if ($i == 1) {
				($g, $b) = ($b, $g);
			} elsif ($i >= $num_games - 1 && !$lowest_division) {
				($r, $b) = ($b, $r);
			}

			printf "        <td style=\"background-color: rgb($r, $g, $b)\" class=\"num\">%.1f%%</td>\n", $pn * 100.0;
		}

		unless ($lowest_division) {
			my $pn = ($prob{$player}->[$num_games - 1] + $prob{$player}->[$num_games - 2]) / $trials;

			my $r = color(1.0);
			my $g = color(1.0 - $pn / 3);
			my $b = color(1.0 - $pn / 3);
			printf "        <td style=\"background-color: rgb($r, $g, $b)\" class=\"num\">%.1f%%</td>\n", $pn * 100.0;
		}
		print "      </tr>\n";
	}

	print << "EOF";
    </table>
EOF
}

sub find_avg_rating {
	my ($ratings) = shift;

	my $sum_rating = 0.0;
	for my $r (values %$ratings) {
		$sum_rating += $r;
	}
	return $sum_rating / scalar keys %ratings;
}

sub get_auxillary_parameters {
	my $q = $dbh->prepare('SELECT * FROM ratings WHERE id < 0');
	$q->execute;

	my $aux_parms = {};
	while (my $ref = $q->fetchrow_hashref) {
		$aux_parms->{$ref->{'id'}} = $ref->{'rating'};
	}
	return $aux_parms;
}

sub print_header {
	my ($cgi, $title) = @_;
	print $cgi->header(-type=>'text/html; charset=utf-8', -expires=>'now');
	print <<"EOF";
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE
  html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
  "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="no">
  <head>
    <title>$title</title>
    <link rel="stylesheet" href="/style" type="text/css" />
  </head>
  <body>
EOF
}

sub print_footer {
	my $dbh = shift;
	wloh_common::output_last_sync($dbh);

	print <<"EOF";
  </body>
</html>
EOF
}

my $aux_parms = get_auxillary_parameters($dbh);
my $match_stddev = $aux_parms->{-2} * sqrt(2.0);

my $season;
my $division = $cgi->param('divisjon') // -1;
my $subdivision = $cgi->param('avdeling') // -1;

my $season = get_max_season($dbh);
my @divisions = get_divisions($dbh, $season);
$division = 1 if (!grep { $_ == $division } @divisions);
my @subdivisions = get_subdivisions($dbh, $season, $division);
$subdivision = 1 if (!grep { $_ == $subdivision } @subdivisions);

get_players_and_ratings($dbh, $season, $division, $subdivision);
my @matches = get_matches($dbh, $season, $division, $subdivision);
my $cov = get_covariance_matrix($dbh, keys %players);

print_header($cgi, 'WLoH-plasseringsannsynlighetsberegning');

POSIX::setlocale(&POSIX::LC_ALL, 'nb_NO.UTF-8');
printf <<"EOF", $match_stddev;
    <h1>WLoH-plasseringsannsynlighetsberegning</h1>

    <p><em>Dette er et hobbyprosjekt fra tredjepart, og ikke en offisiell del av
      <a href="http://wordfeud.aasmul.net/">Wordfeud Leage of Honour</a>.</em></p>

    <p>Beregningen tar ikke hensyn til ujevn spillestyrke, ting som er sagt i forumet e.l.;
      den antar at samtlige uspilte kamper trekkes fra en normalfordeling med standardavvik
      %.1f poeng. Sannsynlighetene kan summere til andre tall enn 100%% pga. avrunding.
      Tallene vil variere litt fra gang til gang fordi utregningen skjer ved randomisering.</p>

    <p>Spillerne er sortert etter nick.</p>
EOF

print_division_selector($dbh, \@divisions, \@subdivisions, $division, $subdivision);

my $max_division = $divisions[$#divisions];
my $lowest_division = ($division == $max_division);
make_table($aux_parms, $match_stddev, $lowest_division, {}, {});

print <<"EOF";
    <p>Under er en variant som tar relativ spillestyrke med i beregningen;
      se <a href="/rating">ratingsiden</a>.</p>
EOF

make_table($aux_parms, $match_stddev, $lowest_division, \%ratings, $cov);

my $avg_rating = find_avg_rating(\%ratings);
printf "    <p>Gjennomsnittlig rating i denne avdelingen er <strong>%.1f</strong>.</p>\n", $avg_rating;

print_footer($dbh);
