# File: Rank.pm
#
# Purpose: Ranks players by various keywords.

# SPDX-FileCopyrightText: 2021-2023 Pragmatic Software <pragma78@gmail.com>
# SPDX-License-Identifier: MIT

package PBot::Plugin::Spinach::Rank;

use PBot::Imports;

use FindBin;
use lib "$FindBin::RealBin/../../..";

use PBot::Plugin::Spinach::Stats;
use Math::Expression::Evaluator;

sub new($class, %conf) {
    my $self = bless {}, $class;
    $self->initialize(%conf);
    return $self;
}

sub initialize($self, %conf) {
    $self->{pbot}     = $conf{pbot}     // Carp::croak("Missing pbot reference to " . __FILE__);
    $self->{channel}  = $conf{channel}  // Carp::croak("Missing channel reference to " . __FILE__);
    $self->{filename} = $conf{filename} // 'stats.sqlite';
    $self->{stats} = PBot::Plugin::Spinach::Stats->new(pbot => $self->{pbot}, filename => $self->{filename});
}

sub sort_generic($self, $key, @rest) {
    if   ($self->{rank_direction} eq '+') { return $b->{$key} <=> $a->{$key}; }
    else                                  { return $a->{$key} <=> $b->{$key}; }
}

sub print_generic($self, $key, $player, @rest) {
    return undef if $player->{games_played} == 0;
    return "$player->{nick}: $player->{$key}";
}

sub print_avg_score($self, $player, @rest) {
    return undef if $player->{games_played} == 0;
    my $result = int $player->{avg_score};
    return "$player->{nick}: $result";
}

sub sort_bad_lies($self, @rest) {
    if   ($self->{rank_direction} eq '+') { return $b->{questions_played} - $b->{good_lies} <=> $a->{questions_played} - $a->{good_lies}; }
    else                                  { return $a->{questions_played} - $a->{good_lies} <=> $b->{questions_played} - $b->{good_lies}; }
}

sub print_bad_lies($self, $player, @rest) {
    return undef if $player->{games_played} == 0;
    my $result = $player->{questions_played} - $player->{good_lies};
    return "$player->{nick}: $result";
}

sub sort_mentions($self, @rest) {
    if ($self->{rank_direction} eq '+') {
        return $b->{games_played} - $b->{times_first} - $b->{times_second} - $b->{times_third} <=> $a->{games_played} - $a->{times_first} - $a->{times_second} -
          $a->{times_third};
    } else {
        return $a->{games_played} - $a->{times_first} - $a->{times_second} - $a->{times_third} <=> $b->{games_played} - $b->{times_first} - $b->{times_second} -
          $b->{times_third};
    }
}

sub print_mentions($self, $player, @rest) {
    return undef if $player->{games_played} == 0;
    my $result = $player->{games_played} - $player->{times_first} - $player->{times_second} - $player->{times_third};
    return "$player->{nick}: $result";
}

sub sort_expr($self, @rest) {
    my $result = eval {
        my $result_a = $self->{expr}->val(
            {
                highscore   => $a->{high_score},
                lowscore    => $a->{low_score},
                avgscore    => $a->{avg_score},
                goodlies    => $a->{good_lies},
                badlies     => $a->{questions_played} - $a->{good_lies},
                first       => $a->{times_first},
                second      => $a->{times_second},
                third       => $a->{times_third},
                mentions    => $a->{games_played} - $a->{times_first} - $a->{times_second} - $a->{times_third},
                games       => $a->{games_played},
                questions   => $a->{questions_played},
                goodguesses => $a->{good_guesses},
                badguesses  => $a->{bad_guesses},
                deceptions  => $a->{players_deceived}
            }
        );

        my $result_b = $self->{expr}->val(
            {
                highscore   => $b->{high_score},
                lowscore    => $b->{low_score},
                avgscore    => $b->{avg_score},
                goodlies    => $b->{good_lies},
                badlies     => $b->{questions_played} - $b->{good_lies},
                first       => $b->{times_first},
                second      => $b->{times_second},
                third       => $b->{times_third},
                mentions    => $b->{games_played} - $b->{times_first} - $b->{times_second} - $b->{times_third},
                games       => $b->{games_played},
                questions   => $b->{questions_played},
                goodguesses => $b->{good_guesses},
                badguesses  => $b->{bad_guesses},
                deceptions  => $b->{players_deceived}
            }
        );

        if   ($self->{rank_direction} eq '+') { return $result_b <=> $result_a; }
        else                                  { return $result_a <=> $result_b; }
    };

    if ($@) {
        $self->{pbot}->{logger}->log("expr sort error: $@\n");
        return 0;
    }

    return $result;
}

sub print_expr($self, $player, @rest) {
    return undef if $player->{games_played} == 0;

    my $result = eval {
        $self->{expr}->val(
            {
                highscore   => $player->{high_score},
                lowscore    => $player->{low_score},
                avgscore    => $player->{avg_score},
                goodlies    => $player->{good_lies},
                badlies     => $player->{questions_played} - $player->{good_lies},
                first       => $player->{times_first},
                second      => $player->{times_second},
                third       => $player->{times_third},
                mentions    => $player->{games_played} - $player->{times_first} - $player->{times_second} - $player->{times_third},
                games       => $player->{games_played},
                questions   => $player->{questions_played},
                goodguesses => $player->{good_guesses},
                badguesses  => $player->{bad_guesses},
                deceptions  => $player->{players_deceived}
            }
        );
    };

    if ($@) {
        $self->{pbot}->{logger}->log("Error in expr print: $@\n");
        return undef;
    }

    return "$player->{nick}: $result";
}

sub rank($self, $arguments, @rest) {
    my %ranks = (
        highscore => {
            sort  => sub { $self->sort_generic('high_score', @_) },
            print => sub { $self->print_generic('high_score', @_) },
            title => 'high score'
        },
        lowscore => {
            sort  => sub { $self->sort_generic('low_score', @_) },
            print => sub { $self->print_generic('low_score', @_) },
            title => 'low score'
        },
        avgscore => {
            sort  => sub { $self->sort_generic('avg_score', @_) },
            print => sub { $self->print_avg_score(@_) },
            title => 'average score'
        },
        goodlies => {
            sort  => sub { $self->sort_generic('good_lies', @_) },
            print => sub { $self->print_generic('good_lies', @_) },
            title => 'good lies'
        },
        badlies => {
            sort  => sub { $self->sort_bad_lies(@_) },
            print => sub { $self->print_bad_lies(@_) },
            title => 'bad lies'
        },
        first => {
            sort  => sub { $self->sort_generic('times_first', @_) },
            print => sub { $self->print_generic('times_first', @_) },
            title => 'first place'
        },
        second => {
            sort  => sub { $self->sort_generic('times_second', @_) },
            print => sub { $self->print_generic('times_second', @_) },
            title => 'second place'
        },
        third => {
            sort  => sub { $self->sort_generic('times_third', @_) },
            print => sub { $self->print_generic('times_third', @_) },
            title => 'third place'
        },
        mentions => {
            sort  => sub { $self->sort_mentions(@_) },
            print => sub { $self->print_mentions(@_) },
            title => 'mentions'
        },
        games => {
            sort  => sub { $self->sort_generic('games_played', @_) },
            print => sub { $self->print_generic('games_played', @_) },
            title => 'games played'
        },
        questions => {
            sort  => sub { $self->sort_generic('questions_played', @_) },
            print => sub { $self->print_generic('questions_played', @_) },
            title => 'questions played'
        },
        goodguesses => {
            sort  => sub { $self->sort_generic('good_guesses', @_) },
            print => sub { $self->print_generic('good_guesses', @_) },
            title => 'good guesses'
        },
        badguesses => {
            sort  => sub { $self->sort_generic('bad_guesses', @_) },
            print => sub { $self->print_generic('bad_guesses', @_) },
            title => 'bad guesses'
        },
        deceptions => {
            sort  => sub { $self->sort_generic('players_deceived', @_) },
            print => sub { $self->print_generic('players_deceived', @_) },
            title => 'players deceived'
        },
        expr => {
            sort  => sub { $self->sort_expr(@_) },
            print => sub { $self->print_expr(@_) },
            title => 'expr'
        },
    );

    my @order = qw/highscore lowscore avgscore first second third mentions games questions goodlies badlies deceptions goodguesses badguesses expr/;

    if (not $arguments) {
        my $result = "Usage: rank [-]<keyword> [offset] or rank [-]<nick>; available keywords: ";
        $result .= join ', ', @order;
        $result .= ".\n";
        $result .= "Prefix with a dash to invert sort.\n";
        return $result;
    }

    $arguments = lc $arguments;

    if   ($arguments =~ s/^([+-])//) { $self->{rank_direction} = $1; }
    else                             { $self->{rank_direction} = '+'; }

    my $offset = 1;
    if ($arguments =~ s/\s+(\d+)$//) { $offset = $1; }

    my $opt_arg;
    if ($arguments =~ /^expr/) {
        if ($arguments =~ s/^expr (.+)$/expr/) { $opt_arg = $1; }
        else                                   { return "Usage: spinach rank expr <expression>"; }
    }

    if (not exists $ranks{$arguments}) {
        $self->{stats}->begin;
        my $player_id   = $self->{stats}->get_player_id($arguments, $self->{channel}, 1);
        my $player_data = $self->{stats}->get_player_data($player_id);

        if (not defined $player_id) {
            $self->{stats}->end;
            return "I don't know anybody named $arguments.";
        }

        my $players = $self->{stats}->get_all_players($self->{channel});
        my @rankings;

        foreach my $key (@order) {
            next if $key eq 'expr';
            my $sort_method = $ranks{$key}->{sort};
            @$players = sort $sort_method @$players;

            my $rank = 0;
            my $stats;
            my $last_value = -1;
            foreach my $player (@$players) {
                $stats = $ranks{$key}->{print}->($player);

                if (defined $stats) {
                    my ($value) = $stats =~ /[^:]+:\s+(.*)/;
                    $rank++ if $value ne $last_value;
                    $last_value = $value;
                } else {
                    $rank++ if lc $player->{nick} eq $arguments;
                }

                last if lc $player->{nick} eq $arguments;
            }

            if (not $rank) { push @rankings, "$ranks{key}->{title}: N/A"; }
            else {
                if (not $stats) { push @rankings, "$ranks{$key}->{title}: N/A"; }
                else {
                    $stats =~ s/[^:]+:\s+//;
                    push @rankings, "$ranks{$key}->{title}: #$rank ($stats)";
                }
            }
        }

        my $result = "$player_data->{nick}'s rankings: ";
        $result .= join ', ', @rankings;
        $self->{stats}->end;
        return $result;
    }

    $self->{stats}->begin;
    my $players = $self->{stats}->get_all_players($self->{channel});

    if ($arguments eq 'expr') {
        $self->{expr} = eval { Math::Expression::Evaluator->new($opt_arg) };
        if (my $except = $@) {
            $except =~ s/ at .*//ms;
            return "Bad expression: $except";
        }

        eval {
            $self->{expr}->optimize;
        };

        if (my $except = $@) {
           $except =~ s/ at .*//ms;
           return $except;
        }
    }

    my $sort_method = $ranks{$arguments}->{sort};
    @$players = sort $sort_method @$players;

    my @ranking;
    my $rank       = 0;
    my $last_value = -1;
    foreach my $player (@$players) {
        my $entry = $ranks{$arguments}->{print}->($player);
        if (defined $entry) {
            my ($value) = $entry =~ /[^:]+:\s+(.*)/;
            $rank++ if $value ne $last_value;
            $last_value = $value;
            next if $rank < $offset;
            push @ranking, "#$rank $entry" if defined $entry;
            last if scalar @ranking >= 15;
        }
    }

    my $result;

    if (not scalar @ranking) {
        if   ($offset > 1) { $result = "No rankings available for $self->{channel} at offset #$offset.\n"; }
        else               { $result = "No rankings available for $self->{channel} yet.\n"; }
    } else {
        if   ($arguments eq 'expr') { $result = "Rankings for $opt_arg: "; }
        else                        { $result = "Rankings for $ranks{$arguments}->{title}: "; }
        $result .= join ', ', @ranking;
    }

    $self->{stats}->end;
    return $result;
}

1;