use v6;

my @deck = new_deck();

my $next = combo(5, @deck);
my @combo;
while ( @combo = $next() ) {
    # Skip all hands that do not contain a 5
    next if ! grep { $_<val> == 5 } @combo;

    # Skip all hands that have a score of at least 2
    my $score = score( @combo );
    next if $score > 1; 

    # Print out the rest
    say join ' ', $score, map -> $_ { $_<disp> ~ $_<suit> } @combo;
}

sub score ( @hand ) returns Int {
    my $score = 0;
    # Last card is always cut card (for purposes of right-jack and flush)


    # [234] of a kind
    my %of_a_kind = (1 => 0, 2 => 2, 3 => 6, 4 => 12);
    my %seen;
    for ( map -> $_ { $_<disp> } @hand ) {
        %seen{$_}++; 
    }
    for ( values %seen ) { $score += %of_a_kind{$_} }

    # Flush
    my %suit = map -> $_ { $_<suit> => 1 } @hand[0 .. 3];
    $score += 4 if +%suit == 1;
    $score++ if %suit{ @hand[ -1 ] };

    # Count 15's
    my @vals = map -> $_ { $_<val> } @hand;
    for ( 2 .. 5 ) {
        my $next = combo($_, @vals);
        my @combo;
        while ( @combo = $next() ) {
            my $tot = 0;
            for ( @combo ) { $tot += $_ }
            $score += 2 if $tot == 15;
        }
    }

    # Check for right-jack
    for ( @hand[0 .. 3] ) {
        if ( $_<disp> eq 'J' ) {
            if ( $_<suit> eq @hand[ -1 ]<suit> ) {
                $score++;
                last;
            }
        } 
    }

    # Check for runs
    my @nums = map -> $_ { $_<num> } @hand;
    my $found;
    for ( 5, 4, 3 ) {
        last if $found;
        my $next = combo($_, @nums);
        my @combo;
        while ( @combo = $next() ) {
            @combo = sort { $^a <=> $^b } @combo;
            my ($prev, $in_sequence) = (0, 1);
            for ( @combo ) {
                if ( ! $prev ) {
                    $prev = $_;
                    next;
                }
                if ( $_ - $prev != 1 ) {
                    $in_sequence = 0;
                    last;
                }
                $prev = $_;
            }
            if ( $in_sequence ) {
                $found = 1;
                $score += $_; 
            }
        }
    }
    
    return $score;
}

sub combo (Int $by is copy, @list is copy) returns Ref {
    my @position = 0 .. ($by - 2), $by - 2;
    my @stop     = @list.elems - $by .. @list.end;
    my $done     = undef;
    return sub {
        return () if $done;
        my $cur = @position.end;
        while ( ++@position[ $cur ] > @stop[ $cur ] ) {
            --$cur;
            @position[ $cur ]++;
            next if @position[ $cur ] > @stop[ $cur ];
            my $new_pos = @position[ $cur ];
            @position[ $cur .. @position.end ] = $new_pos .. ($new_pos + $by);
            last;
        }
        $done = 1 if @position[ 0 ] == @stop[ 0 ]; 
        return @list[ @position ];
    };
}

sub new_deck () returns Array {
    my @deck;
    my %val = map -> $_ { $_ => $_ } 1..10;
    %val{ 11..13 } = (10) xx 3;
    my %disp = map -> $_ { $_ => $_ } 2..10;
    %disp{ 1, 11..13 } = qw<A J Q K>;
    for ( 1..13 ) {
        push @deck,
            { 'num' => $_, 'val' => %val{$_}, 'suit' => 'H', 'disp' => %disp{$_} },
            { 'num' => $_, 'val' => %val{$_}, 'suit' => 'D', 'disp' => %disp{$_} },
            { 'num' => $_, 'val' => %val{$_}, 'suit' => 'C', 'disp' => %disp{$_} },
            { 'num' => $_, 'val' => %val{$_}, 'suit' => 'S', 'disp' => %disp{$_} },
    }
    return @deck;
}