package ChessNot;

use strict;
use warnings;

$|++;

my %is_row = map { $_ => 1 } ( 1 .. 8 );
my %is_col = do {
    my $i = 1;
    map { $_ => $i++ } ( 'a' .. 'h' )
};

my %is_piece = (
    P => 'Pawn',
    B => 'Bishop',
    N => 'Knight',
    R => 'Rook',
    Q => 'Queen',
    K => 'King',
);

sub parse
{
    my $move = shift;

    my @parse = split //, $move;

    my ($row, $col);
    my $piece = 'Pawn';
    my $action = 'moves to';
    my $have_capture = 0;
    my $start_row;
    my $start_col;
    my $check = '';
    while (my $elem = pop @parse)
    {
        $is_row{ $elem } && do {
            ($row ? $start_row : $row) = $elem;
            next;
        };

        $is_col{ $elem } && do {
            ($col ? $start_col : $col) = $is_col{ $elem };

            next;
        };

        $is_piece{ $elem } && do {
            $piece = $is_piece{ $elem };
            next;
        };

        $elem eq 'x' && do {
            $action = 'captures';
            $have_capture = 1;
            next;
        };

        $elem eq '+' && do {
            $check .= $check ? 'mate' : ', check';
            next;
        };
    }

    my $start_piece = '';
    if ($start_row || $start_col)
    {
        $start_piece = join ', ', map { $_ || '?' } $start_row, $start_col;
        $start_piece = "($start_piece) ";
    }

    return "$piece ${start_piece}$action ($row, $col)$check";
}

1;
__END__