#!/usr/bin/perl
use strict;
use warnings 'all';

# create the Map
my $map = new Map;

# set Map size and start position by user
$map->matrix()->position();

# MainLoop
MAIN:
while (1)
{
    # clear screen
    system($^O =~ /win/i ? "cls" : "clear");

    # draw the Map
    $map->draw();

    # get user input
    print "
1/w:forward\t2/s:back\t3/a:left\t4/d:right
5/q:quit
IN: ";
    chomp(my$in = <STDIN>);
    $in =~ s/\s*//;

    # evaluate user input
    if ($in =~ /^[1w]$/i)
    {
        # move forwards
        $map->move(0, -1);
    }
    elsif ($in =~ /^[2s]$/i)
    {
        # move backwards
        $map->move(0, 1);
    }
    elsif ($in =~ /^[3a]$/i)
    {
        # move leftwards
        $map->move(-1, 0);
    }
    elsif ($in =~ /^[4d]$/i)
    {
        # move rightwards
        $map->move(1, 0);
    }
    elsif ($in =~ /^[5q]$/i)
    {
        # stop MainLoop
        last MAIN;
    }
    else
    {
        print "
Wrong input: $in
";
        <STDIN>;
    }
} # MainLoop

# exit if the MainLoop is stopped
exit(0);

package Map;
use strict;
use warnings 'all';

#
# create a new object
#
sub new
{
    my $class = shift;

    my $obj =
    {
        matrix    => ["*"], # 1d matrix to save the Map data
        pos    => [1,1], # array with x and y position in the Map(count from 1)
        width    =>     1, # width of the matrix(count from 1)
        height    =>     1, # height of the matrix(count from 1)
    };
    bless $obj, $class;

    return $obj;
} # new

#
# create the matrix by given width and height
#
sub dat
{
    my $self = shift;
    my($width, $height) = @_;

    $self->{width}  = $width;
    $self->{height} = $height;
    $self->{matrix} = [split("","."x($width*$height))];

    return $self;
} # dat

#
# set the startposition by given x and y coordinate
#
sub pos
{
    my $self   = shift;
    my($x, $y) = @_;

    # we have a 1d matrix, so the index must be: x+width*y
    $self->{matrix}->[$self->{pos}->[0]-1+$self->{width}*($self->{pos}->[1]-1)] = ".";
    $self->{pos}   = [$x, $y];
    $self->{matrix}->[$x               -1+$self->{width}*($y               -1)] = "*";

    return $self;
} # pos

#
# set the matrix by user
#
sub matrix
{
    my $self = shift;

    print "Rows: ";
    chomp(my$r = <STDIN>);

    print "Columns: ";
    chomp(my$c = <STDIN>);

    return $self->dat($c, $r);
} # matrix

#
# set the startposition by user
#
sub position
{
    my $self = shift;

    print "Startrow: ";
    chomp(my$r = <STDIN>);

    print "Startcolumn: ";
    chomp(my$c = <STDIN>);

    return $self->pos($c, $r);
} # position

#
# change position with amount
#
sub move
{
    my $self     = shift;
    my($ax, $ay) = @_;

    # compute new position
    my $nx = $self->{pos}->[0]+$ax;
    my $ny = $self->{pos}->[1]+$ay;

    # if we are out of the Map, go top or respectively bottom
    $nx = $self->{width}  if $nx < 1;
    $ny = $self->{height} if $ny < 1;
    $nx = 1 if $nx > $self->{width} ;
    $ny = 1 if $ny > $self->{height};

    # set the new pos
    return $self->pos($nx, $ny);
} # move

#
# draw the matrix on screen
#
sub draw
{
    my $self = shift;

    for my$y (1..$self->{height})
    {
        for my$x (1..$self->{width})
        {
            print $self->{matrix}->[$x-1+$self->{width}*($y-1)] ." ";
        }
        print "
";
    }

    return $self;
} # draw

__END__