#!/usr/bin/env perl6
use v6;

class Term::Choose {
    has %.opt_global;
    has %!opt;

    method new ( %opt_global? ) {
        validate_options( %opt_global );
        %opt_global<prompt>  //= 'AAAAA';
        %opt_global<justify> //= 1;
        self.bless( :%opt_global );
    }

    sub valid_options {
        return {
            justify => '<[ 0 1 2 ]>',
            lf      => 'Array',
            mark    => 'Array',
            prompt  => 'Str',
        };
    };

    sub validate_options ( %opt ) {
        return without %opt;
        my $valid = valid_options();
        for %opt.kv -> $key, $value {
            when $valid{$key}:!exists {
                die "'$key' is not a valid option name";
            }
            when ! defined $value {
                next;
            }
            when $valid{$key} eq 'Array' {
                die "$key => not an ARRAY reference." if ! $value.isa( Array );
                die "$key => invalid array element"   if $value !~~ /^<[0..9]>+$/; # Int;
                die "$key => too many array elemnts." if $key eq 'lf' && $value.elems > 2;
            }
            when $valid{$key} eq 'Str' {
                die "$key => not a string." if ! $value.isa( Str );
            }
            when $value !~~ m/^{$valid{$key}}$/ {
                die "$key => '$value' is not a valid value.";
            }
        }
    }

    method choose ( Array $orig_list, %!opt? ) {
        validate_options( %!opt );
        for %!opt_global.kv -> $key, $value {
            %!opt{$key} //= $value;
        }
        printf "%-7s: %s\n", .key, .value for %!opt.pairs;
        print "\n";
        # do something with $orig_list

    }
}

my $n = Term::Choose.new(  { mark => [ 4 .. 7 ] }  );
$n.choose( [ 1 .. 10 ] );
$n.choose( [ 1 .. 10 ], { prompt => 'BBBBB', mark => [ 1 .. 3 ] } );
$n.choose( [ 1 .. 10 ] );