package Test2::Compare::Bag;
use strict;
use warnings;

use base 'Test2::Compare::Base';

our $VERSION = '0.000030';

use Test2::Util::HashBase qw/ending items/;

use Carp qw/croak confess/;
use Scalar::Util qw/reftype looks_like_number/;

sub init {
    my $self = shift;

    $self->{+ITEMS} ||= [];

    $self->SUPER::init();
}

sub name { '<BAG>' }

sub verify {
    my $self = shift;
    my %params = @_;

    return 0 unless $params{exists};
    my $got = $params{got} || return 0;
    return 0 unless ref($got);
    return 0 unless reftype($got) eq 'ARRAY';
    return 1;
}

sub add_item {
    my $self = shift;
    my $check = pop;
    my ($idx) = @_;

    push @{$self->{+ITEMS}}, $check;
}

sub deltas {
    my $self = shift;
    my %params = @_;
    my ($got, $convert, $seen) = @params{qw/got convert seen/};

    my @deltas;
    my $state = 0;
    my @items = @{$self->{+ITEMS}};

    # Make a copy that we can munge as needed.
    my @list = @$got;
    my %unmatched = map { $_ => $list[$_] } 0..$#list;

    while (@items) {
        my $item = shift @items;

        my $check = $convert->($item);

        my @item_deltas;
        for my $idx (0..$#list) {
            my $val = $list[$idx];
            my @this_deltas = $check->run(
                id      => [ARRAY => $idx],
                convert => $convert,
                seen    => $seen,
                exists  => 1,
                got     => $val,
            );
            if (@this_deltas) {
                push @item_deltas,@this_deltas;
            }
            else {
                @item_deltas = ();
                delete $unmatched{$idx};
                last;
            }
        }
        if (@item_deltas) {
            push @deltas, $self->delta_class->new(
                dne      => 'got',
                verified => 1,
                id       => [ARRAY => '*'],
                got      => undef,
                check    => $check,
                children => \@item_deltas,
            );
        }
    }

    # if elements are left over, and ending is true, we have a problem!
    if($self->{+ENDING} && keys %unmatched) {
        for my $idx (sort keys %unmatched) {
            my $elem = $list[$idx];
            push @deltas => $self->delta_class->new(
                dne      => 'check',
                verified => undef,
                id       => [ARRAY => $idx],
                got      => $elem,
                check    => undef,
            );
        }
    }

    return @deltas;
}

1;