package DBIx::Custom::Pool;

use Object::Simple -base;

use Carp 'croak';

use Digest::MD5 'md5_hex';

has count => 5;

sub prepare {

  my ($self, $cb) = @_;

  my $count = $self->count;

  for (my $i = 0; $i < $count; $i++) {

    my $dbi = $cb->();

    my $id = $self->_id;

    $self->{_pool}{$id} = $dbi;

  }

  return $self;

}

sub get {

  my $self = shift;

  my @ids = keys %{$self->{_pool}};

  croak "Pool is empty" unless @ids;

  my $id = $ids[0];

  my $dbi = delete $self->{_pool}{$id};

  $self->{_borrow}{$id} = 1;

  $dbi->{_pool_id} = $id;

  return $dbi;

}

sub back {

  my ($self, $dbi) = @_;

  my $id = $dbi->{_pool_id};

  return unless ref $dbi && defined $id;

  croak "This DBIx::Custom object is already returned back"

    if $self->{_pool}{$id};

  delete $self->{_borrow}{$id};

  $self->{_pool}{$id} = $dbi;

  return $self;

}

sub _id {

  my $self = shift;

  my $id;

  do { $id = md5_hex('c' . time . rand 999) }

    while $self->{_pool}->{$id} || $self->{_borrow}->{$id};

  return $id;

}

1;

=head1 NAME

DBIx::Custom::Pool

=head1 DESCRIPTION

DBI Pool. this module is very experimental.