use 5.008003;
use MooseX::Declare;

class Thread::Task {
    use MooseX::Types::Moose qw(ClassName Str Int HashRef);
    use Thread::Task::Types qw(Handle_T Task_T TaskRev_T);
    use Moose::Util::TypeConstraints;

    require Storable;

    require Thread::Task::Role::Task;
    require Thread::Task::Manager;
    require Thread::Task::Exception::Finished;

    our $VERSION='0.001';

    has _owner_taskrev => (
        isa => Int,
        is => 'ro',
        weak_ref => 1,
        required => 0,
        init_arg => 'owner',
        predicate => '_has_owner_taskrev',
    );

    coerce TaskRev_T, from Task_T,
        via {
            $_->task_revision;
        };

    has callback => (
        isa => Str,
        is => 'ro',
        required => 0,
        default => 'task_response',
    );

    has handle => (
        isa => Handle_T,
        is => 'rw',
        required => 0,
        predicate => 'running',
        clearer => 'clear_handle',
    );

    method BUILD(HashRef $params) {
        if ($self->_has_owner_taskrev) {
            my $owner = $self->owner;
            my $callback = $self->callback;
            unless ($owner->can($callback)) {
                die "Owner can't $callback";
            }
        }
    }

    method owner() {
        Thread::Task::Role::Task->task_owner($self->_owner_taskrev);
    }

    method schedule(@args) {
        Thread::Task::Manager->instance->schedule($self,@args);
    }

    method prepare() { return }

    method run() {
        if ($self->_has_owner_taskrev) {
            $self->owner or die Thread::Task::Exception::Finished->new();
        }

        return;
    }

    method finish() {
        if ($self->_has_owner_taskrev) {
            my $owner = $self->owner
                or die Thread::Task::Exception::Finished->new();

            my $callback = $self->callback;

            $owner->$callback($self);
        }

        return;
    }

    method as_string() {
        Storable::nfreeze($self);
    }

    method from_string(ClassName $class: Str $serialization) {
        my $new_self=Storable::thaw($serialization);
        my $self_class=$new_self->meta->name;
        unless ($self_class eq $class) {
            die "Deserialized as $self_class instead of $class";
        }
        return $new_self;
    }

    method _update(Task_T $new_task) {
        if ($self->meta ne $new_task->meta) {
            die "Can't update between different task classes";
        }
        for my $attr ($self->meta->get_all_attributes) {
            if ($attr->has_value($new_task)) {
                $attr->set_value($self,
                                 $attr->get_value($new_task)
                             );
            }
            else {
                $attr->clear_value($self);
            }
        }
        return;
    }
}

1;