######################################################################
#
# EPrints::Plugin::InputForm::Component
#
######################################################################
#
#
######################################################################

=pod

=head1 NAME

B<EPrints::Plugin::InputForm::Component> - A single form component 

=head1 METHODS

=over 4

=cut

package EPrints::Plugin::InputForm::Component;

use strict;

our @ISA = qw/ EPrints::Plugin /;

$EPrints::Plugin::InputForm::Component::DISABLE = 1;

=item $component = EPrints::Plugin::InputForm::Component->new( %opts )

Create a new component object with following parameters:

	session - session object
	collapse - whether the component starts collapsed
	no_help - hide field help
	no_toggle - hide help toggle button
	surround - surround class, defaults to 'Default'
	prefix - prefix for the component id
	dataobj - object the field is being rendered for

See also L<EPrints::Plugin::InputForm::Surround::Default>.

=cut

sub new
{
	my( $class, %opts ) = @_;

	$opts{problems} = [] if !exists $opts{problems};
	$opts{name} = "Base component plugin: This should have been subclassed" if !exists $opts{name};
	$opts{visible} = "all" if !exists $opts{visible};

	my $self = $class->SUPER::new( %opts );

	if( defined &Scalar::Util::weaken )
	{
		Scalar::Util::weaken($self->{workflow});
		Scalar::Util::weaken($self->{processor});
	}

	# don't have a config when we first load this to register it as a plugin class
	if( defined $opts{xml_config} )
	{
		$self->{session} = $opts{session};
		$self->{collapse} = $opts{collapse};
		$self->{no_help} = $opts{no_help};
		$self->{no_toggle} = $opts{no_toggle};
		$self->{surround} = $opts{surround};
		$self->{prefix} = $opts{prefix};
		$self->{dataobj} = $opts{dataobj};
		$self->{dataset} = $opts{dataobj}->get_dataset;
		$self->parse_config( $opts{xml_config} );
	}

	return $self;
}

sub set_note
{
	my( $self, $name, $value ) = @_;

	$self->{processor}->{notes}->{$self->{prefix}}->{$name} = $value;
}

sub note
{
	my( $self, $name ) = @_;

	return $self->{processor}->{notes}->{$self->{prefix}}->{$name};
}

=pod

=item $bool = $component->parse_config( $config_dom )

Parses the supplied DOM object and populates $component->{config}

=cut

sub parse_config
{
	my( $self, $config_dom ) = @_;

	return 1;
}

=pod

=item $bool = $component->is_required()

returns true if this component is required to be completed before the
workflow may proceed

=cut

sub is_required
{
	my( $self ) = @_;
	return 0;
}

=pod

=item $surround = $component->get_surround()

returns the surround for this component.

=cut

sub get_surround
{
	my( $self ) = @_;

	my $surround = "Default";	
	
	if( EPrints::Utils::is_set( $self->{surround} ) )
	{
		$surround = $self->{surround};
	}
		
	my $surround_obj = $self->{session}->plugin( "InputForm::Surround::$surround" );
	
	if( !defined $surround_obj )
	{
		$surround_obj = $self->{session}->plugin( "InputForm::Surround::Default" ); 
	}

	return $surround_obj; 
}

=pod

=item $bool = $component->is_collapsed()

returns true if this component is to be rendered in a compact form
(for example, just title / required / help).

=cut

sub is_collapsed
{
	my( $self ) = @_;

	return 0 if( !$self->{collapse} );

	my $r =  $self->could_collapse;
	
	return $r;
}

# return false if this component does not want to be collapsed, even if
# the config requested it.
sub could_collapse
{
	my( $self ) = @_;

	return 1;
}

sub update_from_form
{
	return ();
}

sub validate
{
	return ();
}


# Useful parameter methods


# Returns all parameters for this component as a hash,
# with the prefix removed.

sub params
{
	my( $self ) = @_;
	my $prefix = $self->{prefix}."_";
	my %params = ();

	foreach my $p ( $self->{session}->param() )
	{
		if( $p =~ /^$prefix(.+)$/ )
		{
			$params{$1} = $self->{session}->param( $p );
		}
	}
	return %params;
}

sub get_internal_value
{
	my( $self ) = @_;

	my $prefix = $self->{prefix}."_";
	foreach my $param ( $self->{session}->param )
	{
		next unless( $param =~ s/^(_internal|passon)_$prefix// );
		my $v = $self->{session}->param( $param );
		next unless EPrints::Utils::is_set( $v );
		return $v;
	}
	return undef;
}

sub get_internal_button
{
	my( $self ) = @_;

	my $internal_button = $self->{session}->get_internal_button;

	return "" unless defined $internal_button;

	my $prefix = $self->{prefix}."_";
	return "" unless $internal_button =~ s/^$prefix//;

	return $internal_button;
}

sub problems
{
	my( $self ) = @_;

	return @{$self->{problems}};
}

=pod

=item $help = $component->render_help( $surround )

Returns DOM containing the help text for this component.

=cut

sub render_help
{
	my( $self, $surround ) = @_;
	return $self->html_phrase( "help" );
}

=pod

=item $name = $component->get_name()

Returns the unique name of this field (for prefixes, etc).

=cut

sub get_name
{
	my( $self ) = @_;
}

=item $bool = $component->wishes_to_export

See L<EPrints::Plugin::Screen/wishes_to_export>.

=cut

sub wishes_to_export
{
	shift->EPrints::Plugin::Screen::wishes_to_export( @_ );
}

=item $mime_type = $component->export_mimetype

See L<EPrints::Plugin::Screen/export_mimetype>.

=cut

sub export_mimetype
{
	my( $self ) = @_;

	binmode(STDOUT, ":utf8");

	return "text/html; charset=UTF-8";
}

=item $component->export

See L<EPrints::Plugin::Screen/export>.

=cut

sub export
{
	shift->EPrints::Plugin::Screen::export( @_ );
}

=item $xhtml = $component->render

Renders the component in its surround.

=cut

sub render
{
	my( $self ) = @_;

	return $self->get_surround->render( $self, $self->{session} );
}

=pod

=item $title = $component->render_title( $surround )

Returns the title of this component as a DOM object.

=cut

sub render_title
{
	my( $self, $surround ) = @_;
	return $self->html_phrase( "title" );
}

=pod

=item $content = $component->render_content( $surround )

Returns the DOM for the content of this component.

=cut

sub render_content
{
	my( $self, $surround ) = @_;

	return $self->{repository}->xml->create_document_fragment;
}

=pod

=item $boolean = $component->has_help()

Returns true if this component has help available.

=cut

sub has_help
{
	my( $self ) = @_;
	return 0;
}

=pod

=item @field_ids = $component->get_fields_handled

Returns an array of the names of the metadata fields which this
field handles. Used for jumps.

=cut

sub get_fields_handled
{
	my( $self ) = @_;

	return ();
}


# $metafield = $self->xml_to_metafield( $xml, [$dataset] )
#
# Take an XML configuration of a field in a component and return a metafield.
# tweak the metafield to make it required if needed.
#
# If dataset is not defined then use the dataset of the current item.

sub xml_to_metafield
{
	my( $self, $xml, $dataset ) = @_;

	my $repo = $self->{repository};

	if( !defined $dataset )
	{
		$dataset = $self->{dataset};
	}

	my $ref = $xml->getAttribute( "ref" );	
	if( !EPrints::Utils::is_set( $ref ) )
	{
		# xml_to_metafield config error: No field ref attribute
		push @{$self->{problems}}, $repo->html_phrase( "Plugin/InputForm/Component:error_missing_field_ref",
			xml => $repo->xml->create_text_node( $repo->xml->to_string( $xml ) ),
		);
		return;
	}

	my $field = $dataset->get_field( $ref );
	
	if( !defined $field )
	{
		# xml_to_metafield config error: Invalid field ref attribute($ref)
		push @{$self->{problems}}, $repo->html_phrase( "Plugin/InputForm/Component:error_invalid_field_ref",
			ref => $repo->xml->create_text_node( $ref ),
			xml => $repo->xml->create_text_node( $repo->xml->to_string( $xml ) ),
		);
		return;
	}

	my %props;

	# e.g. required input_lookup_url input_lookup_params top options
	# input_boxes input_add_boxes input_ordered
	foreach my $attr ($xml->attributes)
	{
		my $value = $attr->nodeValue;
		next if !EPrints::Utils::is_set( $value );
		my $name = $attr->nodeName;
		if( $name eq "required" )
		{
			$value = $value eq "yes";
		}
		elsif( $name eq "options" )
		{
			$value = [split ',', $value];
		}
		$props{$name} = $value;
	}
	foreach my $child ( $xml->childNodes )
	{
		my $name = $child->nodeName;
		if( $name eq "help" )
		{
			$props{help_xhtml} = EPrints::XML::contents_of( $child );
		}
		elsif( $name eq "title" )
		{
			$props{title_xhtml} = EPrints::XML::contents_of( $child );
		}
		elsif( $name eq "sub_field" )
		{
			if( !$field->isa( "EPrints::MetaField::Compound" ) )
			{
				push @{$self->{problems}}, $self->{repository}->xml->create_text_node(
					"xml_to_metafield config error: can only create a nested field definition for Compound fields (".$field->name." is not of type compound)"
				);
				return;
			}
			my $c = $child->cloneNode( 1 );
			$c->setName( "field" );
			my $sub_name = $c->getAttribute( "ref" );
			$c->setAttribute( "ref", $field->name . "_" . $sub_name );
			my $sub_field = $self->xml_to_metafield( $c, $dataset );
			return if !defined $sub_field;
			$sub_field = $sub_field->clone;
			$props{$sub_field} = $sub_field;
			EPrints::XML::dispose( $c );
		}
	}

	return $field if !%props;

	$field = $field->clone;
	while(my( $name, $value ) = each %props)
	{
		if( UNIVERSAL::isa( $value, "EPrints::MetaField" ) )
		{
			foreach my $f (@{$field->property( "fields_cache" )})
			{
				$f = $value, last if $f->name eq $value->name;
			}
		}
		elsif( $field->has_property( $name ) )
		{
			$field->set_property( $name, $value );
		}
		# should maybe warn here?
	}

	return $field;
}

sub get_state_params
{
	my( $self, $processor ) = @_;

	return "";
}

sub get_state_fragment
{
	my( $self, $processor ) = @_;

	return "";
}

#does the workflow specify help should be shown?
sub xml_to_help
{
        my( $self, $xml ) = @_;
        my $show_help = $xml->getAttribute( "show_help" );
        if ( defined( $show_help ) && $show_help eq "always" )
        {
                 return 1;
        }
        return 0;
}

=back

=cut

######################################################################
1;

=head1 COPYRIGHT

=for COPYRIGHT BEGIN

Copyright 2022 University of Southampton.
EPrints 3.4 is supplied by EPrints Services.

http://www.eprints.org/eprints-3.4/

=for COPYRIGHT END

=for LICENSE BEGIN

This file is part of EPrints 3.4 L<http://www.eprints.org/>.

EPrints 3.4 and this file are released under the terms of the
GNU Lesser General Public License version 3 as published by
the Free Software Foundation unless otherwise stated.

EPrints 3.4 is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with EPrints 3.4.
If not, see L<http://www.gnu.org/licenses/>.

=for LICENSE END