#
# Ensembl module for Bio::EnsEMBL::DBSQL::Funcgen::MotifFeatureAdaptor
#
#

=head1 LICENSE

Copyright [1999-2015] Wellcome Trust Sanger Institute and the EMBL-European Bioinformatics Institute
Copyright [2016-2023] EMBL-European Bioinformatics Institute

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

=head1 NAME

Bio::EnsEMBL::Funcgen::DBSQL::MotifFeatureAdaptor - A database adaptor for fetching and
storing MotifFeature objects.

=head1 SYNOPSIS

my $mfa = $db->get_MotifFeatureAdaptor();

my @mfeatures = @{$mfa->fetch_all_by_Slice_Epigenome($slic, $epigenome)};


=head1 DESCRIPTION

The MotifFeatureAdaptor is a database adaptor for storing and retrieving
MotifFeature objects.


=head1 SEE ALSO

Bio::EnsEMBL::Funcgen::MotifFeature



=head1 CONTACT

  Please email comments or questions to the public Ensembl
  developers list at <http://lists.ensembl.org/mailman/listinfo/dev>.

  Questions may also be sent to the Ensembl help desk at
  <http://www.ensembl.org/Help/Contact>.


=cut

package Bio::EnsEMBL::Funcgen::DBSQL::MotifFeatureAdaptor;

use strict;
use warnings;
use Bio::EnsEMBL::Utils::Exception qw( throw warning deprecate );
use Bio::EnsEMBL::Utils::Scalar qw( assert_ref );
use Bio::EnsEMBL::Funcgen::MotifFeature;
use Bio::EnsEMBL::Funcgen::DBSQL::BaseFeatureAdaptor;    #DBI sql_types import
use Bio::EnsEMBL::Utils::SqlHelper;

use base qw( Bio::EnsEMBL::Funcgen::DBSQL::BaseFeatureAdaptor );

sub fetch_by_BindingMatrix_Slice_start_strand {
  my ($self, $binding_matrix, $slice, $start, $strand) =@_;

  $self->db->is_stored_and_valid('Bio::EnsEMBL::Funcgen::BindingMatrix', $binding_matrix);
  assert_ref($slice, 'Bio::EnsEMBL::Slice');
  # $slice->is_stored($self->db->dnadb);

  if ($strand !=1 && $strand !=-1){
    throw('Strand must be equal to 1 or -1');
  }

  if ($start !~ /^[+-]?\d+$/){
    throw('Start must be a positive integer');
  }

  if ($start > $slice->end()){
    throw('Start position is larger than the slice size');
  }

  my $constraint = " mf.binding_matrix_id = ?";
  $constraint .= " AND mf.seq_region_id = ?";
  $constraint .= " AND mf.seq_region_start = ?";
  $constraint .= " AND mf.seq_region_strand = ?";

  $self->bind_param_generic_fetch($binding_matrix->dbID(),    SQL_INTEGER);
  $self->bind_param_generic_fetch($slice->get_seq_region_id(),    SQL_INTEGER);
  $self->bind_param_generic_fetch($start,    SQL_INTEGER);
  $self->bind_param_generic_fetch($strand,    SQL_INTEGER);

  return $self->generic_fetch($constraint)->[0];
}

my $true_final_clause = ' ORDER by mf.seq_region_id, mf.seq_region_start, mf.seq_region_end';
# ORDER by required by fetch_all_by_dbID_list when fetching as regulatory_attributes
# was '' to avoid use of undef warning from BaseAdaptor
my $final_clause = $true_final_clause;

=head2 fetch_all_by_Slice_BindingMatrix

  Arg [1]    : Bio::EnsEMBL::Slice
  Arg [2]    : Bio::EnsEMBL::Funcgen::BindingMatrix
  #Arg [3]    : (optional) string - type e.g. Jaspar/Inferred
  Example    : my $slice = $sa->fetch_by_region('chromosome', '1');
               my $features = $ofa->fetch_all_by_Slice_BindingMatric($slice, $bm);
  Description: Retrieves a list of features on a given slice, specific for a given BindingMatrix.
  Returntype : Listref of Bio::EnsEMBL::MotifFeature objects
  Exceptions : Throws if BindinMatrix is not valid
  Caller     : General
  Status     : At Risk - implement/change type to Analysis

=cut

sub fetch_all_by_Slice_BindingMatrix {
  my ($self, $slice, $bm, $type) = @_;

  #could add logic_name here for motif mapper analysis, motif source analysis
  $self->db->is_stored_and_valid('Bio::EnsEMBL::Funcgen::BindingMatrix', $bm);

  my $constraint = 'mf.binding_matrix_id = ?';

  $self->bind_param_generic_fetch( $bm->dbID(), SQL_INTEGER);
  my $mfs = $self->SUPER::fetch_all_by_Slice_constraint($slice, $constraint);
  $self->reset_true_tables;

  return $mfs;
}

=head2 fetch_all_by_BindingMatrix

  Arg [1]    : Bio::EnsEMBL::Funcgen::BindingMatrix
  Example    : my $features = $mfa->fetch_all_by_BindingMatrix($bm);
  Description: Retrieves a list of motif features specific for a given BindingMatrix.
  Returntype : Listref of Bio::EnsEMBL::MotifFeature objects
  Exceptions : Throws if BindinMatrix is not valid
  Caller     : General
  Status     : At Risk

=cut

sub fetch_all_by_BindingMatrix {
  my ($self, $bm) = @_;

  #could add logic_name here for motif mapper analysis, motif source analysis
  $self->db->is_stored_and_valid('Bio::EnsEMBL::Funcgen::BindingMatrix', $bm);

  my $constraint = 'mf.binding_matrix_id = ?';

  $self->bind_param_generic_fetch( $bm->dbID(), SQL_INTEGER);
  my $mfs = $self->generic_fetch($constraint);

  return $mfs;
}

sub fetch_Iterator {
    my $self      = shift;
   return $self->_generic_fetch_Iterator();
}

sub _generic_fetch_Iterator {

    my ($self, $cache_size, $full_constraint) = @_;

    # prepare and execute a query to fetch all dbIDs
    my $sth = $self->prepare(qq{
        SELECT      motif_feature_id
        FROM        motif_feature
    });
    $sth->execute;

    my $motif_feature_id;
    $sth->bind_columns(\$motif_feature_id);

    $cache_size //= 1000;

    my @cache;

    my $items_to_fetch = 1;

    return Bio::EnsEMBL::Utils::Iterator->new(sub{

        if (@cache == 0 && $items_to_fetch) {

            # our cache is empty, and there are still items to fetch, so
            # fetch the next chunk of dbIDs and create objects from them
        #
            my @dbIDs;

            my $item_count = 0;

            while( $sth->fetch ) {

                push @dbIDs, $motif_feature_id;
                if (++$item_count == $cache_size) {
                    # we have fetched a cache's worth of dbIDs, so flag that
                    # there are still items to fetch and last out of the loop
                    $items_to_fetch = 1;
                    last;
                }
                # if this is the last row, this flag will be 0 outside the loop
                $items_to_fetch = 0;
            }
            $sth->finish unless $items_to_fetch;
            @cache = @{ $self->fetch_all_by_dbID_list(\@dbIDs) } if @dbIDs;
        }
        return shift @cache;
    });
}

=head2 _fetch_all_overlapping_Peaks

  Arg [1]    : Bio::EnsEMBL::Funcgen::MotifFeature
  Example    : None
  Description: Fetches all overlapping Peaks for a particular MotifFeature
  Returntype : Arrayref Bio::EnsEMBL::Funcgen::Peak objects
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _fetch_all_overlapping_Peaks {
    my $deprecation_message = 'Bio::EnsEMBL::Funcgen::DBSQL::'
      . 'MotifFeatureAdaptor::_fetch_all_overlapping_Peaks has '
      . 'been deprecated and will be removed in release 109.';
    deprecate($deprecation_message);
    return;
}

=head2 _fetch_all_overlapping_Peaks_by_Epigenome

  Arg [1]    : Bio::EnsEMBL::Funcgen::MotifFeature
  Arg [2]    : Bio::EnsEMBL::Funcgen::Epigenome
  Example    : None
  Description: Fetches the overlapping Peaks for a particular
             : MotifFeature and Epigenome
  Returntype : arrayref of Bio::EnsEMBL::Funcgen::Peak objects
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _fetch_all_overlapping_Peaks_by_Epigenome {
    my $deprecation_message = 'Bio::EnsEMBL::Funcgen::DBSQL::'
      . 'MotifFeatureAdaptor::_fetch_all_overlapping_Peaks_by_Epigenome has '
      . 'been deprecated and will be removed in release 109.';
    deprecate($deprecation_message);
    return;
}

=head2 _fetch_all_overlapping_Epigenomes
  
  Arg [1]    : Bio::EnsEMBL::Funcgen::MotifFeature
  Description: Fetches list of overlapping Epigenomes
             : for a particular MotifFeature
  Returntype : arrayref of Bio::EnsEMBL::Funcgen::Epigenome objects
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _fetch_all_overlapping_Epigenomes {

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

    if (! defined $motif_feature){
      throw('Must provide a MotifFeature parameter');
    }

    my $sth = $self->prepare( "
      SELECT DISTINCT epigenome_id FROM motif_feature_regulatory_feature
      WHERE motif_feature_id=?
      AND has_matching_Peak = 1
      ORDER BY epigenome_id
      " );

    $sth->execute( $motif_feature->dbID());

    my @epigenome_dbIDs;

    my $epigenome_adaptor = $self->db->get_adaptor('Epigenome');

    while ( my @row = $sth->fetchrow_array ) {
        push @epigenome_dbIDs, $row[0];
    }

    my $epigenomes = $epigenome_adaptor->fetch_all_by_dbID_list(\@epigenome_dbIDs);

    return $epigenomes;

}

=head2 _fetch_all_overlapping_Peak_Callings_by_Epigenome

  Arg [1]    : Bio::EnsEMBL::Funcgen::MotifFeature
  Arg [2]    : Bio::EnsEMBL::Funcgen::Epigenome
  Example    : None
  Description: Fetches list of overlapping peak callings
             : for a particular MotifFeature, Epigenome
  Returntype : arrayref of Bio::EnsEMBL::Funcgen::PeakCalling objects
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _fetch_all_overlapping_Peak_Callings_by_Epigenome {

  my ( $self, $motif_feature, $epigenome ) = @_;

    if (! defined $motif_feature){
      throw('Must provide a MotifFeature parameter');
    }

    if (! defined $epigenome){
      throw('Must provide an Epigenome parameter');
    }

    my $sth = $self->prepare("
      SELECT peak_calling_id FROM motif_feature_regulatory_feature
      JOIN peak_calling USING (epigenome_id)
      WHERE motif_feature_id=? AND epigenome_id=?
      AND has_matching_Peak = 1
      " );
    
    $sth->execute($motif_feature->dbID(), $epigenome->dbID());
    
    my @peak_callings;

    my $peak_calling_adaptor = $self->db->get_adaptor('PeakCalling');
    
    while ( my @row = $sth->fetchrow_array ) {
        push @peak_callings, $peak_calling_adaptor->fetch_by_dbID($row[0]);
    }

    return \@peak_callings;

}

=head2 _fetch_all_overlapping_Peak_Callings_by_Epigenome_and_Regulatory_Feature

  Arg [1]    : Bio::EnsEMBL::Funcgen::MotifFeature
  Arg [2]    : Bio::EnsEMBL::Funcgen::Epigenome
  Arg [3]    : Bio::EnsEMLB::Funcgen::RegulatoryFeature
  Example    : None
  Description: Fetches list of overlapping peak callings
             : for a particular MotifFeature, Epigenome and RegulatoryFeature
  Returntype : arrayref of Bio::EnsEMBL::Funcgen::PeakCalling objects
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _fetch_all_overlapping_Peak_Callings_by_Epigenome_and_Regulatory_Feature {

  my ( $self, $motif_feature, $epigenome, $regulatory_feature ) = @_;

    if (! defined $motif_feature){
      throw('Must provide a MotifFeature parameter');
    }

    if (! defined $epigenome){
      throw('Must provide an Epigenome parameter');
    }

    if (! defined $regulatory_feature){
      throw('Must provide a RegulatoryFeature parameter');
    }

    my $sth = $self->prepare( "
      SELECT peak_calling_id FROM motif_feature_regulatory_feature
      JOIN peak_calling USING (epigenome_id)
      WHERE motif_feature_id=? AND epigenome_id=? AND regulatory_feature_id=?
      AND has_matching_Peak = 1
      " );

    $sth->execute( $motif_feature->dbID(), $epigenome->dbID(), $regulatory_feature->dbID());

    my @peak_callings;

    my $peak_calling_adaptor = $self->db->get_adaptor('PeakCalling');

    while ( my @row = $sth->fetchrow_array ) {
        push @peak_callings, $peak_calling_adaptor->fetch_by_dbID($row[0]);
    }

    return \@peak_callings;

}

=head2 _final_clause

  Args       : None
  Example    : None
  Description: PROTECTED implementation of superclass abstract method.
               Returns an ORDER BY clause. Sorting by probe_feature_id would be
			   enough to eliminate duplicates, but sorting by location might
			   make fetching features on a slice faster.
  Returntype : String
  Exceptions : None
  Caller     : generic_fetch
  Status     : At Risk

=cut

sub _final_clause {
	return $final_clause;
}


=head2 _true_tables

  Args       : None
  Example    : None
  Description: Returns the names and aliases of the tables to use for queries.
  Returntype : List of listrefs of strings
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _true_tables {
  return (['motif_feature', 'mf']);
}

=head2 _columns

  Args       : None
  Example    : None
  Description: PROTECTED implementation of superclass abstract method.
               Returns a list of columns to use for queries.
  Returntype : List of strings
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _columns {
  return qw(
			mf.motif_feature_id   mf.seq_region_id
			mf.seq_region_start   mf.seq_region_end
			mf.seq_region_strand  mf.binding_matrix_id
			mf.score        			mf.stable_id
		   );
}



=head2 _objs_from_sth

  Arg [1]    : DBI statement handle object
  Example    : None
  Description: PROTECTED implementation of superclass abstract method.
               Creates MotifFeature objects from an executed DBI statement
			   handle.
  Returntype : Listref of Bio::EnsEMBL::MotifFeature objects
  Exceptions : None
  Caller     : Internal
  Status     : At Risk

=cut

sub _objs_from_sth {
    my ( $self, $sth, $mapper ) = @_;

    my ( $motif_feature_id, $seq_region_id,
        $seq_region_start, $seq_region_end,
        $seq_region_strand, $binding_matrix_id, $score, $stable_id );

    $sth->bind_columns(
        \$motif_feature_id, \$seq_region_id,     \$seq_region_start,
        \$seq_region_end,   \$seq_region_strand, \$binding_matrix_id,
        \$score,            \$stable_id
    );

    my ( %binding_matrix_cache, %slice_cache, @motif_features );
    my $slice_adaptor          = $self->db->dnadb->get_adaptor('Slice');
    my $binding_matrix_adaptor = $self->db->get_adaptor('BindingMatrix');

	  # Remap the feature coordinates to another coord system if a mapper was provided
	  if ($mapper) {
	         return [];
      }

    while($sth->fetch()){

        #Get the BindingMatrix object, store it in cache
        if ( !exists $binding_matrix_cache{$binding_matrix_id} ) {
            $binding_matrix_cache{$binding_matrix_id}
                = $binding_matrix_adaptor->fetch_by_dbID($binding_matrix_id);
        }

        # Get the Slice object, store it in cache
        if ( !exists $slice_cache{$seq_region_id} ) {
            $slice_cache{$seq_region_id}
                = $slice_adaptor->fetch_by_seq_region_id($seq_region_id);
        }

        push @motif_features,
            Bio::EnsEMBL::Funcgen::MotifFeature->new(
            -START          => $seq_region_start,
            -END            => $seq_region_end,
            -STRAND         => $seq_region_strand,
            -SLICE          => $slice_cache{$seq_region_id},
            -SEQNAME        => $slice_cache{$seq_region_id}->seq_region_name(),
            -ADAPTOR        => $self,
            -dbID           => $motif_feature_id,
            -SCORE          => $score,
            -BINDING_MATRIX => $binding_matrix_cache{$binding_matrix_id},
            -STABLE_ID      => $stable_id,
            );
    }

    return \@motif_features;
}


=head2 store

  Args       : List of Bio::EnsEMBL::Funcgen::MotifFeature objects
  Example    : $ofa->store(@features);
  Description: Stores given MotifFeature objects in the database. Should only
               be called once per feature because no checks are made for
			   duplicates. Sets dbID and adaptor on the objects that it stores.
  Returntype : Listref of stored MotifFeatures
  Exceptions : Throws if a list of MotifFeature objects is not provided or if
               the Analysis, Epigenome and FeatureType objects are not attached or stored
  Caller     : General
  Status     : At Risk

=cut

sub store{
	my ($self, @motif_features) = @_;

	if (scalar(@motif_features) == 0) {
		throw('Must call store with a list of MotifFeature objects');
	}

	my $sth = $self->prepare("
		INSERT INTO motif_feature (
			seq_region_id,     seq_region_start,
			seq_region_end,    seq_region_strand,
      binding_matrix_id, score,
      stable_id)
      VALUES (?, ?, ?, ?, ?, ?, ?)
	");

	my $db = $self->db();

  FEATURE: foreach my $mf (@motif_features) {

	  if( ! (ref($mf) && $mf->isa('Bio::EnsEMBL::Funcgen::MotifFeature'))){
		  throw('Feature must be an MotifFeature object');
	  }

    # check if motif_feature already exists in the db
    my $existing_motif_feature
        = $self->fetch_by_BindingMatrix_Slice_start_strand(
        $mf->get_BindingMatrix(), $mf->slice(), $mf->start(), $mf->strand() );

    if($existing_motif_feature){
      warning('MotifFeature [' . $existing_motif_feature->dbID() . '] is already stored in the database');
      next FEATURE;
    }

    # if ( $mf->is_stored($db) ) {
  	# 	warning('MotifFeature [' . $mf->dbID() . '] is already stored in the database');
  	# 	next FEATURE;
	  # }

	  $self->db->is_stored_and_valid('Bio::EnsEMBL::Funcgen::BindingMatrix', $mf->get_BindingMatrix());


	  my $seq_region_id;
	  ($mf, $seq_region_id) = $self->_pre_store($mf);

	  $sth->bind_param(1, $seq_region_id,              SQL_INTEGER);
	  $sth->bind_param(2, $mf->start(),                SQL_INTEGER);
	  $sth->bind_param(3, $mf->end(),                  SQL_INTEGER);
	  $sth->bind_param(4, $mf->strand(),               SQL_TINYINT);
	  $sth->bind_param(5, $mf->get_BindingMatrix->dbID(), SQL_INTEGER);
	  $sth->bind_param(6, $mf->score(),                SQL_DOUBLE);
	  $sth->bind_param(7, $mf->stable_id(),            SQL_VARCHAR);

	  $sth->execute();

	  $mf->dbID( $self->last_insert_id );
	  $mf->adaptor($self);
	}

  return \@motif_features;
}


=head2 store_associated_Peak

  Args[1]    : Bio::EnsEMBL::Funcgen::MotifFeature
  Args[2]    : Bio::EnsEMBL::Funcgen::Peak
  Example    : $mfa->store_associated_Peak($mf, $peak);
  Description: Store link between TF peaks and MotifFeatures
  Returntype : Bio::EnsEMBL::Funcgen::MotifFeature
  Exceptions : Throws if args are not valid, warns if association already exists
  Caller     : General
  Status     : Stable

=cut

sub store_associated_Peak {
    my $deprecation_message = 'Bio::EnsEMBL::Funcgen::DBSQL::'
      . 'MotifFeatureAdaptor::store_associated_Peak has '
      . 'been deprecated and will be removed in release 109.';
    deprecate($deprecation_message);
    return;
}

=head2 store_associated_RegulatoryFeature

  Args[1]    : Bio::EnsEMBL::Funcgen::MotifFeature
  Args[2]    : Bio::EnsEMBL::Funcgen::RegulatoryFeature
  Example    : $mfa->store_associated_RegulatoryFeature($mf, $regulatory_feature);
  Description: Store link between RegulatoryFeatures and MotifFeatures
  Returntype : Bio::EnsEMBL::Funcgen::MotifFeature
  Exceptions : Throws if args are not valid, warns if association already exists
  Caller     : General
  Status     : Stable

=cut

sub store_associated_RegulatoryFeature {
	my ( $self, $mf, $regulatory_feature, $epigenome, $has_matching_Peak ) = @_;

	$self->db->is_stored_and_valid( 'Bio::EnsEMBL::Funcgen::RegulatoryFeature', $regulatory_feature );
	
  my $epigenome_id = undef;
  if ($epigenome){
    $self->db->is_stored_and_valid( 'Bio::EnsEMBL::Funcgen::Epigenome', $epigenome );
    $epigenome_id = $epigenome->dbID();
  }

	# Replace provided motif feature with the one which is stored in the db
	my $existing_motif_feature= 
    $self->fetch_by_BindingMatrix_Slice_start_strand
    ($mf->get_BindingMatrix(), $mf->slice(), $mf->start(), $mf->strand() );

	$self->db->is_stored_and_valid( 'Bio::EnsEMBL::Funcgen::MotifFeature', $existing_motif_feature );
	$mf = $existing_motif_feature;

    # Validate MotifFeature is entirely contained within the Peak
    if (
        !(
               ( $regulatory_feature->seq_region_start <= $mf->seq_region_start )
            && ( $mf->seq_region_end <= $regulatory_feature->seq_region_end )
        )
      )
    {
        throw('MotifFeature is not entirely contained within associated RegulatoryFeature');
    }

    my $sth = $self->prepare(
"INSERT INTO motif_feature_regulatory_feature 
(motif_feature_id, regulatory_feature_id, epigenome_id, has_matching_Peak) VALUES (?, ?, ?, ?)"
    );

    $sth->bind_param( 1, $mf->dbID,   SQL_INTEGER );
    $sth->bind_param( 2, $regulatory_feature->dbID, SQL_INTEGER );
    $sth->bind_param( 3, $epigenome_id, SQL_INTEGER );
    $sth->bind_param( 4, $has_matching_Peak, SQL_TINYINT );
    $sth->execute();

    # push @{ $mf->{associated_Peaks} }, $peak;

    return $mf;
}

=head2 fetch_by_stable_id

  Arg [1]    : String $stable_id - The stable_id of the motif feature to retrieve
  Example    : my $mf = $mf_adaptor->fetch_by_stable_id($stable_id);
  Description: Retrieves a motif feature via its stable id.
  Returntype : Bio::EnsEMBL::Funcgen::MotifFeature
  Exceptions : none
  Caller     : general
  Status     : Stable

=cut

sub fetch_by_stable_id {
  my ($self, $stable_id) = @_;

  $self->bind_param_generic_fetch($stable_id, SQL_VARCHAR);

  return $self->generic_fetch('mf.stable_id=?')->[0];
}

sub _bulk_export_to_bed {

    my $self   = shift;
    my $bed_fh = shift;

    my $species = $self->db->species;

    if ( $species eq 'DEFAULT' ) {
        die;
    }

    my $slice_adaptor =
      Bio::EnsEMBL::Registry->get_adaptor( $species, 'core', 'Slice' );

    my %seq_region_id_to_name_cache;
    
    my $sql_helper =
      Bio::EnsEMBL::Utils::SqlHelper->new( -DB_CONNECTION => $self->db->dbc );

    $sql_helper->execute_no_return(
        -SQL =>
'select motif_feature_id, seq_region_id, seq_region_start, seq_region_end, seq_region_strand, score, binding_matrix_id, stable_id from motif_feature',
        -USE_HASHREFS => 0,
        -PARAMS       => [ ],
        -CALLBACK     => sub {
            my $row = shift;

            my $seq_region_id = $row->[1];

            my $seq_region_name;
            if ( exists $seq_region_id_to_name_cache{$seq_region_id} ) {
                $seq_region_name = $seq_region_id_to_name_cache{$seq_region_id};
            }
            else {
                my $current_slice =
                  $slice_adaptor->fetch_by_seq_region_id($seq_region_id);
                $seq_region_name = $current_slice->seq_region_name;
                $seq_region_id_to_name_cache{$seq_region_id} = $seq_region_name;
            }

            my $strand = $row->[4];
            if ($strand == 1){
              $strand = '+';
            }
            elsif ($strand == -1){
              $strand = '-';
            }

            my $bed_line = join "\t",
              (
                $seq_region_name, $row->[2], $row->[3], $row->[0], $row->[5],
                $strand, $row->[6]
              );
            
            if ($row->[7]){
              $bed_line .= "\t" . $row->[7];
            }
            
            $bed_line .= "\n";

            $bed_fh->print($bed_line);
            return;
        },
    );
}

1;