package Ernad::Rif::Truncate;

use strict;
use warnings;

## FixMe: should be Ernad::Rif;
use base 'Ernad';

use Carp qw(confess);
use Ernad::Common;

my $xpc = &Ernad::Common::create_xpc;

## truncate by deleting from the current doc
sub by_delete {
  my $t=shift;
  my $doc=shift;
  if(not ref($doc) eq 'XML::LibXML::Document') {
    confess 'I need an XML document here.';
  }
  my $truncate_param=shift // confess 'I need a truncation parameter here.';
  my $max_items=0;
  my $max_percent=0;
  if($truncate_param) {
    if($truncate_param=~m|^\d+$|) {
      $max_items=$truncate_param;
      if($max_percent<100) {
        warn "You want to truncate to $max_items less than 100, did you mean $max_items%?";
      }
    }
    elsif($truncate_param=~m|^(\d+)%$|) {
      $max_percent=$1;
      if($max_percent>100) {
        confess "My percentage can not be larger than 100.";
      }
    }
    else {
      confess "You truncate parameter '$truncate_param' is neither a number nor percentage.";
    }
  }
  my $item_xp='/amf:amf/amf:collection[1]/amf:haspart';
  my @item_eles=$xpc->findnodes($item_xp,$doc)->get_nodelist();
  if(not $max_items) {
    $max_items=int(scalar @item_eles * $max_percent / 100);
  }
  my $count=$max_items;
  while($item_eles[$count]) {
    my $this_item=$item_eles[$count];
    $this_item->parentNode->removeChild($this_item);
    $count++;
  }
  return $doc;
}

1;