use strict;
use warnings;
use XML::Simple;
use Data::Dumper;
$Data::Dumper::Useqq = 1;
$Data::Dumper::Sortkeys = 1;
$Data::Dumper::Indent = 0;

my $xml1 = XMLin("test1.xml",ForceArray => 1, KeyAttr => [],ValueAttr => [],KeepRoot => 1) or die("Error: Cannot load XML1 ($!)");
my $xml2 = XMLin("test2.xml",ForceArray => 1, KeyAttr => [],ValueAttr => [],KeepRoot => 1) or die("Error: Cannot load XML2 ($!)");

my @Differences;

###
# wir arbeiten uns durch den Baum:
my @stack=({path => 'ROOT', childs1 => [$xml1], childs2 => [$xml2] });

while(@stack) {
  my $elm = shift(@stack);
  my $cnt = -1;

  if(ref($elm->{childs1}) eq 'ARRAY') {
    if(!ref($elm->{childs2}) eq 'ARRAY') {
      push(@Differences,"In $elm->{path} XML1 hat Kinder XML2 nicht!");
      next;
    }

    if($#{$elm->{childs1}} != $#{$elm->{childs2}}) {
      push(@Differences,"In $elm->{path} Kinder haben unterschiedliche Anzahl");
    }

    for my $child1 (@{$elm->{childs1}}) {
      my $child2 = $elm->{childs2}->[++$cnt];

      unless($child2) {
        push(@Differences,"In $elm->{path}[$cnt] aus XML1 hat keinen Partner in XML2");
        next;
      }

      if(ref($child1) eq 'HASH') {
        for my $key (sort keys(%$child1)) {
          if(!exists($child2->{$key})) {
            push(@Differences,"In $elm->{path}[$cnt]/$key aus XML1 hat keine entsprechung in XML2");
            next();
          }
          my $c1 = $child1->{$key};
          my $c2 = $child2->{$key};

          # Spezialbehandlung für "Parameter"
          # Die Attribute "name" und "value" bestimmen den Inhalt.
          if($key eq 'Parameter') {
            my $ok = 0;
            my %e2;

            for my $elm (@$c2) {
              next if(!defined($elm->{name}));
              next if(!defined($elm->{value}));
              $e2{$elm->{name}} = $elm->{value};
            }

            my $c = -1;
            for my $e1 (@$c1) {
              $c++;
              next if(!defined($e1->{name}));
              next if(!defined($e1->{value}));
              $ok++;
              push(@stack,{path => $elm->{path}.qq([$cnt]/$key).qq([$c] name=").$e1->{name}.qq("/value), childs1 => $e1->{value}, childs2 => $e2{$e1->{name}} });
            }

            # wenn das Aktiv ist wird die Reihenfolge der "Parameter" nicht geprüft
            #next if($ok);
          }

          if(ref($c1) and ref($c1) eq ref($c2) and ref($c1) ne 'ARRAY') {
            $c1 = [ $c1 ];
            $c2 = [ $c2 ];
          }
          push(@stack,{path => $elm->{path}."[$cnt]/$key", childs1 => $c1, childs2 => $c2 })
        }
        next;
      }

      if(Dumper($child1) ne Dumper($child2)) {
        push(@Differences,"In $elm->{path}[$cnt] aus XML1 hat einen anderen Wert als XML2 ($child1 <> $child2)");
      }
    }
    next;
  }

  if(Dumper($elm->{childs1}) ne Dumper($elm->{childs2})) {
    push(@Differences,"In $elm->{path} aus XML1 hat einen anderen Wert in XML2 ($elm->{childs1} <> $elm->{childs2})");
  }
}


open(my $fh, '>', "result.txt") or die("ERROR open ($!)");
if(@Differences) {
  print $fh join("\n",@Differences);
}
else {
  print $fh "Datei XML2 hat die selben Einträge wie XML1\n";
}
close($fh);