#if TOOLS

using Godot;
using System.Collections.Generic;

namespace Rokojori.Tools
{
  using Rokojori;

  // Like Node.Duplicate(), but [Export] Node/array/list members that point outside the
  // duplicated subtree (parent, siblings, cousins, ...) keep pointing at the original
  // external target instead of being nulled out. Members pointing inside the subtree are
  // remapped to the corresponding duplicated node, same as native duplicate already does.
  public static class NodeDuplicator
  {
    public static Node DuplicateDeep( Node original )
    {
      if ( original == null )
      {
        return null;
      }

      var parent = original.GetParent();

      if ( parent == null )
      {
        original.LogError( "Duplicate Deep needs a parent node, can't duplicate the scene root." );
        return null;
      }

      var duplicate = original.Duplicate( (int) Node.DuplicateFlags.Default );

      parent.AddChild( duplicate );
      parent.MoveChild( duplicate, original.GetIndex() + 1 );

      SetOwnerRecursively( duplicate, original.Owner );
      RemapExternalReferences( original, duplicate );

      duplicate.LogInfo( "Duplicated", original.Name, "as", duplicate.Name );

      return duplicate;
    }

    static void SetOwnerRecursively( Node node, Node sceneOwner )
    {
      if ( sceneOwner == null )
      {
        return;
      }

      node.Owner = sceneOwner;

      foreach ( Node child in node.GetChildren() )
      {
        SetOwnerRecursively( child, sceneOwner );
      }
    }

    static void RemapExternalReferences( Node originalRoot, Node duplicateRoot )
    {
      var originalNodes = new List<Node>();
      var duplicateNodes = new List<Node>();

      NodesWalker.Get().Iterate( originalRoot, n => originalNodes.Add( n ), false );
      NodesWalker.Get().Iterate( duplicateRoot, n => duplicateNodes.Add( n ), false );

      var originalToDuplicate = new Dictionary<Node, Node>();

      for ( var i = 0; i < originalNodes.Count && i < duplicateNodes.Count; i++ )
      {
        originalToDuplicate[ originalNodes[ i ] ] = duplicateNodes[ i ];
      }

      for ( var i = 0; i < originalNodes.Count; i++ )
      {
        RemapNodeExports( originalNodes[ i ], duplicateNodes[ i ], originalToDuplicate );
      }
    }

    static void RemapNodeExports( Node original, Node duplicate, Dictionary<Node, Node> map )
    {
      var properties = original.GetPropertyList();

      foreach ( var propertyInfo in properties )
      {
        var dict = (Godot.Collections.Dictionary) propertyInfo;

        if ( ! IsStored( dict ) )
        {
          continue;
        }

        var name = dict[ "name" ].AsString();

        if ( string.IsNullOrEmpty( name ) )
        {
          continue;
        }

        var type = (Variant.Type) dict[ "type" ].AsInt32();

        if ( type == Variant.Type.Object )
        {
          RemapSingleProperty( original, duplicate, name, map );
        }
        else if ( type == Variant.Type.Array )
        {
          RemapArrayProperty( original, duplicate, name, map );
        }
      }
    }

    static bool IsStored( Godot.Collections.Dictionary propertyInfo )
    {
      if ( ! propertyInfo.ContainsKey( "usage" ) )
      {
        return false;
      }

      var usage = propertyInfo[ "usage" ].AsInt64();
      return ( usage & (long) PropertyUsageFlags.Storage ) != 0;
    }

    static void RemapSingleProperty( Node original, Node duplicate, string name, Dictionary<Node, Node> map )
    {
      var value = original.Get( name );

      if ( value.VariantType != Variant.Type.Object )
      {
        return;
      }

      if ( value.AsGodotObject() is not Node targetNode )
      {
        return;
      }

      var remapped = Remap( targetNode, map );

      if ( remapped != targetNode )
      {
        duplicate.Set( name, remapped );
      }
    }

    static void RemapArrayProperty( Node original, Node duplicate, string name, Dictionary<Node, Node> map )
    {
      var value = original.Get( name );

      if ( value.VariantType != Variant.Type.Array )
      {
        return;
      }

      var array = value.AsGodotArray();
      var changed = false;

      for ( var i = 0; i < array.Count; i++ )
      {
        var element = array[ i ];

        if ( element.VariantType != Variant.Type.Object || element.AsGodotObject() is not Node elementNode )
        {
          continue;
        }

        var remapped = Remap( elementNode, map );

        if ( remapped != elementNode )
        {
          array[ i ] = remapped;
          changed = true;
        }
      }

      if ( changed )
      {
        duplicate.Set( name, array );
      }
    }

    static Node Remap( Node originalTarget, Dictionary<Node, Node> map )
    {
      if ( map.TryGetValue( originalTarget, out var mapped ) )
      {
        return mapped;
      }

      return originalTarget;
    }
  }
}

#endif