exml 0.7.3-deprecated

use std::{
    cell::RefCell,
    rc::{Rc, Weak},
    sync::Arc,
};

use crate::{
    tree::XML_XML_NAMESPACE,
    uri::{XmlURI, build_uri},
};

use super::{
    DOCUMENT_POSITION_CONTAINED_BY, DOCUMENT_POSITION_CONTAINS, DOCUMENT_POSITION_DISCONNECTED,
    DOCUMENT_POSITION_FOLLOWING, DOCUMENT_POSITION_PRECEDING, DOMException, DocumentPosition,
    NodeType,
    attr::{Attr, AttrRef},
    character_data::{
        CDATASection, CDATASectionRef, CharacterData, Comment, CommentRef, Text, TextRef,
    },
    check_no_modification_allowed_err, check_owner_document_sameness, check_vertical_hierarchy,
    document::{Document, DocumentRef},
    document_fragment::{DocumentFragment, DocumentFragmentRef},
    document_type::{DocumentType, DocumentTypeRef},
    element::{Element, ElementRef},
    entity::{Entity, EntityRef},
    entity_reference::{EntityReference, EntityReferenceRef},
    named_node_map::{AttributeMap, NamedNodeMap},
    node_list::ChildNodesList,
    notation::{Notation, NotationRef},
    pi::{ProcessingInstruction, ProcessingInstructionRef},
    user_data::{DOMUserData, OperationType, UserDataHandler},
};

/// Implementation of [Node](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-1950641247)
/// interface on [1.4 Fundamental Interfaces: Core Module](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-BBACDC08)
///
/// Actual node representations are implemented as [`NodeRef`].
#[allow(private_bounds)]
pub trait Node: NodeConnection {
    /// Implementation of [`nodeName`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-F68D095) attribute.
    ///
    /// # Specification
    /// ```text
    /// nodeName of type DOMString, readonly
    ///     The name of this node, depending on its type; see the table above.
    /// ```
    fn node_name(&self) -> Rc<str>;
    /// Implementation of [`nodeValue`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-F68D080) attribute.
    ///
    /// # Specification
    /// ```text
    /// nodeValue of type DOMString
    ///     The value of this node, depending on its type; see the table above.
    ///     When it is defined to be null, setting it has no effect, including
    ///     if the node is read-only.
    ///
    ///     Exceptions on retrieval
    ///         DOMException
    ///         DOMSTRING_SIZE_ERR: Raised when it would return more characters than fit
    ///                             in a DOMString variable on the implementation platform.
    /// ```
    fn node_value(&self) -> Option<Rc<str>>;
    /// Implementation of [`nodeValue`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-F68D080) attribute.
    ///
    /// # Specification
    /// ```text
    /// nodeValue of type DOMString
    ///     The value of this node, depending on its type; see the table above.
    ///     When it is defined to be null, setting it has no effect, including
    ///     if the node is read-only.
    ///
    ///     Exceptions on setting
    ///         DOMException
    ///         NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly and
    ///                                      if it is not defined to be null.
    /// ```
    fn set_node_value(&mut self, value: impl Into<String>) -> Result<(), DOMException>;

    /// Implementation of [`nodeType`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-111237558) attribute.
    ///
    /// # Specification
    /// ```text
    /// nodeType of type unsigned short, readonly
    ///     A code representing the type of the underlying object, as defined above.
    /// ```
    fn node_type(&self) -> NodeType;
    /// Implementation of [`parentNode`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-1060184317) attribute.
    ///
    /// # Specification
    /// ```text
    /// parentNode of type Node, readonly
    ///     The parent of this node. All nodes, except Attr, Document, DocumentFragment,
    ///     Entity, and Notation may have a parent. However, if a node has just been
    ///     created and not yet added to the tree, or if it has been removed from the tree,
    ///     this is null.
    /// ```
    fn parent_node(&self) -> Option<NodeRef> {
        None
    }
    /// Implementation of [`childNodes`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-1451460987) attribute.
    ///
    /// # Specification
    /// ```text
    /// childNodes of type NodeList, readonly
    ///     A NodeList that contains all children of this node. If there are no children,
    ///     this is a NodeList containing no nodes.
    /// ```
    fn child_nodes(&self) -> ChildNodesList<NodeRef> {
        ChildNodesList::new(self.clone().into())
    }
    /// Implementation of [`firstChild`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-169727388) attribute.
    ///
    /// # Specification
    /// ```text
    /// firstChild of type Node, readonly
    ///     The first child of this node. If there is no such node, this returns null.
    /// ```
    fn first_child(&self) -> Option<NodeRef> {
        None
    }
    /// Implementation of [`lastChild`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-61AD09FB) attribute.
    ///
    /// # Specification
    /// ```text
    /// lastChild of type Node, readonly
    ///     The last child of this node. If there is no such node, this returns null.
    /// ```
    fn last_child(&self) -> Option<NodeRef> {
        None
    }
    /// Implementation of [`previousSibling`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-640FB3C8) attribute.
    ///
    /// # Specification
    /// ```text
    /// previousSibling of type Node, readonly
    ///     The node immediately preceding this node. If there is no such node,
    ///     this returns null.
    /// ```
    fn previous_sibling(&self) -> Option<NodeRef> {
        None
    }
    /// Implementation of [`nextSibling`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-6AC54C2F) attribute.
    ///
    /// # Specification
    /// ```text
    /// nextSibling of type Node, readonly
    ///     The node immediately following this node. If there is no such node,
    ///     this returns null.
    /// ```
    fn next_sibling(&self) -> Option<NodeRef> {
        None
    }
    /// Implementation of [`attributes`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-84CF096) attribute.
    ///
    /// # Specification
    /// ```text
    /// attributes of type NamedNodeMap, readonly
    ///     A NamedNodeMap containing the attributes of this node (if it is an Element)
    ///     or null otherwise.
    /// ```
    fn attributes(&self) -> Option<AttributeMap> {
        None
    }
    /// Implementation of [`ownerDocument`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-node-ownerDoc) attribute.
    ///
    /// # Specification
    /// ```text
    /// ownerDocument of type Document, readonly, modified in DOM Level 2
    ///     The Document object associated with this node. This is also the Document object
    ///     used to create new nodes. When this node is a Document or a DocumentType which
    ///     is not used with any Document yet, this is null.
    /// ```
    fn owner_document(&self) -> Option<DocumentRef> {
        None
    }

    /// Implementation of [`insertBefore`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-952280727) method.
    ///
    /// If `new_child` and `ref_child` are same nodes,
    /// this method does nothing and return `Ok(new_child)`.
    ///
    /// # Specification
    /// ```text
    /// Inserts the node newChild before the existing child node refChild.
    /// If refChild is null, insert newChild at the end of the list of children.
    /// If newChild is a DocumentFragment object, all of its children are inserted,
    /// in the same order, before refChild.
    /// If the newChild is already in the tree, it is first removed.
    ///
    /// Note: Inserting a node before itself is implementation dependent.
    ///
    /// Parameters
    ///     newChild of type Node
    ///         The node to insert.
    ///     refChild of type Node
    ///         The reference node, i.e., the node before which the new node must be inserted.
    ///
    /// Return Value
    ///     Node The node being inserted.
    ///
    /// Exceptions
    ///     DOMException
    ///     HIERARCHY_REQUEST_ERR:       Raised if this node is of a type that does not allow
    ///                                  children of the type of the newChild node, or if the
    ///                                  node to insert is one of this node's ancestors or
    ///                                  this node itself, or if this node is of type Document
    ///                                  and the DOM application attempts to insert a second
    ///                                  DocumentType or Element node.
    ///     WRONG_DOCUMENT_ERR:          Raised if newChild was created from a different
    ///                                  document than the one that created this node.
    ///     NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or if the parent of
    ///                                  the node being inserted is readonly.
    ///     NOT_FOUND_ERR:               Raised if refChild is not a child of this node.
    ///     NOT_SUPPORTED_ERR:           if this node is of type Document, this exception
    ///                                  might be raised if the DOM implementation doesn't
    ///                                  support the insertion of a DocumentType or Element
    ///                                  node.
    /// ```
    fn insert_before(
        &mut self,
        mut new_child: NodeRef,
        ref_child: Option<NodeRef>,
    ) -> Result<NodeRef, DOMException> {
        // In this implementation, if `new_child` and `ref_child` are same node,
        // do nothing and return `new_child`.
        if ref_child
            .as_ref()
            .is_some_and(|ref_child| new_child.is_same_node(ref_child))
        {
            return Ok(new_child);
        }

        check_no_modification_allowed_err(self)?;

        // HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not allow children
        // of the type of the newChild node (..snip)
        if new_child.node_type() == NodeType::DocumentFragment {
            let mut children = new_child.first_child();
            while let Some(child) = children {
                children = child.next_sibling();
                if !check_vertical_hierarchy(self.node_type(), child.node_type()) {
                    return Err(DOMException::HierarchyRequestErr);
                }
            }
        } else if !check_vertical_hierarchy(self.node_type(), new_child.node_type()) {
            return Err(DOMException::HierarchyRequestErr);
        }
        // NOT_FOUND_ERR: Raised if refChild is not a child of this node.
        if ref_child.as_ref().is_some_and(|ref_child| {
            ref_child
                .parent_node()
                .is_none_or(|par| !self.is_same_node(&par))
        }) {
            return Err(DOMException::NotFoundErr);
        }
        // WRONG_DOCUMENT_ERR: Raised if newChild was created from a different document
        // than the one that created this node.
        if !check_owner_document_sameness(self, &new_child) {
            return Err(DOMException::WrongDocumentErr);
        }

        // HIERARCHY_REQUEST_ERR: Raised if (..snip..) the node to insert is
        // one of this node's ancestors or this node itself, (..snip..)
        if self.is_same_node(&new_child) {
            return Err(DOMException::HierarchyRequestErr);
        }
        let mut par = self.parent_node();
        while let Some(cur) = par {
            par = cur.parent_node();
            if new_child.is_same_node(&cur) {
                return Err(DOMException::HierarchyRequestErr);
            }
        }

        // HIERARCHY_REQUEST_ERR: Raised if (..snip..) this node is of type Document
        // and the DOM application attempts to insert a second DocumentType or Element node.
        if self.node_type() == NodeType::Document
            && matches!(
                new_child.node_type(),
                NodeType::Element | NodeType::DocumentType
            )
        {
            let mut chilren = self.first_child();
            while let Some(child) = chilren {
                chilren = child.next_sibling();
                if child.node_type() == new_child.node_type() {
                    return Err(DOMException::HierarchyRequestErr);
                }
            }
        }

        let read_only = self.is_read_only();
        if let Some(ref_child) = ref_child {
            match &mut new_child {
                // If newChild is a DocumentFragment object, all of its children are inserted,
                // in the same order, before refChild.
                NodeRef::DocumentFragment(frag) => {
                    let mut child = frag.first_child();
                    while let Some(mut now) = child {
                        child = now.next_sibling();
                        now.connect_as_previous_sibling(ref_child.clone());
                        if read_only {
                            now.set_read_only();
                        }
                    }
                }
                other => {
                    other.connect_as_previous_sibling(ref_child);
                    if read_only {
                        other.set_read_only();
                    }
                }
            }
        } else {
            let mut children = match new_child.clone() {
                NodeRef::DocumentFragment(frag) => frag.first_child(),
                mut other => {
                    other.disconnect_parent_and_sibling();
                    Some(other)
                }
            };
            while let Some(mut child) = children {
                children = child.next_sibling();
                child.set_parent_node(Some(self.clone().into()));
                let last = self.set_last_child(Some(child.clone()));
                if let Some(mut last) = last {
                    // If old last child is found,
                    // it is set as the previous sibling of `new_child`.
                    last.set_next_sibling(Some(child.clone()));
                    child.set_previous_sibling(Some(last));
                } else {
                    // Otherwise, `self` has no children.
                    // Therefore, I need to set `new_child` as also the first child of `self`.
                    self.set_first_child(Some(child.clone()));
                }
                if read_only {
                    child.set_read_only();
                }
            }
        }

        Ok(new_child)
    }

    /// Implementation of [`replaceChild`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-785887307) method.
    ///
    /// # Specification
    /// ```text
    /// Replaces the child node oldChild with newChild in the list of children,
    /// and returns the oldChild node.  
    /// If newChild is a DocumentFragment object, oldChild is replaced by all of
    /// the DocumentFragment children, which are inserted in the same order.  
    /// If the newChild is already in the tree, it is first removed.
    ///
    /// Note: Replacing a node with itself is implementation dependent.
    ///
    /// Parameters
    ///     newChild of type Node
    ///         The new node to put in the child list.
    ///     oldChild of type Node
    ///         The node being replaced in the list.
    ///
    /// Return Value
    ///     Node The node replaced.
    ///
    /// Exceptions
    ///     DOMException
    ///     HIERARCHY_REQUEST_ERR:       Raised if this node is of a type that does not allow
    ///                                  children of the type of the newChild node, or if the
    ///                                  node to put in is one of this node's ancestors or
    ///                                  this node itself, or if this node is of type Document
    ///                                  and the result of the replacement operation would add
    ///                                  a second DocumentType or Element on the Document node.
    ///     WRONG_DOCUMENT_ERR:          Raised if newChild was created from a different
    ///                                  document than the one that created this node.
    ///     NO_MODIFICATION_ALLOWED_ERR: Raised if this node or the parent of the new node is
    ///                                  readonly.
    ///     NOT_FOUND_ERR:               Raised if oldChild is not a child of this node.
    ///     NOT_SUPPORTED_ERR:           if this node is of type Document, this exception
    ///                                  might be raised if the DOM implementation doesn't
    ///                                  support the replacement of the DocumentType child or
    ///                                  Element child.
    /// ```
    fn replace_child(
        &mut self,
        new_child: NodeRef,
        mut old_child: NodeRef,
    ) -> Result<NodeRef, DOMException> {
        // In this implementation, if `new_child` and `ref_child` are same node,
        // do nothing and return `new_child`.
        if new_child.is_same_node(&old_child) {
            return Ok(new_child);
        }

        check_no_modification_allowed_err(self)?;

        // HIERARCHY_REQUEST_ERR: Raised if this node is of a type that does not allow children
        // of the type of the newChild node (..snip)
        if new_child.node_type() == NodeType::DocumentFragment {
            let mut children = new_child.first_child();
            while let Some(child) = children {
                children = child.next_sibling();
                if !check_vertical_hierarchy(self.node_type(), child.node_type()) {
                    return Err(DOMException::HierarchyRequestErr);
                }
            }
        } else if !check_vertical_hierarchy(self.node_type(), new_child.node_type()) {
            return Err(DOMException::HierarchyRequestErr);
        }
        // NOT_FOUND_ERR: Raised if oldChild is not a child of this node.
        if old_child
            .parent_node()
            .is_none_or(|par| !self.is_same_node(&par))
        {
            return Err(DOMException::NotFoundErr);
        }
        // WRONG_DOCUMENT_ERR: Raised if newChild was created from a different document
        // than the one that created this node.
        if !check_owner_document_sameness(self, &new_child) {
            return Err(DOMException::WrongDocumentErr);
        }

        // HIERARCHY_REQUEST_ERR: Raised if (..snip..) the node to put in is
        // one of this node's ancestors or this node itself, (..snip..)
        if self.is_same_node(&new_child) {
            return Err(DOMException::HierarchyRequestErr);
        }
        let mut par = self.parent_node();
        while let Some(cur) = par {
            par = cur.parent_node();
            if new_child.is_same_node(&cur) {
                return Err(DOMException::HierarchyRequestErr);
            }
        }

        // HIERARCHY_REQUEST_ERR: Raised if (..snip..) this node is of type Document
        // and the result of the replacement operation would add
        // a second DocumentType or Element on the Document node.
        if self.node_type() == NodeType::Document
            && matches!(
                new_child.node_type(),
                NodeType::Element | NodeType::DocumentType
            )
        {
            let mut chilren = self.first_child();
            while let Some(child) = chilren {
                chilren = child.next_sibling();
                if child.node_type() == new_child.node_type() && !child.is_same_node(&old_child) {
                    return Err(DOMException::HierarchyRequestErr);
                }
            }
        }

        let mut children = match new_child {
            NodeRef::DocumentFragment(frag) => frag.first_child(),
            mut other => {
                other.disconnect_parent_and_sibling();
                Some(other)
            }
        };
        let read_only = self.is_read_only();
        let par = old_child.set_parent_node(None);
        let prev = old_child.set_previous_sibling(None);
        let next = old_child.set_next_sibling(None);
        old_child.unset_read_only();
        let prev = prev.or_else(|| {
            let mut child = children.clone()?;
            children = child.next_sibling();
            child.set_parent_node(par.clone());
            if read_only {
                child.set_read_only();
            }
            self.set_first_child(Some(child.clone()));
            Some(child)
        });
        if let Some(mut prev) = prev {
            while let Some(mut child) = children {
                children = child.next_sibling();
                child.set_parent_node(par.clone());
                child.set_previous_sibling(Some(prev.clone()));
                if read_only {
                    child.set_read_only();
                }
                prev.set_next_sibling(Some(child.clone()));
                prev = child;
            }
            prev.set_next_sibling(next.clone());
            if let Some(mut next) = next {
                next.set_previous_sibling(Some(prev));
            }
        }
        Ok(old_child)
    }

    /// Implementation of [`removeChild`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-1734834066) method.
    ///
    /// # Specification
    /// ```text
    /// Removes the child node indicated by oldChild from the list of children, and returns it.
    ///
    /// Parameters
    ///     oldChild of type Node
    ///         The node being removed.
    ///
    /// Return Value
    ///     Node The node removed.
    ///
    /// Exceptions
    ///     DOMException
    ///     NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
    ///     NOT_FOUND_ERR:               Raised if oldChild is not a child of this node.
    ///     NOT_SUPPORTED_ERR:           if this node is of type Document, this exception
    ///                                  might be raised if the DOM implementation doesn't
    ///                                  support the removal of the DocumentType child or the
    ///                                  Element child.
    /// ```
    fn remove_child(&mut self, mut old_child: NodeRef) -> Result<NodeRef, DOMException> {
        check_no_modification_allowed_err(self)?;

        // NOT_FOUND_ERR: Raised if oldChild is not a child of this node.
        if old_child
            .parent_node()
            .is_none_or(|par| !self.is_same_node(&par))
        {
            return Err(DOMException::NotFoundErr);
        }

        old_child.disconnect_parent_and_sibling();
        old_child.unset_read_only();
        Ok(old_child)
    }

    /// Implementation of [`appendChild`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-184E7107) method.
    ///
    /// # Specification
    /// ```text
    /// Adds the node newChild to the end of the list of children of this node.
    /// If the newChild is already in the tree, it is first removed.
    ///
    /// Parameters
    ///     newChild of type Node
    ///         The node to add.
    ///         If it is a DocumentFragment object, the entire contents of
    ///         the document fragment are moved into the child list of this node
    ///
    /// Return Value
    ///     Node The node added.
    ///
    /// Exceptions
    ///     DOMException
    ///     HIERARCHY_REQUEST_ERR:       Raised if this node is of a type that does not allow
    ///                                  children of the type of the newChild node, or if the
    ///                                  node to append is one of this node's ancestors or
    ///                                  this node itself, or if this node is of type Document
    ///                                  and the DOM application attempts to append a second
    ///                                  DocumentType or Element node.
    ///     WRONG_DOCUMENT_ERR:          Raised if newChild was created from a different
    ///                                  document than the one that created this node.
    ///     NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly or if the previous
    ///                                  parent of the node being inserted is readonly.
    ///     NOT_SUPPORTED_ERR:           if the newChild node is a child of the Document node,
    ///                                  this exception might be raised if the DOM
    ///                                  implementation doesn't support the removal of the
    ///                                  DocumentType child or Element child.
    /// ```
    fn append_child(&mut self, new_child: NodeRef) -> Result<NodeRef, DOMException> {
        self.insert_before(new_child, None)
    }

    /// Implementation of [`hasChildNodes`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-810594187) method.
    ///
    /// # Specification
    /// ```text
    /// Returns whether this node has any children.
    ///
    /// Return Value
    ///     boolean Returns true if this node has any children, false otherwise.
    ///
    /// No Parameters
    /// No Exceptions
    /// ```
    fn has_child_nodes(&self) -> bool {
        self.first_child().is_some()
    }

    /// Implementation of [`cloneNode`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-3A0ED0A4) method.
    ///
    /// # Specification
    /// ```text
    /// Returns a duplicate of this node, i.e., serves as a generic copy constructor for nodes.
    /// The duplicate node has no parent (parentNode is null) and no user data.
    /// User data associated to the imported node is not carried over.
    /// However, if any UserDataHandlers has been specified along with the associated data
    /// these handlers will be called with the appropriate parameters before this method returns.
    /// Cloning an Element copies all attributes and their values,
    /// including those generated by the XML processor to represent defaulted attributes,
    /// but this method does not copy any children it contains unless it is a deep clone.
    /// This includes text contained in an the Element since the text is contained
    /// in a child Text node. Cloning an Attr directly, as opposed to be cloned as part of
    /// an Element cloning operation, returns a specified attribute (specified is true).
    /// Cloning an Attr always clones its children, since they represent its value,
    /// no matter whether this is a deep clone or not.
    /// Cloning an EntityReference automatically constructs its subtree
    /// if a corresponding Entity is available, no matter whether this is a deep clone or not.
    /// Cloning any other type of node simply returns a copy of this node.
    /// Note that cloning an immutable subtree results in a mutable copy,
    /// but the children of an EntityReference clone are readonly.
    /// In addition, clones of unspecified Attr nodes are specified.
    /// And, cloning Document, DocumentType, Entity, and Notation nodes is implementation dependent.
    ///
    /// Parameters
    ///     deep of type boolean
    ///         If true, recursively clone the subtree under the specified node;
    ///         if false, clone only the node itself (and its attributes, if it is an Element).
    ///
    /// Return Value
    ///     Node The duplicate node.
    ///
    /// No Exceptions
    /// ```
    fn clone_node(&self, deep: bool) -> NodeRef;

    /// Implementation of [`normalize`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-normalize) method.
    ///
    /// # Specification
    /// ```text
    /// Puts all Text nodes in the full depth of the sub-tree underneath this Node, including
    /// attribute nodes, into a "normal" form where only structure (e.g., elements, comments,
    /// processing instructions, CDATA sections, and entity references) separates Text nodes,
    /// i.e., there are neither adjacent Text nodes nor empty Text nodes. This can be used to
    /// ensure that the DOM view of a document is the same as if it were saved and re-loaded,
    /// and is useful when operations (such as XPointer [XPointer] lookups) that depend on a
    /// particular document tree structure are to be used. If the parameter
    /// "normalize-characters" of the DOMConfiguration object attached to the
    /// Node.ownerDocument is true, this method will also fully normalize the characters of
    /// the Text nodes.
    ///
    /// Note: In cases where the document contains CDATASections, the normalize operation
    /// alone may not be sufficient, since XPointers do not differentiate between Text nodes
    /// and CDATASection nodes.
    ///
    /// No Parameters
    /// No Return Value
    /// No Exceptions
    /// ```
    fn normalize(&mut self) {
        let mut children = self.first_child();
        while let Some(child) = children {
            match child {
                NodeRef::Text(mut text) => {
                    children = text.next_sibling();
                    while let Some(next) = children {
                        match next {
                            NodeRef::Text(next) => {
                                text.append_data(next.data().as_str()).ok();
                                self.remove_child(next.into()).ok();
                                children = text.next_sibling();
                            }
                            next => {
                                children = Some(next);
                                break;
                            }
                        }
                    }
                    if text.length() == 0 {
                        self.remove_child(text.into()).ok();
                    }
                }
                NodeRef::Element(mut elem) => {
                    elem.normalize();
                    children = elem.next_sibling();
                }
                child => children = child.next_sibling(),
            }
        }

        if let Some(attrs) = self.attributes() {
            for i in 0..attrs.length() {
                let mut attr = attrs.item(i).unwrap();
                attr.normalize();
            }
        }
    }

    /// Implementation of [`isSupported`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Level-2-Core-Node-supports) attribute.
    ///
    /// # Specification
    /// ```text
    /// Tests whether the DOM implementation implements a specific feature and that feature
    /// is supported by this node, as specified in DOM Features.
    ///
    /// Parameters
    ///     feature of type DOMString
    ///         The name of the feature to test.
    ///     version of type DOMString
    ///         This is the version number of the feature to test.
    ///
    /// Return Value
    ///     boolean Returns true if the specified feature is supported on this node,
    ///             false otherwise.
    ///
    /// No Exceptions
    /// ```
    fn is_supported(&self, feature: &str, version: Option<&str>) -> bool {
        self.owner_document()
            .is_some_and(|doc| doc.implementation().has_feature(feature, version))
    }

    /// Implementation of [`namespaceURI`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-NodeNSname) attribute.
    ///
    /// # Specification
    /// ```text
    /// namespaceURI of type DOMString, readonly, introduced in DOM Level 2
    ///     The namespace URI of this node, or null if it is unspecified (see XML Namespaces).
    ///     This is not a computed value that is the result of a namespace lookup
    ///     based on an examination of the namespace declarations in scope.
    ///     It is merely the namespace URI given at creation time.
    ///     For nodes of any type other than ELEMENT_NODE and ATTRIBUTE_NODE and
    ///     nodes created with a DOM Level 1 method, such as Document.createElement(),
    ///     this is always null.
    ///
    ///     Note: Per the Namespaces in XML Specification [XML Namespaces] an attribute
    ///     does not inherit its namespace from the element it is attached to.
    ///     If an attribute is not explicitly given a namespace, it simply has no namespace.
    /// ```
    fn namespace_uri(&self) -> Option<Rc<str>> {
        None
    }

    /// Implementation of [`prefix`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-NodeNSPrefix) attribute.
    ///
    /// # Specification
    /// ```text
    /// prefix of type DOMString, introduced in DOM Level 2
    ///     The namespace prefix of this node, or null if it is unspecified. When it is
    ///     defined to be null, setting it has no effect, including if the node is read-only.
    ///     Note that setting this attribute, when permitted, changes the nodeName
    ///     attribute, which holds the qualified name, as well as the tagName and name
    ///     attributes of the Element and Attr interfaces, when applicable.
    ///     Setting the prefix to null makes it unspecified, setting it to an empty string
    ///     is implementation dependent.
    ///     Note also that changing the prefix of an attribute that is known to have
    ///     a default value, does not make a new attribute with the default value and the
    ///     original prefix appear, since the namespaceURI and localName do not change.
    ///     For nodes of any type other than ELEMENT_NODE and ATTRIBUTE_NODE and nodes
    ///     created with a DOM Level 1 method, such as createElement from the Document
    ///     interface, this is always null.
    /// ```
    fn prefix(&self) -> Option<Rc<str>> {
        None
    }
    /// Implementation of [`prefix`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-NodeNSPrefix) attribute.
    ///
    /// # Specification
    /// ```text
    /// prefix of type DOMString, introduced in DOM Level 2
    ///     The namespace prefix of this node, or null if it is unspecified. When it is
    ///     defined to be null, setting it has no effect, including if the node is read-only.
    ///     Note that setting this attribute, when permitted, changes the nodeName
    ///     attribute, which holds the qualified name, as well as the tagName and name
    ///     attributes of the Element and Attr interfaces, when applicable.
    ///     Setting the prefix to null makes it unspecified, setting it to an empty string
    ///     is implementation dependent.
    ///     Note also that changing the prefix of an attribute that is known to have
    ///     a default value, does not make a new attribute with the default value and the
    ///     original prefix appear, since the namespaceURI and localName do not change.
    ///     For nodes of any type other than ELEMENT_NODE and ATTRIBUTE_NODE and nodes
    ///     created with a DOM Level 1 method, such as createElement from the Document
    ///     interface, this is always null.
    ///
    ///     Exceptions on setting
    ///         DOMException
    ///         INVALID_CHARACTER_ERR:       Raised if the specified prefix contains an
    ///                                      illegal character according to the XML version
    ///                                      in use specified in the Document.xmlVersion
    ///                                      attribute.
    ///         NO_MODIFICATION_ALLOWED_ERR: Raised if this node is readonly.
    ///         NAMESPACE_ERR:               Raised if the specified prefix is malformed
    ///                                      per the Namespaces in XML specification, if
    ///                                      the namespaceURI of this node is null, if the
    ///                                      specified prefix is "xml" and the namespaceURI
    ///                                      of this node is different from
    ///                                      "http://www.w3.org/XML/1998/namespace", if this
    ///                                      node is an attribute and the specified prefix
    ///                                      is "xmlns" and the namespaceURI of this node is
    ///                                      different from "http://www.w3.org/2000/xmlns/",
    ///                                      or if this node is an attribute and the
    ///                                      qualifiedName of this node is "xmlns"
    ///                                      [XML Namespaces].
    /// ```
    fn set_prefix(&mut self, _prefix: Option<impl Into<Rc<str>>>) -> Result<(), DOMException> {
        Ok(())
    }

    /// Implementation of [`localName`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-NodeNSLocalN) attribute.
    ///
    /// # Specification
    /// ```text
    /// localName of type DOMString, readonly, introduced in DOM Level 2
    ///     Returns the local part of the qualified name of this node.
    ///     For nodes of any type other than ELEMENT_NODE and ATTRIBUTE_NODE and nodes
    ///     created with a DOM Level 1 method, such as Document.createElement(), this is
    ///     always null.
    /// ```
    fn local_name(&self) -> Option<Rc<str>> {
        None
    }

    /// Implementation of [`hasAttributes`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-NodeHasAttrs) method.
    ///
    /// # Specification
    /// ```text
    /// Returns whether this node (if it is an element) has any attributes.
    ///
    /// Return Value
    ///     boolean Returns true if this node has any attributes, false otherwise.
    /// ```
    fn has_attributes(&self) -> bool {
        self.attributes().is_some_and(|attr| !attr.is_empty())
    }

    /// Implementation of [`baseURI`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-baseURI) attribute.
    ///
    /// # Specification
    /// ```text
    /// baseURI of type DOMString, readonly, introduced in DOM Level 3
    ///     The absolute base URI of this node or null if the implementation wasn't able
    ///     to obtain an absolute URI. This value is computed as described in Base URIs.
    ///     However, when the Document supports the feature "HTML" [DOM Level 2 HTML],
    ///     the base URI is computed using first the value of the href attribute
    ///     of the HTML BASE element if any, and the value of the documentURI attribute
    ///     from the Document interface otherwise.
    /// ```
    fn base_uri(&self) -> Option<String> {
        if let Some(doc) = self.owner_document().filter(|doc| doc.is_html()) {
            // when the Document supports the feature "HTML" [DOM Level 2 HTML],
            // the base URI is computed using first the value of the href attribute
            // of the HTML BASE element if any, and the value of the documentURI attribute
            // from the Document interface otherwise.
            let mut children = doc.first_child();
            while let Some(child) = children {
                children = child.next_sibling();
                if let NodeRef::Element(elem) = child {
                    let name = elem.node_name();
                    if name.eq_ignore_ascii_case("html") || name.eq_ignore_ascii_case("head") {
                        children = elem.first_child();
                        continue;
                    } else if name.eq_ignore_ascii_case("base") {
                        return elem
                            .get_attribute_node("href")
                            .and_then(|attr| attr.text_content());
                    }
                }
            }
            return None;
        }

        let mut bases = vec![];
        if let Some(base) = self
            .attributes()
            .and_then(|attrs| {
                attrs
                    .get_named_item_ns(Some(XML_XML_NAMESPACE), "base")
                    .ok()
                    .flatten()
            })
            .and_then(|attr| attr.node_value())
        {
            let base = base.to_string();
            if XmlURI::parse(&base).is_some_and(|base| base.scheme.is_some()) {
                return Some(base);
            }
            bases.push(base);
        }
        let mut parents = self.parent_node();
        while let Some(parent) = parents {
            parents = parent.parent_node();

            if let NodeRef::Element(elem) = parent {
                if let Some(attr) = elem
                    .get_attribute_ns(Some(XML_XML_NAMESPACE), "base")
                    .ok()
                    .filter(|base| !base.is_empty())
                {
                    if XmlURI::parse(&attr).is_some_and(|base| base.scheme.is_some()) {
                        return bases
                            .into_iter()
                            .rev()
                            .try_fold(attr, |base, uri| build_uri(&uri, &base));
                    }
                    bases.push(attr);
                }
            }
        }

        if let Some(url) = self.owner_document().and_then(|doc| doc.document_uri()) {
            bases.push(url.to_string());
        }

        let base = bases.pop()?;
        bases
            .into_iter()
            .rev()
            .try_fold(base, |base, uri| build_uri(&uri, &base))
    }

    /// Implementation of [`compareDocumentPosition`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-compareDocumentPosition) method.
    ///
    /// # Specification
    /// ```text
    /// Compares the reference node, i.e. the node on which this method is being called,
    /// with a node, i.e. the one passed as a parameter, with regard to their position
    /// in the document and according to the document order.
    ///
    /// Parameters
    ///     other of type Node
    ///         The node to compare against the reference node.
    ///
    /// Return Value
    ///     unsigned short Returns how the node is positioned relatively to the reference
    ///                    node.
    ///
    /// Exceptions
    ///     DOMException
    ///     NOT_SUPPORTED_ERR: when the compared nodes are from different DOM implementations
    ///                        that do not coordinate to return consistent
    ///                        implementation-specific results.
    /// ```
    fn compare_document_position(&self, other: &NodeRef) -> DocumentPosition {
        // reference:
        // https://github.com/apache/xerces2-j/blob/trunk/src/org/apache/xerces/dom/NodeImpl.java

        // If the nodes are the same, no flags should be set
        if self.is_same_node(other) {
            return DocumentPosition::new();
        }

        // If from different documents, we know they are disconnected.
        if !check_owner_document_sameness(self, other) {
            return DocumentPosition::new().set_flag(DOCUMENT_POSITION_DISCONNECTED);
        }

        // get the respective Document owners.
        let this_owner_doc = if let NodeRef::Document(doc) = self.clone().into() {
            doc
        } else {
            self.owner_document().expect("Internal Error")
        };
        let other_owner_doc = if let NodeRef::Document(doc) = other {
            doc.clone()
        } else {
            other.owner_document().expect("Internal Erorr")
        };

        // Find the ancestor of each node, and the distance each node is from
        // its ancestor.
        // During this traversal, look for ancestor/descendent relationships
        // between the 2 nodes in question.
        // We do this now, so that we get this info correct for attribute nodes
        // and their children.

        let mut this_ancestor: NodeRef = self.clone().into();
        let mut this_depth = 0;
        while let Some(node) = this_ancestor.parent_node() {
            this_depth += 1;
            if this_ancestor.is_same_node(other) {
                // The other node is an ancestor of this one.
                return DocumentPosition::new()
                    .set_flag(DOCUMENT_POSITION_CONTAINS)
                    .set_flag(DOCUMENT_POSITION_PRECEDING);
            }
            this_ancestor = node;
        }

        let mut other_ancestor = other.clone();
        let mut other_depth = 0;
        while let Some(node) = other_ancestor.parent_node() {
            other_depth += 1;
            if self.is_same_node(&node) {
                // The other node is a descendent of the reference node.
                return DocumentPosition::new()
                    .set_flag(DOCUMENT_POSITION_CONTAINED_BY)
                    .set_flag(DOCUMENT_POSITION_FOLLOWING);
            }
            other_ancestor = node;
        }

        let mut this_node: NodeRef = self.clone().into();
        let mut other_node = other.clone();
        if let Some(doctype) = this_owner_doc.doctype() {
            match doctype.compare_decl_position(&this_node, &other_node) {
                Ok(cmp) => {
                    return match cmp {
                        std::cmp::Ordering::Less => {
                            DocumentPosition::new().set_flag(DOCUMENT_POSITION_FOLLOWING)
                        }
                        std::cmp::Ordering::Equal => DocumentPosition::new(),
                        std::cmp::Ordering::Greater => {
                            DocumentPosition::new().set_flag(DOCUMENT_POSITION_PRECEDING)
                        }
                    };
                }
                Err((Some(_), None)) => {
                    this_depth = doctype.parent_node().is_some() as i32;
                    this_node = doctype.into();
                    this_ancestor = this_owner_doc.clone().into();
                }
                Err((None, Some(_))) => {
                    other_depth = doctype.parent_node().is_some() as i32;
                    other_node = doctype.into();
                    other_ancestor = other_owner_doc.clone().into();
                }
                _ => {}
            }
        }
        let this_ancestor_type = this_ancestor.node_type();
        let other_ancestor_type = other_ancestor.node_type();

        // Special casing for ENTITY, NOTATION, DOCTYPE and ATTRIBUTES
        // LM:  should rewrite this.
        match this_ancestor_type {
            NodeType::Notation | NodeType::Entity => {
                let container = this_owner_doc.doctype();
                if container
                    .as_ref()
                    .is_some_and(|doctype| doctype.is_same_node(&other_ancestor))
                {
                    return DocumentPosition::new()
                        .set_flag(DOCUMENT_POSITION_CONTAINS)
                        .set_flag(DOCUMENT_POSITION_PRECEDING);
                }
                match other_ancestor_type {
                    NodeType::Notation | NodeType::Entity => {
                        // If neither `self` nor `other` is a Notation or Entity
                        // but the positional relationship cannot be determined,
                        // they should not belong to the same tree.
                        return DocumentPosition::new().set_flag(DOCUMENT_POSITION_DISCONNECTED);
                    }
                    _ => {}
                }
                this_node = this_owner_doc.clone().into();
                this_ancestor = this_owner_doc.clone().into();
            }
            NodeType::DocumentType => {
                return if this_owner_doc.is_same_node(&other_node) {
                    DocumentPosition::new()
                        .set_flag(DOCUMENT_POSITION_PRECEDING)
                        .set_flag(DOCUMENT_POSITION_CONTAINS)
                } else {
                    DocumentPosition::new().set_flag(DOCUMENT_POSITION_FOLLOWING)
                };
            }
            NodeType::Attribute => {
                let attr = this_ancestor.as_attribute().unwrap();
                let Some(elem) = attr.owner_element() else {
                    let mut ancestor = other.parent_node();
                    while let Some(par) = ancestor {
                        ancestor = par.parent_node();
                        if attr.is_same_node(&par) {
                            return DocumentPosition::new()
                                .set_flag(DOCUMENT_POSITION_FOLLOWING)
                                .set_flag(DOCUMENT_POSITION_CONTAINED_BY);
                        }
                    }
                    return DocumentPosition::new().set_flag(DOCUMENT_POSITION_DISCONNECTED);
                };
                if let NodeRef::Attribute(oattr) = &other_ancestor {
                    let Some(oelem) = oattr.owner_element() else {
                        return DocumentPosition::new().set_flag(DOCUMENT_POSITION_DISCONNECTED);
                    };
                    if oelem.is_same_node(&NodeRef::Element(elem.clone())) {
                        let attrs = elem.attributes();
                        return if attrs.index_of(&attr) < attrs.index_of(oattr) {
                            DocumentPosition::new().set_flag(DOCUMENT_POSITION_FOLLOWING)
                        } else {
                            DocumentPosition::new().set_flag(DOCUMENT_POSITION_PRECEDING)
                        };
                    }
                }

                // Now, find the ancestor of the element
                this_depth = 0;
                this_node = NodeRef::Element(elem);
                this_ancestor = this_node.clone();
                while let Some(node) = this_ancestor.parent_node() {
                    this_depth += 1;
                    if this_node.is_same_node(&other_node) {
                        // The other node is an ancestor of the owning element
                        return DocumentPosition::new()
                            .set_flag(DOCUMENT_POSITION_CONTAINS)
                            .set_flag(DOCUMENT_POSITION_PRECEDING);
                    }
                    this_ancestor = node;
                }
            }
            _ => {}
        }
        match other_ancestor_type {
            NodeType::Notation | NodeType::Entity => {
                let container = this_owner_doc.doctype();
                if container.is_some_and(|doctype| self.is_same_node(&doctype.into())) {
                    return DocumentPosition::new()
                        .set_flag(DOCUMENT_POSITION_CONTAINED_BY)
                        .set_flag(DOCUMENT_POSITION_FOLLOWING);
                }
                other_node = this_owner_doc.clone().into();
                other_ancestor = this_owner_doc.clone().into();
            }
            NodeType::DocumentType => {
                return if other_owner_doc.is_same_node(&this_node) {
                    DocumentPosition::new()
                        .set_flag(DOCUMENT_POSITION_FOLLOWING)
                        .set_flag(DOCUMENT_POSITION_CONTAINED_BY)
                } else {
                    DocumentPosition::new().set_flag(DOCUMENT_POSITION_PRECEDING)
                };
            }
            NodeType::Attribute => {
                other_depth = 0;
                let NodeRef::Attribute(oattr) = &other_ancestor else {
                    unimplemented!()
                };
                let Some(oelem) = oattr.owner_element() else {
                    return DocumentPosition::new().set_flag(DOCUMENT_POSITION_DISCONNECTED);
                };
                other_node = NodeRef::Element(oelem);
                other_ancestor = other_node.clone();
                while let Some(node) = other_ancestor.parent_node() {
                    other_depth += 1;
                    if other_ancestor.is_same_node(&this_node) {
                        // The other node is a descendent of the reference
                        // node's element
                        return DocumentPosition::new()
                            .set_flag(DOCUMENT_POSITION_FOLLOWING)
                            .set_flag(DOCUMENT_POSITION_CONTAINED_BY);
                    }
                    other_ancestor = node;
                }
            }
            _ => {}
        }

        // thisAncestor and otherAncestor must be the same at this point,
        // otherwise, the original nodes are disconnected
        if !this_ancestor.is_same_node(&other_ancestor) {
            return DocumentPosition::new().set_flag(DOCUMENT_POSITION_DISCONNECTED);
        }

        // Go up the parent chain of the deeper node, until we find a node
        // with the same depth as the shallower node

        if this_depth > other_depth {
            for _ in 0..this_depth - other_depth {
                this_node = this_node.parent_node().unwrap();
            }
            // Check if the node we have reached is in fact "otherNode". This can
            // happen in the case of attributes.  In this case, otherNode
            // "precedes" this.
            if this_node.is_same_node(&other_node) {
                return DocumentPosition::new().set_flag(DOCUMENT_POSITION_PRECEDING);
            }
        } else {
            for _ in 0..other_depth - this_depth {
                other_node = other_node.parent_node().unwrap();
            }
            // Check if the node we have reached is in fact "thisNode".  This can
            // happen in the case of attributes.  In this case, otherNode
            // "follows" this.
            if other_node.is_same_node(&this_node) {
                return DocumentPosition::new().set_flag(DOCUMENT_POSITION_FOLLOWING);
            }
        }

        // We now have nodes at the same depth in the tree.  Find a common
        // ancestor.
        while let Some((tp, op)) = this_node
            .parent_node()
            .zip(other_node.parent_node())
            .filter(|(t, p)| !t.is_same_node(p))
        {
            this_node = tp;
            other_node = op;
        }

        let parent = this_node.parent_node().unwrap();
        // At this point, thisNode and otherNode are direct children of
        // the common ancestor.
        // See whether thisNode or otherNode is the leftmost
        let mut children = parent.first_child();
        while let Some(child) = children {
            children = child.next_sibling();
            if child.is_same_node(&this_node) {
                return DocumentPosition::new().set_flag(DOCUMENT_POSITION_FOLLOWING);
            } else if child.is_same_node(&other_node) {
                return DocumentPosition::new().set_flag(DOCUMENT_POSITION_PRECEDING);
            }
        }
        // REVISIT:  shouldn't get here.   Should probably throw an  exception
        unreachable!()
    }

    /// Implementation of [`textContent`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-textContent) attribute.
    ///
    /// # Specification
    /// ```text
    /// textContent of type DOMString, introduced in DOM Level 3
    ///     This attribute returns the text content of this node and its descendants.
    ///     When it is defined to be null, setting it has no effect. On setting, any
    ///     possible children this node may have are removed and, if it the new string is
    ///     not empty or null, replaced by a single Text node containing the string this
    ///     attribute is set to.
    ///     On getting, no serialization is performed, the returned string does not contain
    ///     any markup. No whitespace normalization is performed and the returned string
    ///     does not contain the white spaces in element content (see the attribute
    ///     Text.isElementContentWhitespace). Similarly, on setting, no parsing is performed
    ///     either, the input string is taken as pure textual content.
    ///     The string returned is made of the text content of this node depending on its
    ///     type, as defined below:
    ///
    ///     <omitted>
    ///
    ///     Exceptions on retrieval
    ///         DOMException
    ///         DOMSTRING_SIZE_ERR: Raised when it would return more characters than fit
    ///                             in a DOMString variable on the implementation platform.
    /// ```
    fn text_content(&self) -> Option<String> {
        use NodeRef::*;

        let mut children = self.first_child();
        let mut res = String::new();
        while let Some(child) = children {
            children = child.next_sibling();

            match child {
                Comment(_) | ProcessingInstruction(_) => {}
                child => {
                    if let Some(value) = child.text_content().filter(|text| !text.is_empty()) {
                        res.push_str(&value);
                    }
                }
            }
        }
        Some(res)
    }

    /// Implementation of [`textContent`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-textContent) attribute.
    ///
    /// # Specification
    /// ```text
    /// textContent of type DOMString, introduced in DOM Level 3
    ///     This attribute returns the text content of this node and its descendants.
    ///     When it is defined to be null, setting it has no effect. On setting, any
    ///     possible children this node may have are removed and, if it the new string is
    ///     not empty or null, replaced by a single Text node containing the string this
    ///     attribute is set to.
    ///     On getting, no serialization is performed, the returned string does not contain
    ///     any markup. No whitespace normalization is performed and the returned string
    ///     does not contain the white spaces in element content (see the attribute
    ///     Text.isElementContentWhitespace). Similarly, on setting, no parsing is performed
    ///     either, the input string is taken as pure textual content.
    ///     The string returned is made of the text content of this node depending on its
    ///     type, as defined below:
    ///
    ///     <omitted>
    ///
    ///     Exceptions on setting
    ///         DOMException
    ///         NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
    /// ```
    fn set_text_content(&mut self, text: impl Into<String>) -> Result<(), DOMException> {
        check_no_modification_allowed_err(self)?;

        let mut children = self.first_child();
        while let Some(child) = children {
            children = child.next_sibling();
            self.remove_child(child).ok();
        }

        let doc = self.owner_document().expect("Internal Error");
        let text = doc.create_text_node(text);
        self.append_child(text.into()).ok();
        Ok(())
    }

    /// Implementation of [`isSameNode`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-isSameNode) method.
    ///
    /// # Specification
    /// ```text
    /// Returns whether this node is the same node as the given one.
    /// This method provides a way to determine whether two Node references returned by the
    /// implementation reference the same object. When two Node references are references to
    /// the same object, even if through a proxy, the references may be used completely
    /// interchangeably, such that all attributes have the same values and calling the same
    /// DOM method on either reference always has exactly the same effect.
    ///
    /// Parameters
    ///     other of type Node
    ///         The node to test against.
    ///
    /// Return Value
    ///     boolean Returns true if the nodes are the same, false otherwise.
    ///
    /// No Exceptions
    /// ```
    fn is_same_node(&self, other: &NodeRef) -> bool;

    /// Implementation of [`lookupPrefix`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-lookupNamespacePrefix) method.
    ///
    /// The implementation was based on
    /// [Appendix B.2 Namespace Prefix Lookup](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#namespaces-algorithms-lookupNamespacePrefixAlgo).
    ///
    /// # Specification
    /// ```text
    /// Look up the prefix associated to the given namespace URI, starting from this node.
    /// The default namespace declarations are ignored by this method.
    /// See Namespace Prefix Lookup for details on the algorithm used by this method.
    ///
    /// Parameters
    ///     namespaceURI of type DOMString
    ///         The namespace URI to look for.
    ///
    /// Return Value
    ///     DOMString Returns an associated namespace prefix if found or null if none is
    ///               found. If more than one prefix are associated to the namespace prefix,
    ///               the returned namespace prefix is implementation dependent.
    ///
    /// No Exceptions
    /// ```
    fn lookup_prefix(&self, namespace_uri: &str) -> Option<Rc<str>> {
        let mut ancestor = self.parent_node();
        while let Some(par) = ancestor {
            ancestor = par.parent_node();
            if let NodeRef::Element(elem) = par {
                return elem.lookup_prefix(namespace_uri);
            }
        }
        None
    }

    /// Implementation of [`isDefaultNamespace`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-isDefaultNamespace) method.
    ///
    /// The implementation was based on
    /// [Appendix B.3 Default Namespace Lookup](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#namespaces-algorithms-isDefaultNamespaceAlgo).
    ///
    /// # Specification
    /// ```text
    /// This method checks if the specified namespaceURI is the default namespace or not.
    ///
    /// Parameters
    ///     namespaceURI of type DOMString
    ///         The namespace URI to look for.
    ///
    /// Return Value
    ///     boolean Returns true if the specified namespaceURI is the default namespace,
    ///             false otherwise.
    ///
    /// No Exceptions
    /// ```
    fn is_default_namespace(&self, namespace_uri: &str) -> bool {
        let mut ancestor = self.parent_node();
        while let Some(par) = ancestor {
            ancestor = par.parent_node();
            if let NodeRef::Element(elem) = par {
                return elem.is_default_namespace(namespace_uri);
            }
        }
        false
    }

    /// Implementation of [`lookupNamespaceURI`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-lookupNamespaceURI) method.
    ///
    /// The implementation was based on
    /// [Appendix B.4 Namespace URI Lookup](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#namespaces-algorithms-lookupNamespaceURIAlgo).
    ///
    /// # Specification
    /// ```text
    /// Look up the namespace URI associated to the given prefix, starting from this node.
    /// See Namespace URI Lookup for details on the algorithm used by this method.
    ///
    /// Parameters
    ///     prefix of type DOMString
    ///         The prefix to look for. If this parameter is null, the method will return
    ///         the default namespace URI if any.
    ///
    /// Return Value
    ///     DOMString Returns the associated namespace URI or null if none is found.
    ///
    /// No Exceptions
    /// ```
    fn lookup_namespace_uri(&self, prefix: Option<&str>) -> Option<Rc<str>> {
        self.parent_node()?.lookup_namespace_uri(prefix)
    }

    /// Implementation of [`isEqualNode`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-isEqualNode) method.
    ///
    /// # Note
    /// Normalization can affect equality, but this method does not normalize nodes.\
    /// If need, the caller should normalize nodes before calling this method.
    ///
    /// # Specification
    /// ```text
    /// Tests whether two nodes are equal.
    /// This method tests for equality of nodes, not sameness
    /// (i.e., whether the two nodes are references to the same object)
    /// which can be tested with Node.isSameNode().
    /// All nodes that are the same will also be equal, though the reverse may not be true.
    /// Two nodes are equal if and only if the following conditions are satisfied:
    ///
    /// - The two nodes are of the same type.
    /// - The following string attributes are equal: nodeName, localName, namespaceURI,
    ///   prefix, nodeValue. This is: they are both null, or they have the same length
    ///   and are character for character identical.
    /// - The attributes NamedNodeMaps are equal.
    ///   This is: they are both null, or they have the same length and for each node
    ///   that exists in one map there is a node that exists in the other map and is equal,
    ///   although not necessarily at the same index.
    /// - The childNodes NodeLists are equal.
    ///   This is: they are both null, or they have the same length and contain equal nodes
    ///   at the same index. Note that normalization can affect equality;
    ///   to avoid this, nodes should be normalized before being compared.
    ///
    /// For two DocumentType nodes to be equal, the following conditions must also be satisfied:
    ///
    /// - The following string attributes are equal: publicId, systemId, internalSubset.
    /// - The entities NamedNodeMaps are equal.
    /// - The notations NamedNodeMaps are equal.
    ///
    /// On the other hand, the following do not affect equality: the ownerDocument,
    /// baseURI, and parentNode attributes, the specified attribute for Attr nodes,
    /// the schemaTypeInfo attribute for Attr and Element nodes,
    /// the Text.isElementContentWhitespace attribute for Text nodes, as well as any user data
    /// or event listeners registered on the nodes.
    ///
    /// Note: As a general rule, anything not mentioned in the description above
    ///       is not significant in consideration of equality checking.
    ///       Note that future versions of this specification may take into account
    ///       more attributes and implementations conform to this specification are expected
    ///       to be updated accordingly.
    ///
    /// Parameters
    ///     arg of type Node
    ///         The node to compare equality with.
    ///
    /// Return Value
    ///     boolean Returns true if the nodes are equal, false otherwise.
    /// ```
    fn is_equal_node(&self, arg: &NodeRef) -> bool {
        if self.is_same_node(arg) {
            return true;
        }
        if self.node_type() != arg.node_type()
            || self.node_name() != arg.node_name()
            || self.local_name() != arg.local_name()
            || self.namespace_uri() != arg.namespace_uri()
            || self.prefix() != arg.prefix()
            || self.node_value() != arg.node_value()
        {
            return false;
        }

        match (self.attributes(), arg.attributes()) {
            (Some(lattrs), Some(rattrs)) => {
                if lattrs.length() != rattrs.length() {
                    return false;
                }

                let mut r = vec![];
                for i in 0..rattrs.length() {
                    r.push(rattrs.item(i).unwrap());
                }
                // Simply scanning and deleting.
                // Not efficient, but probably sufficient.
                for i in 0..lattrs.length() {
                    let attr = NodeRef::Attribute(lattrs.item(i).unwrap());
                    let Some(pos) = r.iter().position(|r| r.is_equal_node(&attr)) else {
                        return false;
                    };
                    r.swap_remove(pos);
                }
            }
            (None, None) => {}
            _ => return false,
        }

        let mut lch = self.first_child();
        let mut rch = arg.first_child();
        while let Some((l, r)) = lch.as_ref().zip(rch.as_ref()) {
            if !l.is_equal_node(r) {
                return false;
            }
            lch = l.next_sibling();
            rch = r.next_sibling();
        }
        lch.is_some() == rch.is_some()
    }

    /// Implementation of [`getFeature`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-getFeature) method.
    ///
    /// # Note
    /// In this crate, this method simply clones and returns `self` if
    /// [`DOMImplementation::has_feature`](crate::dom::dom_implementation::DOMImplementation::has_feature)
    /// returns `true`.\
    /// Since cast possibilities are uniquely determined by the type implementation,
    /// there is basically no need to use this method.
    ///
    /// # Specification
    /// ```text
    /// This method returns a specialized object which implements the specialized APIs of the specified feature and version, as specified in DOM Features. The specialized object may also be obtained by using binding-specific casting methods but is not necessarily expected to, as discussed in Mixed DOM Implementations. This method also allow the implementation to provide specialized objects which do not support the Node interface.
    ///
    /// Parameters
    ///     feature of type DOMString
    ///         The name of the feature requested. Note that any plus sign "+" prepended to the name of the feature will be ignored since it is not significant in the context of this method.
    ///     version of type DOMString
    ///         This is the version number of the feature to test.
    ///
    /// Return Value
    ///     DOMObject Returns an object which implements the specialized APIs of the
    ///               specified feature and version, if any, or null if there is no
    ///               object which implements interfaces associated with that feature.
    ///               If the DOMObject returned by this method implements the Node
    ///               interface, it must delegate to the primary core Node and not return
    ///               results inconsistent with the primary core Node such as attributes,
    ///               childNodes, etc.
    ///
    /// No Exceptions
    /// ```
    fn get_feature(&self, feature: &str, version: Option<&str>) -> Option<Self> {
        self.is_supported(feature, version).then(|| self.clone())
    }

    /// Implementation of [`setUserData`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-setUserData) method.
    ///
    /// # Specification
    /// ```text
    /// Associate an object to a key on this node. The object can later be retrieved
    /// from this node by calling getUserData with the same key.
    ///
    /// Parameters
    ///     key of type DOMString
    ///         The key to associate the object to.
    ///     data of type DOMUserData
    ///         The object to associate to the given key, or null to remove any
    ///         existing association to that key.
    ///     handler of type UserDataHandler
    ///         The handler to associate to that key, or null.
    ///
    /// Return Value
    ///     DOMUserData Returns the DOMUserData previously associated to the given key
    ///                 on this node, or null if there was none.
    ///
    /// No Exceptions
    /// ```
    fn set_user_data(
        &mut self,
        key: impl Into<String>,
        data: DOMUserData,
        handler: Option<Arc<dyn UserDataHandler>>,
    ) -> Option<DOMUserData>;

    /// Implementation of [`getUserData`](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-Node3-getUserData) method.
    ///
    /// # Specification
    /// ```text
    /// Retrieves the object associated to a key on a this node. The object must first
    /// have been set to this node by calling setUserData with the same key.
    ///
    /// Parameters
    ///     key of type DOMString
    ///         The key the object is associated to.
    ///
    /// Return Value
    ///     DOMUserData Returns the DOMUserData associated to the given key on this node,
    ///                 or null if there was none.
    ///
    /// No Exceptions
    /// ```
    fn get_user_data(&self, key: &str) -> Option<DOMUserData>;

    /// Check if this node is a read-only node.
    ///
    /// This method is independent of the Document setting and always returns
    /// whether this node is read-only based on the DOM specification.
    fn is_read_only(&self) -> bool;
}

/// A set of operations that change the adjacency of nodes.
///
/// None of these methods are exposed to the user
/// because they may cause inconsistencies in the tree constraints.
///
/// These method does not check the tree constraints.  
/// It is the responsibility of the user to maintain tree constraints.
pub(super) trait NodeConnection: Clone + Into<NodeRef> {
    // The setter method (set_xxx) simply sets the given node
    // and is not required to check the node's type constraints.

    /// Set new parent node.  
    /// Return old parent node if exists.
    fn set_parent_node(&mut self, new_parent: Option<NodeRef>) -> Option<NodeRef>;
    /// Set new first child node.  
    /// Return old first child node if exists.
    fn set_first_child(&mut self, new_child: Option<NodeRef>) -> Option<NodeRef>;
    /// Set new last child node.  
    /// Return old last child node if exists.
    fn set_last_child(&mut self, new_child: Option<NodeRef>) -> Option<NodeRef>;
    /// Set new previous sibling node.  
    /// Return old previous sibling node if exists.
    fn set_previous_sibling(&mut self, new_sibling: Option<NodeRef>) -> Option<NodeRef>;
    /// Set new next sibling node.  
    /// Return old next sibling node if exists.
    fn set_next_sibling(&mut self, new_sibling: Option<NodeRef>) -> Option<NodeRef>;
    /// Set new owner Document node.  
    /// Return old owner Document node if exists.
    fn set_owner_document(&mut self, new_doc: DocumentRef) -> Option<DocumentRef>;

    /// Set this node as the read-only node.
    fn set_read_only(&mut self) {}
    /// Unset this node as the read-only node.
    fn unset_read_only(&mut self) {}

    /// Replace ownerDocument of self and all elements of the subtree.
    ///
    /// The ownerDocument of siblings and ancestors must not be changed.
    fn adopted_to(&mut self, new_doc: DocumentRef);

    /// Connect `self` to the front of `next`.
    ///
    /// If `next` has a previous sibling, it is connected to the front of `self`.  
    /// Otherwise, `self` is set as a first child of the parent of `next`.
    ///
    /// If `self` already has a parent or siblings, these will be disconnected from `self`.
    ///
    /// # Note
    /// If `next` does not have a parent,
    /// the constraint that the root node is unique is broken.
    fn connect_as_previous_sibling(&mut self, mut next: NodeRef) {
        let prev = next.set_previous_sibling(None);
        let par = next.parent_node();
        let slf: NodeRef = self.clone().into();
        self.disconnect_parent_and_sibling();
        // new parent
        self.set_parent_node(par.clone());
        // self <-> next
        next.set_previous_sibling(Some(slf.clone()));
        self.set_next_sibling(Some(next));
        if let Some(mut prev) = prev {
            // prev <-> self
            prev.set_next_sibling(Some(slf));
            self.set_previous_sibling(Some(prev));
        } else if let Some(mut par) = par {
            // If a previous sibling does not exists,
            // `self` becomes the first child of its parent.
            par.set_first_child(Some(slf));
        }
    }
    /// Connect `self` to the back of `prev`.
    ///
    /// If `prev` has a next sibling, it is connected to the back of `self`.  
    /// Otherwise, `self` is set as a last child of the parent of `prev`.
    ///
    /// If `self` already has a parent or siblings, these will be disconnected from `self`.
    ///
    /// # Note
    /// If `prev` does not have a parent,
    /// the constraint that the root node is unique is broken.
    fn connect_as_next_sibling(&mut self, mut prev: NodeRef) {
        let next = prev.set_next_sibling(None);
        let par = prev.parent_node();
        let slf: NodeRef = self.clone().into();
        self.disconnect_parent_and_sibling();
        // new parent
        self.set_parent_node(par.clone());
        // prev <-> self
        prev.set_next_sibling(Some(slf.clone()));
        self.set_previous_sibling(Some(prev));
        if let Some(mut next) = next {
            // self <-> next
            next.set_previous_sibling(Some(slf));
            self.set_next_sibling(Some(next));
        } else if let Some(mut par) = par {
            // If a next sibling does not exists,
            // `self` becomes the last child of its parent.
            par.set_last_child(Some(slf));
        }
    }
    /// Disconnect the parent node of `self`.  
    /// If `self` has siblings, it is also disconnected from its siblings,
    /// and the siblings before and after it establish adjacency.
    ///
    /// As a result, `self` is the root node of the detached subtree.
    ///
    /// Return old parent node if exists.
    fn disconnect_parent_and_sibling(&mut self) -> Option<NodeRef> {
        let mut par = self.set_parent_node(None);
        let prev = self.set_previous_sibling(None);
        let next = self.set_next_sibling(None);
        match (prev, next) {
            (Some(mut prev), Some(mut next)) => {
                prev.set_next_sibling(Some(next.clone()));
                next.set_previous_sibling(Some(prev));
            }
            (Some(mut prev), None) => {
                prev.set_next_sibling(None);
                if let Some(par) = par.as_mut() {
                    par.set_last_child(Some(prev));
                }
            }
            (None, Some(mut next)) => {
                next.set_previous_sibling(None);
                if let Some(par) = par.as_mut() {
                    par.set_first_child(Some(next));
                }
            }
            (None, None) => {
                if let Some(par) = par.as_mut() {
                    par.set_first_child(None);
                    par.set_last_child(None);
                }
            }
        }
        par
    }

    fn handle_user_data(&self, operation: OperationType, dst: Option<NodeRef>);
}

/// Implementation of [Node](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-1950641247)
/// interface on [1.4 Fundamental Interfaces: Core Module](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-BBACDC08)
#[derive(Clone)]
pub enum NodeRef {
    Element(ElementRef),
    Attribute(AttrRef),
    Text(TextRef),
    CDATASection(CDATASectionRef),
    EntityReference(EntityReferenceRef),
    Entity(EntityRef),
    ProcessingInstruction(ProcessingInstructionRef),
    Comment(CommentRef),
    Document(DocumentRef),
    DocumentType(DocumentTypeRef),
    DocumentFragment(DocumentFragmentRef),
    Notation(NotationRef),
}

impl NodeRef {
    /// Generate [`NodeWeakRef`] from `self`.
    pub(super) fn downgrade(&self) -> NodeWeakRef {
        use NodeRef::*;
        match self {
            Element(node) => NodeWeakRef::Element(Rc::downgrade(&node.0)),
            Attribute(node) => NodeWeakRef::Attribute(Rc::downgrade(&node.0)),
            Text(node) => NodeWeakRef::Text(Rc::downgrade(&node.0)),
            CDATASection(node) => NodeWeakRef::CDATASection(Rc::downgrade(&node.0)),
            EntityReference(node) => NodeWeakRef::EntityReference(Rc::downgrade(&node.0)),
            Entity(node) => NodeWeakRef::Entity(Rc::downgrade(&node.0)),
            ProcessingInstruction(node) => {
                NodeWeakRef::ProcessingInstruction(Rc::downgrade(&node.0))
            }
            Comment(node) => NodeWeakRef::Comment(Rc::downgrade(&node.0)),
            Document(node) => NodeWeakRef::Document(Rc::downgrade(&node.0)),
            DocumentType(node) => NodeWeakRef::DocumentType(Rc::downgrade(&node.0)),
            DocumentFragment(node) => NodeWeakRef::DocumentFragment(Rc::downgrade(&node.0)),
            Notation(node) => NodeWeakRef::Notation(Rc::downgrade(&node.0)),
        }
    }
}

macro_rules! impl_node_trait_to_noderef {
    (
        $(
            fn $( ($mut:tt) )? $fn:ident($( $arg_name:ident : $arg_type:ty ),*) -> $ret:ty
        ),*
    ) => {
        impl Node for NodeRef {
            $(
                fn $fn(& $( $mut )? self, $( $arg_name: $arg_type),* ) -> $ret {
                    match self {
                        NodeRef::Element(elem) => <ElementRef as Node>::$fn(elem, $( $arg_name ),* ),
                        NodeRef::Attribute(attr) => attr.$fn( $( $arg_name ),* ),
                        NodeRef::Text(text) => text.$fn( $( $arg_name ),* ),
                        NodeRef::CDATASection(cdata) => cdata.$fn( $( $arg_name ),* ),
                        NodeRef::EntityReference(entref) => entref.$fn( $( $arg_name ),* ),
                        NodeRef::Entity(ent) => ent.$fn( $( $arg_name ),* ),
                        NodeRef::ProcessingInstruction(pi) => pi.$fn( $( $arg_name ),* ),
                        NodeRef::Comment(comment) => comment.$fn( $( $arg_name ),* ),
                        NodeRef::Document(doc) => doc.$fn( $( $arg_name ),* ),
                        NodeRef::DocumentType(doctype) => doctype.$fn( $( $arg_name ),* ),
                        NodeRef::DocumentFragment(frag) => frag.$fn( $( $arg_name ),* ),
                        NodeRef::Notation(nota) => nota.$fn( $( $arg_name ),* ),
                    }
                }
            )*
        }
    };
}

impl_node_trait_to_noderef! {
    fn node_name() -> Rc<str>,
    fn node_value() -> Option<Rc<str>>,
    fn(mut) set_node_value(value: impl Into<String>) -> Result<(), DOMException>,
    fn node_type() -> NodeType,
    fn parent_node() -> Option<NodeRef>,
    fn child_nodes() -> ChildNodesList<NodeRef>,
    fn first_child() -> Option<NodeRef>,
    fn last_child() -> Option<NodeRef>,
    fn previous_sibling() -> Option<NodeRef>,
    fn next_sibling() -> Option<NodeRef>,
    fn attributes() -> Option<AttributeMap>,
    fn owner_document() -> Option<DocumentRef>,
    fn(mut) insert_before(new_child: NodeRef, ref_child: Option<NodeRef>) -> Result<NodeRef, DOMException>,
    fn(mut) replace_child(new_child: NodeRef, old_child: NodeRef) -> Result<NodeRef, DOMException>,
    fn(mut) remove_child(old_child: NodeRef) -> Result<NodeRef, DOMException>,
    fn(mut) append_child(new_child: NodeRef) -> Result<NodeRef, DOMException>,
    fn has_child_nodes() -> bool,
    fn clone_node(deep: bool) -> NodeRef,
    fn(mut) normalize() -> (),
    fn namespace_uri() -> Option<Rc<str>>,
    fn prefix() -> Option<Rc<str>>,
    fn(mut) set_prefix(prefix: Option<impl Into<Rc<str>>>) -> Result<(), DOMException>,
    fn local_name() -> Option<Rc<str>>,
    fn has_attributes() -> bool,
    fn base_uri() -> Option<String>,
    fn compare_document_position(other: &NodeRef) -> DocumentPosition,
    fn text_content() -> Option<String>,
    fn is_same_node(other: &NodeRef) -> bool,
    fn lookup_prefix(ns_uri: &str) -> Option<Rc<str>>,
    fn is_default_namespace(ns_uri: &str) -> bool,
    fn lookup_namespace_uri(prefix: Option<&str>) -> Option<Rc<str>>,
    fn is_equal_node(arg: &NodeRef) -> bool,
    fn(mut) set_user_data(key: impl Into<String>, data: DOMUserData, handler: Option<Arc<dyn UserDataHandler>>) -> Option<DOMUserData>,
    fn get_user_data(key: &str) -> Option<DOMUserData>,
    fn is_read_only() -> bool
}

macro_rules! impl_node_connection_to_noderef {
    (
        $(
            fn $( ($mut:tt) )? $fn:ident($( $arg_name:ident : $arg_type:ty ),*) -> $ret:ty
        ),*
    ) => {
        impl NodeConnection for NodeRef {
            $(
                fn $fn(& $( $mut )? self, $( $arg_name: $arg_type),* ) -> $ret {
                    match self {
                        NodeRef::Element(elem) => elem.$fn( $( $arg_name ),* ),
                        NodeRef::Attribute(attr) => attr.$fn( $( $arg_name ),* ),
                        NodeRef::Text(text) => text.$fn( $( $arg_name ),* ),
                        NodeRef::CDATASection(cdata) => cdata.$fn( $( $arg_name ),* ),
                        NodeRef::EntityReference(entref) => entref.$fn( $( $arg_name ),* ),
                        NodeRef::Entity(ent) => ent.$fn( $( $arg_name ),* ),
                        NodeRef::ProcessingInstruction(pi) => pi.$fn( $( $arg_name ),* ),
                        NodeRef::Comment(comment) => comment.$fn( $( $arg_name ),* ),
                        NodeRef::Document(doc) => doc.$fn( $( $arg_name ),* ),
                        NodeRef::DocumentType(doctype) => doctype.$fn( $( $arg_name ),* ),
                        NodeRef::DocumentFragment(frag) => frag.$fn( $( $arg_name ),* ),
                        NodeRef::Notation(nota) => nota.$fn( $( $arg_name ),* ),
                    }
                }
            )*
        }
    };
}

impl_node_connection_to_noderef! {
    fn(mut) set_parent_node(new_parent: Option<NodeRef>) -> Option<NodeRef>,
    fn(mut) set_first_child(new_child: Option<NodeRef>) -> Option<NodeRef>,
    fn(mut) set_last_child(new_child: Option<NodeRef>) -> Option<NodeRef>,
    fn(mut) set_previous_sibling(new_sibling: Option<NodeRef>) -> Option<NodeRef>,
    fn(mut) set_next_sibling(new_sibling: Option<NodeRef>) -> Option<NodeRef>,
    fn(mut) set_owner_document(new_doc: DocumentRef) -> Option<DocumentRef>,
    fn(mut) set_read_only() -> (),
    fn(mut) unset_read_only() -> (),
    fn(mut) adopted_to(new_doc: DocumentRef) -> (),
    fn(mut) connect_as_previous_sibling(next: NodeRef) -> (),
    fn(mut) connect_as_next_sibling(prev: NodeRef) -> (),
    fn(mut) disconnect_parent_and_sibling() -> Option<NodeRef>,
    fn handle_user_data(operation: OperationType, dst: Option<NodeRef>) -> ()
}

macro_rules! impl_node_conversion {
    ( $( ( $fn:ident, $var:ident, $t:ty ) ),* ) => {
        impl NodeRef {
            $(
                pub fn $fn (&self) -> Option<$t> {
                    match self {
                        NodeRef:: $var (node) => Some(node.clone()),
                        _ => None
                    }
                }
            )*
        }
    };
}

impl_node_conversion! {
    ( as_element, Element, ElementRef ),
    ( as_attribute, Attribute, AttrRef ),
    ( as_text_node, Text, TextRef ),
    ( as_cdata_section, CDATASection, CDATASectionRef ),
    ( as_entity, Entity, EntityRef ),
    ( as_entity_reference, EntityReference, EntityReferenceRef ),
    ( as_processing_instruction, ProcessingInstruction, ProcessingInstructionRef ),
    ( as_comment, Comment, CommentRef ),
    ( as_document, Document, DocumentRef ),
    ( as_document_type, DocumentType, DocumentTypeRef ),
    ( as_document_fragment, DocumentFragment, DocumentFragmentRef ),
    ( as_notation, Notation, NotationRef )
}

/// Implementation of [Node](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-1950641247)
/// interface on [1.4 Fundamental Interfaces: Core Module](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-BBACDC08)
#[derive(Clone)]
pub(super) enum NodeStrongRef {
    Element(Rc<RefCell<Element>>),
    Attribute(Rc<RefCell<Attr>>),
    Text(Rc<RefCell<Text>>),
    CDATASection(Rc<RefCell<CDATASection>>),
    EntityReference(Rc<RefCell<EntityReference>>),
    Entity(Rc<RefCell<Entity>>),
    ProcessingInstruction(Rc<RefCell<ProcessingInstruction>>),
    Comment(Rc<RefCell<Comment>>),
    Document(Rc<RefCell<Document>>),
    DocumentType(Rc<RefCell<DocumentType>>),
    DocumentFragment(Rc<RefCell<DocumentFragment>>),
    Notation(Rc<RefCell<Notation>>),
}

impl From<NodeStrongRef> for NodeRef {
    fn from(value: NodeStrongRef) -> Self {
        match value {
            NodeStrongRef::Element(node) => From::from(ElementRef::from(node)),
            NodeStrongRef::Attribute(node) => From::from(AttrRef::from(node)),
            NodeStrongRef::Text(node) => From::from(TextRef::from(node)),
            NodeStrongRef::CDATASection(node) => From::from(CDATASectionRef::from(node)),
            NodeStrongRef::EntityReference(node) => From::from(EntityReferenceRef::from(node)),
            NodeStrongRef::Entity(node) => From::from(EntityRef::from(node)),
            NodeStrongRef::ProcessingInstruction(node) => {
                From::from(ProcessingInstructionRef::from(node))
            }
            NodeStrongRef::Comment(node) => From::from(CommentRef::from(node)),
            NodeStrongRef::Document(node) => From::from(DocumentRef::from(node)),
            NodeStrongRef::DocumentType(node) => From::from(DocumentTypeRef::from(node)),
            NodeStrongRef::DocumentFragment(node) => From::from(DocumentFragmentRef::from(node)),
            NodeStrongRef::Notation(node) => From::from(NotationRef::from(node)),
        }
    }
}

impl From<NodeRef> for NodeStrongRef {
    fn from(value: NodeRef) -> Self {
        match value {
            NodeRef::Element(node) => NodeStrongRef::Element(node.0),
            NodeRef::Attribute(node) => NodeStrongRef::Attribute(node.0),
            NodeRef::Text(node) => NodeStrongRef::Text(node.0),
            NodeRef::CDATASection(node) => NodeStrongRef::CDATASection(node.0),
            NodeRef::EntityReference(node) => NodeStrongRef::EntityReference(node.0),
            NodeRef::Entity(node) => NodeStrongRef::Entity(node.0),
            NodeRef::ProcessingInstruction(node) => NodeStrongRef::ProcessingInstruction(node.0),
            NodeRef::Comment(node) => NodeStrongRef::Comment(node.0),
            NodeRef::Document(node) => NodeStrongRef::Document(node.0),
            NodeRef::DocumentType(node) => NodeStrongRef::DocumentType(node.0),
            NodeRef::DocumentFragment(node) => NodeStrongRef::DocumentFragment(node.0),
            NodeRef::Notation(node) => NodeStrongRef::Notation(node.0),
        }
    }
}

/// Implementation of [Node](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-1950641247)
/// interface on [1.4 Fundamental Interfaces: Core Module](https://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/DOM3-Core.html#core-ID-BBACDC08)
#[derive(Clone)]
pub(super) enum NodeWeakRef {
    Element(Weak<RefCell<Element>>),
    Attribute(Weak<RefCell<Attr>>),
    Text(Weak<RefCell<Text>>),
    CDATASection(Weak<RefCell<CDATASection>>),
    EntityReference(Weak<RefCell<EntityReference>>),
    Entity(Weak<RefCell<Entity>>),
    ProcessingInstruction(Weak<RefCell<ProcessingInstruction>>),
    Comment(Weak<RefCell<Comment>>),
    Document(Weak<RefCell<Document>>),
    DocumentType(Weak<RefCell<DocumentType>>),
    DocumentFragment(Weak<RefCell<DocumentFragment>>),
    Notation(Weak<RefCell<Notation>>),
}

impl NodeWeakRef {
    /// Generate [`NodeRef`] from `self`.  
    /// Success conditions are the same as for [`std::rc::Weak::upgrade`].
    pub fn upgrade(&self) -> Option<NodeRef> {
        match self {
            NodeWeakRef::Element(node) => {
                let elem = node.upgrade()?;
                let doc = elem.borrow().owner_document()?;
                Some(NodeRef::Element(ElementRef(elem, doc)))
            }
            NodeWeakRef::Attribute(node) => {
                let attr = node.upgrade()?;
                let doc = attr.borrow().owner_document()?;
                Some(NodeRef::Attribute(AttrRef(attr, doc)))
            }
            NodeWeakRef::Text(node) => {
                let text = node.upgrade()?;
                let doc = text.borrow().owner_document()?;
                Some(NodeRef::Text(TextRef(text, doc)))
            }
            NodeWeakRef::CDATASection(node) => {
                let cdata = node.upgrade()?;
                let doc = cdata.borrow().owner_document()?;
                Some(NodeRef::CDATASection(CDATASectionRef(cdata, doc)))
            }
            NodeWeakRef::EntityReference(node) => {
                let entref = node.upgrade()?;
                let doc = entref.borrow().owner_document()?;
                Some(NodeRef::EntityReference(EntityReferenceRef(entref, doc)))
            }
            NodeWeakRef::Entity(node) => {
                let ent = node.upgrade()?;
                let doc = ent.borrow().owner_document();
                Some(NodeRef::Entity(EntityRef(ent, doc)))
            }
            NodeWeakRef::ProcessingInstruction(node) => {
                let pi = node.upgrade()?;
                let doc = pi.borrow().owner_document()?;
                Some(NodeRef::ProcessingInstruction(ProcessingInstructionRef(
                    pi, doc,
                )))
            }
            NodeWeakRef::Comment(node) => {
                let comment = node.upgrade()?;
                let doc = comment.borrow().owner_document()?;
                Some(NodeRef::Comment(CommentRef(comment, doc)))
            }
            NodeWeakRef::Document(node) => {
                node.upgrade().map(DocumentRef::from).map(NodeRef::Document)
            }
            NodeWeakRef::DocumentType(node) => {
                let doctype = node.upgrade()?;
                let doc = doctype.borrow().owner_document();
                Some(NodeRef::DocumentType(DocumentTypeRef(doctype, doc)))
            }
            NodeWeakRef::DocumentFragment(node) => {
                let frag = node.upgrade()?;
                let doc = frag.borrow().owner_document()?;
                Some(NodeRef::DocumentFragment(DocumentFragmentRef(frag, doc)))
            }
            NodeWeakRef::Notation(node) => {
                let not = node.upgrade()?;
                let doc = not.borrow().owner_document();
                Some(NodeRef::Notation(NotationRef(not, doc)))
            }
        }
    }
}