/**
* @license Copyright (c) 2003-2026, CKSource Holding sp. z o.o. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
*/
/**
* @module engine/model/node
*/
import { ModelTypeCheckable } from "./typecheckable.js";
import { type ModelDocument } from "./document.js";
import { type ModelDocumentFragment } from "./documentfragment.js";
import { type ModelElement } from "./element.js";
/**
* Model node. Most basic structure of model tree.
*
* This is an abstract class that is a base for other classes representing different nodes in model.
*
* **Note:** If a node is detached from the model tree, you can manipulate it using it's API.
* However, it is **very important** that nodes already attached to model tree should be only changed through
* {@link module:engine/model/writer~ModelWriter Writer API}.
*
* Changes done by `Node` methods, like {@link module:engine/model/element~ModelElement#_insertChild _insertChild} or
* {@link module:engine/model/node~ModelNode#_setAttribute _setAttribute}
* do not generate {@link module:engine/model/operation/operation~Operation operations}
* which are essential for correct editor work if you modify nodes in {@link module:engine/model/document~ModelDocument document} root.
*
* The flow of working on `Node` (and classes that inherits from it) is as such:
* 1. You can create a `Node` instance, modify it using it's API.
* 2. Add `Node` to the model using `Batch` API.
* 3. Change `Node` that was already added to the model using `Batch` API.
*
* Similarly, you cannot use `Batch` API on a node that has not been added to the model tree, with the exception
* of {@link module:engine/model/writer~ModelWriter#insert inserting} that node to the model tree.
*
* Be aware that using {@link module:engine/model/writer~ModelWriter#remove remove from Batch API} does not allow to use `Node` API because
* the information about `Node` is still kept in model document.
*
* In case of {@link module:engine/model/element~ModelElement element node}, adding and removing children also counts as changing a node and
* follows same rules.
*/
export declare abstract class ModelNode extends ModelTypeCheckable {
	/**
	* Parent of this node. It could be {@link module:engine/model/element~ModelElement}
	* or {@link module:engine/model/documentfragment~ModelDocumentFragment}.
	* Equals to `null` if the node has no parent.
	*/
	readonly parent: ModelElement | ModelDocumentFragment | null;
	/**
	* Unique root name used to identify this root element by {@link module:engine/model/document~ModelDocument}.
	*/
	readonly rootName: string | undefined;
	/**
	* Attributes set on this node.
	*/
	private _attrs;
	/**
	* Index of this node in its parent or `null` if the node has no parent.
	*
	* @internal
	*/
	_index: number | null;
	/**
	* Offset at which this node starts in its parent or `null` if the node has no parent.
	*
	* @internal
	*/
	_startOffset: number | null;
	/**
	* Creates a model node.
	*
	* This is an abstract class, so this constructor should not be used directly.
	*
	* @param attrs Node's attributes. See {@link module:utils/tomap~toMap} for a list of accepted values.
	*/
	constructor(attrs?: ModelNodeAttributes);
	/**
	* {@link module:engine/model/document~ModelDocument Document} that owns this root element.
	*/
	get document(): ModelDocument | null;
	/**
	* Index of this node in its parent or `null` if the node has no parent.
	*/
	get index(): number | null;
	/**
	* Offset at which this node starts in its parent. It is equal to the sum of {@link #offsetSize offsetSize}
	* of all its previous siblings. Equals to `null` if node has no parent.
	*/
	get startOffset(): number | null;
	/**
	* Offset size of this node.
	*
	* Represents how much "offset space" is occupied by the node in its parent. It is important for
	* {@link module:engine/model/position~ModelPosition position}. When node has `offsetSize` greater
	* than `1`, position can be placed between that node start and end. `offsetSize` greater than `1` is for
	* nodes that represents more than one entity, i.e. a {@link module:engine/model/text~ModelText text node}.
	*/
	get offsetSize(): number;
	/**
	* Offset at which this node ends in its parent. It is equal to the sum of this node's
	* {@link module:engine/model/node~ModelNode#startOffset start offset} and {@link #offsetSize offset size}.
	* Equals to `null` if the node has no parent.
	*/
	get endOffset(): number | null;
	/**
	* Node's next sibling or `null` if the node is a last child of it's parent or if the node has no parent.
	*/
	get nextSibling(): ModelNode | null;
	/**
	* Node's previous sibling or `null` if the node is a first child of it's parent or if the node has no parent.
	*/
	get previousSibling(): ModelNode | null;
	/**
	* The top-most ancestor of the node. If node has no parent it is the root itself. If the node is a part
	* of {@link module:engine/model/documentfragment~ModelDocumentFragment}, it's `root` is equal to that `DocumentFragment`.
	*/
	get root(): ModelNode | ModelDocumentFragment;
	/**
	* Returns `true` if the node is inside a document root that is attached to the document.
	*/
	isAttached(): boolean;
	/**
	* Gets path to the node. The path is an array containing starting offsets of consecutive ancestors of this node,
	* beginning from {@link module:engine/model/node~ModelNode#root root}, down to this node's starting offset. The path can be used to
	* create {@link module:engine/model/position~ModelPosition Position} instance.
	*
	* ```ts
	* const abc = new Text( 'abc' );
	* const foo = new Text( 'foo' );
	* const h1 = new ModelElement( 'h1', null, new Text( 'header' ) );
	* const p = new ModelElement( 'p', null, [ abc, foo ] );
	* const div = new ModelElement( 'div', null, [ h1, p ] );
	* foo.getPath(); // Returns [ 1, 3 ]. `foo` is in `p` which is in `div`. `p` starts at offset 1, while `foo` at 3.
	* h1.getPath(); // Returns [ 0 ].
	* div.getPath(); // Returns [].
	* ```
	*/
	getPath(): Array<number>;
	/**
	* Returns ancestors array of this node.
	*
	* @param options Options object.
	* @param options.includeSelf When set to `true` this node will be also included in parent's array.
	* @param options.parentFirst When set to `true`, array will be sorted from node's parent to root element,
	* otherwise root element will be the first item in the array.
	* @returns Array with ancestors.
	*/
	getAncestors(options?: {
		includeSelf?: boolean;
		parentFirst?: boolean;
	}): Array<ModelNode | ModelDocumentFragment>;
	/**
	* Returns a {@link module:engine/model/element~ModelElement} or {@link module:engine/model/documentfragment~ModelDocumentFragment}
	* which is a common ancestor of both nodes.
	*
	* @param node The second node.
	* @param options Options object.
	* @param options.includeSelf When set to `true` both nodes will be considered "ancestors" too.
	* Which means that if e.g. node A is inside B, then their common ancestor will be B.
	*/
	getCommonAncestor(node: ModelNode, options?: {
		includeSelf?: boolean;
	}): ModelElement | ModelDocumentFragment | null;
	/**
	* Returns whether this node is before given node. `false` is returned if nodes are in different trees (for example,
	* in different {@link module:engine/model/documentfragment~ModelDocumentFragment}s).
	*
	* @param node Node to compare with.
	*/
	isBefore(node: ModelNode): boolean;
	/**
	* Returns whether this node is after given node. `false` is returned if nodes are in different trees (for example,
	* in different {@link module:engine/model/documentfragment~ModelDocumentFragment}s).
	*
	* @param node Node to compare with.
	*/
	isAfter(node: ModelNode): boolean;
	/**
	* Checks if the node has an attribute with given key.
	*
	* @param key Key of attribute to check.
	* @returns `true` if attribute with given key is set on node, `false` otherwise.
	*/
	hasAttribute(key: string): boolean;
	/**
	* Gets an attribute value for given key or `undefined` if that attribute is not set on node.
	*
	* @param key Key of attribute to look for.
	* @returns Attribute value or `undefined`.
	*/
	getAttribute(key: string): unknown;
	/**
	* Returns iterator that iterates over this node's attributes.
	*
	* Attributes are returned as arrays containing two items. First one is attribute key and second is attribute value.
	* This format is accepted by native `Map` object and also can be passed in `Node` constructor.
	*/
	getAttributes(): IterableIterator<[string, unknown]>;
	/**
	* Returns iterator that iterates over this node's attribute keys.
	*/
	getAttributeKeys(): IterableIterator<string>;
	/**
	* Converts `Node` to plain object and returns it.
	*
	* @returns `Node` converted to plain object.
	*/
	toJSON(): unknown;
	/**
	* Creates a copy of this node, that is a node with exactly same attributes, and returns it.
	*
	* @internal
	* @returns Node with same attributes as this node.
	*/
	_clone(_deep?: boolean): ModelNode;
	/**
	* Removes this node from its parent.
	*
	* @internal
	* @see module:engine/model/writer~ModelWriter#remove
	*/
	_remove(): void;
	/**
	* Sets attribute on the node. If attribute with the same key already is set, it's value is overwritten.
	*
	* @see module:engine/model/writer~ModelWriter#setAttribute
	* @internal
	* @param key Key of attribute to set.
	* @param value Attribute value.
	*/
	_setAttribute(key: string, value: unknown): void;
	/**
	* Removes all attributes from the node and sets given attributes.
	*
	* @see module:engine/model/writer~ModelWriter#setAttributes
	* @internal
	* @param attrs Attributes to set. See {@link module:utils/tomap~toMap} for a list of accepted values.
	*/
	_setAttributesTo(attrs: ModelNodeAttributes): void;
	/**
	* Removes an attribute with given key from the node.
	*
	* @see module:engine/model/writer~ModelWriter#removeAttribute
	* @internal
	* @param key Key of attribute to remove.
	* @returns `true` if the attribute was set on the element, `false` otherwise.
	*/
	_removeAttribute(key: string): boolean;
	/**
	* Removes all attributes from the node.
	*
	* @see module:engine/model/writer~ModelWriter#clearAttributes
	* @internal
	*/
	_clearAttributes(): void;
}
/**
* Represents a set of model node attributes, accepted as either a plain object
* with string keys or an iterable of `[ key, value ]` pairs (e.g., a `Map`).
*
* See {@link module:utils/tomap~toMap} for more details and examples.
*/
export type ModelNodeAttributes = Record<string, unknown> | Iterable<[string, unknown]>;