/**
* @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/conversion/modelconsumable
*/
import { ModelTextProxy } from "../model/textproxy.js";
import { type ModelItem } from "../model/item.js";
import { type ModelSelection } from "../model/selection.js";
import { type ModelDocumentSelection } from "../model/documentselection.js";
import { type ModelRange } from "../model/range.js";
/**
* Manages a list of consumable values for the {@link module:engine/model/item~ModelItem model items}.
*
* Consumables are various aspects of the model. A model item can be broken down into separate, single properties that might be
* taken into consideration when converting that item.
*
* `ModelConsumable` is used by {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher} while analyzing the changed
* parts of {@link module:engine/model/document~ModelDocument the document}. The added / changed / removed model items are broken down
* into singular properties (the item itself and its attributes). All those parts are saved in `ModelConsumable`. Then,
* during conversion, when the given part of a model item is converted (i.e. the view element has been inserted into the view,
* but without attributes), the consumable value is removed from `ModelConsumable`.
*
* For model items, `ModelConsumable` stores consumable values of one of following types: `insert`, `addattribute:<attributeKey>`,
* `changeattributes:<attributeKey>`, `removeattributes:<attributeKey>`.
*
* In most cases, it is enough to let th {@link module:engine/conversion/downcastdispatcher~DowncastDispatcher}
* gather consumable values, so there is no need to use
* the {@link module:engine/conversion/modelconsumable~ModelConsumable#add add method} directly.
* However, it is important to understand how consumable values can be
* {@link module:engine/conversion/modelconsumable~ModelConsumable#consume consumed}.
* See {@link module:engine/conversion/downcasthelpers default downcast converters} for more information.
*
* Keep in mind that one conversion event may have multiple callbacks (converters) attached to it. Each of those is
* able to convert one or more parts of the model. However, when one of those callbacks actually converts
* something, the others should not, because they would duplicate the results. Using `ModelConsumable` helps to avoid
* this situation, because callbacks should only convert these values that were not yet consumed from `ModelConsumable`.
*
* Consuming multiple values in a single callback:
*
* ```ts
* // Converter for custom `imageBlock` element that might have a `caption` element inside which changes
* // how the image is displayed in the view:
* //
* // Model:
* //
* // [imageBlock]
* //   └─ [caption]
* //       └─ foo
* //
* // View:
* //
* // <figure>
* //   ├─ <img />
* //   └─ <caption>
* //       └─ foo
* modelConversionDispatcher.on( 'insert:imageBlock', ( evt, data, conversionApi ) => {
* 	// First, consume the `imageBlock` element.
* 	conversionApi.consumable.consume( data.item, 'insert' );
*
* 	// Just create normal image element for the view.
* 	// Maybe it will be "decorated" later.
* 	const viewImage = new ViewElement( 'img' );
* 	const insertPosition = conversionApi.mapper.toViewPosition( data.range.start );
* 	const viewWriter = conversionApi.writer;
*
* 	// Check if the `imageBlock` element has children.
* 	if ( data.item.childCount > 0 ) {
* 		const modelCaption = data.item.getChild( 0 );
*
* 		// `modelCaption` insertion change is consumed from consumable values.
* 		// It will not be converted by other converters, but it's children (probably some text) will be.
* 		// Through mapping, converters for text will know where to insert contents of `modelCaption`.
* 		if ( conversionApi.consumable.consume( modelCaption, 'insert' ) ) {
* 			const viewCaption = new ViewElement( 'figcaption' );
*
* 			const viewImageHolder = new ViewElement( 'figure', null, [ viewImage, viewCaption ] );
*
* 			conversionApi.mapper.bindElements( modelCaption, viewCaption );
* 			conversionApi.mapper.bindElements( data.item, viewImageHolder );
* 			viewWriter.insert( insertPosition, viewImageHolder );
* 		}
* 	} else {
* 		conversionApi.mapper.bindElements( data.item, viewImage );
* 		viewWriter.insert( insertPosition, viewImage );
* 	}
*
* 	evt.stop();
* } );
* ```
*/
export declare class ModelConsumable {
	/**
	* Contains list of consumable values.
	*/
	private _consumable;
	/**
	* For each {@link module:engine/model/textproxy~ModelTextProxy} added to `ModelConsumable`, this registry holds a parent
	* of that `ModelTextProxy` and the start and end indices of that `ModelTextProxy`. This allows identification of the `ModelTextProxy`
	* instances that point to the same part of the model but are different instances. Each distinct `ModelTextProxy`
	* is given a unique `Symbol` which is then registered as consumable. This process is transparent for the `ModelConsumable`
	* API user because whenever `ModelTextProxy` is added, tested, consumed or reverted, the internal mechanisms of
	* `ModelConsumable` translate `ModelTextProxy` to that unique `Symbol`.
	*/
	private _textProxyRegistry;
	/**
	* Adds a consumable value to the consumables list and links it with a given model item.
	*
	* ```ts
	* modelConsumable.add( modelElement, 'insert' ); // Add `modelElement` insertion change to consumable values.
	* modelConsumable.add( modelElement, 'addAttribute:bold' ); // Add `bold` attribute insertion on `modelElement` change.
	* modelConsumable.add( modelElement, 'removeAttribute:bold' ); // Add `bold` attribute removal on `modelElement` change.
	* modelConsumable.add( modelSelection, 'selection' ); // Add `modelSelection` to consumable values.
	* modelConsumable.add( modelRange, 'range' ); // Add `modelRange` to consumable values.
	* ```
	*
	* @param item Model item, range or selection that has the consumable.
	* @param type Consumable type. Will be normalized to a proper form, that is either `<word>` or `<part>:<part>`.
	* Second colon and everything after will be cut. Passing event name is a safe and good practice.
	*/
	add(item: ModelItem | ModelSelection | ModelDocumentSelection | ModelRange, type: string): void;
	/**
	* Removes a given consumable value from a given model item.
	*
	* ```ts
	* modelConsumable.consume( modelElement, 'insert' ); // Remove `modelElement` insertion change from consumable values.
	* modelConsumable.consume( modelElement, 'addAttribute:bold' ); // Remove `bold` attribute insertion on `modelElement` change.
	* modelConsumable.consume( modelElement, 'removeAttribute:bold' ); // Remove `bold` attribute removal on `modelElement` change.
	* modelConsumable.consume( modelSelection, 'selection' ); // Remove `modelSelection` from consumable values.
	* modelConsumable.consume( modelRange, 'range' ); // Remove 'modelRange' from consumable values.
	* ```
	*
	* @param item Model item, range or selection from which consumable will be consumed.
	* @param type Consumable type. Will be normalized to a proper form, that is either `<word>` or `<part>:<part>`.
	* Second colon and everything after will be cut. Passing event name is a safe and good practice.
	* @returns `true` if consumable value was available and was consumed, `false` otherwise.
	*/
	consume(item: ModelItem | ModelSelection | ModelDocumentSelection | ModelRange, type: string): boolean;
	/**
	* Tests whether there is a consumable value of a given type connected with a given model item.
	*
	* ```ts
	* modelConsumable.test( modelElement, 'insert' ); // Check for `modelElement` insertion change.
	* modelConsumable.test( modelElement, 'addAttribute:bold' ); // Check for `bold` attribute insertion on `modelElement` change.
	* modelConsumable.test( modelElement, 'removeAttribute:bold' ); // Check for `bold` attribute removal on `modelElement` change.
	* modelConsumable.test( modelSelection, 'selection' ); // Check if `modelSelection` is consumable.
	* modelConsumable.test( modelRange, 'range' ); // Check if `modelRange` is consumable.
	* ```
	*
	* @param item Model item, range or selection to be tested.
	* @param type Consumable type. Will be normalized to a proper form, that is either `<word>` or `<part>:<part>`.
	* Second colon and everything after will be cut. Passing event name is a safe and good practice.
	* @returns `null` if such consumable was never added, `false` if the consumable values was
	* already consumed or `true` if it was added and not consumed yet.
	*/
	test(item: ModelItem | ModelSelection | ModelDocumentSelection | ModelRange, type: string): boolean | null;
	/**
	* Reverts consuming of a consumable value.
	*
	* ```ts
	* modelConsumable.revert( modelElement, 'insert' ); // Revert consuming `modelElement` insertion change.
	* modelConsumable.revert( modelElement, 'addAttribute:bold' ); // Revert consuming `bold` attribute insert from `modelElement`.
	* modelConsumable.revert( modelElement, 'removeAttribute:bold' ); // Revert consuming `bold` attribute remove from `modelElement`.
	* modelConsumable.revert( modelSelection, 'selection' ); // Revert consuming `modelSelection`.
	* modelConsumable.revert( modelRange, 'range' ); // Revert consuming `modelRange`.
	* ```
	*
	* @param item Model item, range or selection to be reverted.
	* @param type Consumable type.
	* @returns `true` if consumable has been reversed, `false` otherwise. `null` if the consumable has
	* never been added.
	*/
	revert(item: ModelItem | ModelSelection | ModelDocumentSelection | ModelRange, type: string): boolean | null;
	/**
	* Verifies if all events from the specified group were consumed.
	*
	* @param eventGroup The events group to verify.
	*/
	verifyAllConsumed(eventGroup: string): void;
	/**
	* Gets a unique symbol for the passed {@link module:engine/model/textproxy~ModelTextProxy} instance.
	* All `ModelTextProxy` instances that have same parent, same start index and same end index will get the same symbol.
	*
	* Used internally to correctly consume `ModelTextProxy` instances.
	*
	* @internal
	* @param textProxy `ModelTextProxy` instance to get a symbol for.
	* @returns Symbol representing all equal instances of `ModelTextProxy`.
	*/
	_getSymbolForTextProxy(textProxy: ModelTextProxy): symbol;
	/**
	* Adds a symbol for the given {@link module:engine/model/textproxy~ModelTextProxy} instance.
	*
	* Used internally to correctly consume `ModelTextProxy` instances.
	*
	* @param textProxy Text proxy instance.
	* @returns Symbol generated for given `ModelTextProxy`.
	*/
	private _addSymbolForTextProxy;
}