import GltfLoader from "../io/GltfLoader";
import Gltf2 from "../types/Gltf2";
import { ElementOfType, PropertyType } from "../types/Elements";
/**
 * Interface that all gltf extensions must implement to be loaded by the gltf loader.
 * An ExtensionInstance is created by an ExtensionFactory, by calling createInstance().
 */
export interface IExtensionInstance {
    /**
     * Name of the extension
     */
    readonly name: string;
    /**
     * Priority order of the extension, used to sort extensions, higher priority first.
     */
    readonly priority: number;
    /**
     * Function called when an element is loaded/created, for extensions that need to create the element themselves.
     * @param data Data of the element to load, coming from the gltf file.
     */
    loadElement<P extends Gltf2.Property>(data: P): null | Promise<ElementOfType<PropertyType<P>>>;
    /**
     * Function called after an element has been loaded/created, for extensions that need to modify the element after loading.
     * @param data Data of the loaded element, coming from the gltf file.
     * @param element The element that has been loaded.
     */
    acceptElement<P extends Gltf2.Property>(data: P, element: ElementOfType<PropertyType<P>>): Promise<ElementOfType<PropertyType<P>>>;
}
/**
 * The implementation of an extension factory.
 * Passing by factories instead of direct instances allow to pass additional parameters to the extension and keep the extension instance simple.
 */
export interface IExtensionFactory {
    /**
     * Name of the extension
     */
    readonly name: string;
    /**
     * Create an instance of the extension.
     * @param gltfLoader GLTF loader to use
     */
    createInstance(gltfLoader: GltfLoader): IExtensionInstance;
}