/**
 * This mixin makes it so that we can provide a specific layout template without
 * needing to reference each of the inner areas via a partial embedded in the root,
 * enabling partial re-renders for parts of the sheet without losing advanced
 * layout capabilities.
 *
 * @param {ReturnType<HandlebarsApp>} HandlebarsApp The mixin'd class from HAM to further mix
 */
export function LaidOutAppMixin(HandlebarsApp) {
	class LaidOutApp extends HandlebarsApp {
		#partDescriptors;

		/**
		 * This caches the part descriptors into this class of the heirarchy, because
		 * Foundry doesn't expose the partDescriptors from the HAM directly, so we
		 * inject a heirarchy call so that we can nab the pointer that Foundry has
		 * in the HAM so that we can also read/write it from this class.
		 */
		_configureRenderParts(options) {
			const parts = super._configureRenderParts(options);
			this.#partDescriptors = parts;
			return parts;
		};

		/**
		 * @override
		 * This is essentially Foundry's HandlebarsApplicationMixin implementation,
		 * however if an existing part for non-root elements don't get concatenated
		 * into the DOM.
		 */
		_replaceHTML(result, content, options) {
			const partInfo = this.#partDescriptors;
			for ( const [partId, htmlElement] of Object.entries(result) ) {
				const part = partInfo[partId];
				const priorElement = part.root ? content : content.querySelector(`[data-application-part="${partId}"]`);
				const state = {};
				if ( priorElement ) {
					this._preSyncPartState(partId, htmlElement, priorElement, state);
					if ( part.root ) {
						priorElement.replaceChildren(...htmlElement.children);
					}
					else {
						priorElement.replaceWith(htmlElement);
					}
					this._syncPartState(partId, htmlElement, priorElement, state);
				}
				else {
					continue;
				};
				this._attachPartListeners(partId, htmlElement, options);
				this.parts[partId] = htmlElement;
			}
		};
	};
	return LaidOutApp;
};