import type { MenuRootContextValue } from "../root/menu-root-context";

/** Payload of the floating tree's `itemhover` event. */
export interface MenuItemHoverEvent {
	/** Floating node of the menu the hovered item belongs to. */
	nodeId: string;
	/** The hovered item element. */
	target: EventTarget | null;
}

/**
 * Returns an `onMouseMove` handler that announces an item hover on the
 * floating tree, so an open submenu of the same menu can close when a
 * different item is hovered (see `<Menu.Positioner>`). Mirrors React's
 * `useMenuItemCommonProps` `onMouseMove`.
 *
 * `nodeId` is the floating node of the menu the item renders in, which is what
 * a child submenu sees as its `floatingParentNodeId`.
 */
export function createItemHoverEmitter(
	menu: Pick<MenuRootContextValue, "floatingTreeRoot">,
	nodeId: string | null | undefined,
): (event: MouseEvent) => void {
	return (event) => {
		if (!nodeId) return;
		const payload: MenuItemHoverEvent = {
			nodeId,
			target: event.currentTarget,
		};
		menu.floatingTreeRoot()?.events.emit("itemhover", payload);
	};
}