/*
 * Portions of this file are based on code from react-spectrum.
 * Apache License Version 2.0, Copyright 2020 Adobe.
 *
 * Credits to the React Spectrum team:
 * https://github.com/adobe/react-spectrum/blob/8f2f2acb3d5850382ebe631f055f88c704aa7d17/packages/@react-stately/list/src/useSingleSelectListState.ts
 */

import { access } from "@kobalte/utils";
import { type Accessor, createMemo, mergeProps, splitProps } from "solid-js";

import {
	type CollectionBase,
	type CollectionNode,
	createControllableSignal,
} from "../primitives";
import type { SingleSelection } from "../selection";
import {
	type CreateListStateProps,
	type ListState,
	createListState,
} from "./create-list-state";

export interface CreateSingleSelectListStateProps
	extends CollectionBase,
		Omit<SingleSelection, "disallowEmptySelection"> {
	/** Filter function to generate a filtered list of nodes. */
	filter?: (nodes: Iterable<CollectionNode>) => Iterable<CollectionNode>;
}

export interface SingleSelectListState extends ListState {
	/** The value of the currently selected item. */
	selectedItem: Accessor<CollectionNode | undefined>;

	/** The key for the currently selected item. */
	selectedKey: Accessor<string | undefined>;

	/** Sets the selected key. */
	setSelectedKey(key: string): void;
}

/**
 * Provides state management for list-like components with single selection.
 * Handles building a collection of items from props, and manages selection state.
 */
export function createSingleSelectListState(
	props: CreateSingleSelectListStateProps,
): SingleSelectListState {
	const [selectedKey, setSelectedKey] = createControllableSignal<string>({
		value: () => access(props.selectedKey),
		defaultValue: () => access(props.defaultSelectedKey),
		onChange: (value) => props.onSelectionChange?.(value),
	});

	const selectedKeys = createMemo(() => {
		const selection = selectedKey();
		return selection != null ? [selection] : [];
	});

	const [, defaultCreateListStateProps] = splitProps(props, [
		"onSelectionChange",
	]);

	const createListStateProps = mergeProps(defaultCreateListStateProps, {
		selectionMode: "single",
		disallowEmptySelection: true,
		allowDuplicateSelectionEvents: true,
		selectedKeys,
		onSelectionChange: (keys: Set<string>) => {
			const key = (keys as Set<string>).values().next().value;

			// Always fire onSelectionChange, even if the key is the same
			// as the current key (createControllableSignal does not).
			if (key === selectedKey()) {
				props.onSelectionChange?.(key);
			}

			setSelectedKey(key);
		},
	} as Partial<CreateListStateProps>);

	const { collection, selectionManager } =
		createListState(createListStateProps);

	const selectedItem = createMemo(() => {
		const selection = selectedKey();
		return selection != null ? collection().getItem(selection) : undefined;
	});

	return {
		collection,
		selectionManager,
		selectedKey,
		setSelectedKey,
		selectedItem,
	};
}