/**
 * WordPress dependencies
 */
import deprecated from '@wordpress/deprecated';

/**
 * Internal dependencies
 */
import * as children from './children';

/**
 * A representation of a single node within a block's rich text value. If
 * representing a text node, the value is simply a string of the node value.
 * As representing an element node, it is an object of:
 *
 * 1. `type` (string): Tag name.
 * 2. `props` (object): Attributes and children array of BlockNode.
 */
type BlockNode = string | { type: string; props: Record< string, unknown > };

/**
 * Given a single node and a node type (e.g. `'br'`), returns true if the node
 * corresponds to that type, false otherwise.
 *
 * @param node Block node to test
 * @param type Node to type to test against.
 *
 * @return Whether node is of intended type.
 */
function isNodeOfType( node: BlockNode, type: string ): boolean {
	deprecated( 'wp.blocks.node.isNodeOfType', {
		since: '6.1',
		version: '6.3',
		link: 'https://developer.wordpress.org/block-editor/how-to-guides/block-tutorial/introducing-attributes-and-editable-fields/',
	} );

	return typeof node !== 'string' && node?.type === type;
}

/**
 * Given an object implementing the NamedNodeMap interface, returns a plain
 * object equivalent value of name, value key-value pairs.
 *
 * @see https://dom.spec.whatwg.org/#interface-namednodemap
 *
 * @param nodeMap NamedNodeMap to convert to object.
 *
 * @return Object equivalent value of NamedNodeMap.
 */
export function getNamedNodeMapAsObject(
	nodeMap: NamedNodeMap
): Record< string, string > {
	const result: Record< string, string > = {};
	for ( let i = 0; i < nodeMap.length; i++ ) {
		const { name, value } = nodeMap[ i ];
		result[ name ] = value;
	}

	return result;
}

/**
 * Given a DOM Element or Text node, returns an equivalent block node. Throws
 * if passed any node type other than element or text.
 *
 * @throws {TypeError} If non-element/text node is passed.
 *
 * @param  domNode DOM node to convert.
 *
 * @return Block node equivalent to DOM node.
 */
export function fromDOM( domNode: Node ): BlockNode {
	deprecated( 'wp.blocks.node.fromDOM', {
		since: '6.1',
		version: '6.3',
		alternative: 'wp.richText.create',
		link: 'https://developer.wordpress.org/block-editor/how-to-guides/block-tutorial/introducing-attributes-and-editable-fields/',
	} );

	if ( domNode.nodeType === domNode.TEXT_NODE ) {
		return domNode.nodeValue!;
	}

	if ( domNode.nodeType !== domNode.ELEMENT_NODE ) {
		throw new TypeError(
			'A block node can only be created from a node of type text or ' +
				'element.'
		);
	}

	return {
		type: domNode.nodeName.toLowerCase(),
		props: {
			...getNamedNodeMapAsObject( ( domNode as Element ).attributes ),
			children: children.fromDOM( domNode.childNodes ),
		},
	};
}

/**
 * Given a block node, returns its HTML string representation.
 *
 * @param node Block node to convert to string.
 *
 * @return String HTML representation of block node.
 */
export function toHTML( node: BlockNode ): string {
	deprecated( 'wp.blocks.node.toHTML', {
		since: '6.1',
		version: '6.3',
		alternative: 'wp.richText.toHTMLString',
		link: 'https://developer.wordpress.org/block-editor/how-to-guides/block-tutorial/introducing-attributes-and-editable-fields/',
	} );

	return children.toHTML( [ node ] as children.BlockChildren );
}

/**
 * Given a selector, returns an hpq matcher generating a BlockNode value
 * matching the selector result.
 *
 * @param selector DOM selector.
 *
 * @return hpq matcher.
 */
export function matcher(
	selector?: string
): ( domNode: Element ) => BlockNode | null {
	deprecated( 'wp.blocks.node.matcher', {
		since: '6.1',
		version: '6.3',
		alternative: 'html source',
		link: 'https://developer.wordpress.org/block-editor/how-to-guides/block-tutorial/introducing-attributes-and-editable-fields/',
	} );

	return ( domNode: Element ): BlockNode | null => {
		let match: Element | null = domNode;

		if ( selector ) {
			match = domNode.querySelector( selector );
		}

		try {
			return fromDOM( match! );
		} catch {
			return null;
		}
	};
}

/**
 * Object of utility functions used in managing block attribute values of
 * source `node`.
 *
 * @see https://github.com/WordPress/gutenberg/pull/10439
 *
 * @deprecated since 4.0. The `node` source should not be used, and can be
 *             replaced by the `html` source.
 *
 * @private
 */
export default {
	isNodeOfType,
	fromDOM,
	toHTML,
	matcher,
};