import { visit as _visit, SKIP } from 'unist-util-visit';

// This is a workaround.
// It fixes a compatibility issue between different, incompatible ASTs given by plugins to Unist
const visit = _visit as (node: any, type: string, callback?: (node: any, index: number, parent: any) => any) => any;

// Remove the wrapping paragraph for <astro-root> islands
export default function remarkUnwrap() {
	const astroRootNodes = new Set();
	let insideAstroRoot = false;

	return (tree: any) => {
		// reset state
		insideAstroRoot = false;
		astroRootNodes.clear();

		visit(tree, 'html', (node) => {
			if (node.value.indexOf('<astro-root') > -1 && !insideAstroRoot) {
				insideAstroRoot = true;
			}
			if (node.value.indexOf('</astro-root') > -1 && insideAstroRoot) {
				insideAstroRoot = false;
			}
			astroRootNodes.add(node);
		});

		visit(tree, 'paragraph', (node, index, parent) => {
			if (parent && typeof index === 'number' && containsAstroRootNode(node)) {
				parent.children.splice(index, 1, ...node.children);
				return [SKIP, index];
			}
		});
	};

	function containsAstroRootNode(node: any) {
		return node.children.map((child: any) => astroRootNodes.has(child)).reduce((all: boolean, v: boolean) => (all ? all : v), false);
	}
}