import { LayoutMode, RouteGraph, RouteHandler, RouteInfo } from '../Route';

export interface ScreenGraph extends RouteGraph {
	layout: 'screen';
	sceneId: string;
	mode: LayoutMode;
	moduleName: string;
}

export function isScreenGraph(graph: RouteGraph): graph is ScreenGraph {
	return graph.layout === 'screen';
}

function extractModuleNames(graph: RouteGraph, set: string[]) {
	if (isScreenGraph(graph)) {
		set.push(graph.moduleName);
	} else {
		const children = graph.children!;
		for (let i = 0; i < children.length; i++) {
			extractModuleNames(children[i], set);
		}
	}
}

export function isTargetLocateIn(graph: RouteGraph, target: RouteInfo) {
	const existings: string[] = [];
	extractModuleNames(graph, existings);
	const { dependencies, moduleName } = target;
	const expectations = [...dependencies, moduleName];
	return expectations.some(name => existings.includes(name));
}

export class ScreenRouteHandler implements RouteHandler {
	process(graph: RouteGraph, target: RouteInfo): Promise<[boolean, RouteGraph | null]> {
		if (!isScreenGraph(graph)) {
			throw new Error(`${graph} is Not a ScreenGraph`);
		}

		if (graph.moduleName === target.moduleName) {
			return Promise.resolve([true, null]);
		}

		return Promise.resolve([false, graph]);
	}
}