import { interfaces } from 'inversify';
import { ServiceIdentifiersMap } from '../interfaces';

function lookupServiceIdentifiers(
  request: interfaces.Request,
  ServiceIdentifiers: ServiceIdentifiersMap
) {
  // It is used to perform the required dependency collection when dynamically importing modules.
  if (!ServiceIdentifiers.has(request.serviceIdentifier)) {
    ServiceIdentifiers.set(request.serviceIdentifier, []);
  }
  const depServiceIdentifier = request.childRequests.map(
    (childRequest) => childRequest.serviceIdentifier
  );
  ServiceIdentifiers.set(request.serviceIdentifier, depServiceIdentifier);
  if (request.childRequests.length === 0) return;
  request.childRequests.forEach((childRequest) => {
    lookupServiceIdentifiers(childRequest, ServiceIdentifiers);
  });
}

export function createCollector(ServiceIdentifiers: ServiceIdentifiersMap) {
  return (planAndResolve: interfaces.Next): interfaces.Next =>
    (args: interfaces.NextArgs) => {
      const nextContextInterceptor = args.contextInterceptor;
      const contextInterceptor = (context: interfaces.Context) => {
        lookupServiceIdentifiers(context.plan.rootRequest, ServiceIdentifiers);
        return nextContextInterceptor(context);
      };
      const result = planAndResolve({
        ...args,
        contextInterceptor,
      });
      return result;
    };
}