import { Eta, OrderedStop, Resolvers, Route, Shuttle, Stop, System } from "./generated/graphql";
import { ServerContext } from "./serverContext";

export const resolvers: Resolvers<ServerContext> = {
  Query: {
    systems: (parent, args, contextValue, info) => {
      return contextValue.sharedMemory.systems;
    },
    system: (parent, args, contextValue, info) => {
      const systems = contextValue.sharedMemory.systems;
      const system = systems.find((system) => system.id === args.id);
      if (!system) {
        return null;
      }

      return system;
    }
  },
  System: {
    stop: (parent, args, contextValue, info) => {
      // TODO implement interface with ID and one function to perform search
      const stops = parent.stops;
      const stop = stops.find((stop) => stop.id === args.id);
      if (!stop) {
        return null;
      }

      return stop;
    },
    route: (parent, args, contextValue, info) => {
      const routes = parent.routes
      const route = routes.find((route) => route.id === args.id);
      if (!route) {
        return null;
      }

      return route;
    },
    shuttle: (parent, args, contextValue, info) => {
      const shuttles = parent.shuttles;
      const shuttle = shuttles.find((shuttle) => shuttle.id === args.id);
      if (!shuttle) {
        return null;
      }

      return shuttle;
    }
  },
  Route: {
    nextOrderedStop: (parent, args, contextValue, info) => {
      const orderedStop = parent.orderedStops.find((orderedStop) => orderedStop.stop.id === args.forStopId);
      if (!orderedStop || !orderedStop.nextStop) {
        return null;
      }

      return orderedStop.nextStop;
    },
  },
  Shuttle: {
    eta: (parent, args, contextValue, info) => {
      const etaForNextStop = parent.etas.find((eta) => eta.stop.id === args.forStopId);
      if (!etaForNextStop) {
        return null;
      }

      return etaForNextStop;
    },
  },
};