import { ShuttleGetterSetterRepository } from "./ShuttleGetterSetterRepository";
import { IEta, IOrderedStop, IRoute, IShuttle, IStop } from "../entities/ShuttleRepositoryEntities";
import { IEntityWithId } from "../entities/SharedEntities";

/**
 * An unoptimized in memory repository.
 * (I would optimize it with actual data structures, but I'm
 * switching to another data store later anyways)
 */
export class UnoptimizedInMemoryShuttleRepository implements ShuttleGetterSetterRepository {
  private stops: IStop[] = [];
  private routes: IRoute[] = [];
  private shuttles: IShuttle[] = [];
  private etas: IEta[] = [];
  private orderedStops: IOrderedStop[] = [];

  private subscribers: ((eta: IEta) => void)[] = [];

  public async getStops(): Promise<IStop[]> {
    return this.stops;
  }

  public async getStopById(stopId: string) {
    return this.findEntityById(stopId, this.stops);
  }

  public async getRoutes(): Promise<IRoute[]> {
    return this.routes;
  }

  public async getRouteById(routeId: string) {
    return this.findEntityById(routeId, this.routes);
  }

  public async getShuttles(): Promise<IShuttle[]> {
    return this.shuttles;
  }

  public async getShuttlesByRouteId(routeId: string) {
    return this.shuttles.filter(shuttle => shuttle.routeId === routeId);
  }

  public async getShuttleById(shuttleId: string) {
    return this.findEntityById(shuttleId, this.shuttles);
  }

  public async getEtasForShuttleId(shuttleId: string): Promise<IEta[]> {
    return this.etas.filter(eta => eta.shuttleId === shuttleId);
  }

  public async getEtasForStopId(stopId: string) {
    return this.etas.filter(eta => eta.stopId === stopId);
  }

  public subscribeToEtaUpdates(listener: (eta: IEta) => void) {
    this.subscribers.push(listener);
  }

  public unsubscribeFromEtaUpdates(listener: (eta: IEta) => void) {
    const index = this.subscribers.findIndex((existingListener) => existingListener == listener);
    if (index >= 0) {
      this.subscribers.splice(index, 1);
    }
  }

  public async getEtaForShuttleAndStopId(shuttleId: string, stopId: string) {
    return this.findEntityByMatcher<IEta>((value) => value.stopId === stopId && value.shuttleId === shuttleId, this.etas);
  }

  public async getOrderedStopByRouteAndStopId(routeId: string, stopId: string) {
    return this.findEntityByMatcher<IOrderedStop>((value) => value.routeId === routeId && value.stopId === stopId, this.orderedStops)
  }

  public async getOrderedStopsByStopId(stopId: string) {
    return this.orderedStops.filter((value) => value.stopId === stopId);
  }

  public async getOrderedStopsByRouteId(routeId: string) {
    return this.orderedStops.filter((value) => value.routeId === routeId);
  }

  private findEntityById<T extends IEntityWithId>(entityId: string, arrayToSearchIn: T[]) {
    return this.findEntityByMatcher((value) => value.id === entityId, arrayToSearchIn);
  }

  private findEntityByMatcher<T>(callback: (value: T) => boolean, arrayToSearchIn: T[]): T | null {
    const entity = arrayToSearchIn.find(callback);
    if (!entity) {
      return null;
    }
    return entity;
  }

  public async addOrUpdateRoute(route: IRoute): Promise<void> {
    const index = this.routes.findIndex((r) => r.id === route.id);
    if (index !== -1) {
      this.routes[index] = route;
    } else {
      this.routes.push(route);
    }
  }

  public async addOrUpdateShuttle(shuttle: IShuttle): Promise<void> {
    const index = this.shuttles.findIndex((s) => s.id === shuttle.id);
    if (index !== -1) {
      this.shuttles[index] = shuttle;
    } else {
      this.shuttles.push(shuttle);
    }
  }

  public async addOrUpdateStop(stop: IStop): Promise<void> {
    const index = this.stops.findIndex((s) => s.id === stop.id);
    if (index !== -1) {
      this.stops[index] = stop;
    } else {
      this.stops.push(stop);
    }
  }

  public async addOrUpdateOrderedStop(orderedStop: IOrderedStop): Promise<void> {
    const index = this.orderedStops.findIndex((value) => value.stopId === orderedStop.stopId && value.routeId === orderedStop.routeId);
    if (index !== -1) {
      this.orderedStops[index] = orderedStop;
    } else {
      this.orderedStops.push(orderedStop);
    }
  }

  public async addOrUpdateEta(eta: IEta): Promise<void> {
    const index = this.etas.findIndex((e) => e.stopId === eta.stopId && e.shuttleId === eta.shuttleId);
    if (index !== -1) {
      this.etas[index] = eta;
    } else {
      this.etas.push(eta);
    }
    this.publishEtaUpdateToSubscribers(eta);
  }

  private publishEtaUpdateToSubscribers(eta: IEta) {
    this.subscribers.forEach(subscriber => {
      subscriber(eta);
    });
  }

  private async removeEntityByMatcherIfExists<T>(callback: (value: T) => boolean, arrayToSearchIn: T[]) {
    const index = arrayToSearchIn.findIndex(callback);
    if (index > -1) {
      const entityToReturn = arrayToSearchIn[index];
      arrayToSearchIn.splice(index, 1);
      return entityToReturn;
    }

    return null;
  }

  private async removeEntityByIdIfExists<T extends IEntityWithId>(entityId: string, arrayToSearchIn: T[]) {
    return await this.removeEntityByMatcherIfExists((value) => value.id === entityId, arrayToSearchIn);
  }

  public async removeRouteIfExists(routeId: string): Promise<IRoute | null> {
    return await this.removeEntityByIdIfExists(routeId, this.routes);
  }

  public async removeShuttleIfExists(shuttleId: string): Promise<IShuttle | null> {
    return await this.removeEntityByIdIfExists(shuttleId, this.shuttles);
  }

  public async removeStopIfExists(stopId: string): Promise<IStop | null> {
    return await this.removeEntityByIdIfExists(stopId, this.stops);
  }

  public async removeOrderedStopIfExists(stopId: string, routeId: string): Promise<IOrderedStop | null> {
    return await this.removeEntityByMatcherIfExists((orderedStop) => {
      return orderedStop.stopId === stopId
        && orderedStop.routeId === routeId
    }, this.orderedStops);
  }

  public async removeEtaIfExists(shuttleId: string, stopId: string): Promise<IEta | null> {
    return await this.removeEntityByMatcherIfExists((eta) => {
      return eta.stopId === stopId
        && eta.shuttleId === shuttleId
    }, this.etas);
  }

  public async clearShuttleData(): Promise<void> {
    this.shuttles = [];
  }

  public async clearEtaData(): Promise<void> {
    this.etas = [];
  }

  public async clearOrderedStopData(): Promise<void> {
    this.orderedStops = [];
  }

  public async clearRouteData(): Promise<void> {
    this.routes = [];
  }

  public async clearStopData(): Promise<void> {
    this.stops = [];
  }

}