import { Injectable } from '@nestjs/common';
import { AsyncLocalStorage } from 'node:async_hooks';

export interface AuthenticatedDeviceContextValue {
  deviceId: string;
  userId: string;
}

interface RequestContextState {
  authenticatedDevice: AuthenticatedDeviceContextValue | null;
  legacyDeviceId: string | null;
}

@Injectable()
export class RequestContextService {
  private readonly storage = new AsyncLocalStorage<RequestContextState>();

  run<T>(callback: () => T): T {
    return this.storage.run(
      {
        authenticatedDevice: null,
        legacyDeviceId: null,
      },
      callback,
    );
  }

  getAuthenticatedDevice(): AuthenticatedDeviceContextValue | null {
    return this.storage.getStore()?.authenticatedDevice ?? null;
  }

  setAuthenticatedDevice(device: AuthenticatedDeviceContextValue): void {
    const store = this.storage.getStore();

    if (!store) {
      return;
    }

    store.authenticatedDevice = device;
  }

  getLegacyDeviceId(): string | null {
    return this.storage.getStore()?.legacyDeviceId ?? null;
  }

  setLegacyDeviceId(deviceId: string): void {
    const store = this.storage.getStore();

    if (!store) {
      return;
    }

    store.legacyDeviceId = deviceId;
  }
}