import {
  NgModule,
  Inject,
  Optional,
  ModuleWithProviders,
  OnDestroy,
  InjectionToken,
  Injector,
} from '@angular/core';

import { Store, StoreModule, ReducerManager, combineReducers } from '@ngrx/store';

import {
  _STORE,
  _STORE_FEATURE,
  createReducer,
} from './core';

import { NgRxStoreSelect } from './service';

@NgModule({})
export class NgRxStoreRootModule {
  constructor(
    @Optional() @Inject(_STORE) reducers: any,
    reducerFactory: ReducerManager,
    store: Store<any>,
    parentInjector: Injector,
    select: NgRxStoreSelect,
  ) {
    select.connect(store);

    if (reducers) {
      for (const key in reducers) {
        if (!reducers.hasOwnProperty(key)) {
          continue;
        }
        const clazz = reducers[key];
        const inst = parentInjector.get(clazz, new clazz());
        reducerFactory.addReducer(key, createReducer(inst));
      }
    }
  }
}

@NgModule({})
export class NgRStoreFeatureModule implements OnDestroy {
  constructor(
    @Optional() @Inject(_STORE_FEATURE) featureReducers: any,
    reducerFactory: ReducerManager,
    store: Store<any>,
    parentInjector: Injector,
    select: NgRxStoreSelect,
  ) {
    select.connect(store);

    if (featureReducers) {
      if (typeof featureReducers.key !== 'string') {
        featureReducers.reducers = featureReducers.key;
        featureReducers.key = undefined;
      }

      const mapped: {[key: string]: any} = {};
      for (const key in featureReducers.reducers) {
        if (!featureReducers.reducers.hasOwnProperty(key)) {
          continue;
        }

        const clazz = featureReducers.reducers[key];
        const inst = parentInjector.get(clazz, new clazz());
        mapped[key] = createReducer(inst);
      }

      if (featureReducers.key) {
        reducerFactory.addFeature({
          reducers: mapped,
          reducerFactory: <any>combineReducers,
          key: featureReducers.key
        });
      }
    }
  }

  ngOnDestroy() {

  }
}

@NgModule({
  imports: [
    StoreModule,
  ],
  providers: [
    NgRxStoreSelect
  ],
})
export class NgRxStoreModule {
  static forRoot(reducers: any): ModuleWithProviders {
    return {
      ngModule: NgRxStoreRootModule,
      providers: [
        { provide: _STORE, useValue: reducers },
      ],
    };
  }

  static forFeature(featureName: string, reducers?: any): ModuleWithProviders {
    return {
      ngModule: NgRStoreFeatureModule,
      providers: [
        { provide: _STORE_FEATURE, useValue: { featureName, reducers } },
      ],
    };
  }
}