import { EntityAdapter, EntityState } from '@ngrx/entity/src/models';
import { createEntityAdapter } from '@ngrx/entity';
import * as coreActions from '../actions/core.action';
import { map, assign } from 'lodash';
import { ReferenceData } from '../../shared/models/reference-data';
import { TypedReferenceData } from '../../shared/models/typed-reference-data';

export interface LocalState extends EntityState<TypedReferenceData<ReferenceData>> {
  loading: boolean;
}

export const adapter: EntityAdapter<TypedReferenceData<ReferenceData>> =
  createEntityAdapter<TypedReferenceData<ReferenceData>>( {
    selectId: ( t: TypedReferenceData<ReferenceData> ) => t.type,
  } );

export const initialState: LocalState = adapter.getInitialState( {
  loading: false,
} );

export function reducer<T extends ReferenceData>( state: LocalState = initialState, action: coreActions.CoreReferenceDataActions<T> ): LocalState {
  switch ( action.type ) {
    case coreActions.CoreActionTypes.LoadReferenceData: {
      return assign( {}, state, { loading: true } );
    }
    case coreActions.CoreActionTypes.LoadReferenceDataSuccess: {
      if ( !action.payload ) {
        return state;
      }
      const updatedState: LocalState = adapter.removeMany( map( action.payload, ( p: TypedReferenceData<ReferenceData> ) => p.type ), state );
      return adapter.addMany( action.payload, updatedState );
    }
    case coreActions.CoreActionTypes.LoadReferenceDataFail: {
      return assign( {}, state, { loading: false, errors: action.payload } );
    }
    default: {
      return state;
    }
  }
}