import update from 'immutability-helper';
import * as _ from 'lodash';

import {
  APPEND_DATASET_PAGE,
  RECEIVE_DATASET,
  APPEND_ACCESSIONS_PAGE,
  RECEIVE_DATASET_OVERVIEW,
} from 'datasets/constants';

import { LOGIN_APP, LOGIN_USER, LOGOUT } from 'constants/login';

import Dataset from 'model/catalog/Dataset';
import { AccessionRef } from 'model/accession/AccessionRef';
import Page from 'model/Page';
import FilteredPage from 'model/FilteredPage';
import ApiCall from 'model/ApiCall';
import DatasetOverview from 'model/catalog/DatasetOverview';
import {dereferenceReferences} from 'utilities';

const INITIAL_STATE: {
  dataset: ApiCall<Dataset>,
  paged: ApiCall<FilteredPage<Dataset>>,
  overview: ApiCall<DatasetOverview>,
  accessionRefs: ApiCall<Page<AccessionRef>>,
} = {
  dataset: null,
  paged: null,
  overview: null,
  accessionRefs: null,
};

function datasetsPublic(state = INITIAL_STATE, action: { type?: string, payload?: any } = { type: '', payload: {} }) {

  switch (action.type) {
    case LOGIN_USER:
    case LOGIN_APP:
    case LOGOUT: {
      return update(state, { $set: INITIAL_STATE });
    }

    case RECEIVE_DATASET: {
      const {apiCall} = action.payload;

      const receivedIndex = state.paged && state.paged.data ? _.findIndex(state.paged.data.content, (item) => item.uuid === apiCall.uuid) : -1;
      const mustRemoveAccessions = state.dataset && state.dataset.data && apiCall.data && (apiCall.uuid !== state.dataset.data.uuid);

      if (receivedIndex !== -1) {
        return update(state, {
          dataset: { $set: apiCall },
          accessionRefs: { $set: mustRemoveAccessions ? null : state.accessionRefs },
          paged: {
            content: {
              [receivedIndex]: { $set: apiCall.data },
            },
            loading: {$set: false},
          },
        });
      } else {
        return update(state, {
          dataset: { $set: apiCall },
          accessionRefs: { $set: mustRemoveAccessions ? null : state.accessionRefs },
        });
      }
    }

    case APPEND_ACCESSIONS_PAGE: {
      const {apiCall: {loading, error, timestamp, data}} = action.payload;

      return update(state, {
        accessionRefs: {
          $set: {
            loading,
            error,
            timestamp,
            data: Page.merge(state.accessionRefs && state.accessionRefs.data, data),
          },
        },
      });
    }

    case APPEND_DATASET_PAGE: {
      const {apiCall: {loading, error, timestamp, data}} = action.payload;
      if (data) {
        dereferenceReferences(data.content, 'owner');
      }
      return update(state, {
        paged: {
          $set: {
            loading,
            error,
            timestamp,
            data: FilteredPage.merge(state.paged && state.paged.data, data),
          },
        },
      });
    }

    case RECEIVE_DATASET_OVERVIEW: {
      const { apiCall: { loading, error, timestamp, data } } = action.payload;
      return update(state, {
        overview: {
          $set: {
            loading,
            error,
            timestamp,
            data: data !== undefined ? data : state.overview && state.overview.data,
          },
        },
      });
    }

    default:
      return state;
  }
}

export default datasetsPublic;