lbry-desktop/src/renderer/redux/selectors/cost_info.js

import { createSelector } from 'reselect';
import { selectCurrentParams } from 'redux/selectors/navigation';

export const selectState = state => state.costInfo || {};

export const selectAllCostInfoByUri = createSelector(selectState, state => state.byUri || {});

export const makeSelectCostInfoForUri = uri =>
  createSelector(selectAllCostInfoByUri, costInfos => costInfos && costInfos[uri]);

export const selectCostForCurrentPageUri = createSelector(
  selectAllCostInfoByUri,
  selectCurrentParams,
  (costInfo, params) => (params.uri && costInfo[params.uri] ? costInfo[params.uri].cost : undefined)
);

export const selectFetchingCostInfo = createSelector(selectState, state => state.fetching || {});

export const makeSelectFetchingCostInfoForUri = uri =>
  createSelector(selectFetchingCostInfo, fetchingByUri => fetchingByUri && fetchingByUri[uri]);