lbry-desktop/ui/redux/selectors/reactions.js

import * as REACTION_TYPES from 'constants/reactions';
import { createSelector } from 'reselect';
import { makeSelectClaimForUri } from 'redux/selectors/claims';

const selectState = (state) => state.reactions || {};

export const selectReactionsById = (state) => selectState(state).reactionsById;
export const selectFetchingReactions = (state) => selectState(state).fetchingReactions;

export const makeSelectReactionsForUri = (uri) =>
  createSelector(makeSelectClaimForUri(uri), selectReactionsById, (claim, reactionsById) => {
    return claim ? reactionsById[claim.claim_id] : {};
  });

export const makeSelectMyReactionForUri = (uri) =>
  createSelector(makeSelectClaimForUri(uri), makeSelectReactionsForUri(uri), (claim, reactions) => {
    if (!claim || !reactions || reactions.my_reactions === null) {
      return undefined;
    }
    const claimId = claim.claim_id;

    const myReactions = reactions.my_reactions[claimId];
    if (myReactions[REACTION_TYPES.LIKE]) {
      return REACTION_TYPES.LIKE;
    } else if (myReactions[REACTION_TYPES.DISLIKE]) {
      return REACTION_TYPES.DISLIKE;
    } else {
      // Ignore other types of reactions for now
      return undefined;
    }
  });

export const makeSelectLikeCountForUri = (uri) =>
  createSelector(makeSelectClaimForUri(uri), makeSelectReactionsForUri(uri), (claim, reactions) => {
    if (!claim || !reactions || reactions.my_reactions === null || reactions.others_reactions === null) {
      return 0;
    }
    const claimId = claim.claim_id;

    let count = 0;
    if (reactions.others_reactions) {
      const likeCount = reactions.others_reactions[claimId][REACTION_TYPES.LIKE] || 0;

      count += likeCount;
    }
    if (reactions.my_reactions) {
      const likeCount = reactions.my_reactions[claimId][REACTION_TYPES.LIKE] || 0;
      count += likeCount;
    }

    return count;
  });

export const makeSelectDislikeCountForUri = (uri) =>
  createSelector(makeSelectClaimForUri(uri), makeSelectReactionsForUri(uri), (claim, reactions) => {
    if (!claim || !reactions || reactions.my_reactions === null || reactions.others_reactions === null) {
      return 0;
    }
    const claimId = claim.claim_id;

    let count = 0;
    if (reactions.others_reactions) {
      const dislikeCount = reactions.others_reactions[claimId][REACTION_TYPES.DISLIKE] || 0;
      count += dislikeCount;
    }
    if (reactions.my_reactions) {
      const dislikeCount = reactions.my_reactions[claimId][REACTION_TYPES.DISLIKE] || 0;
      count += dislikeCount;
    }

    return count;
  });