/* eslint-disable import/prefer-default-export */

import { createSelector } from '@reduxjs/toolkit';

import { selectDiscussionProvider, selectGroupAtSubsection } from '../discussions/data/selectors';
import { DiscussionProvider } from './constants';

export const selectTopicContext = (topicId) => (state) => state.blocks.topics[topicId];

export const selectBlocks = (state) => state.blocks.blocks;

export const selectorForUnitSubsection = createSelector(
  selectBlocks,
  blocks => key => blocks[blocks[key]?.parent],
);

// If subsection grouping is enabled, and the current selection is a unit, then get the current subsection.
export const selectCurrentCategoryGrouping = createSelector(
  selectDiscussionProvider,
  selectGroupAtSubsection,
  selectBlocks,
  (provider, groupAtSubsection, blocks) => blockId => (
    (provider !== 'openedx' || !groupAtSubsection || blocks[blockId]?.type !== 'vertical')
      ? blockId
      : blocks[blockId].parent
  ),
);

export const selectChapters = (state) => state.blocks.chapters;
export const selectTopicsUnderCategory = createSelector(
  selectDiscussionProvider,
  selectBlocks,
  state => state.topics.topicsInCategory,
  (provider, blocks, topicsInCategory) => (
    provider === DiscussionProvider.LEGACY
      ? category => topicsInCategory?.[category]
      : category => blocks[category]?.topics
  ),
);

export const selectArchivedTopics = createSelector(
  state => state.topics.topics,
  state => state.topics.archivedIds || [],
  (topics, ids) => ids.map(id => topics[id]),
);

export const selectTopicIds = () => (state) => state.blocks.chapters;