import _ from 'underscore';
import { PARALLEL_DIFF_VIEW_TYPE, INLINE_DIFF_VIEW_TYPE } from '../constants';

export const isParallelView = state => state.diffViewType === PARALLEL_DIFF_VIEW_TYPE;

export const isInlineView = state => state.diffViewType === INLINE_DIFF_VIEW_TYPE;

export const areAllFilesCollapsed = state => state.diffFiles.every(file => file.collapsed);

export const commitId = state => (state.commit && state.commit.id ? state.commit.id : null);

/**
 * Checks if the diff has all discussions expanded
 * @param {Object} diff
 * @returns {Boolean}
 */
export const diffHasAllExpandedDiscussions = (state, getters) => diff => {
  const discussions = getters.getDiffFileDiscussions(diff);

  return (discussions.length && discussions.every(discussion => discussion.expanded)) || false;
};

/**
 * Checks if the diff has all discussions collpased
 * @param {Object} diff
 * @returns {Boolean}
 */
export const diffHasAllCollpasedDiscussions = (state, getters) => diff => {
  const discussions = getters.getDiffFileDiscussions(diff);

  return (discussions.length && discussions.every(discussion => !discussion.expanded)) || false;
};

/**
 * Checks if the diff has any open discussions
 * @param {Object} diff
 * @returns {Boolean}
 */
export const diffHasExpandedDiscussions = (state, getters) => diff => {
  const discussions = getters.getDiffFileDiscussions(diff);

  return (
    (discussions.length && discussions.find(discussion => discussion.expanded) !== undefined) ||
    false
  );
};

/**
 * Returns an array with the discussions of the given diff
 * @param {Object} diff
 * @returns {Array}
 */
export const getDiffFileDiscussions = (state, getters, rootState, rootGetters) => diff =>
  rootGetters.discussions.filter(
    discussion =>
      discussion.diff_discussion && _.isEqual(discussion.diff_file.file_hash, diff.fileHash),
  ) || [];

// prevent babel-plugin-rewire from generating an invalid default during karma∂ tests
export const getDiffFileByHash = state => fileHash =>
  state.diffFiles.find(file => file.fileHash === fileHash);

// prevent babel-plugin-rewire from generating an invalid default during karma tests
export default () => {};