/**
 * External dependencies
 */
import { map } from 'lodash';
import { EMPTY_ARRAY } from '@nelio-content/constants';
import { createIndexedSelector, isDefined } from '@nelio-content/utils';
import type { EditorialTask, Maybe, PostId, Uuid } from '@nelio-content/types';

/**
 * Internal dependencies
 */
import type { State } from '../../config';

export function getTask( state: State, id?: Uuid ): Maybe< EditorialTask > {
	return id ? state.entities.tasks.byId[ id ] : undefined;
}

export const getTasksRelatedToPost = createIndexedSelector(
	( state: State, postId?: PostId ): ReadonlyArray< EditorialTask > => {
		const summaries =
			!! postId && state.entities.tasks.byRelatedPost[ postId ];
		if ( ! summaries ) {
			return EMPTY_ARRAY;
		}

		return map( summaries, ( { id } ) => getTask( state, id ) ).filter(
			isDefined
		);
	},
	( state: State, postId?: PostId ) => ( {
		key: postId || 0,
		dependants: [
			!! postId && state.entities.tasks.byRelatedPost[ postId ],
			state.entities.tasks.byId,
		],
	} )
);

export const getTaskIdsRelatedToPost = createIndexedSelector(
	( state: State, postId?: PostId ): ReadonlyArray< Uuid > => {
		return map( getTasksRelatedToPost( state, postId ), 'id' );
	},
	( state: State, postId?: PostId ) => ( {
		key: postId || 0,
		dependants: [ getTasksRelatedToPost( state, postId ) ],
	} )
);