/**
 * WordPress dependencies
 */
import { useSelect } from '@safe-wordpress/data';

/**
 * External dependencies
 */
import {
	flatten,
	filter,
	find,
	keyBy,
	keys,
	map,
	mapValues,
	omit,
	values,
} from 'lodash';
import { store as NC_DATA } from '@nelio-content/data';
import { isAutoSelectedUuid } from '@nelio-content/utils';
import type {
	AutoSelectedUuid,
	Maybe,
	Post,
	SocialTemplate,
	Uuid,
} from '@nelio-content/types';

/**
 * Internal dependencies
 */
import { store as NC_SOCIAL_EDITOR } from '../store';

export type PostTemplates = {
	readonly recommendedTemplates: ReadonlyArray< SocialTemplate >;
	readonly otherTemplates: ReadonlyArray< SocialTemplate >;
};

export const usePostTemplates = ( post: Maybe< Post > ): PostTemplates => {
	const templates = useSelect(
		( select ) => select( NC_DATA ).getSocialTemplates( post ),
		[ post ]
	);

	const recommendedTemplates = useSelect(
		( select ) => {
			const selectedProfiles =
				select( NC_SOCIAL_EDITOR ).getSelectedSocialProfiles();

			const selectedNetworks =
				select( NC_SOCIAL_EDITOR ).getSelectedSocialNetworks();

			const profiles = map(
				selectedProfiles,
				( id: Uuid | AutoSelectedUuid ) =>
					isAutoSelectedUuid( id ) ? id.value : id
			);

			const targets = flatten(
				map(
					profiles,
					select( NC_SOCIAL_EDITOR ).getSelectedTargetsInProfile
				)
			);

			return keyBy(
				filter( templates, ( t ) => {
					if ( ! post && hasPlaceholders( t.text ) ) {
						return false;
					}
					if ( ! impliesIn( t.profileId, profiles ) ) {
						return false;
					}
					if ( ! impliesIn( t.network, selectedNetworks ) ) {
						return false;
					}
					if ( ! impliesIn( t.targetName, targets ) ) {
						return false;
					}

					if ( ! post ) {
						return true;
					}

					if ( t.author && t.author !== post.author ) {
						return false;
					}

					const taxOk = values(
						mapValues( post.taxonomies, ( terms, tax ) => {
							const required = t.taxonomies?.[ tax ];
							if ( ! required ) {
								return true;
							}
							return !! find( terms, { id: required } );
						} )
					).every( Boolean );

					return taxOk;
				} ),
				'text'
			);
		},
		[ post, templates ]
	);

	return {
		recommendedTemplates: values( recommendedTemplates ),
		otherTemplates: values(
			omit( keyBy( templates, 'text' ), keys( recommendedTemplates ) )
		),
	};
};

// =======
// HELPERS
// =======

const hasPlaceholders = ( text: string ) => text.includes( '{permalink}' );

const impliesIn = ( el: Maybe< string >, list: ReadonlyArray< string > ) =>
	! el || ! list.length || list.includes( el );