<?php
namespace WPGraphQL\Type\Union;

use WPGraphQL\Registry\TypeRegistry;

/**
 * @todo Remove in 3.0.0
 * @deprecated 1.14.1
 * @codeCoverageIgnore
 */
class TermObjectUnion {

	/**
	 * Registers the Type
	 *
	 * @param ?\WPGraphQL\Registry\TypeRegistry $type_registry
	 *
	 * @throws \Exception
	 */
	public static function register_type( ?TypeRegistry $type_registry = null ): void {
		register_graphql_union_type(
			'TermObjectUnion',
			[
				'kind'        => 'union',
				'typeNames'   => self::get_possible_types(),
				'description' => static function () {
					return __( 'Union between the Category, Tag and PostFormatPost types', 'wp-graphql' );
				},
				'resolveType' => static function ( $value ) {
					_doing_it_wrong(
						self::class,
						esc_attr__( 'The TermObjectUnion GraphQL type is deprecated and will be removed in the next version of WordPress. Use the TermNode interface instead.', 'wp-graphql' ),
						'1.14.1'
					);

					$type = null;
					if ( isset( $value->taxonomyName ) ) {
						$tax_object = get_taxonomy( $value->taxonomyName );
						if ( isset( $tax_object->graphql_single_name ) ) {
							$type = \WPGraphQL::get_type_registry()->get_type( $tax_object->graphql_single_name );
						}
					}

					return ! empty( $type ) ? $type : null;
				},
			]
		);
	}

	/**
	 * Returns a list of possible types for the union
	 *
	 * @return array<string,string>
	 */
	public static function get_possible_types() {
		$possible_types     = [];
		$allowed_taxonomies = \WPGraphQL::get_allowed_taxonomies( 'objects', [ 'graphql_kind' => 'object' ] );

		foreach ( $allowed_taxonomies as $tax_object ) {
			if ( empty( $possible_types[ $tax_object->name ] ) ) {
				if ( isset( $tax_object->graphql_single_name ) ) {
					$possible_types[ $tax_object->name ] = $tax_object->graphql_single_name;
				}
			}
		}

		return $possible_types;
	}
}