<?php
namespace Elementor\App\Modules\ImportExport\Runners\Export;

use Elementor\App\Modules\ImportExport\Utils as ImportExportUtils;

class Taxonomies extends Export_Runner_Base {

	public static function get_name() : string {
		return 'taxonomies';
	}

	public function should_export( array $data ) {
		return (
			isset( $data['include'] ) &&
			in_array( 'content', $data['include'], true )
		);
	}

	public function export( array $data ) {
		$wp_builtin_post_types = ImportExportUtils::get_builtin_wp_post_types();
		$selected_custom_post_types = isset( $data['selected_custom_post_types'] ) ? $data['selected_custom_post_types'] : [];
		$post_types = array_merge( $wp_builtin_post_types, $selected_custom_post_types );

		$export = $this->export_taxonomies( $post_types );

		$manifest_data['taxonomies'] = $export['manifest'];

		return [
			'files' => $export['files'],
			'manifest' => [
				$manifest_data,
			],
		];
	}

	private function export_taxonomies( array $post_types ) {
		$files = [];
		$manifest = [];

		$taxonomies = get_taxonomies();

		foreach ( $taxonomies as $taxonomy ) {
			$taxonomy_post_types = get_taxonomy( $taxonomy )->object_type;
			$intersected_post_types = array_intersect( $taxonomy_post_types, $post_types );

			if ( empty( $intersected_post_types ) ) {
				continue;
			}

			$data = $this->export_terms( $taxonomy );

			if ( empty( $data ) ) {
				continue;
			}

			foreach ( $intersected_post_types as $post_type ) {
				$manifest[ $post_type ][] = $taxonomy;
			}

			$files[] = [
				'path' => 'taxonomies/' . $taxonomy,
				'data' => $data,
			];
		}

		return [
			'files' => $files,
			'manifest' => $manifest,
		];
	}

	private function export_terms( $taxonomy ) {
		$terms = get_terms( [
			'taxonomy' => (array) $taxonomy,
			'hide_empty' => true,
			'get' => 'all',
		] );

		$ordered_terms = $this->order_terms( $terms );

		if ( empty( $ordered_terms ) ) {
			return [];
		}

		$data = [];

		foreach ( $ordered_terms as $term ) {
			$data[] = [
				'term_id' => $term->term_id,
				'name' => $term->name,
				'slug' => $term->slug,
				'taxonomy' => $term->taxonomy,
				'description' => $term->description,
				'parent' => $term->parent,
			];
		}

		return $data;
	}

	// Put terms in order with no child going before its parent.
	private function order_terms( array $terms ) {
		$ordered_terms = [];

		while ( $term = array_shift( $terms ) ) {
			$is_top_level = 0 === $term->parent;
			$is_parent_exits = isset( $ordered_terms[ $term->parent ] );

			if ( $is_top_level || $is_parent_exits ) {
				$ordered_terms[ $term->term_id ] = $term;
			} else {
				$terms[] = $term;
			}
		}

		return $ordered_terms;
	}
}