<?php

class WPML_Term_Translation_Utils extends WPML_SP_User {

	/**
	 * Duplicates all terms, that exist in the given target language,
	 * from the original post to the translation in that language.
	 *
	 * @param int    $original_post_id
	 * @param string $lang
	 */
	function sync_terms( $original_post_id, $lang ) {
		$this->synchronize_terms( $original_post_id, $lang, false );
	}

	/**
	 * Duplicates all terms on the original post to its translation in the given target language.
	 * Missing terms are created with the same name as their originals.
	 *
	 * @param int    $original_post_id
	 * @param string $lang
	 */
	function duplicate_terms( $original_post_id, $lang ) {
		$this->synchronize_terms( $original_post_id, $lang, true );
	}

	/**
	 * @param int    $original_post_id
	 * @param string $lang
	 * @param bool   $duplicate sets whether missing terms should be created by duplicating the original term
	 */
	private function synchronize_terms( $original_post_id, $lang, $duplicate ) {
		global $wpml_post_translations;

		$wpml_post_translations->reload();
		$translated_post_id = $wpml_post_translations->element_id_in( $original_post_id, $lang );
		if ( (bool) $translated_post_id === true ) {
			$taxonomies = get_post_taxonomies( $original_post_id );

			foreach ( $taxonomies as $tax ) {
				$terms_on_original = wp_get_object_terms( $original_post_id, $tax );

				if ( ! $this->sitepress->is_translated_taxonomy( $tax ) ) {
					if ( $this->sitepress->get_setting( 'sync_post_taxonomies' ) ) {
						// Taxonomy is not translated so we can just copy from the original
						foreach ( $terms_on_original as $key => $term ) {
							$terms_on_original[ $key ] = $term->term_id;
						}
						wp_set_object_terms( $translated_post_id, $terms_on_original, $tax );
					}
				} else {

					/** @var int[] $translated_terms translated term_ids */
					$translated_terms = $this->get_translated_term_ids( $terms_on_original, $lang, $tax, $duplicate );
					wp_set_object_terms( $translated_post_id, $translated_terms, $tax );
				}
			}
		}
		clean_object_term_cache( $original_post_id, get_post_type( $original_post_id ) );
	}

	/**
	 * @param object[] $terms
	 * @param string   $lang
	 * @param string   $taxonomy
	 * @param bool     $duplicate sets whether missing terms should be created by duplicating the original term
	 *
	 * @return array
	 */
	private function get_translated_term_ids( $terms, $lang, $taxonomy, $duplicate ) {
		/** @var WPML_Term_Translation $wpml_term_translations */
		global $wpml_term_translations;

		$term_utils = new WPML_Terms_Translations();
		$wpml_term_translations->reload();
		$translated_terms = array();
		foreach ( $terms as $orig_term ) {
			$translated_id = (int) $wpml_term_translations->term_id_in( $orig_term->term_id, $lang );
			if ( ! $translated_id && $duplicate ) {
				$translation   = $term_utils->create_automatic_translation(
					array(
						'lang_code'       => $lang,
						'taxonomy'        => $taxonomy,
						'trid'            => $wpml_term_translations->get_element_trid( $orig_term->term_taxonomy_id ),
						'source_language' => $wpml_term_translations->get_element_lang_code(
							$orig_term->term_taxonomy_id
						),
					)
				);
				$translated_id = isset( $translation['term_id'] ) ? $translation['term_id'] : false;
			}
			if ( $translated_id ) {
				$translated_terms[] = $translated_id;
			}
		}

		return $translated_terms;
	}
}
