<?php
/**
 * @package Polylang
 */

/**
 * A class to handle the WPML API based on hooks, introduced since WPML 3.2.
 * It partly relies on the legacy API.
 *
 * @see https://wpml.org/documentation/support/wpml-coding-api/wpml-hooks-reference/
 *
 * @since 2.0
 */
class PLL_WPML_API {
	/**
	 * Stores the original language when the language is switched.
	 *
	 * @var PLL_Language|null
	 */
	private static $original_language = null;

	/**
	 * Constructor.
	 *
	 * @since 2.0
	 */
	public function __construct() {
		/*
		 * Site Wide Language information.
		 */
		add_filter( 'wpml_active_languages', array( $this, 'wpml_active_languages' ), 10, 2 );
		add_filter( 'wpml_display_language_names', array( $this, 'wpml_display_language_names' ), 10, 2 ); // Because we don't translate language names, 3rd to 5th parameters are not supported.
		// wpml_translated_language_name           => not applicable.
		add_filter( 'wpml_current_language', 'pll_current_language', 10, 0 );
		add_filter( 'wpml_default_language', 'pll_default_language', 10, 0 );
		// wpml_add_language_selector              => not implemented.
		// wpml_footer_language_selector           => not applicable.
		add_action( 'wpml_add_language_form_field', array( $this, 'wpml_add_language_form_field' ) );
		add_filter( 'wpml_language_is_active', array( $this, 'wpml_language_is_active' ), 10, 2 );
		add_filter( 'wpml_is_rtl', array( $this, 'wpml_is_rtl' ) );
		// wpml_language_form_input_field          => See wpml_add_language_form_field
		// wpml_language_has_switched              => See wpml_switch_language
		add_filter( 'wpml_element_trid', array( $this, 'wpml_element_trid' ), 10, 3 );
		add_filter( 'wpml_get_element_translations', array( $this, 'wpml_get_element_translations' ), 10, 3 );
		// wpml_language_switcher                  => not implemented.
		// wpml_browser_redirect_language_params   => not implemented.
		// wpml_enqueue_browser_redirect_language  => not applicable.
		// wpml_enqueued_browser_redirect_language => not applicable.
		// wpml_encode_string                      => not applicable.
		// wpml_decode_string                      => not applicable.

		/*
		 * Retrieving Language Information for Content.
		 */
		add_filter( 'wpml_post_language_details', 'wpml_get_language_information', 10, 2 );
		add_action( 'wpml_switch_language', array( self::class, 'wpml_switch_language' ), 10, 2 );
		add_filter( 'wpml_element_language_code', array( $this, 'wpml_element_language_code' ), 10, 2 );
		// wpml_element_language_details           => not applicable.

		/*
		 * Retrieving Localized Content.
		 */
		add_filter( 'wpml_home_url', 'pll_home_url', 10, 0 );
		add_filter( 'wpml_element_link', 'icl_link_to_element', 10, 7 );
		add_filter( 'wpml_object_id', 'icl_object_id', 10, 4 );
		add_filter( 'wpml_translate_single_string', array( $this, 'wpml_translate_single_string' ), 10, 4 );
		// wpml_translate_string                   => not applicable.
		// wpml_unfiltered_admin_string            => not implemented.
		add_filter( 'wpml_permalink', array( $this, 'wpml_permalink' ), 10, 2 );
		// wpml_elements_without_translations      => not implemented.
		add_filter( 'wpml_get_translated_slug', array( $this, 'wpml_get_translated_slug' ), 10, 3 );

		/*
		 * Finding the Translation State of Content.
		 */
		// wpml_element_translation_type           => not implemented.
		add_filter( 'wpml_element_has_translations', array( $this, 'wpml_element_has_translations' ), 10, 3 );
		// wpml_master_post_from_duplicate         => not applicable.
		// wpml_post_duplicates                    => not applicable.

		/*
		 * Inserting Content.
		 */
		// wpml_admin_make_post_duplicates         => not applicable.
		// wpml_make_post_duplicates               => not applicable.
		add_action( 'wpml_register_single_string', 'icl_register_string', 10, 3 );
		// wpml_register_string                    => not applicable.
		// wpml_register_string_packages           => not applicable.
		// wpml_delete_package_action              => not applicable.
		// wpml_show_package_language_ui           => not applicable.
		// wpml_set_element_language_details       => not implemented.
		// wpml_multilingual_options               => not applicable.

		/*
		 * Miscellaneous
		 */
		// wpml_element_type                       => not applicable.
		// wpml_setting                            => not applicable.
		// wpml_sub_setting                        => not applicable.
		// wpml_editor_cf_to_display               => not applicable.
		// wpml_tm_save_translation_cf             => not implemented.
		// wpml_tm_xliff_export_translated_cf      => not applicable.
		// wpml_tm_xliff_export_original_cf        => not applicable.
		// wpml_duplicate_generic_string           => not applicable.
		// wpml_translatable_user_meta_fields      => not implemented.
		// wpml_cross_domain_language_data         => not applicable.
		// wpml_get_cross_domain_language_data     => not applicable.
		// wpml_loaded                             => not applicable.
		// wpml_st_loaded                          => not applicable.
		// wpml_tm_loaded                          => not applicable.
		// wpml_hide_management_column (3.4.1)     => not applicable.
		// wpml_ls_directories_to_scan             => not applicable.
		// wpml_ls_model_css_classes               => not applicable.
		// wpml_ls_model_language_css_classes      => not applicable.
		// wpml_tf_feedback_open_link              => not applicable.
		// wpml_sync_custom_field                  => not implemented.
		// wpml_sync_all_custom_fields             => not implemented.
		// wpml_is_redirected                      => not implemented.

		/*
		 * Updating Content
		 */
		// wpml_set_translation_mode_for_post_type => not implemented.

		/*
		 * Undocumented
		 */
		add_filter( 'wpml_is_translated_post_type', array( $this, 'wpml_is_translated_post_type' ), 10, 2 );
		add_filter( 'wpml_is_translated_taxonomy', array( $this, 'wpml_is_translated_taxonomy' ), 10, 2 );
	}

	/**
	 * Get a list of the languages enabled for a site.
	 *
	 * @since 2.0
	 *
	 * @param mixed         $null Not used.
	 * @param array| string $args See arguments of icl_get_languages().
	 * @return array Array of arrays per language.
	 */
	public function wpml_active_languages( $null, $args = '' ) {
		return icl_get_languages( $args );
	}

	/**
	 * In WPML, get a language's native and translated name for display in a custom language switcher
	 * Since Polylang does not implement the translated name, always returns only the native name,
	 * so the 3rd, 4th and 5th parameters are not used.
	 *
	 * @since 2.2
	 *
	 * @param mixed  $null        Not used.
	 * @param string $native_name The language native name.
	 * @return string
	 */
	public function wpml_display_language_names( $null, $native_name ) {
		return $native_name;
	}

	/**
	 * Returns an HTML hidden input field with name=”lang” and as value the current language.
	 *
	 * @since 2.0
	 *
	 * @return void
	 */
	public function wpml_add_language_form_field() {
		$lang = pll_current_language();

		if ( empty( $lang ) ) {
			return;
		}

		$field = sprintf( '<input type="hidden" name="lang" value="%s" />', esc_attr( $lang ) );
		$field = apply_filters( 'wpml_language_form_input_field', $field, $lang );
		echo $field; // phpcs:ignore WordPress.Security.EscapeOutput
	}

	/**
	 * Find out if a specific language is enabled for the site.
	 *
	 * @since 2.0
	 *
	 * @param mixed  $null Not used.
	 * @param string $slug Language code.
	 * @return bool
	 */
	public function wpml_language_is_active( $null, $slug ) {
		$language = PLL()->model->get_language( $slug );
		return ! empty( $language ) && $language->active;
	}

	/**
	 * Find out whether the current language text direction is RTL or not.
	 *
	 * @since 2.0
	 *
	 * @return bool
	 */
	public function wpml_is_rtl() {
		return pll_current_language( 'is_rtl' );
	}

	/**
	 * Returns the id of the translation group of a translated element.
	 *
	 * @since 3.4
	 *
	 * @param mixed  $empty_value  Not used.
	 * @param int    $element_id   The id of the item, post id for posts, term_taxonomy_id for terms.
	 * @param string $element_type Optional. The type of an element.
	 * @return int
	 */
	public function wpml_element_trid( $empty_value, $element_id, $element_type = 'post_post' ) {
		if ( 0 === strpos( $element_type, 'tax_' ) ) {
			$element = get_term_by( 'term_taxonomy_id', $element_id );
			if ( $element instanceof WP_Term ) {
				$tr_term = PLL()->model->term->get_object_term( $element->term_id, 'term_translations' );
			}
		}

		if ( 0 === strpos( $element_type, 'post_' ) ) {
			$tr_term = PLL()->model->post->get_object_term( $element_id, 'post_translations' );
		}

		if ( isset( $tr_term ) && $tr_term instanceof WP_Term ) {
			return $tr_term->term_id;
		}

		return 0;
	}

	/**
	 * Returns the element translations info using the ID of the translation group.
	 *
	 * @since 3.4
	 *
	 * @param mixed  $empty_value  Not used.
	 * @param int    $trid         The ID of the translation group.
	 * @param string $element_type Optional. The type of an element.
	 * @return stdClass[]
	 */
	public function wpml_get_element_translations( $empty_value, $trid, $element_type = 'post_post' ) {
		$return = array();

		if ( 0 === strpos( $element_type, 'tax_' ) ) {
			$translations = PLL()->model->term->get_translations_from_term_id( $trid );
			if ( empty( $translations ) ) {
				return array();
			}

			$original    = min( $translations ); // We suppose that the original is the first term created.
			$source_lang = array_search( $original, $translations );

			$args = array(
				'include'    => $translations,
				'hide_empty' => false,
			);
			$_terms = get_terms( $args );

			if ( ! is_array( $_terms ) ) {
				return array();
			}

			$terms = array();
			foreach ( $_terms as $term ) {
				$terms[ $term->term_id ] = $term;
			}

			foreach ( $translations as $lang => $term_id ) {
				if ( empty( $terms[ $term_id ] ) ) {
					continue;
				}

				/*
				 * It seems that WPML fills the `instances` property with the total number of posts
				 * related to this term, while `WP_Term::$count` includes only *published* posts.
				 * We intentionally accept this difference to avoid extra DB queries.
				 */
				$return[ $lang ] = (object) array(
					'translation_id'       => '0', // We have nothing equivalent.
					'language_code'        => $lang,
					'element_id'           => (string) $terms[ $term_id ]->term_taxonomy_id,
					'source_language_code' => $source_lang === $lang ? null : $source_lang,
					'element_type'         => $element_type,
					'original'             => $original === $term_id ? '1' : '0',
					'name'                 => $terms[ $term_id ]->name,
					'term_id'              => (string) $term_id,
					'instances'            => (string) $terms[ $term_id ]->count,
				);
			}
		}

		if ( 0 === strpos( $element_type, 'post_' ) ) {
			$translations = PLL()->model->post->get_translations_from_term_id( $trid );
			if ( empty( $translations ) ) {
				return array();
			}

			$original    = min( $translations ); // We suppose that the original is the first post created.
			$source_lang = array_search( $original, $translations );

			$args  = array(
				'post__in'               => $translations,
				'no_paging'              => true,
				'posts_per_page'         => -1,
				'update_post_meta_cache' => false,
				'update_post_term_cache' => false,
				'lang'                   => '',
			);
			$_posts = get_posts( $args );

			$posts = array();
			foreach ( $_posts as $post ) {
				$posts[ $post->ID ] = $post;
			}

			foreach ( $translations as $lang => $post_id ) {
				if ( empty( $posts[ $post_id ] ) ) {
					continue;
				}

				$return[ $lang ] = (object) array(
					'translation_id'       => '0', // We have nothing equivalent.
					'language_code'        => $lang,
					'element_id'           => (string) $post_id,
					'source_language_code' => $source_lang === $lang ? null : $source_lang,
					'element_type'         => $element_type,
					'original'             => $original === $post_id ? '1' : '0',
					'post_title'           => $posts[ $post_id ]->post_title,
					'post_status'          => $posts[ $post_id ]->post_status,
				);
			}
		}

		return $return;
	}

	/**
	 * Switches whole site to the given language or restores the language that was set when first calling this function.
	 * Unlike the WPML original action, it is not possible to set the current language and the cookie to different values.
	 *
	 * @since 2.7
	 *
	 * @param null|string $lang   Language code to switch into, restores the original language if null.
	 * @param bool|string $cookie Optionally also switches the cookie.
	 * @return void
	 */
	public static function wpml_switch_language( $lang = null, $cookie = false ) {
		if ( null === self::$original_language ) {
			self::$original_language = PLL()->curlang;
		}

		if ( empty( $lang ) ) {
			PLL()->curlang = self::$original_language;
		} elseif ( 'all' === $lang ) {
			PLL()->curlang = null;
		} elseif ( in_array( $lang, pll_languages_list() ) ) {
			PLL()->curlang = PLL()->model->get_language( $lang );
		}

		if ( $cookie && isset( PLL()->choose_lang ) ) {
			PLL()->choose_lang->maybe_setcookie();
		}

		do_action( 'wpml_language_has_switched', $lang, $cookie, self::$original_language );
	}

	/**
	 * Get the language code for a translatable element.
	 *
	 * @since 2.0
	 *
	 * @param mixed $language_code A 2-letter language code.
	 * @param array $args          An array with two keys element_id => post_id or term_taxonomy_id, element_type => post type or taxonomy
	 * @return string|null
	 */
	public function wpml_element_language_code( $language_code, $args ) {
		$type = $args['element_type'];
		$id   = $args['element_id'];

		if ( 'post' === $type || pll_is_translated_post_type( $type ) ) {
			$language = pll_get_post_language( $id );
			return is_string( $language ) ? $language : null;
		}

		if ( 'term' === $type || pll_is_translated_taxonomy( $type ) ) {
			$term = get_term_by( 'term_taxonomy_id', $id );
			if ( $term instanceof WP_Term ) {
				$id = $term->term_id;
			}
			$language = pll_get_term_language( $id );
			return is_string( $language ) ? $language : null;
		}

		return null;
	}

	/**
	 * Translates a string.
	 *
	 * @since 2.0
	 *
	 * @param string      $string  The string's original value.
	 * @param string      $context The string's registered context.
	 * @param string      $name    The string's registered name.
	 * @param null|string $lang    Optional, return the translation in this language, defaults to current language.
	 * @return string The translated string.
	 */
	public function wpml_translate_single_string( $string, $context, $name, $lang = null ) {
		$has_translation = null; // Passed by reference.
		return icl_translate( $context, $name, $string, false, $has_translation, $lang );
	}

	/**
	 * Converts a permalink to a language specific permalink.
	 *
	 * @since 2.2
	 *
	 * @param string      $url  The url to filter.
	 * @param null|string $lang Language code, optional, defaults to the current language.
	 * @return string
	 */
	public function wpml_permalink( $url, $lang = '' ) {
		$lang = PLL()->model->get_language( $lang );

		if ( empty( $lang ) && ! empty( PLL()->curlang ) ) {
			$lang = PLL()->curlang;
		}

		return empty( $lang ) ? $url : PLL()->links_model->switch_language_in_link( $url, $lang );
	}

	/**
	 * Translates a post type slug.
	 *
	 * @since 2.2
	 *
	 * @param string $slug      Post type slug.
	 * @param string $post_type Post type name.
	 * @param string $lang      Optional language code (defaults to current language).
	 * @return string
	 */
	public function wpml_get_translated_slug( $slug, $post_type, $lang = null ) {
		if ( isset( PLL()->translate_slugs ) ) {
			if ( empty( $lang ) ) {
				$lang = pll_current_language();
			}

			$slug = PLL()->translate_slugs->slugs_model->get_translated_slug( $post_type, $lang );
		}
		return $slug;
	}

	/**
	 * Find out whether a post type or a taxonomy term is translated.
	 *
	 * @since 2.0
	 *
	 * @param mixed  $null Not used.
	 * @param int    $id   The post_id or term_id.
	 * @param string $type The post type or taxonomy.
	 * @return bool
	 */
	public function wpml_element_has_translations( $null, $id, $type ) {
		if ( 'post' === $type || pll_is_translated_post_type( $type ) ) {
			return count( pll_get_post_translations( $id ) ) > 1;
		} elseif ( 'term' === $type || pll_is_translated_taxonomy( $type ) ) {
			return count( pll_get_term_translations( $id ) ) > 1;
		}

		return false;
	}

	/**
	 * Returns true if languages and translations are managed for this post type.
	 *
	 * @since 3.4
	 *
	 * @param mixed  $value     Not used.
	 * @param string $post_type The post type name.
	 * @return bool
	 */
	public function wpml_is_translated_post_type( $value, $post_type ) {
		return pll_is_translated_post_type( $post_type );
	}

	/**
	 * Returns true if languages and translations are managed for this taxonomy.
	 *
	 * @since 3.4
	 *
	 * @param mixed  $value    Not used.
	 * @param string $taxonomy The taxonomy name.
	 * @return bool
	 */
	public function wpml_is_translated_taxonomy( $value, $taxonomy ) {
		return pll_is_translated_taxonomy( $taxonomy );
	}
}
