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

/**
 * Filters content by language on frontend
 *
 * @since 1.2
 */
class PLL_Frontend_Filters extends PLL_Filters {
	/**
	 * Constructor: setups filters and actions
	 *
	 * @since 1.2
	 *
	 * @param object $polylang The Polylang object.
	 */
	public function __construct( &$polylang ) {
		parent::__construct( $polylang );

		// Filters the WordPress locale
		add_filter( 'locale', array( $this, 'get_locale' ) );

		// Filter sticky posts by current language
		add_filter( 'option_sticky_posts', array( $this, 'option_sticky_posts' ) );

		// Rewrites archives links to filter them by language
		add_filter( 'getarchives_join', array( $this, 'getarchives_join' ), 10, 2 );
		add_filter( 'getarchives_where', array( $this, 'getarchives_where' ), 10, 2 );

		// Filters the widgets according to the current language
		add_filter( 'widget_display_callback', array( $this, 'widget_display_callback' ) );

		if ( $this->options['media_support'] ) {
			add_filter( 'widget_media_image_instance', array( $this, 'widget_media_instance' ), 1 ); // Since WP 4.8
		}

		// Strings translation ( must be applied before WordPress applies its default formatting filters )
		foreach ( array( 'widget_text', 'widget_title' ) as $filter ) {
			add_filter( $filter, 'pll__', 1 );
		}

		// Translates biography
		add_filter( 'get_user_metadata', array( $this, 'get_user_metadata' ), 10, 4 );

		if ( Polylang::is_ajax_on_front() ) {
			add_filter( 'load_textdomain_mofile', array( $this, 'load_textdomain_mofile' ) );
		}
	}

	/**
	 * Returns the locale based on current language
	 *
	 * @since 0.1
	 *
	 * @return string
	 */
	public function get_locale() {
		return $this->curlang->locale;
	}

	/**
	 * Filters sticky posts by current language.
	 *
	 * @since 0.8
	 *
	 * @param int[] $posts List of sticky posts ids.
	 * @return int[] Modified list of sticky posts ids.
	 */
	public function option_sticky_posts( $posts ) {
		global $wpdb;

		// Do not filter sticky posts on REST requests as $this->curlang is *not* the 'lang' parameter set in the request.
		if ( defined( 'REST_REQUEST' ) || empty( $this->curlang ) || empty( $posts ) ) {
			return $posts;
		}

		$_posts = wp_cache_get( 'sticky_posts', 'options' ); // This option is usually cached in 'all_options' by WP.
		$tt_id  = $this->curlang->get_tax_prop( 'language', 'term_taxonomy_id' );

		if ( ! empty( $_posts ) && is_array( $_posts ) && ! empty( $_posts[ $tt_id ] ) && is_array( $_posts[ $tt_id ] ) ) {
			return $_posts[ $tt_id ];
		}

		$languages = array();
		foreach ( $this->model->get_languages_list() as $language ) {
			$languages[] = $language->get_tax_prop( 'language', 'term_taxonomy_id' );
		}

		$relations = $wpdb->get_results(
			$wpdb->prepare(
				sprintf(
					"SELECT object_id, term_taxonomy_id FROM {$wpdb->term_relationships} WHERE object_id IN (%s) AND term_taxonomy_id IN (%s)",
					implode( ',', array_fill( 0, count( $posts ), '%d' ) ),
					implode( ',', array_fill( 0, count( $languages ), '%d' ) )
				),
				array_merge( $posts, $languages )
			)
		);

		$_posts = array_fill_keys( $languages, array() ); // Init with empty arrays.

		foreach ( $relations as $relation ) {
			$_posts[ $relation->term_taxonomy_id ][] = (int) $relation->object_id;
		}

		wp_cache_add( 'sticky_posts', $_posts, 'options' );
		return $_posts[ $tt_id ];
	}

	/**
	 * Modifies the sql request for wp_get_archives to filter by the current language
	 *
	 * @since 1.9
	 *
	 * @param string $sql JOIN clause
	 * @param array  $r   wp_get_archives arguments
	 * @return string modified JOIN clause
	 */
	public function getarchives_join( $sql, $r ) {
		return ! empty( $r['post_type'] ) && $this->model->is_translated_post_type( $r['post_type'] ) ? $sql . $this->model->post->join_clause() : $sql;
	}

	/**
	 * Modifies the sql request for wp_get_archives to filter by the current language
	 *
	 * @since 1.9
	 *
	 * @param string $sql WHERE clause
	 * @param array  $r   wp_get_archives arguments
	 * @return string modified WHERE clause
	 */
	public function getarchives_where( $sql, $r ) {
		if ( ! $this->curlang instanceof PLL_Language ) {
			return $sql;
		}

		if ( empty( $r['post_type'] ) || ! $this->model->is_translated_post_type( $r['post_type'] ) ) {
			return $sql;
		}

		return $sql . $this->model->post->where_clause( $this->curlang );
	}

	/**
	 * Filters the widgets according to the current language
	 * Don't display if a language filter is set and this is not the current one
	 * Needed for {@see https://developer.wordpress.org/reference/functions/the_widget/ the_widget()}.
	 *
	 * @since 0.3
	 *
	 * @param array $instance Widget settings
	 * @return bool|array false if we hide the widget, unmodified $instance otherwise
	 */
	public function widget_display_callback( $instance ) {
		return ! empty( $instance['pll_lang'] ) && $instance['pll_lang'] != $this->curlang->slug ? false : $instance;
	}

	/**
	 * Translates media in media widgets
	 *
	 * @since 2.1.5
	 *
	 * @param array $instance Widget instance data
	 * @return array
	 */
	public function widget_media_instance( $instance ) {
		if ( empty( $instance['pll_lang'] ) && $instance['attachment_id'] && $tr_id = pll_get_post( $instance['attachment_id'] ) ) {
			$instance['attachment_id'] = $tr_id;
			$attachment = get_post( $tr_id );

			if ( $instance['caption'] && ! empty( $attachment->post_excerpt ) ) {
				$instance['caption'] = $attachment->post_excerpt;
			}

			if ( $instance['alt'] && $alt_text = get_post_meta( $tr_id, '_wp_attachment_image_alt', true ) ) {
				$instance['alt'] = $alt_text;
			}

			if ( $instance['image_title'] && ! empty( $attachment->post_title ) ) {
				$instance['image_title'] = $attachment->post_title;
			}
		}
		return $instance;
	}

	/**
	 * Translates the biography.
	 *
	 * @since 0.9
	 *
	 * @param null   $null     Expecting the default null value.
	 * @param int    $id       The user id.
	 * @param string $meta_key The metadata key.
	 * @param bool   $single   Whether to return only the first value of the specified $meta_key.
	 * @return string|null
	 */
	public function get_user_metadata( $null, $id, $meta_key, $single ) {
		return 'description' === $meta_key && ! empty( $this->curlang ) && ! $this->curlang->is_default ? get_user_meta( $id, 'description_' . $this->curlang->slug, $single ) : $null;
	}

	/**
	 * Filters the translation files to load when doing ajax on front
	 * This is needed because WP the language files associated to the user locale when a user is logged in
	 *
	 * @since 2.2.6
	 *
	 * @param string $mofile Translation file name
	 * @return string
	 */
	public function load_textdomain_mofile( $mofile ) {
		$user_locale = get_user_locale();
		return str_replace( "{$user_locale}.mo", "{$this->curlang->locale}.mo", $mofile );
	}
}