<?php

class WPML_Frontend_Tax_Filters {

	public function __construct() {
		add_filter( 'taxonomy_template', array( $this, 'slug_template' ) );
		add_filter( 'category_template', array( $this, 'slug_template' ) );
		add_filter( 'tag_template', array( $this, 'slug_template' ) );
	}

	/**
	 * Adjust template (taxonomy-)$taxonomy-$term.php for translated term slugs and IDs
	 *
	 * @since 3.1
	 *
	 * @param string $template
	 *
	 * @return string The template filename if found.
	 */
	function slug_template( $template ) {
		global $sitepress;

		$term = $this->get_queried_tax_term();

		if ( $term === false || ! is_taxonomy_translated( $term->taxonomy ) ) {
			return $template;
		}

		$templates = array();

		$has_filter = remove_filter( 'get_term', array( $sitepress, 'get_term_adjust_id' ), 1 );

		$current_language = $sitepress->get_current_language();
		$default_language = $sitepress->get_default_language();

		$templates = $this->add_term_templates( $term, $current_language, $templates );
		$templates = $this->add_original_term_templates( $term, $default_language, $current_language, $templates );

		if ( ! in_array( $term->taxonomy, array( 'category', 'post_tag' ), true ) ) {
			$templates[] = 'taxonomy-' . $current_language . '.php';
			$templates[] = 'taxonomy.php';
		}

		if ( $has_filter ) {
			add_filter( 'get_term', array( $sitepress, 'get_term_adjust_id' ), 1, 1 );
		}

		$new_template = locate_template( array_unique( $templates ) );
		$template     = $new_template ? $new_template : $template;

		return $template;
	}

	private function get_template_prefix( $taxonomy ) {

		$prefix  = in_array( $taxonomy, array( 'category', 'post_tag' ), true ) ? '' : 'taxonomy-';
		$prefix .= $taxonomy == 'post_tag' ? 'tag' : $taxonomy;

		return $prefix;
	}

	private function add_term_templates( $term, $current_language, $templates ) {
		$prefix      = $this->get_template_prefix( $term->taxonomy );
		$templates[] = "$prefix-{$current_language}-{$term->slug}.php";
		$templates[] = "$prefix-{$current_language}-{$term->term_id}.php";
		$templates[] = "$prefix-{$current_language}.php";
		$templates[] = "$prefix-{$term->slug}.php";
		$templates[] = "$prefix-{$term->term_id}.php";

		return $templates;
	}

	private function add_original_term_templates( $term, $default_language, $current_language, $templates ) {
		$taxonomy         = $term->taxonomy;
		$prefix           = $this->get_template_prefix( $taxonomy );
		$original_term_id = icl_object_id( $term->term_id, $taxonomy, true, $default_language );
		$original_term    = get_term_by( 'id', $original_term_id, $taxonomy );
		if ( $original_term ) {
			$templates[] = "$prefix-{$current_language}-{$original_term->slug}.php";
			$templates[] = "$prefix-{$current_language}-{$original_term_id}.php";
			$templates[] = "$prefix-{$original_term->slug}.php";
			$templates[] = "$prefix-{$original_term_id}.php";
			$templates[] = "$prefix-{$current_language}.php";
			$templates[] = "$prefix.php";
		}

		return $templates;
	}

	private function get_queried_tax_term() {
		global $wp_query;
		/** @var WP_Query $wp_query */
		$term = $wp_query->get_queried_object();
		$res  = false;

		if ( (bool) $term === true && isset( $term->taxonomy ) && $term->taxonomy ) {
			$res = $term;
		}

		return $res;
	}

}