<?php
/**
 * Compatibility: WPML.
 *
 * A self-contained module. It hooks the plugin's shared "should this page be
 * skipped?" extension point (the same one the noindex skip uses) and drops
 * posts whose WPML language is no longer active.
 *
 * Why: when a site owner removes a language in WPML but keeps its posts, each
 * of those posts still exists as a published post, so the site scan queues it -
 * but its permalink now 301-redirects to another language. The scan iframe
 * follows the redirect, lands on a different post, and its "done" message
 * carries that other post's ID; the queued target's ID never matches, so the
 * page never completes and burns the full per-page timeout. On a site with
 * hundreds of orphaned translations the scan appears frozen.
 *
 * Reading the language from WPML's own data is instant (no HTTP request), so
 * these posts are dropped before the scan starts and never inflate the count -
 * exactly like a noindex page.
 *
 * Scope: WPML only. Polylang, TranslatePress, etc. store the language
 * elsewhere and each get their own module in this folder; the core is not
 * touched to add them.
 *
 * @package Acceguru
 */

declare(strict_types=1);

if ( ! defined( 'ABSPATH' ) ) {
	die;
}

/**
 * Class Acceguru_Compat_WPML
 */
class Acceguru_Compat_WPML {

	/**
	 * Per-module on/off option. On by default: an orphaned-language post has
	 * no content of its own to scan, so there is no case where scanning it is
	 * useful. Surfaced as a toggle in the Compatibility settings section.
	 */
	public const OPTION = 'acceguru_compat_wpml';

	/**
	 * Registers the module on the shared skip extension point.
	 *
	 * @return void
	 */
	public static function init(): void {
		add_filter( 'acceguru_should_skip_page', array( __CLASS__, 'skip_inactive_language' ), 10, 3 );
	}

	/**
	 * True when WPML is running on this site. Used to show the settings toggle
	 * only where it applies. Detected by WPML's own version constant: unlike
	 * the wpml_active_languages filter, it does not depend on the query being
	 * set up, so it is safe on admin screens and in REST requests.
	 *
	 * @return bool
	 */
	public static function is_active(): bool {
		return defined( 'ICL_SITEPRESS_VERSION' );
	}

	/**
	 * Skip decision for one post. Returns true to drop the post from the scan.
	 *
	 * @param mixed $skip    Current decision from earlier modules (bool-ish).
	 * @param mixed $post_id Post being considered.
	 * @param mixed $target  Resolved target array (unused).
	 * @return bool
	 */
	public static function skip_inactive_language( $skip, $post_id, $target = array() ): bool {
		unset( $target );

		// Respect a skip already decided by an earlier module.
		if ( (bool) $skip ) {
			return true;
		}

		// Module toggle (Compatibility settings). Default on.
		if ( 1 !== absint( get_option( self::OPTION, 1 ) ) ) {
			return false;
		}

		return self::post_language_is_inactive( (int) $post_id );
	}

	/**
	 * True when WPML is running AND WPML itself says the post's language is
	 * not active. Whenever WPML does not give an unambiguous answer - absent,
	 * unknown language, unexpected return type - the post is NOT skipped:
	 * err on the side of scanning, not hiding.
	 *
	 * Uses WPML's own read filters, so it works through whatever storage WPML
	 * uses internally and stays correct across WPML versions:
	 *   - wpml_post_language_details -> the post's language ('language_code')
	 *   - wpml_language_is_active    -> whether one given language is active;
	 *     unlike wpml_active_languages it does not depend on the main query,
	 *     so it is safe during REST target collection.
	 *
	 * @param int $post_id Post ID.
	 * @return bool
	 */
	public static function post_language_is_inactive( int $post_id ): bool {
		if ( ! self::is_active() ) {
			return false;
		}

		// This post's language.
		// phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- WPML filter name.
		$details = apply_filters( 'wpml_post_language_details', null, $post_id );
		$code    = is_array( $details ) ? (string) ( $details['language_code'] ?? '' ) : '';
		if ( '' === $code ) {
			return false;
		}

		// Ask WPML about this one language. Only an explicit boolean "not
		// active" answer drops the post; null or anything else means WPML
		// did not answer, and the post stays in the scan.
		// phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- WPML filter name.
		$is_active = apply_filters( 'wpml_language_is_active', null, $code );
		return false === $is_active;
	}
}

Acceguru_Compat_WPML::init();