<?php
/**
 * IndexNow: key file + batched, non-blocking pings when products change.
 *
 * @package FlareOps
 */

namespace FlareOps;

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

final class IndexNow {

	public const CRON         = 'flareops_indexnow_flush';
	public const QUEUE_OPTION = 'flareops_indexnow_queue';
	public const STATE_OPTION = 'flareops_indexnow_state';
	public const ENDPOINT     = 'https://api.indexnow.org/indexnow';
	public const MIN_INTERVAL = 60;
	public const BATCH_DELAY  = 15;

	public static function key_url(): string {
		$k = Settings::indexnow_key();
		return '' === $k ? '' : home_url( '/' . $k . '.txt' );
	}

	public static function key_url_fallback(): string {
		return add_query_arg( 'flareops_indexnow', '1', home_url( '/' ) );
	}

	/** Serve the key at /{key}.txt or /?flareops_indexnow=1. Runs on init (early). */
	public static function maybe_serve_key(): void {
		$key = Settings::indexnow_key();
		if ( '' === $key ) {
			return;
		}
		$hit = isset( $_GET['flareops_indexnow'] ); // phpcs:ignore WordPress.Security.NonceVerification
		if ( ! $hit ) {
			$path = Util::request_path();
			$home = (string) wp_parse_url( home_url( '/' ), PHP_URL_PATH );
			$hit  = untrailingslashit( $home ) . '/' . $key . '.txt' === $path;
		}
		if ( ! $hit ) {
			return;
		}
		status_header( 200 );
		header( 'Content-Type: text/plain; charset=UTF-8' );
		header( 'X-Robots-Tag: noindex' );
		echo esc_html( $key );
		exit;
	}

	public static function enabled(): bool {
		return Settings::feature( 'indexnow' ) && Settings::outbound_allowed() && '' !== Settings::indexnow_key();
	}

	/** Hook: product created/updated. */
	public static function on_product_change( $product_id ): void {
		if ( ! self::enabled() ) {
			return;
		}
		$product_id = (int) $product_id;
		$p          = function_exists( 'wc_get_product' ) ? wc_get_product( $product_id ) : null;
		if ( ! $p ) {
			return;
		}
		if ( $p->get_parent_id() ) {
			$p = wc_get_product( $p->get_parent_id() );
			if ( ! $p ) {
				return;
			}
		}
		if ( 'publish' !== $p->get_status() || 'hidden' === $p->get_catalog_visibility() || post_password_required( $p->get_id() ) ) {
			return;
		}
		$url = (string) get_permalink( $p->get_id() );
		if ( '' === $url ) {
			return;
		}
		self::enqueue( array( $url ) );
	}

	public static function enqueue( array $urls ): void {
		$q = get_option( self::QUEUE_OPTION, array() );
		$q = is_array( $q ) ? $q : array();
		$q = array_values( array_unique( array_merge( $q, $urls ) ) );
		$q = array_slice( $q, -10000 );
		update_option( self::QUEUE_OPTION, $q, false );

		if ( ! wp_next_scheduled( self::CRON ) ) {
			$state = self::state();
			$last  = isset( $state['last_ping_ts'] ) ? (int) $state['last_ping_ts'] : 0;
			$when  = max( time() + self::BATCH_DELAY, $last + self::MIN_INTERVAL );
			wp_schedule_single_event( $when, self::CRON );
		}
	}

	public static function state(): array {
		$s = get_option( self::STATE_OPTION, array() );
		return is_array( $s ) ? $s : array();
	}

	/** Cron: send the queue in one request (runs in WP-Cron, never in the save request). */
	public static function flush(): void {
		$q = get_option( self::QUEUE_OPTION, array() );
		$q = is_array( $q ) ? array_values( $q ) : array();
		if ( ! $q ) {
			return;
		}
		if ( ! self::enabled() ) {
			update_option( self::QUEUE_OPTION, array(), false );
			return;
		}
		$state = self::state();
		if ( isset( $state['last_ping_ts'] ) && time() - (int) $state['last_ping_ts'] < self::MIN_INTERVAL ) {
			wp_schedule_single_event( (int) $state['last_ping_ts'] + self::MIN_INTERVAL, self::CRON );
			return;
		}
		$batch = array_slice( $q, 0, 10000 );
		update_option( self::QUEUE_OPTION, array_slice( $q, count( $batch ) ), false );

		$body = array(
			'host'        => (string) wp_parse_url( home_url( '/' ), PHP_URL_HOST ),
			'key'         => Settings::indexnow_key(),
			'keyLocation' => self::key_url(),
			'urlList'     => $batch,
		);
		$res  = wp_remote_post(
			self::ENDPOINT,
			array(
				'timeout' => 10,
				'headers' => array( 'Content-Type' => 'application/json; charset=utf-8' ),
				'body'    => wp_json_encode( $body ),
			)
		);
		$status = is_wp_error( $res ) ? 'error: ' . $res->get_error_message() : (string) wp_remote_retrieve_response_code( $res );
		update_option(
			self::STATE_OPTION,
			array(
				'last_ping'    => Util::iso(),
				'last_ping_ts' => time(),
				'last_status'  => $status,
				'last_count'   => count( $batch ),
			),
			false
		);
	}
}